Almost All 'Natural' Skincare Products Contain Allergens, Scientists Warn
Nearly 90 percent of the 1,651 personal skin care products studied – including lotions, soaps, and moisturizers – contained at least one of the top 100 most common allergens known to cause contact dermatitis.
Contact dermatitis is more than a fleeting irritation. It's a red, itchy rash that, at its worst, can blister, caused by exposure to substances that either irritate or inflame the skin. The latter is an allergic reaction that occurs once the skin becomes sensitized to an otherwise harmless substance.
According to some estimates, rates of contact dermatitis areon the riseworldwide, up almost three-fold in three decades since 1996.
The researchers say that this uptick in contact dermatitis, a rapidly growing skincare and beauty industry worth billions, and a lack of regulation on its marketing motivated the study.
Contact dermatitisis preventable, so long as you can navigate and interpret the long list of ingredients found in skincare products and know which ones might aggravate the skin. Easier said than done.
A typical skincare or cosmetic product may contain anywhere from 15 to 50 ingredients. Research suggests people could be applyingover 500 different chemicalsto their skin each day, depending on their skincare routine.
In other words, the more products you use, the more you expose your skin to potential allergens.
Many of the allergens identified in the study were fragrances – thinklavenderand other botanical extracts – which have become a leading cause of contact dermatitis.
On average, skincare products contained between four and five known allergens. In total, 73 different allergens were listed 7,487 times across the 1,651 products studied.
That's only based on product information available online, but it still gives you a sense of the scale of the problem.
In 2017, another US study found few moisturizers were free from allergens, and even 'fragrance-free' products sometimes contained fragrances, which can irritate the skin.
Babies born to mothers with preeclampsia found to be at increased risk of stroke and heart disease later in life
Preeclampsia is a condition involving blood pressure elevation and heightened levels of proteins in urine that can damage kidneys and sometimes other organs of pregnant women. Preeclampsia tends to occur later in pregnancy, though it can sometimes happen earlier. Preeclampsia has been found to stymie fetal growth if not properly treated by causing problems in the arteries that carry blood in the placenta.
A team of researchers has found evidence that suggests babies born to mothers with preeclampsia have an increased risk of a stroke and/or heart disease later in life. They also found that it can also lead to other health problems for the baby later in life.
The work involved obtaining and analyzing the medical records of 8.5 million babies born in the 1970s and 1980s and tracking instances of ischemic heart disease (IHD) or stroke in those babies for 40 years after they were born. They found that babies born to mothers experiencing preeclampsia were 33% more likely to develop IHD in later life than babies born to mothers without the condition. They also found a 34% increased risk of stroke. The researchers also found a small increase in risk for stroke in siblings of babies born to mothers with preeclampsia. The researchers suggest the large sample size ensures accuracy of the results and also allowed them to evaluate the role of preterm babies in increased risk of heart disease later on in life. They note also that theirs is the first study to find a link between babies born to mothers with preeclampsia and an increased risk of heart disease and/or stroke later on in life. The researchers note that the risk associations for preeclampsia were more notable in mothers who developed the condition later in their pregnancies than for those who developed it early.
Fen Yang et al, Association of Maternal Preeclampsia With Offspring Risks of Ischemic Heart Disease and Stroke in Nordic Countries, JAMA Network Open (2022). DOI: 10.1001/jamanetworkopen.2022.42064
Earth can regulate its own temperature over millennia, new study finds
The Earth's climate has undergone some big changes, from global volcanism to planet-cooling ice ages and dramatic shifts in solar radiation. And yet life, for the last 3.7 billion years, has kept on beating.
Now, a study by MIT researchers in Science Advances confirms that the planet harbors a "stabilizing feedback" mechanism that acts over hundreds of thousands of years to pull the climate back from the brink, keeping global temperatures within a steady, habitable range. Just how does it accomplish this? A likely mechanism is "silicate weathering"—a geological process by which the slow and steady weathering of silicate rocks involves chemical reactions that ultimately draw carbon dioxide out of the atmosphere and into ocean sediments, trapping the gas in rocks. Scientists have long suspected that silicate weathering plays a major role in regulating the Earth's carbon cycle. The mechanism of silicate weathering could provide a geologically constant force in keeping carbon dioxide—and global temperatures—in check. But there's never been direct evidence for the continual operation of such a feedback, until now. The new findings are based on a study of paleoclimate data that record changes in average global temperatures over the last 66 million years. The MIT team applied a mathematical analysis to see whether the data revealed any patterns characteristic of stabilizing phenomena that reined in global temperatures on a geologic timescale. They found that indeed there appears to be a consistent pattern in which the Earth's temperature swings are dampened over timescales of hundreds of thousands of years. The duration of this effect is similar to the timescales over which silicate weathering is predicted to act. The results are the first to use actual data to confirm the existence of a stabilizing feedback, the mechanism of which is likely silicate weathering. This stabilizing feedback would explain how the Earth has remained habitable through dramatic climate events in the geologic past.
Constantin Arnscheidt, Presence or absence of stabilizing Earth system feedbacks on different timescales, Science Advances (2022). DOI: 10.1126/sciadv.adc9241
Over a billion young people are potentially at risk of hearing loss from headphones, earbuds, loud music venues
More than 1 billion teens and young people are potentially at risk of hearing loss because of their use of headphones and earbuds and attendance at loud music venues, concludes a pooled data analysis of the available evidence, published in the open access journal BMJ Global Health.
The World Health Organization (WHO) estimates that over 430 million people worldwide currently have disabling hearing loss. Young people are particularly vulnerable because of their use of personal listening devices (PLDs), such as smartphones, headphones and earbuds, and attendance at loud music venues, amid poor regulatory enforcement. Previously published research suggests that PLD users often choose volumes as high as 105 dB while average sound levels at entertainment venues range from 104 to 112 dB, exceeding permissible levels (80 dB for adults; 75 dB for children) even if for very short periods of time.
A group of 33 studies, corresponding to data from 35 records and 19,046 participants, was included in this research work to come to this conclusion; 17 records focused on PLD use and 18 focused on loud entertainment venues .
The pooled data analysis indicates that the prevalence of unsafe listening practices from PLD use and attendance at loud entertainment venues is common worldwide—24% and 48%, respectively, among teens and young peopel.
Based on these figures, the researchers estimate that the global number of teens and young adultswho could potentially be at risk of hearing loss as a result ranges from 0.67 to 1.35 billion.
The researchers acknowledge some limitations to their findings, including the varied study design—a particular feature of the studies on entertainment venues—and the absence of standardized methodology.
These findings prompted the researchers to conclude, "There is an urgent need for governments, industry, and civil society to prioritize global hearing loss prevention by promoting safe listening practices."
Prevalence and global estimates of unsafe listening practices in adolescents and young adults: a systematic review and meta-analysis, BMJ Global Health (2022). DOI: 10.1136/bmjgh-2022-010501
Climate change: Increasing heat waves will threaten every child, says UNICEF report
A new report by UNICEF, supported by University of Southampton researchers, says 559 million children currently exposed to high heat waves could rise to 2.02 billion globally by the year 2050.
Thereport, produced in collaboration with The Data for Children Collaborative, underscores the urgent need to address the impacts of global warming tofuture generationsand follows on from previous work identifying specific risk to children from climate change (Child Climate Risk Index, UNICEF, 2021).
It comes as world leaders meet to discussclimate actionthis month at the COP27 conference in Egypt.
The report estimates that by 2050, all of the world's 2.02 billion children are expected to be exposed to high heat wave frequency, regardless of whether:
the world achieves a "low greenhouse gas emission scenario" with an estimated 1.7 degrees of warming, or;
a "very high greenhouse gas emission scenario" with an estimated 2.4 degrees of warming.
The report found that specifically highheat waveduration currently impacts 538 million (23%) of children globally and by 2050 will rise to:
1.6 billion at 1.7 degrees warming or;
1.9 billion at 2.4 degrees warming.
Heat waves are especially damaging to children, as they are less able to regulate their body temperature compared to adults, with babies and young children being at greater risk of heat-related mortality.
Further exposure to heat waves can result in children developinghealth problemssuch as chronic respiratory conditions, asthma, and cardiovascular diseases.
Heat waves can also affect children's environments, their safety, nutrition and access to water, and their education and future livelihood.
At a minimum, governments must urgently limit global warming to 1.5 degrees Celsius and double adaptation funding by 2025.
"This is the only way to savechildren's lives and futures—and the future of the planet."
Researchers discover how music could be used to trigger a deadly pathogen release
Researchers have discovered that the safe operation of a negative pressure room—a space in a hospital or biological research laboratory designed to protect outside areas from exposure to deadly pathogens—can be disrupted by an attacker armed with little more than a smartphone.
According to UCI cyber-physical systems security experts, who shared their findings with attendees at the Association for Computing Machinery's recent Conference on Computer and Communications Security in Los Angeles, mechanisms that control airflow in and out of biocontainment facilities can be tricked into functioning irregularly by a sound of a particular frequency, possibly tucked surreptitiously into a popular song.
Someone could play a piece of music loaded on their smartphone or get it to transmit from a television or other audio device in or near a negative pressureroom. If that music is embedded with a tone that matches the resonant frequency of the pressure controls of one of these spaces, it could cause a malfunction and a leak of deadly microbes.
Heating, ventilation and air conditioning infrastructure maintains the flow of fresh air into and contaminated air out of a given space. HVAC systems in scientific facilities typically include room pressure monitors, which in turn utilize differential pressure sensors that compare the atmospheres inside and outside rooms.
The researchers said that commonly used differential pressure sensors (DPSs) are vulnerable to remote manipulation, posing a previously unrealized threat to biosafety facilities. They tested their hypothesis on eight industry-standard DPSs from five manufacturers, demonstrating that all the devices operate with resonant frequencies in the audible range and are, therefore, subject to tampering.
When sound wavescollide with the diaphragms inside a DPS, it starts vibrating with the same frequency. An informed attacker can use this technique to artificially displace the diaphragm, changing the pressure reading and causing the whole system to malfunction.
Attackers could thwart negative pressure room systems in a variety of ways. They could manipulate them wirelessly or pose as maintenance personnel to place an audio device inside or near such a room.A more sophisticated attack might involve perpetrators embedding sound-emitting technologies into a DPS before it's installed in a biocontainment facility.
In their conference presentation, the researchers suggested several countermeasures to prevent a musical assault on biosafety facilities. Sound dampening can be achieved by lengthening the sampling tube of a DPS's port by as much as 7 meters. The team also proposed enclosing the pressure port in a boxlike structure. Both these measures would reduce the sensitivity of the DPS.
Anomadarshi Barua et al, A Wolf in Sheep's Clothing, Proceedings of the 2022 ACM SIGSAC Conference on Computer and Communications Security (2022). DOI: 10.1145/3548606.3560643
New technology for growing printed tissues for transplantation
Researchers have developed an innovative technology for growing tissue for transplantation by printing it into a microgel bath as support material.
Tissue printing is an innovative approach for creating tissue for transplantation. In this technique, also called bio-printing, living cells are embedded in biological ink and printed layer upon layer. The printed tissue then undergoes growth for days or weeks until it is ready for printing.
This new work focused on preventing the uneven shrinkage of the printed tissue in the weeks after printing. The solution was found through changing the medium in which the tissue is printed and grown.
The new concept, print-and-grow, is based on an original medium developed by the researchers—an innovative microgel used as a support material in the process, CarGrow, which is a substance mainly composed of carrageenan (Carrageenan-K) and is produced from red algae. In fact, the new support bath preserves the size of the tissue after printing and prevents it from shrinking and losing its shape.
This process allows reliable and controlled production of functional tissue in the desired size and shape. Since this material is transparent, it makes it possible for the scientists to monitor the development of the tissue through imaging.
The Technion researchers hope the new method will lead to the development of new technologies for bio-printing.
Majd Machour et al, Print‐and‐Grow within a Novel Support Material for 3D Bioprinting and Post‐Printing Tissue Growth, Advanced Science (2022). DOI: 10.1002/advs.202200882
Nanostructured ceramic coatings do not fatigue, finds study
Extremely thin ceramic coatings can completely change the properties of technical components. Coatings are used, for example, to increase the resistance of metals to heat or corrosion. Coating processes play a role for large turbine blades as well as for extremely stressed tools in production technology.
Researchers now investigated what determines the stability of such coatings. And the results, some of which were obtained at the DESY synchrotron in Hamburg, are quite surprising: the ceramic layers break down in a completely different way than metals. Material fatigue hardly plays a role; the decisive factor is the intensity of extreme load peaks (the so called stress intensity factor). This finding will change the method used to measure and further improve the resistance of thin films in the future.
L. Zauner et al, Assessing the fracture and fatigue resistance of nanostructured thin films, Acta Materialia (2022). DOI: 10.1016/j.actamat.2022.118260
In a study recently published in the Journal of Extracellular Vesicles, researchers from Kanazawa University use high-speed microscopy to capture the dynamics of nanosized sacs released from cells.
Air pollutants kill around 7 million people every year. Much of this pollution is tiny particles suspended in the air which, when inhaled, can cause people to develop heart and lung diseases, as well as cancer.
Study shows hundreds of thousands of tons of bacteria are being released by melting glaciers
A team of researchers affiliated with multiple institutions across Europe, the U.K. and Canada has found that hundreds of thousands of tons of bacteria are currently being released annually into the environment by melting glaciers in the northern latitudes. In their paper published in the journalCommunications Earth & Environment, the group describes sampling glacial runoff from multiple sites in Europe, North America and Greenland.
As climate changeprogresses, doomsday reports from around the world have proliferated. One alarming claim is that a virus or strain of bacteriawill emerge from ancient ice that is impervious to the human immune system, killing off most, if not all, of humankind. In this new effort, the researchers have joined a growing effort to take samples of melting runoff from glaciers to learn more about their microbial ecosystems as a means to discover whether a threat exists, and if so, what sort.
The researchers did not study the bacteria individually, and thus did not spot any species that might pose a threat to human health. They did note that most of the bacteria were killed by the sun soon after exposure, suggesting that even if a human pathogen is among them, the chance of infection is slight. Bacteria in water samples, the researchers note, tend to have pigments that absorb sunlight, which further adds to warming in northern regions.
Ian T. Stevens et al, Spatially consistent microbial biomass and future cellular carbon release from melting Northern Hemisphere glacier surfaces, Communications Earth & Environment (2022). DOI: 10.1038/s43247-022-00609-0
No gene variant is a bigger risk factor for Alzheimer’s disease than one calledAPOE4. But exactly how the gene spurs brain damage has been a mystery. A study has nowlinkedAPOE4with faulty cholesterol processing in the brain, which in turn leads to defects in the insulating sheaths that surround nerve fibres and facilitate their electrical activity. Preliminary results hint that these changes could cause memory and learning deficits. And the work suggests that drugs that restore the brain’s cholesterol processing could treat the disease.
What is a 'Carbon Cage,' and why are you stuck in one right now?
This knowledge is extremely important
Our current carbon-heavy economic system creates bars around us that stop effective climate change action. Here's why: The world is too accustomed to the luxuries and privileges which depend on co2 emissions
Earth now weighs six ronnagrams: New metric prefixes voted in
Say hello to ronnagrams and quettameters: International scientists gathered in France voted on Friday for new metric prefixes to express the world's largest and smallest measurements, prompted by an ever-growing amount of data.
It marks the first time in more than three decades that new prefixes have been added to the International System of Units (SI), the agreed global standard for the metric system.
Joining the ranks of well-known prefixes like kilo and milli are ronna and quetta for the largest numbers—and ronto and quecto for the smallest.
The change was voted on by scientists and government representatives from across the world attending the 27th General Conference on Weights and Measures, which governs the SI and meets roughly every four years at Versailles Palace, west of Paris.
The UK's National Physical Laboratory, which led the push for the new prefixes, confirmed that the resolution had passed in a statement.
The prefixes make it easier to express large amounts—for example, always referring to a kilometer as 1,000 meters or a millimeter as one thousandth of a meter would quickly become cumbersome.
Since the SI was established in 1960, scientific need has led to a growing number of prefixes. The last time was in 1991, when chemists wanting to express vast molecular quantities spurred the addition of zetta and yotta.
A yottameter is a one followed by 24 zeroes.
But even the mighty yotta is not enough to handle the world's voracious appetite for data.
So the Earth weighs approximately six ronnagrams,which is a six followed by 27 zeroes !
Jupiter, that's about two quettagrams—a two followed by 30 zeros.
Down syndrome, like Alzheimer's, is a double-prion disorder
The brains of people with Down syndrome develop the same neurodegenerative tangles and plaques associated with Alzheimer's disease and frequently demonstrate signs of the neurodegenerative disorder in their forties or fifties. A new study from researchers shows that these tangles and plaques are driven by the same amyloid beta (Aß) and tau prions that they showed are behind Alzheimer's disease in 2019.
Prions begin as normal proteins that become misshapen and self-propagate. They spread through tissue like an infection by forcing normal proteins to adopt the same misfolded shape. In both Alzheimer's and Down syndrome, as Aß and tau prions accumulate in the brain, they cause neurological dysfunction that often manifests as dementia.
Tau tangles and Aß plaques are evident in most people with Down syndrome by age 40, according to the National Institute on Aging, with at least 50% of this population developing Alzheimer's as they age.
The new study, published Nov. 7, 2022, inProceedings of the National Academy of Sciences, highlights how a better understanding of Down syndrome can lead to new insights about Alzheimer's, as well.
Carlo Condello et al, Aβ and tau prions feature in the neuropathogenesis of Down syndrome, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2212954119
Messel boa: Live birth in a 47-million-year-old snake
team of scientists, including Senckenberg’s Krister Smith, has discovered the world’s first fossil evidence of live birth in snakes. The fossil they examined came from the Hessian UNESCO World Heritage Site “Messel Pit.” In the study, published in the journal “The Science of Nature,” the researchers describe bones of snake embryos discovered in the mother’s body. The finding shows that viviparous snakes already existed at least 47 million years ago.
Most reptiles alive today lay eggs; this so-called oviparity is their most common mode of reproduction. But there are exceptions: Numerous species of lizards and snakes are known to deviate from the norm and give birth to their offspring alive – viviparously. Fossil preservation of reproductive events is generally very rare. In total, only two fossil records of viviparous land reptiles have been discovered to date. Scientists have now succeeded in describing the world’s first fossil evidence of a viviparous snake.
The fossil Messelophis variatus, from a family of boa-like snakes, is about 50 centimeters long, dates from the Eocene, and is related to modern-day dwarf boas from Central America. The species is among the most common snakes known from Messel. Nevertheless, this specimen, is about 47 million years old.
It is a pregnant female with at least two embryos found in the posterior third of her trunk area. These bones were located quite a distance behind the stomach – if they were part of the snake’s prey, they would have already been digested this far back in the intestine and would no longer be recognizable. Thus, they must represent the boa’s embryos. The fact that the bones are from very young snakes, yet already further developed than in an unlaid egg, supports the assumption that scientists are dealing with a pregnant, viviparous female.
In live births, the young remain in the female’s body until they are viable – eliminating the need for a protective eggshell. This is considered an advantageous evolutionary strategy for reptiles in cold climates, as the temperature inside the female’s body is more stable and thus safer for their offspring. Therefore, many of today’s viviparous lizards and snakes have evolved in rather cooler climates. “During the Eocene, however, the Earth was dominated by a persistent greenhouse climate with warm temperatures, a high carbon dioxide content in the atmosphere, and ice-free poles. Around the Messel Lake, average temperatures at that time were about 20 degrees Celsius, and winter temperatures did not fall below freezing. Why the boas gave birth to live offspring 47 million years ago in spite of this fact is still unknown. Perhaps additional fossils from this unique site will help us solve this mystery!
Mariana Chuliver et al, Live birth in a 47-million-year-old snake, The Science of Nature (2022). DOI: 10.1007/s00114-022-01828-3
A team of researchers have developed a new method that may help control mosquito populations. The annoying buzzing sound that mosquitoes make when flying inspired this technique.
Mosquitoes are not just a nuisance to people sitting outside on warm summer evenings. They also spread deadly diseases that kill thousands of people every year, including dengue, malaria, and the Zika virus. Therefore, it is vital to reduce mosquito populations around the world. Unfortunately, commonly used insecticides have become less effective over time because mosquitoes have developed resistance. They also have a negative impact on the environment. Therefore, alternative methods are needed for mosquito control.
One promising method for controlling mosquitoes takes advantage of perhaps their most annoying feature—their high-pitched buzzing. Females create this sound as they fly around seeking sources of blood. Male mosquitoes listen specifically for this characteristic high-pitched noise. Shaped like antennas, male mosquito ears vibrate at the same frequency as the female mosquito's wings. When a female flies by, the male's ears detect this frequency and resonate, sending a signal to their brain that helps them identify a potential mate.
A team of researchers tested whether they could control mosquito mating behavior by altering the frequency at which male mosquitoes listen. By making the male mosquitoes' ears go "out of tune," they sought to influence their mating behavior.
he team first identified the involvement of the major neurotransmitter serotonin in the auditory system of the insect. Serotonin plays an important role in nervous systems and brains of various animals', influencing a wide range of behaviors.
After demonstrating serotonin in the mosquito auditory system, the team's next step was to manipulate serotonin levels. To do this, they used a method called "laser doppler vibrometry." This involves using a laser as a highly sensitive measurement tool to detect changes in the nanoscale vibrations of mosquito ears after exposure to serotonin-related compounds.
The researchers discovered that after feeding mosquitoes a serotonin-inhibiting compound, the male ears' vibration frequency decreased. When they gave the mosquitoes glucose laced with a compound that inhibited serotonin, both the range of frequencies the mosquitoes responded to, and their response itself, were reduced.
The next step in the development of a potential auditory-based "birth control" will involve identifying the exact receptors responsible for tuning the ears of mosquitoes. This could enable researchers to administer targeted compounds to disrupt mating behavior.
Yifeng Y. J. Xu, YuMin M. Loh, Tai-Ting Lee, Takuro S. Ohashi, Matthew P. Su, Azusa Kamikouchi. Serotonin modulation in the male Aedes aegypti ear influences hearing. Frontiers in Physiology, 2022; 13 DOI: 10.3389/fphys.2022.931567
Lab mice fed processed food found to fare worse against flu than those eating grains
A team of researchers has found that lab mice are more likely to survive a flu infection if they are fed grain-based foods rather than processed food. The paper is published in Cell Reports.
In recent years, medical researchers have reported evidence that diet plays a larger role in illness recovery than was thought. Some studies have shown, for example, that caloric density and the concentration of nutrients consumed while recovering from an infection can have a major impact on the severity of the infection. In this new effort, the researchers found evidence suggesting that other characteristics of food can also play a role in illness recovery, at least in mice.
In this new effort, the researchers were studying how mammals such as mice fight off influenza infections. As part of that effort, they inadvertently fed two groups of lab miceslightly different meals that were thought to be equivalent in nutritional valueand hence unlikely to have an impact on disease recovery. More specifically, they fed one group of mice a diet consisting mostly of grains. The other mice were fed a highly processed diet.
Both groups were subsequently infected with the influenza virusand were kept on the same diets they had prior to being infected. The researchers note that prior studies had shown that mice fed either diet when not battling an infection displayed little difference in health or behavior. But when infected with influenza, the researchers found that all of those fed the highly processed diet died. They also found that those fed the highly processed diet failed to regain weight lost due to the illness. In sharp contrast, all of the mice on the grain-based diet began regaining weight within 10 days of initial infection, and all of them recovered.
The researchers note that the difference in survival was not due to differences in an immune response, but was instead due to recovery issues. They note that the mice on the highly processed food diet ate less than those given grains and wound up getting less nutrients. They also had cooler body cores. The researchers also found some evidence that suggested IFN-γ, a signaling protein, played a role in the outcomes for the mice.
Taylor A. Cootes et al, The quality of energy- and macronutrient-balanced diets regulates host susceptibility to influenza in mice, Cell Reports (2022). DOI: 10.1016/j.celrep.2022.111638
Discovery reveals 'brain-like computing' at molecular level is possible
A discovery has revealed for the first time that unconventional brain-like computing at the tiniest scale of atoms and molecules is possible.
Researchers which consisted an international team of scientists created a new type of organic material that learns from its past behaviour. The discovery of the "dynamic molecular switch" that emulates synaptic behavior is revealed in a new study in the journal Nature Materials.
The team developed a two-nanometer thick layer of molecules, which is 50,000 times thinner than a strand of hair and remembers its history as electrons pass through it. Switching probability and the values of the on/off states continually change in the molecular material, which provides a disruptive new alternative to conventional silicon-based digital switches that can only ever be either on or off.
The newly discovered dynamic organic switch displays all the mathematical logic functions necessary fordeep learning, successfully emulating Pavlovian "call and response" synaptic brain-like behavior.
The researchers demonstrated the new materials properties using extensive experimental characterization and electrical measurements supported by multi-scale modeling spanning from predictive modeling of the molecular structures at the quantum level to analytical mathematical modeling of the electrical data.
Enrique del Barco, Dynamic molecular switches with hysteretic negative differential conductance emulating synaptic behaviour, Nature Materials (2022). DOI: 10.1038/s41563-022-01402-2
A new technology developed at Tel Aviv University makes it possible to destroy cancerous tumors in a targeted manner, via a combination of ultrasound and the injection of nanobubbles into the bloodstream. According to the research team, unlike invasive treatment methods or the injection of microbubbles into the tumor itself, this latest technology enables the destruction of the tumor in a non-invasive manner.
Oregon State University scientists have produced a proof of concept for a new and better way of caring for women facing the life-threatening situation of ectopic pregnancy, which occurs when a fertilized egg implants somewhere other than the lining of the uterus.
Things that make people feel more awake and alert during mornings and afternoons
A team of researchers affiliated with multiple institutions has isolated factors that they think have an impact on how awake and/or alert people feel during the day.
Prior research has shown that more people than ever are complaining of feeling tired, sleepy and unalert during the daytime. Such complaints have been connected to increases in motor vehicle and work accidents and also sloppy job performance. In this new effort, the researchers noted that little research has been conducted looking into the factors that contribute to daytime alertness. To rectify that problem, they conducted a study of their own.
The researchers recruited 833 volunteers (many of whom were either identical or fraternal twins) to undergo testing for two weeks. Each adhered to a prescribed diet and wore a watch that recorded their sleep and physical activity and also their glucose levels. They also recorded the food they ate using a custom phone app, which they also used to record their level of alertness. After the two-week period, the researchers found some patterns. For example, those people who slept longer reported feeling more alert the next day—no surprise there.
But they also found that it was not duration that led to an increase in alertness, but the time that they woke up—waking up later than normal, they found, made the volunteers feel more alert, at least during the morning, even if they did not go to bed late. They also found that the volunteers were more alert on days when they were physically active the day before. And they found that eating a high-carb breakfast, such as muffins, resulted in higher morning alertness.
Drinking pure glucose had them feeling even more alert. A high-protein breakfast, on the other hand, had the volunteers dragging in the morning. The researchers also found four factors that most contributed to daily variances for the volunteers: age, sleep, mood and frequency of eating—eating less often seemed to reduce next-day fatigue.
Raphael Vallat et al, How people wake up is associated with previous night's sleep together with physical activity and food intake, Nature Communications (2022). DOI: 10.1038/s41467-022-34503-2
Scientists unlock nature's secret to super-selective binding
Researchers have discovered that it is not just molecular density, but also pattern and structural rigidity, that control super-selective binding interactions between nanomaterials and protein surfaces. The breakthrough could help optimize existing approaches to virus prevention and cancer detection.
So much of biology comes down to the biophysical process of binding: making a strong connection between one or more groups of atoms—known as ligands—to their corresponding receptor molecule on a surface. A binding event is the first fundamental process that allows a virus to infect a host, or chemotherapy to fight cancer. But binding interactions—at least, our understanding of them—have a "Goldilocks problem": too few ligands on one molecule makes it impossible for it to stably bind with the correct target, while too many can result in undesirable side-effects.
When binding is triggered by a threshold density of target receptors, scientists call this 'super-selective' binding, which is key to preventing random interactions that could dysregulate biological function.
Since nature typically doesn't overcomplicate things, researchers wanted to know the minimum number of binding interactions that would still allow for super-selective binding to occur. They were also interested to know whether the pattern the ligand molecules are arranged in makes a difference in selectivity. As it turns out, it does.
They have recently published a study in the Journal of the American Chemical Society that identifies the optimal ligand number for super-selective binding: six. But they also found, to their excitement, that the arrangement of these ligands—in a line, circle, or triangle, for example—also significantly impacted binding efficacy. They have dubbed the phenomenon "multivalent pattern recognition" or MPR.
After engineering a series of ligand-receptor architectures to explore how density, geometry, and nano-spacing influenced binding super-selectivity, the team realized that rigidity was a key factor. The more flexible, the less precise.
Diagnostics and therapeutics such as chemotherapy could also benefit from super-selectivity, which could allow for more reliable binding with cancer cells, for which certain receptor molecules are known to have a higher density. In this case, healthy cellswould remain undetected, drastically reducing side effects.
Finally, such selectivity engineering could offer key insights into complex interactions within the immune system.
Hale Bila et al, Multivalent Pattern Recognition through Control of Nano-Spacing in Low-Valency Super-Selective Materials, Journal of the American Chemical Society (2022). DOI: 10.1021/jacs.2c08529
The interplay between epidemics, prevention information, and mass media
When an epidemic strikes, more than just infections spread. As cases mount, information about the disease, how to spot it, and how to prevent it propagates rapidly among people in affected areas as well. Relatively little is known, however, about the interplay between the course of epidemics and this diffusion of information to the public.
A pair of researchers developed a model that examines epidemics through two lenses—the spread of disease and the spread of information—to understand how reliable information can be better disseminated during these events.
They report their two-layered model can predict the effects of mass media and infection prevention information on the epidemic threshold.
To tackle their question, the researchers' model compares the interactions between two layers of information. The first is the transmission of the disease itself, propagated through physical contact between people. The second occupies the information space of social networks, where different voices are sharing the do's and don'ts of infection prevention, called positive and negative information respectively. The model provides a set of equations that can be used to calculate the epidemic threshold using a technique called microscopic Markov chains. Central to this calculation is the time delay between becoming infected and recovering. The longer it takes for patients to recover from an infection, they found, the less likely a patient is cured, leading to a lower recovery rate and making it easier for a disease to break out. Disseminating effective prevention practices and using mass media, however, can increase the epidemic threshold, making it more difficult for the infection to spread. They simulate this by reducing the time delays related to recovery, which boosts recovery rates.
The impact of positive and negative information on SIR-like epidemics in delayed multiplex networks, Chaos An Interdisciplinary Journal of Nonlinear Science (2022). DOI: 10.1063/5.0126799
In a new breakthrough to understand more about the mammalian brain, University of Copenhagen researchers have made an incredible discovery. Namely, a vital enzyme that enables brain signals is switching on and off at random, even taking hours-long "breaks from work". These findings may have a major impact on our understanding of the brain and the development of pharmaceuticals.
Millions of neurons are constantly messaging each other to shape thoughts and memories and let us move our bodies at will. When two neurons meet to exchange a message, neurotransmitters are transported from one neuron to another with the aid of a unique enzyme.
This process is crucial for neuronal communication and the survival of all complex organisms. Until now, researchers worldwide thought that these enzymes were active at all times to convey essential signals continuously. But this is far from the case.
Using an innovative method, researchers have closely studied the enzyme and discovered that its activity is switching on and off at random intervals, which contradicts our previous understanding.
This is the first time anyone has studied these mammalian brainenzymes one molecule at a time, and we are awed by the result. Contrary to popular belief, and unlike many other proteins, these enzymes could stop working for minutes to hours. Still, the brains of humans and other mammals are miraculously able to function.
Dimitrios Stamou, Regulation of the mammalian-brain V-ATPase through ultraslow mode-switching, Nature (2022). DOI: 10.1038/s41586-022-05472-9
World's heaviest flying bird may be self-medicating on plants used in traditional medicine
Do you think only humans can use plant based medicines based on experience? Then think again. Even animals can do this. Humans aren't the only species that self-medicates.
If you see a great bustard (Otis tarda) in the wild, you're unlikely to forget it. Massive, colorful, and impossible to mistake, they are the heaviest birds living today capable of flight, with the greatest size difference between the sexes. They are also "lek breeders," where males gather at chosen sites to put on an audiovisual show for the visiting females, who choose a mate based on his appearance and the quality of his showbirdship.
But now, a study in Frontiers in Ecology and Evolution suggests that great bustards have another claim to our interest: they actively seek out two plants with compounds that can kill pathogens. They may thus be a rare example of a bird that uses plants against disease—that is, self-medication.
Self-medication in animals is suspected to occur, with a lesser or greater degree of confidence, in animals as diverse as primates, bears, deer, elk, macaws, honeybees, and fruit flies. But it's tricky to prove beyond doubt in wild animals.
We can't compare between control and experimental treatments. And double-blind trials or dose-effect studies, obligatory steps in human or veterinary medicine, are obviously impossible in wild animals.
Great bustards breed on grasslands from western Europe and northwest Africa to central and eastern Asia. Approximately 70% of the world's population live in the Iberian peninsula. Females typically remain faithful to the home range where they hatched for life—10 to 15 years—while after dispersal, males revisit the same lake site year after year. By staying (and importantly, pooping) in the same area for prolonged periods, they risk re-infecting themselves. And males need exceptional stamina during the mating season, which is expected to cause their immune defenses to nose-dive.
In theory, both sexes of great bustards might benefit from seeking out medicinal plants in the mating season when sexually transmitted diseases are common—while males that use plants with compounds active against diseases might appear more healthy, vigorous, and attractive to females.
The research team have studied great bustards since since the early 1980s, mainly in the regions of Madrid and Castille-Leon, Spain. They collected a total of 623 droppings from female and male great bustards, including 178 during the mating season in April. Under a microscope, they counted the abundance of recognizable remains (tissue from stems, leaves, and flowers) of 90 plant species that grow locally and are known to on the bustards' menu.
The results showed that two species are eaten by great bustards more often than expected from their abundance: corn poppies, Papaver rhoeas and purple viper's bugloss, Echium plantagineum.
"Great bustards select corn poppies and purple viper's bugloss mainly in the mating season , in April, when their energy expenditure is greatest. And males, who during these months spend much of their time and energy budgets on sexual display, prefer them more than females.
Of these two species, the first is avoided by cattle and is used in traditional medicine as a pain reliever, sedative, and immune booster. The second is toxic for humans and cattle if eaten in great quantities. They also have nutritional value: fatty acids abound in corn poppy seeds, while the seeds of purple viper's bugloss are rich in edible oils.
The authors isolated water- and fat-soluble compounds from both species and determined their chemical identity with gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (HPLC-MS). They focused on lipids, volatile essential oils, and alkaloids, produced by many plants as defense against herbivores. For example, they found that corn poppies are rich in bioactive alkaloids like rhoeadine, rhoeagenine, epiberberine, and canadine.
The authors then tested the activity of the isolated molecular fractions against three common parasites of birds: the protozoon Trichomonas gallinae, the nematode (parasitic worm) Meloidogyne javanica, and the fungus Aspergillus niger.
The results show that extracts from both plants are highly effective at inhibiting or killing protozoa and nematodes in vitro, while purple viper's bugloss is also moderately active against fungi.
The authors conclude that great bustards are prime candidates for birds that seek out specific plants to self-medicate. But more research is needed, they caution.The ultimate proof of self-medication requires experimental protocols developed in the biomedical, veterinary, and pharmacological sciences.
Luis M. Bautista-Sopelana et al, Bioactivity of plants eaten by wild birds against laboratory models of parasites and pathogens, Frontiers in Ecology and Evolution (2022). DOI: 10.3389/fevo.2022.1027201
Zombie viruses on a hijacking trip: Retroviral gene fragments affect embryonic cells
Ancient, dormant sequences in the genome impact embryonic development in unexpected ways. The mammalian genome contains retroviral sequences that are in an undead but mostly "harmless" state. An international research team recently discovered how some of these retroviral gene fragments affect embryonic cells if they are unleashed. Unexpectedly, not the viral proteins, but rather copies of the genetic material itself generate an imbalance in the cell.
Over thousands of years of evolution, countless viruses have embedded themselves in our genome. A staggering ten percent of mammalian genomes consist of ancient retroviral sequences. These no longer seem to pose any danger, because most of them have mutated beyond recognition. Additionally, these genes have been epigenetically silenced by the cell. But as the silencing of the viral remains fails, they will rise from their graves, causing chaos in the cell.
Researchers found that the messenger copies of some of the viral genes, the RNA, have an important impact on embryonic cells. The viral sequences seem to remember their original mission of hijacking the molecular machinery that ensures the flow of information from DNA to RNA to protein. Interestingly, the messenger RNA itself seems to be responsible.
Scientists described that the RNA of the resurrected viruses exerts attractive forces on the enzymes that read the information from the DNA. The tasks of the embryonic cell—such as reading important embryonic genes—are neglected and a fatal imbalance develops. This unleashed state occurs, for example, in some types of cancer and neurological diseases.
Viruses are cleverly constructed snippets of genetic information. Some of them incorporate themselves into the genome of their hosts and persist there. Thousands of copies of Endogenous Retroviruses (ERVs) have spread throughout mammalian genomes, often in droves of hundreds of repetitive copies.
As retroviruses jump from one section of DNA to the next during their life cycle, they can alter genes and even recombine them. This makes them an important tool for evolution to create new genes. For an individual organism however, uncontrolled gene modification does not bode well, especially during embryonic development.
This is why the cell will identify ERV sequences and recruit dedicated repressive machinery to their sites and keep them silent. Additionally, the chromosome is getting compacted at these sites.
But what happens if you turn off these protective mechanisms? Chaos!
Vahid Asimi et al, Hijacking of transcriptional condensates by endogenous retroviruses, Nature Genetics (2022). DOI: 10.1038/s41588-022-01132-w
Plastic in foraminifera and possible consequences for the environment
Single-celled organisms with calcareous shells, called foraminifera, contribute significantly to the formation of sand deposited on beaches, islands and coastal areas. Researchers have now found for the first time that foraminifera can take up tiny plastic particles and incorporate them into their calcareous shells. The results were published in Scientific Reports and Limnology and Oceanography Letters.
Gleaming white tropical beaches are coveted destinations for many recreation-seekers. But how do we perceive such beaches if we have to fear that they consist to a not inconsiderable extent of micro- and nanoplastics—invisible to our eyes?
Tropical beaches are mainly formed by calcifying marine animals such as corals, mussels and snails. The fact that corals incorporate microplastics into their calcareous skeleton has already been proven in studies. In some regions of the world, however, such as Indonesia, the Philippines and Australia, many beaches consist largely of the calcareous shells of foraminifera. These are single-celled organisms, a few millimeters in size and with a protective calcareous shell, that can be found in warm, shallow coastal areas worldwide.
Foraminifera feed on, among other things, microalgae or organic material particles they find on the seafloor. Micro- and nanoplastic particles have similar sizes and could easily be mistaken for potential food.
In a series of experiments, the team exposed several hundred foraminifera to seawater tanks for several weeks. They fed them partly with tiny micro- or nanoplastic particles, partly with natural food particles or a mixture of both. They observed that while the foraminifera preferred the natural food, when both were available at the same time, they frequently ate plastic pieces.
Using a fluorescence microscope, the researchers were able to observe a large number of yellow glowing nanoplastic particles in the foraminifera. Although some of the unicellular organisms rejected the plastic after the feeding experiments, about half of the foraminifera retained the plastic load inside the cell.
After eight weeks, a scanning electron microscope with 80,000x magnification revealed that many of the single-celled organisms had already encrusted the plastic particles with a layer of calcium carbonate and were apparently in the process of incorporating them into their shell.
So if the plastic particles are small enough, the foraminifera will take them in as food. For the environment, this could have advantages and disadvantages. For example, the trillions of foraminifera on the seafloor could be a sink for nanoplastics, a system that removes plastic from the ocean.
One problem the researcher sees, however, is potential impacts on the health of the foraminifera. On beaches and in shallow marine areas, the shells of foraminifera are often deposited at high densities of more than 1 kg per m2. However, if the protozoa interchange plastic particles with their natural food and incorporate them into their calcareous shells, their fitness, shell formation and stability could be disrupted—with consequences for their population as a whole. Part 1
This, in turn, could have a long-term impact on coasts and islands, which are already suffering greatly under the weight of sea-level rise and erosion from increasingly frequent and powerful storm surges.
Marlena Joppien et al, Nanoplastic incorporation into an organismal skeleton,Scientific Reports(2022).DOI: 10.1038/s41598-022-18547-4
Marlena Joppien et al, Microplastics alter feeding strategies of a coral reef organism,Limnology and Oceanography Letters(2022).DOI: 10.1002/lol2.10237
Researchers suggest that wormholes may look almost identical to black holes
A group of researchers has found evidence that suggests the reason that a wormhole has never been observed is that they appear almost identical to black holes.
They describe studying theoretical linear polarization from an accretion diskthat would be situated around a class of static traversable wormholes and compared the findings to images of black holes.
For many years, scientists and science fiction writers have considered the theoretical possibility of a wormhole. Such an object, theorysuggests, would take the form of a tunnel of sorts that connects two different parts of the universe. Moving through the tunnel would allow for travel to distant destinations in ways not available to spaceships incapable of moving faster than the speed of light—by taking a shortcut.
Unfortunately, no one has ever observed a worm hole or even any physical evidencethat they actually exist. Still, because the theory for their existence is so strong, astrophysicists assume they do exist. The problem is that we either lack the technology to see them, or we have not been looking for them in the right way.
In this new effort, the researchers suggest that the latter is the problem. They have found evidence, via theory, that suggests that they might be sitting out there in the night sky in plain sight, and that the reason we are not seeing them is because we are mistaking them for black holes.
The work involved studying wormhole theories and then applying findings to the creation of simulations, with an emphasis on the polarity of the light that would be emitted by such an object—and by also taking account of the characteristics of an assumed disk surrounding its mouth. They then created both direct and indirect images to depict what a wormhole would look like and compared them to black holes; they found them to look remarkably similar.
The researchers noted that it should be possible to tell wormholes and black holes apart by noting subtle differences between them, such as polarization patterns and intensities and also their radii.
Valentin Deliyski et al, Polarized image of equatorial emission in horizonless spacetimes: Traversable wormholes,Physical Review D(2022).DOI: 10.1103/PhysRevD.106.104024
New CRISPR-based tool inserts large DNA sequences at desired sites in cells
Building on the CRISPR gene-editing system, researchers have designed a new tool that can snip out faulty genes and replace them with new ones, in a safer and more efficient way.
Using this system, the researchers showed that they could deliver genes as long as 36,000 DNA base pairs to several types of human cells, as well as to liver cells in mice. The new technique, known as PASTE, could hold promise for treating diseases that are caused by defective genes with a large number of mutations, such as cystic fibrosis.
The new tool combines the precise targeting of CRISPR-Cas9, a set of molecules originally derived from bacterial defense systems, with enzymes called integrases, which viruses use to insert their own genetic material into a bacterial genome.
Just like CRISPR, these integrases come from the ongoing battle between bacteria and the viruses that infect them.
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The CRISPR-Cas9 gene editing system consists of a DNA-cutting enzyme called Cas9 and a short RNA strand that guides the enzyme to a specific area of the genome, directing Cas9 where to make its cut. When Cas9 and the guide RNA targeting a disease gene are delivered into cells, a specific cut is made in the genome, and the cells' DNA repair processes glue the cut back together, often deleting a small portion of the genome.
If a DNA template is also delivered, the cells can incorporate a corrected copy into their genomes during the repair process. However, this process requires cells to make double-stranded breaks in their DNA, which can cause chromosomal deletions or rearrangements that are harmful to cells. Another limitation is that it only works in cells that are dividing, as nondividing cells don't have active DNA repair processes.
This new work deals with a tool that could cut out a defective gene and replace it with a new one without inducing any double-stranded DNA breaks. To achieve this goal, they turned to a family of enzymes called integrases, which viruses called bacteriophages use to insert themselves into bacterial genomes.
For this study, the researchers focused on serine integrases, which can insert huge chunks of DNA, as large as 50,000 base pairs. These enzymes target specific genome sequences known as attachment sites, which function as "landing pads." When they find the correct landing pad in the host genome, they bind to it and integrate their DNA payload. Combining these enzymes with a CRISPR-Cas9 system that inserts the correct landing site would enable easy reprogramming of the powerful insertion system.
The new tool, PASTE (Programmable Addition via Site-specific Targeting Elements), includes a Cas9 enzyme that cuts at a specific genomic site, guided by a strand of RNA that binds to that site. This allows them to target any site in the genome for insertion of the landing site, which contains 46 DNA base pairs. This insertion can be done without introducing any double-stranded breaks by adding one DNA strand first via a fused reverse transcriptase, then its complementary strand.
Once the landing site is incorporated, the integrase can come along and insert its much larger DNA payload into the genome at that site.
Scientists reveal first close-up look at bats' immune response to live infection
In a world first, scientists have sequenced the response to viral infection in colony-bred cave nectar bats (Eonycteris spelaea) at single-cell resolution. Published in the journal Immunity, the findings contribute to insights into bat immunity that could be harnessed to protect human health.
Bats harbor many types of viruses. Even when they are infected with viruses deadly to humans, they show no notable signs or symptoms of disease. By understanding how bats' immune responses protect them from infections, we may find clues that will help humans to better combat viral infections.
And knowing how to better fight viral infections can aid in the development of treatments that will help us to be more bat-like—by falling sick less and aging better.
In this study, the scientists investigated bat immune responses to Malacca virus, a double-stranded RNA virus that uses bats as its natural reservoir. This virus also causes mild respiratory disease in humans.
The team used single-cell transcriptome sequencing to study lung immune responses to infections at thecellular level, identifying the different types of immune cells in bats—some of which are different from those in other mammals, including humans—and uncovering what they do in response to suchviral infections.
They found that a type of white blood cell, called neutrophils, showed a very high expression of a gene called IDO1, which is known to play a role in mediating immune suppression in humans. The scientists think that IDO1 expression in cave nectar bats could play an important role in limiting inflammation following infection.
Researchers also found marked anti-viral gene signatures in white blood cells known as monocytes and alveolar macrophages, which—in a sense—consume viral particles and then teach T cells how to recognize the virus. This observation is interesting as it shows that bats clearly activate an immune response following infection despite showing few outward symptoms or pathology. The team also identified an unusual diversity and abundance of T cells and natural killer cells—named for their ability to kill tumor cells and cells infected with a virus—in the cave nectar bat, which are broadly activated to respond to the infection.
Akshamal M. Gamage et al, Single-cell transcriptome analysis of the in vivo response to viral infection in the cave nectar bat Eonycteris spelaea, Immunity (2022). DOI: 10.1016/j.immuni.2022.10.008
Bacteria that break down nicotine found in the guts of mice
A team of researchers, has isolated a type of bacteria in the guts of mice that break down nicotine. In their paper published in the journal Nature, the group describes how they isolated the bacteria and why their finding could reduce incidences of fatty liver disease in humans.
Prior research has shown that smoking cigarettes is the leading cause of preventable deaths around the world. In addition to its association with lung disease, smoking cigarettes has also been linked to fatty liver disease. In this new effort, the researchers have found that a certain kind of bacteria breaks down nicotine in the guts of mice (due to forced smoking), and thereby reduces the likelihood of developing fatty liver disease.
When people (or mice) smoke cigarettes, it has been found, some of the nicotine makes its way into the gut, leading to an increased risk of fatty liver disease, associated with scarring, and in some cases, liver cancer.
In this new work, the researchers measured the amount of nicotine that makes its way to the gut by comparing stool samples of 30 human smokers and 30 nonsmokers. They then did the same with mice and found the results to be similar.
Next, they sterilized the guts of several lab mice and ran the nicotine experiment again. They found that the mice with the sterilized guts had more nicotine in their systems, indicating that at least one type of gut bacteria was breaking down the nicotine. Then, by process of elimination, they were able to track down the bacteria (Bacteroides xylanisolvens) that was responsible for the breakdown—it was producing a type of enzyme that breaks down nicotine.
Prior research has shown that B xylanisolven also live in the human gut. The researchers next plan to study it and the enzymes it produces to find out if the enzyme can be produced commercially and given to smokers to reduce their chances of developing fatty liver disease and by extension, liver cancer.
More information:Bo Chen et al, Gut bacteria alleviate smoking-related NASH by degrading gut nicotine,Nature(2022).DOI: 10.1038/s41586-022-05299-4
Bats have lived with coronaviruses for millennia. Details are still hazy about how one of these viruses evolved into SARS-CoV-2, which causes COVID in humans. Did it go directly from bats to humans or via another animal species? When? And why? If we can't answer these questions for this now-infamous virus, we have little hope of preventing the next pandemic.
When we consume fats (also called lipids) in our diet, they can be metabolized or stored to provide energy for the body. But they are also involved in regulating the genes expressed within—and the signaling between—cells. Lipids influence how our cells behave and function, which affects many processes in the body including the immune system.
Sugar substitutes found in many supermarket foods have been shown to kill off antibiotic-resistant bacteria that cause pneumonia and sepsis. Three artificial sweeteners used in products such as diet drinks, yogurts and desserts dramatically halt the growth of multidrug-resistant priority pathogens.
To stop new viruses jumping across to humans, we must protect and restore bat habitat
Bats have lived with coronaviruses for millennia. Details are still hazy about how one of these viruses evolved into SARS-CoV-2, which causes COVID in humans. Did it go directly from bats to humans or via another animal species? When? And why? If we can't answer these questions for this now-infamous virus, we have little hope of preventing the next pandemic.
Somebat speciesare hosts for other viruses lethal to humans, from rabies toNipahtoHendra. But their supercharged immune systems allow them to co-exist with these viruses without appearing sick.
So what can we do to prevent these viruses emerging in the first place? Researchers found one surprisingly simple answer in their new researchon flying foxes in Australia: protect and restore native bat habitat to boost natural protection.
When we destroynative forests, we force nectar-eating flying foxes into survival mode. They shift from primarily nomadic animals following eucalypt flowering and forming large roosts to less mobile animals living in a large number of small roosts near agricultural land where they may come in contact with horses.
Hendra virus is carried by bats and can spill over to horses. It doesn't often spread from horses to humans, but when it does, it'sextremely dangerous.
Now we know how habitat destruction and spillover are linked, we can act. Protecting the eucalyptus species flying foxes rely on will reduce the risk of the virus spreading to horses and then humans. The data scientists gathered also makes it possible to predict times of heightened Hendra virus risk—up to two years in advance.
By restoring and protecting the natural barriers which for so long kept us safe from bat-borne viruses. It is far better to prevent viruses from spilling over in the first place than to scramble to stop a possible pandemic once it's begun.
Planting trees can help stop dangerous new viruses reaching us. It really is as simple as that.
Bees aren’t the only insects to make honey, some ants can make the sweet treat too.
The honeypot ant,Camponotus inflatus, lives in the deserts of Australia where worker bees harvest nectar from the flowers of the mulga tree. The bees carry it underground and feed it to specialised workers known as ‘rotunds’ whose job it is to dangle upside down and eat.
Indeed, the tubby little insects are fed so much nectar that their abdomens swell up to the size of a small grape, and the abdomen wall is stretched so thin that the honey can be seen inside.
The rotunds form roughly 50 per cent of the colony, and live in cool, underground galleries. They are highly prized by Indigenous Australians who have been excavating and eating them for thousands of years. In the 1990 documentary,Trials Of Life, David Attenborough was filmed quaffing one.
The honey is said to be runnier and less sweet than the better-known bee alternative, but remains rich in antioxidants.
These literal honeypots are an insurance policy against hard times. When the regular workers run out of food, they stroke the rotunds’ antennae, causing the ants to regurgitate the stored honey. They also groom and clean the honeypots to keep the living larders in good condition.
Wolves infected with a common parasite may be much more likely to become pack leaders
A team of researchers with the Yellowstone Wolf Project at the Yellowstone Center for Resources, in Yellowstone National Park, in Wyoming, has found that wolves in the park who become infected with Toxoplasma gondii, a common parasite, are much more likely to become leaders of their pack. In their study, reported in the journal Communications Biology, the group analyzed data from studies of the wolves in the park over a 26-year period.
T. gondii is an obligate parasite that infects the protozoa in cells of infected animals. Such infections are known as toxoplasmosis, and they occur in almost all warm-blooded animals, including humans. Prior research has shown that in most cases, symptoms are few, through there is some evidence that suggests that they can lead to an increase in erratic or aggressive behaviour.
In this new effort, the researchers wondered what sort of impact of T. gondii infections might have on wild wolves. To find out, they conducted an extensive study of wolves living in Yellowstone National Park.
The work involved studying data from blood samplestaken from over 200 wolves living in the park over the years 1995–2020, while looking for evidence of infection. The researchers also looked at the notes made by research observers to learn more about any behavior changes that might have been evident in the wolves.
The researchers found that young, infected wolves tended to leave their packs earlier than those uninfected. Infected males were 50% more likely to leave their pack as early as six months after birth. Males normally stay for up to 21 months. And infected females were 25% more likely to leave their pack at 30 months, rather than the normal 48.
The researchers also found that infected males were more than 46 times more likely to become pack leaders than uninfected males. The researchers also found that infection rates were higher in wolves that mingled with cougars. The researchers suggest the differences in behavior were likely due to the impact of the parasite on the brains of wolves, making them bolder and less likely to back down when challenged by others.
Connor J. Meyer et al, Parasitic infection increases risk-taking in a social, intermediate host carnivore, Communications Biology (2022). DOI: 10.1038/s42003-022-04122-0
'SuperGPS' Technology Accurately Pinpoints Your Position Within Inches
Many of us rely on GPS (Global Positioning System) to estimate travel times, find our way to new places, avoid traffic congestion, keep track of the kids, and generally avoid getting lost.
But it's not always the most reliable of systems, especially in built-up areas where it's difficult to get a straight line of sight to and from a satellite.
Now researchers have come up with a new and improved technology that could eventually replace GPS in some scenarios. Called SuperGPS, it's accurate within 10 centimeters (or 3.9 inches) and doesn't rely on navigation satellite systems.
The new approach makes use of networks similar to cell networks, but instead of streaming data to our phones the network gets a precise fix on the device.
A combination of radio transmitters and fiber-optic networks form the foundation of the system, with some smart tweaks on top.
In a test site with six radio transmitters, the researchers were able to demonstrate their system in action across an area of 660 square meters (7,104 square feet). The timings of the transmitted radio signals can be measured and interpreted to gauge distance, which then reveals the position of individual devices.
One of the key components of the new network positioing system is a synchronized atomic clock: perfect timing means more precise positioning. Essentially, the fiber optic cables act as connections that keep everything in sync, and accurate to one billionth of a second. The system also deploys a radio signal bandwidth that's much larger than normal.
Developers used several small bandwidth radio signals combined together to form a larger virtual bandwidth for the network communication.
This additional bandwidth overcomes one of the biggest problems with standard GPS, which is that radio signals get reflected off buildings and can quickly become confused.
"This can make GPS unreliable in urban settings, for instance, which is a problem if we ever want to use automated vehicles.As well as automated vehicles, the new system could be useful in planning quantum communication networks and next-generation networks for mobile devices, according to the researchers who developed it.
Mars Sample Return: Bringing Mars Rock Samples Back to Earth
NASA and the European Space Agency are developing plans for one of the most ambitious campaigns ever attempted in space: bringing the first samples of Mars material safely back to Earth for detailed study. The diverse set of scientifically curated samples now being collected by NASA’s Mars Perseverance rover could help scientists answer the question of whether ancient life ever arose on the Red Planet. Bringing samples of Mars to Earth for future study would happen in several steps with multiple spacecraft, and in some ways, in a synchronized manner. This short animation features key moments of the Mars Sample Return campaign: from landing on Mars and securing the sample tubes to launching them off the surface and ferrying them back to Earth.
Researchers recreate the adrenal gland in a petri dish
Sitting atop the kidneys, the adrenal gland plays a pivotal role in maintaining a healthy body. Responding to signals from the brain, the gland secretes hormones that support critical functions like blood pressure, metabolism, and fertility.
People with adrenal gland disorders—such as primary adrenal insufficiency, in which the gland does not release sufficient hormones—can suffer fatigue, dangerously low blood pressure, coma, and even death if untreated. No cure for primary adrenal insufficiency exists, and the lifelong hormone-replacement therapy used to treat it carries significant side effects.
A preferable alternative would be a regenerative medicine approach, regrowing a functional adrenal gland capable of synthesizing hormones and appropriately releasing them in tune with the brain's feedback. In a new study in the journal Developmental Cell, researchershave coaxed stem cells in a petri dish to divide, mature, and take on some of the functions of a human fetal adrenal gland, bringing that goal one step closer.
To begin, the researchers used what's known as an "organoid culture" system, in which cells grow first as a floating aggregate for three weeks, then on a membrane exposed to air on one side, promoting better survival and allowing them to proliferate in three dimensions. Utilizing a carefully selected growth medium, they prompted the iPSCs to elicit an intermediate tissue type in the adrenal development process, the posterior intermediate mesoderm (PIM).
After verifying they had cultured PIM-like cells, the researchers embarked on directing those cells to transition to the next stage, adrenocortical progenitor-like cells, during which cells turn on markers indicating they have "committed" to becoming adrenal gland cells.
Molecular assays to check for adrenal markers, as well as transmission electron microscope analyses, all told the researchers they were on the right track to recreating a tissue that resembled the early adrenal gland.
The process we developed was highly efficient, with around 50% of cells in organoids acquiring adrenocortical cell fate. They also showed that the cells they grew could respond to what's known as the hypothalamic-pituitary-adrenal axis, a feedback loop that governs communication from the brain to the adrenal gland and back again.
Yuka Sakata, Keren Cheng, Michinori Mayama, Yasunari Seita, Andrea J. Detlefsen, Clementina A. Mesaros, Trevor M. Penning, Kyosuke Shishikura, Wenli Yang, Richard J. Auchus, Jerome F. Strauss, Kotaro Sasaki. Reconstitution of human adrenocortical specification and steroidogenesis using induced pluripotent stem cells. Developmental Cell, 2022; 57 (22): 2566 DOI: 10.1016/j.devcel.2022.10.010
Study shows prestigious institutions produce more published manuscripts because they have a bigger labour pool
A quartet of researchers has found that the reason more prestigious universities are able to publish more scientific papers than lesser institutions is that they have a larger pool of undergrads, fellows and postdocs to assist with such efforts.
In their paper, published in the journalScience Advances, Sam Zhang, Hunter Wapman, Daniel Larremore and Aaron Clauset describe analyzing massive amounts of data in the Web of Science database to learn more aboutpublishingby institutions in the U.S.
Most of the prestigious science paper publishing institutions in the U.S. are college- or university-based. Some of the most well known are MIT, Harvard, Stanford and the University of California. Researchers at these institutions conduct a lot of science research and publish a corresponding number of science-research based papers in peer-reviewed journals.
In this new effort, the research group sought to better understand the factors underlying the tendency of prestigious institutions to produce more published manuscripts than other, less-prestigious institutions.
The work involved sifting data from the Web of Science database, which is actually a portal to several other databases, all of which contain massive amounts of data related to science research efforts. In their effort, the researchers included data from 1.6 million published articles, written by 78,802 authors, all of whom were either tenured or on a tenure track.
The data involved research efforts at 26 U.S. universities that grant Ph.Ds. The researchers focused on data describing productivity of both the authors involved in research efforts and publishing groups as a whole.
The researchers found a pattern—more prestigious schools tend to produce more papers because they have more people available to work on research teams. They noted that neither the senior- nor junior-level people working on the papers were more productive than others working at less-prestigious institutions; it was just more people working and getting more done.
The researchers suggest the possibility that less-prestigious institutions could increase their publication rates if they chose to increase the number of qualified people available to work on research and publishing efforts.
Sam Zhang et al, Labor advantages drive the greater productivity of faculty at elite universities, Science Advances (2022). DOI: 10.1126/sciadv.abq7056
New kind of tropical cyclone identified in the Indian Ocean
Oceanography experts have described a new kind of cyclone in the Indian Ocean near Sumatra after observing satellite surface winds in the region.
The experts' search for the trigger mechanisms of the Indian Ocean Dipole has led to the discovery of the new type of atmospheric tropical cyclone forming in the South-East Tropical Indian Ocean (SETIO) that they call SETIO Cyclone.
The Indian Ocean Dipole (IOD) is a coupled atmosphere-ocean interaction in the tropical Indian Ocean that strongly affects the climate and rainfall variability of surrounding countries including Australia.
Researchers found that SETIO cyclones are short-lived weather-like events that develop frequently during austral winter/spring and operate to maintain a warm surface ocean in the region.
Dramatic changes happen in some years when SETIO cyclones fail to develop, and ambient winds trigger the appearance of cold seawater in a vast area strongly disturbing both winds and rainfall patterns over the Indian Ocean.
In the natural sciences, it is of uttermost importance to identify so-called trigger processes, such as SETIO cyclones, that link the cause to an effect.
This is a rare new discovery that sheds new light into the functioning of the IOD.
Ankit Kavi et al, Synoptic-scale atmospheric cyclones in the South-East Tropical Indian Ocean (SETIO) and their relation to IOD variability, Journal of Southern Hemisphere Earth Systems Science (2022). DOI: 10.1071/ES22020
The largest source of abiotic methane gas on Earth
Methane (CH4), the chief constituent of natural gas, is one of the most widely used "clean" fuels. Although methane is usually considered to originate from organic matter, recently, more and more evidence shows that methane can be produced by abiotic processes.
Researchers demonstrated that large amounts of methane gas can form during prograde metamorphism in a cold subduction zone, evidenced by the massive CH4-rich fluid inclusions in eclogites from Western Tianshan, China.
Based on their calculation, the potential CH4flux from worldwide modern subduction zones is estimated to be as much as ~10.8 Mt/y. Consequently, the subducted cold oceanic crust may produce the largest amount of abiotic methane, along with other abiotic methane sources such as that from mid-ocean ridges or that from by high-pressure serpentinization.
Massive CH4-richfluidinclusions have been found in garnet and omphcite, which are the main constituent minerals of eclogite in the West Tianshan subduction zone (eclogite is the most important high grade metamorphic rock during cold subduction). Isotopic analyses and petrological studies both demonstrated that this methane was of abiotic origin and formed by water-rocks reactions during the prograde high-pressure to ultrahigh-pressure metamorphism.
Lijuan Zhang et al, Massive abiotic methane production in eclogite during cold subduction, National Science Review (2022). DOI: 10.1093/nsr/nwac207
Blood Thinner Ineffective for COVID-19 Patients: Study
A clinical trial finds that the anticoagulant apixaban, which has been prescribed to help COVID-19 patients recover, is ineffective and in rare instances dangerous.
N
ew data from a clinical trial suggest that apixaban, an anticoagulant that’s widely been prescribed to promote recovery in patients with severe cases of COVID-19, doesn’t offer any discernable benefit for people with the disease.
TheUK-wide trial, which is run by Addenbrooke’s Hospital and the University of Cambridge, involved more than 1,000 hospitalized COVID-19 patients and compared the outcomes of those who had been randomly assigned to receive apixaban to those who had not, according toFinancial Times. It found that 29.1 percent of those who received the blood thinner either ended up back in the hospital or died within a year, compared to 30.8 percent of people who weren’t given the drug. That finding doesn’t support apixaban as an effective treatment for COVID-19, and the researchers conclude that doctors ought to stop prescribing it to their coronavirus patients. Meanwhile,BBC Newsreports that a “small number” of the 402 patients who took apixaban had to discontinue treatment due to severe bleeding.
The trial will continue with other drugs thought to help against COVID-19, according to BBC News, including a statin called atorvastatin that may help lessen the inflammatory response launched by COVID-19 patients’ immune systems and so prevent tissue damage.
A secret of developing life: In some instances the fetus helps repair a ruptured amniotic sac
Premature rupture of the amniotic sac can have devastating consequences, but scientists are studying instances when the damaged sac repairs itself—a phenomenon that requires cooperation of the developing fetus.
A new investigation of the amnion, the innermost layer of epithelial cells in the amniotic sac reveals a cascade of cellular events that result in sac repair. The new research helps lay the groundwork for a keener understanding of both healthy pregnancies and when things go awry.
Aware that premature ruptureof the amniotic membranes can lead to premature birth, researchers are asking what causes the sac to reseal. Producing a definitive answer to that question may ultimately lead to interventions that prevent premature birthfor those whose membranes don't reseal. The biggest potential benefit down the road is guarding against the sometimes lethal outcomes when babies are born too small, too soon.
The premature rupture of the amniotic sac, a condition referred to as a preterm prelabour rupture of membranes (pPROM) is a leading cause of preterm birth. In some cases, these ruptured membranes heal spontaneously. Researchers investigated repair mechanisms of the amnion, a layer of epithelial cells in the amniotic sac closest to the fetus.
Amniotic membranes normally remain intact until the onset of active labor or within 24 hours before labor starts. pPROM may not be easy to detect. For some women, fluid leaks slowly and may be mistaken for urine. Obstetricians say it's important to note that amniotic fluid usually has no color and doesn't smell like urine. They also underscore that premature membrane rupture can occur for a variety of reasons.
In some women the amnion can rupture early for reasons ranging from infections of the uterus, cervix, or vagina to too much stretching of the amniotic sac. The latter may occur as a direct result of too much fluid in the sac, or more than one baby putting pressure on the membranes. Other causes of membrane rupture include conditions such as malnutrition, or intrauterine bleeding. Smoking is another factor that can cause rupture.
In this new study the research team found that fetal macrophages are recruited to rupture sites in both the human and mouse amnion and assist in the repair of torn membranes.
Macrophages migrated to and resided at rupture sites in both human and mouse amnion. A process called epithelial-mesenchymal transition, in which epithelial cells acquire a mesenchymal phenotype and which is implicated in tissue repair, was observed at rupture sites.
In short, epithelial cells took on the role of mesenchymal cells and helped begin the process of resealing. None of the cascade of biological events would have occurred without macrophages first migrating to and taking up residence at the rupture site. This shows that ruptures are reversible with repairs
The membrane repair is highly reliant on signaling molecules: in this case, transformation growth factor-β/Smad—TGF-β/Smad—signaling. TGF-β/Smad was prominent in both mouse and human samples.
This study's findings could potentially inform research into treatments for preterm membrane ruptures to prevent preterm birth.
Yosuke Kawamura et al, Fetal macrophages assist in the repair of ruptured amnion through the induction of epithelial-mesenchymal transition, Science Signaling (2022). DOI: 10.1126/scisignal.abi5453
The effects of climate change on body size evolution
The Northern Treeshrew, a small, bushy-tailed mammal native to South and Southeast Asia, defies two of the most widely tested ecological "rules" of body size variation within species, according to a new study.
The unexpected finding, researchers say, may be attributable to climate change—the body sizerules reversed in Northern Treeshrews as average temperaturesclimbed—and likely exists in other species.
The first-of-its-kind study, published Nov. 29 in the journalScientific Reports, found that the Northern Treeshrew (Tupaia belangeri) breaks both Bergmann's rule and the island rule. The former describes a common pattern wherein individuals of a warm-blooded species inhabiting colder climates—generally located at higher latitudes—have larger average body sizes than those in warmer climates, which are usually at lower latitudes. The latter predicts that small mammal species evolve larger body sizes on islands than their mainland counterparts, whereas island-bound large mammals evolve smaller body sizes.
Although both rules have been repeatedly tested from a strictly geographic standpoint, how they interact—and possibly even change over shorter timescales amidst rapid climate change—has never been rigorously examined.
In the first published study to do so, researchers analyzed 839 museum specimens of adult Northern Treeshrews collected over 130 years from across their entire geographic range, including mainland and island populations, along with historical climate data.
They found that, contrary to Bergmann's rule, body size of the Northern Treeshrew increased in warmer climates closer to the equator. More importantly—and quite unexpectedly—they discovered that both rules have reversed over a remarkably brief period between the late 19th and 20th centuries, with the reversal accelerating as average temperatures rose.
This study highlights that body size is linked to complex, dynamic and potentially interdependent ecological factors. This is the first time a rule reversal like this has been found in any species. The study also found that the two rules are intertwined.
Maya M. Juman et al, Recent and rapid ecogeographical rule reversals in Northern Treeshrews, Scientific Reports (2022). DOI: 10.1038/s41598-022-23774-w
Testing time perception in an unusually lifelike setting—a virtual reality ride on a New York City subway train—an interdisciplinary Cornell research team found that crowding makes time seem to pass more slowly.
As a result, rush-hour commutes onpublic transitmay feel significantly longer than other rides that objectively take the same amount oftime.
The research adds to evidence thatsocial contextandsubjective feelingsdistort our sense of the passage of time, and may have practical implications for people's willingness to use public transit, particularly after the pandemic.
It's a new way of thinking about social crowding, showing that it changes how we perceive time. Crowding creates stressful feelings, and that makes a trip feel longer.
: Saeedeh Sadeghi et al, Affective experience in a virtual crowd regulates perceived travel time, Virtual Reality (2022). DOI: 10.1007/s10055-022-00713-8 Saeedeh
Saeedeh Sadeghi et al, Crowding and Perceived Travel Time in Public Transit: Virtual Reality Compared With Stated Choice Surveys,Transportation Research Record: Journal of the Transportation Research Board(2022).DOI: 10.1177/03611981221130346
Dr. Krishna Kumari Challa
Almost All 'Natural' Skincare Products Contain Allergens, Scientists Warn
Nearly 90 percent of the 1,651 personal skin care products studied – including lotions, soaps, and moisturizers – contained at least one of the top 100 most common allergens known to cause contact dermatitis.
Contact dermatitis is more than a fleeting irritation. It's a red, itchy rash that, at its worst, can blister, caused by exposure to substances that either irritate or inflame the skin. The latter is an allergic reaction that occurs once the skin becomes sensitized to an otherwise harmless substance.
According to some estimates, rates of contact dermatitis are on the rise worldwide, up almost three-fold in three decades since 1996.
The researchers say that this uptick in contact dermatitis, a rapidly growing skincare and beauty industry worth billions, and a lack of regulation on its marketing motivated the study.
Contact dermatitis is preventable, so long as you can navigate and interpret the long list of ingredients found in skincare products and know which ones might aggravate the skin. Easier said than done.
A typical skincare or cosmetic product may contain anywhere from 15 to 50 ingredients. Research suggests people could be applying over 500 different chemicals to their skin each day, depending on their skincare routine.
In other words, the more products you use, the more you expose your skin to potential allergens.
Many of the allergens identified in the study were fragrances – think lavender and other botanical extracts – which have become a leading cause of contact dermatitis.
On average, skincare products contained between four and five known allergens. In total, 73 different allergens were listed 7,487 times across the 1,651 products studied.
That's only based on product information available online, but it still gives you a sense of the scale of the problem.
In 2017, another US study found few moisturizers were free from allergens, and even 'fragrance-free' products sometimes contained fragrances, which can irritate the skin.
https://jamanetwork.com/journals/jamadermatology/article-abstract/2...
Nov 16, 2022
Dr. Krishna Kumari Challa
How Secrets of the Arctic decoded
Nov 16, 2022
Dr. Krishna Kumari Challa
Babies born to mothers with preeclampsia found to be at increased risk of stroke and heart disease later in life
Preeclampsia is a condition involving blood pressure elevation and heightened levels of proteins in urine that can damage kidneys and sometimes other organs of pregnant women. Preeclampsia tends to occur later in pregnancy, though it can sometimes happen earlier. Preeclampsia has been found to stymie fetal growth if not properly treated by causing problems in the arteries that carry blood in the placenta.
A team of researchers has found evidence that suggests babies born to mothers with preeclampsia have an increased risk of a stroke and/or heart disease later in life. They also found that it can also lead to other health problems for the baby later in life.
The work involved obtaining and analyzing the medical records of 8.5 million babies born in the 1970s and 1980s and tracking instances of ischemic heart disease (IHD) or stroke in those babies for 40 years after they were born. They found that babies born to mothers experiencing preeclampsia were 33% more likely to develop IHD in later life than babies born to mothers without the condition. They also found a 34% increased risk of stroke. The researchers also found a small increase in risk for stroke in siblings of babies born to mothers with preeclampsia. The researchers suggest the large sample size ensures accuracy of the results and also allowed them to evaluate the role of preterm babies in increased risk of heart disease later on in life. They note also that theirs is the first study to find a link between babies born to mothers with preeclampsia and an increased risk of heart disease and/or stroke later on in life. The researchers note that the risk associations for preeclampsia were more notable in mothers who developed the condition later in their pregnancies than for those who developed it early.
Fen Yang et al, Association of Maternal Preeclampsia With Offspring Risks of Ischemic Heart Disease and Stroke in Nordic Countries, JAMA Network Open (2022). DOI: 10.1001/jamanetworkopen.2022.42064
Nov 17, 2022
Dr. Krishna Kumari Challa
Earth can regulate its own temperature over millennia, new study finds
The Earth's climate has undergone some big changes, from global volcanism to planet-cooling ice ages and dramatic shifts in solar radiation. And yet life, for the last 3.7 billion years, has kept on beating.
Now, a study by MIT researchers in Science Advances confirms that the planet harbors a "stabilizing feedback" mechanism that acts over hundreds of thousands of years to pull the climate back from the brink, keeping global temperatures within a steady, habitable range. Just how does it accomplish this? A likely mechanism is "silicate weathering"—a geological process by which the slow and steady weathering of silicate rocks involves chemical reactions that ultimately draw carbon dioxide out of the atmosphere and into ocean sediments, trapping the gas in rocks. Scientists have long suspected that silicate weathering plays a major role in regulating the Earth's carbon cycle. The mechanism of silicate weathering could provide a geologically constant force in keeping carbon dioxide—and global temperatures—in check. But there's never been direct evidence for the continual operation of such a feedback, until now. The new findings are based on a study of paleoclimate data that record changes in average global temperatures over the last 66 million years. The MIT team applied a mathematical analysis to see whether the data revealed any patterns characteristic of stabilizing phenomena that reined in global temperatures on a geologic timescale. They found that indeed there appears to be a consistent pattern in which the Earth's temperature swings are dampened over timescales of hundreds of thousands of years. The duration of this effect is similar to the timescales over which silicate weathering is predicted to act. The results are the first to use actual data to confirm the existence of a stabilizing feedback, the mechanism of which is likely silicate weathering. This stabilizing feedback would explain how the Earth has remained habitable through dramatic climate events in the geologic past.
Constantin Arnscheidt, Presence or absence of stabilizing Earth system feedbacks on different timescales, Science Advances (2022). DOI: 10.1126/sciadv.adc9241
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Nov 17, 2022
Dr. Krishna Kumari Challa
Over a billion young people are potentially at risk of hearing loss from headphones, earbuds, loud music venues
More than 1 billion teens and young people are potentially at risk of hearing loss because of their use of headphones and earbuds and attendance at loud music venues, concludes a pooled data analysis of the available evidence, published in the open access journal BMJ Global Health.
The World Health Organization (WHO) estimates that over 430 million people worldwide currently have disabling hearing loss. Young people are particularly vulnerable because of their use of personal listening devices (PLDs), such as smartphones, headphones and earbuds, and attendance at loud music venues, amid poor regulatory enforcement. Previously published research suggests that PLD users often choose volumes as high as 105 dB while average sound levels at entertainment venues range from 104 to 112 dB, exceeding permissible levels (80 dB for adults; 75 dB for children) even if for very short periods of time.
A group of 33 studies, corresponding to data from 35 records and 19,046 participants, was included in this research work to come to this conclusion; 17 records focused on PLD use and 18 focused on loud entertainment venues .
The pooled data analysis indicates that the prevalence of unsafe listening practices from PLD use and attendance at loud entertainment venues is common worldwide—24% and 48%, respectively, among teens and young peopel.
Based on these figures, the researchers estimate that the global number of teens and young adults who could potentially be at risk of hearing loss as a result ranges from 0.67 to 1.35 billion.
The researchers acknowledge some limitations to their findings, including the varied study design—a particular feature of the studies on entertainment venues—and the absence of standardized methodology.
These findings prompted the researchers to conclude, "There is an urgent need for governments, industry, and civil society to prioritize global hearing loss prevention by promoting safe listening practices."
Prevalence and global estimates of unsafe listening practices in adolescents and young adults: a systematic review and meta-analysis, BMJ Global Health (2022). DOI: 10.1136/bmjgh-2022-010501
Nov 17, 2022
Dr. Krishna Kumari Challa
Climate change: Increasing heat waves will threaten every child, says UNICEF report
A new report by UNICEF, supported by University of Southampton researchers, says 559 million children currently exposed to high heat waves could rise to 2.02 billion globally by the year 2050.
The report, produced in collaboration with The Data for Children Collaborative, underscores the urgent need to address the impacts of global warming to future generations and follows on from previous work identifying specific risk to children from climate change (Child Climate Risk Index, UNICEF, 2021).
It comes as world leaders meet to discuss climate action this month at the COP27 conference in Egypt.
The report estimates that by 2050, all of the world's 2.02 billion children are expected to be exposed to high heat wave frequency, regardless of whether:
The report found that specifically high heat wave duration currently impacts 538 million (23%) of children globally and by 2050 will rise to:
Heat waves are especially damaging to children, as they are less able to regulate their body temperature compared to adults, with babies and young children being at greater risk of heat-related mortality.
Further exposure to heat waves can result in children developing health problems such as chronic respiratory conditions, asthma, and cardiovascular diseases.
Heat waves can also affect children's environments, their safety, nutrition and access to water, and their education and future livelihood.
At a minimum, governments must urgently limit global warming to 1.5 degrees Celsius and double adaptation funding by 2025.
"This is the only way to save children's lives and futures—and the future of the planet."
https://www.unicef.org/reports/coldest-year-rest-of-their-lives-chi...
Nov 17, 2022
Dr. Krishna Kumari Challa
Researchers discover how music could be used to trigger a deadly pathogen release
Researchers have discovered that the safe operation of a negative pressure room—a space in a hospital or biological research laboratory designed to protect outside areas from exposure to deadly pathogens—can be disrupted by an attacker armed with little more than a smartphone.
According to UCI cyber-physical systems security experts, who shared their findings with attendees at the Association for Computing Machinery's recent Conference on Computer and Communications Security in Los Angeles, mechanisms that control airflow in and out of biocontainment facilities can be tricked into functioning irregularly by a sound of a particular frequency, possibly tucked surreptitiously into a popular song.
Someone could play a piece of music loaded on their smartphone or get it to transmit from a television or other audio device in or near a negative pressure room. If that music is embedded with a tone that matches the resonant frequency of the pressure controls of one of these spaces, it could cause a malfunction and a leak of deadly microbes.
Heating, ventilation and air conditioning infrastructure maintains the flow of fresh air into and contaminated air out of a given space. HVAC systems in scientific facilities typically include room pressure monitors, which in turn utilize differential pressure sensors that compare the atmospheres inside and outside rooms.
The researchers said that commonly used differential pressure sensors (DPSs) are vulnerable to remote manipulation, posing a previously unrealized threat to biosafety facilities. They tested their hypothesis on eight industry-standard DPSs from five manufacturers, demonstrating that all the devices operate with resonant frequencies in the audible range and are, therefore, subject to tampering.
When sound waves collide with the diaphragms inside a DPS, it starts vibrating with the same frequency. An informed attacker can use this technique to artificially displace the diaphragm, changing the pressure reading and causing the whole system to malfunction.
Attackers could thwart negative pressure room systems in a variety of ways. They could manipulate them wirelessly or pose as maintenance personnel to place an audio device inside or near such a room.A more sophisticated attack might involve perpetrators embedding sound-emitting technologies into a DPS before it's installed in a biocontainment facility.
In their conference presentation, the researchers suggested several countermeasures to prevent a musical assault on biosafety facilities. Sound dampening can be achieved by lengthening the sampling tube of a DPS's port by as much as 7 meters. The team also proposed enclosing the pressure port in a boxlike structure. Both these measures would reduce the sensitivity of the DPS.
Anomadarshi Barua et al, A Wolf in Sheep's Clothing, Proceedings of the 2022 ACM SIGSAC Conference on Computer and Communications Security (2022). DOI: 10.1145/3548606.3560643
Full paper (arXiv preprint): A Wolf in Sheep's Clothing: Spreading Deadly Pathogens Under the Di...
Nov 18, 2022
Dr. Krishna Kumari Challa
New technology for growing printed tissues for transplantation
Researchers have developed an innovative technology for growing tissue for transplantation by printing it into a microgel bath as support material.
Tissue printing is an innovative approach for creating tissue for transplantation. In this technique, also called bio-printing, living cells are embedded in biological ink and printed layer upon layer. The printed tissue then undergoes growth for days or weeks until it is ready for printing.
This new work focused on preventing the uneven shrinkage of the printed tissue in the weeks after printing. The solution was found through changing the medium in which the tissue is printed and grown.
The new concept, print-and-grow, is based on an original medium developed by the researchers—an innovative microgel used as a support material in the process, CarGrow, which is a substance mainly composed of carrageenan (Carrageenan-K) and is produced from red algae. In fact, the new support bath preserves the size of the tissue after printing and prevents it from shrinking and losing its shape.
This process allows reliable and controlled production of functional tissue in the desired size and shape. Since this material is transparent, it makes it possible for the scientists to monitor the development of the tissue through imaging.
The Technion researchers hope the new method will lead to the development of new technologies for bio-printing.
Majd Machour et al, Print‐and‐Grow within a Novel Support Material for 3D Bioprinting and Post‐Printing Tissue Growth, Advanced Science (2022). DOI: 10.1002/advs.202200882
Nov 18, 2022
Dr. Krishna Kumari Challa
Nanostructured ceramic coatings do not fatigue, finds study
Extremely thin ceramic coatings can completely change the properties of technical components. Coatings are used, for example, to increase the resistance of metals to heat or corrosion. Coating processes play a role for large turbine blades as well as for extremely stressed tools in production technology.
Researchers now investigated what determines the stability of such coatings. And the results, some of which were obtained at the DESY synchrotron in Hamburg, are quite surprising: the ceramic layers break down in a completely different way than metals. Material fatigue hardly plays a role; the decisive factor is the intensity of extreme load peaks (the so called stress intensity factor). This finding will change the method used to measure and further improve the resistance of thin films in the future.
L. Zauner et al, Assessing the fracture and fatigue resistance of nanostructured thin films, Acta Materialia (2022). DOI: 10.1016/j.actamat.2022.118260
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The offshoot of cells visualized in real time
In a study recently published in the Journal of Extracellular Vesicles, researchers from Kanazawa University use high-speed microscopy to capture the dynamics of nanosized sacs released from cells.
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Air pollution cools climate more than expected—this makes cutting c...
Air pollutants kill around 7 million people every year. Much of this pollution is tiny particles suspended in the air which, when inhaled, can cause people to develop heart and lung diseases, as well as cancer.
Nov 18, 2022
Dr. Krishna Kumari Challa
Study shows hundreds of thousands of tons of bacteria are being released by melting glaciers
A team of researchers affiliated with multiple institutions across Europe, the U.K. and Canada has found that hundreds of thousands of tons of bacteria are currently being released annually into the environment by melting glaciers in the northern latitudes. In their paper published in the journal Communications Earth & Environment, the group describes sampling glacial runoff from multiple sites in Europe, North America and Greenland.
As climate change progresses, doomsday reports from around the world have proliferated. One alarming claim is that a virus or strain of bacteria will emerge from ancient ice that is impervious to the human immune system, killing off most, if not all, of humankind. In this new effort, the researchers have joined a growing effort to take samples of melting runoff from glaciers to learn more about their microbial ecosystems as a means to discover whether a threat exists, and if so, what sort.
The researchers did not study the bacteria individually, and thus did not spot any species that might pose a threat to human health. They did note that most of the bacteria were killed by the sun soon after exposure, suggesting that even if a human pathogen is among them, the chance of infection is slight. Bacteria in water samples, the researchers note, tend to have pigments that absorb sunlight, which further adds to warming in northern regions.
Ian T. Stevens et al, Spatially consistent microbial biomass and future cellular carbon release from melting Northern Hemisphere glacier surfaces, Communications Earth & Environment (2022). DOI: 10.1038/s43247-022-00609-0
Nov 18, 2022
Dr. Krishna Kumari Challa
How an Alzheimer’s gene ravages the brain
No gene variant is a bigger risk factor for Alzheimer’s disease than one called APOE4. But exactly how the gene spurs brain damage has been a mystery. A study has now linked APOE4 with faulty cholesterol processing in the brain, which in turn leads to defects in the insulating sheaths that surround nerve fibres and facilitate their electrical activity. Preliminary results hint that these changes could cause memory and learning deficits. And the work suggests that drugs that restore the brain’s cholesterol processing could treat the disease.
Nov 18, 2022
Dr. Krishna Kumari Challa
What is a 'Carbon Cage,' and why are you stuck in one right now?
This knowledge is extremely importantOur current carbon-heavy economic system creates bars around us that stop effective climate change action. Here's why: The world is too accustomed to the luxuries and privileges which depend on co2 emissions
Nov 19, 2022
Dr. Krishna Kumari Challa
A butterfly-stroke-like soft robotic swimmer that is fast and efficient
Nov 19, 2022
Dr. Krishna Kumari Challa
Earth now weighs six ronnagrams: New metric prefixes voted in
Say hello to ronnagrams and quettameters: International scientists gathered in France voted on Friday for new metric prefixes to express the world's largest and smallest measurements, prompted by an ever-growing amount of data.
It marks the first time in more than three decades that new prefixes have been added to the International System of Units (SI), the agreed global standard for the metric system.
Joining the ranks of well-known prefixes like kilo and milli are ronna and quetta for the largest numbers—and ronto and quecto for the smallest.
The change was voted on by scientists and government representatives from across the world attending the 27th General Conference on Weights and Measures, which governs the SI and meets roughly every four years at Versailles Palace, west of Paris.
The UK's National Physical Laboratory, which led the push for the new prefixes, confirmed that the resolution had passed in a statement.
The prefixes make it easier to express large amounts—for example, always referring to a kilometer as 1,000 meters or a millimeter as one thousandth of a meter would quickly become cumbersome.
Since the SI was established in 1960, scientific need has led to a growing number of prefixes. The last time was in 1991, when chemists wanting to express vast molecular quantities spurred the addition of zetta and yotta.
A yottameter is a one followed by 24 zeroes.
But even the mighty yotta is not enough to handle the world's voracious appetite for data.
So the Earth weighs approximately six ronnagrams,which is a six followed by 27 zeroes !
Jupiter, that's about two quettagrams—a two followed by 30 zeros.
Source: AFP
https://phys.org/news/2022-11-earth-ronnagrams-metric-prefixes-vote...
Nov 19, 2022
Dr. Krishna Kumari Challa
Down syndrome, like Alzheimer's, is a double-prion disorder
The brains of people with Down syndrome develop the same neurodegenerative tangles and plaques associated with Alzheimer's disease and frequently demonstrate signs of the neurodegenerative disorder in their forties or fifties. A new study from researchers shows that these tangles and plaques are driven by the same amyloid beta (Aß) and tau prions that they showed are behind Alzheimer's disease in 2019.
Prions begin as normal proteins that become misshapen and self-propagate. They spread through tissue like an infection by forcing normal proteins to adopt the same misfolded shape. In both Alzheimer's and Down syndrome, as Aß and tau prions accumulate in the brain, they cause neurological dysfunction that often manifests as dementia.
Tau tangles and Aß plaques are evident in most people with Down syndrome by age 40, according to the National Institute on Aging, with at least 50% of this population developing Alzheimer's as they age.
The new study, published Nov. 7, 2022, in Proceedings of the National Academy of Sciences, highlights how a better understanding of Down syndrome can lead to new insights about Alzheimer's, as well.
Carlo Condello et al, Aβ and tau prions feature in the neuropathogenesis of Down syndrome, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2212954119
Nov 19, 2022
Dr. Krishna Kumari Challa
Messel boa: Live birth in a 47-million-year-old snake
team of scientists, including Senckenberg’s Krister Smith, has discovered the world’s first fossil evidence of live birth in snakes. The fossil they examined came from the Hessian UNESCO World Heritage Site “Messel Pit.” In the study, published in the journal “The Science of Nature,” the researchers describe bones of snake embryos discovered in the mother’s body. The finding shows that viviparous snakes already existed at least 47 million years ago.
Most reptiles alive today lay eggs; this so-called oviparity is their most common mode of reproduction. But there are exceptions: Numerous species of lizards and snakes are known to deviate from the norm and give birth to their offspring alive – viviparously. Fossil preservation of reproductive events is generally very rare. In total, only two fossil records of viviparous land reptiles have been discovered to date. Scientists have now succeeded in describing the world’s first fossil evidence of a viviparous snake.
The fossil Messelophis variatus, from a family of boa-like snakes, is about 50 centimeters long, dates from the Eocene, and is related to modern-day dwarf boas from Central America. The species is among the most common snakes known from Messel. Nevertheless, this specimen, is about 47 million years old.
It is a pregnant female with at least two embryos found in the posterior third of her trunk area. These bones were located quite a distance behind the stomach – if they were part of the snake’s prey, they would have already been digested this far back in the intestine and would no longer be recognizable. Thus, they must represent the boa’s embryos. The fact that the bones are from very young snakes, yet already further developed than in an unlaid egg, supports the assumption that scientists are dealing with a pregnant, viviparous female.
In live births, the young remain in the female’s body until they are viable – eliminating the need for a protective eggshell. This is considered an advantageous evolutionary strategy for reptiles in cold climates, as the temperature inside the female’s body is more stable and thus safer for their offspring. Therefore, many of today’s viviparous lizards and snakes have evolved in rather cooler climates. “During the Eocene, however, the Earth was dominated by a persistent greenhouse climate with warm temperatures, a high carbon dioxide content in the atmosphere, and ice-free poles. Around the Messel Lake, average temperatures at that time were about 20 degrees Celsius, and winter temperatures did not fall below freezing. Why the boas gave birth to live offspring 47 million years ago in spite of this fact is still unknown. Perhaps additional fossils from this unique site will help us solve this mystery!
Mariana Chuliver et al, Live birth in a 47-million-year-old snake, The Science of Nature (2022). DOI: 10.1007/s00114-022-01828-3
Nov 19, 2022
Dr. Krishna Kumari Challa
Making mosquitoes' love songs fall on deaf ears
A team of researchers have developed a new method that may help control mosquito populations. The annoying buzzing sound that mosquitoes make when flying inspired this technique.
Mosquitoes are not just a nuisance to people sitting outside on warm summer evenings. They also spread deadly diseases that kill thousands of people every year, including dengue, malaria, and the Zika virus. Therefore, it is vital to reduce mosquito populations around the world. Unfortunately, commonly used insecticides have become less effective over time because mosquitoes have developed resistance. They also have a negative impact on the environment. Therefore, alternative methods are needed for mosquito control.
One promising method for controlling mosquitoes takes advantage of perhaps their most annoying feature—their high-pitched buzzing. Females create this sound as they fly around seeking sources of blood. Male mosquitoes listen specifically for this characteristic high-pitched noise. Shaped like antennas, male mosquito ears vibrate at the same frequency as the female mosquito's wings. When a female flies by, the male's ears detect this frequency and resonate, sending a signal to their brain that helps them identify a potential mate.
A team of researchers tested whether they could control mosquito mating behavior by altering the frequency at which male mosquitoes listen. By making the male mosquitoes' ears go "out of tune," they sought to influence their mating behavior.
he team first identified the involvement of the major neurotransmitter serotonin in the auditory system of the insect. Serotonin plays an important role in nervous systems and brains of various animals', influencing a wide range of behaviors.
After demonstrating serotonin in the mosquito auditory system, the team's next step was to manipulate serotonin levels. To do this, they used a method called "laser doppler vibrometry." This involves using a laser as a highly sensitive measurement tool to detect changes in the nanoscale vibrations of mosquito ears after exposure to serotonin-related compounds.
The researchers discovered that after feeding mosquitoes a serotonin-inhibiting compound, the male ears' vibration frequency decreased. When they gave the mosquitoes glucose laced with a compound that inhibited serotonin, both the range of frequencies the mosquitoes responded to, and their response itself, were reduced.
The next step in the development of a potential auditory-based "birth control" will involve identifying the exact receptors responsible for tuning the ears of mosquitoes. This could enable researchers to administer targeted compounds to disrupt mating behavior.
Yifeng Y. J. Xu, YuMin M. Loh, Tai-Ting Lee, Takuro S. Ohashi, Matthew P. Su, Azusa Kamikouchi. Serotonin modulation in the male Aedes aegypti ear influences hearing. Frontiers in Physiology, 2022; 13 DOI: 10.3389/fphys.2022.931567
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Nov 19, 2022
Dr. Krishna Kumari Challa
Some Sugar Free Gummy Bears Are In Reality Laxatives!
Nov 21, 2022
Dr. Krishna Kumari Challa
Why Scientists Are Listening to Coral Reefs
Nov 21, 2022
Dr. Krishna Kumari Challa
Lab mice fed processed food found to fare worse against flu than those eating grains
A team of researchers has found that lab mice are more likely to survive a flu infection if they are fed grain-based foods rather than processed food. The paper is published in Cell Reports.
In recent years, medical researchers have reported evidence that diet plays a larger role in illness recovery than was thought. Some studies have shown, for example, that caloric density and the concentration of nutrients consumed while recovering from an infection can have a major impact on the severity of the infection. In this new effort, the researchers found evidence suggesting that other characteristics of food can also play a role in illness recovery, at least in mice.
In this new effort, the researchers were studying how mammals such as mice fight off influenza infections. As part of that effort, they inadvertently fed two groups of lab mice slightly different meals that were thought to be equivalent in nutritional value and hence unlikely to have an impact on disease recovery. More specifically, they fed one group of mice a diet consisting mostly of grains. The other mice were fed a highly processed diet.
Both groups were subsequently infected with the influenza virus and were kept on the same diets they had prior to being infected. The researchers note that prior studies had shown that mice fed either diet when not battling an infection displayed little difference in health or behavior. But when infected with influenza, the researchers found that all of those fed the highly processed diet died. They also found that those fed the highly processed diet failed to regain weight lost due to the illness. In sharp contrast, all of the mice on the grain-based diet began regaining weight within 10 days of initial infection, and all of them recovered.
The researchers note that the difference in survival was not due to differences in an immune response, but was instead due to recovery issues. They note that the mice on the highly processed food diet ate less than those given grains and wound up getting less nutrients. They also had cooler body cores. The researchers also found some evidence that suggested IFN-γ, a signaling protein, played a role in the outcomes for the mice.
Taylor A. Cootes et al, The quality of energy- and macronutrient-balanced diets regulates host susceptibility to influenza in mice, Cell Reports (2022). DOI: 10.1016/j.celrep.2022.111638
Nov 22, 2022
Dr. Krishna Kumari Challa
Discovery reveals 'brain-like computing' at molecular level is possible
A discovery has revealed for the first time that unconventional brain-like computing at the tiniest scale of atoms and molecules is possible.
Researchers which consisted an international team of scientists created a new type of organic material that learns from its past behaviour. The discovery of the "dynamic molecular switch" that emulates synaptic behavior is revealed in a new study in the journal Nature Materials.
The team developed a two-nanometer thick layer of molecules, which is 50,000 times thinner than a strand of hair and remembers its history as electrons pass through it. Switching probability and the values of the on/off states continually change in the molecular material, which provides a disruptive new alternative to conventional silicon-based digital switches that can only ever be either on or off.
The newly discovered dynamic organic switch displays all the mathematical logic functions necessary for deep learning, successfully emulating Pavlovian "call and response" synaptic brain-like behavior.
The researchers demonstrated the new materials properties using extensive experimental characterization and electrical measurements supported by multi-scale modeling spanning from predictive modeling of the molecular structures at the quantum level to analytical mathematical modeling of the electrical data.
Enrique del Barco, Dynamic molecular switches with hysteretic negative differential conductance emulating synaptic behaviour, Nature Materials (2022). DOI: 10.1038/s41563-022-01402-2
https://phys.org/news/2022-11-discovery-reveals-brain-like-molecula...
Nov 22, 2022
Dr. Krishna Kumari Challa
A combination of ultrasound and nanobubbles allows cancerous tumors...
A new technology developed at Tel Aviv University makes it possible to destroy cancerous tumors in a targeted manner, via a combination of ultrasound and the injection of nanobubbles into the bloodstream. According to the research team, unlike invasive treatment methods or the injection of microbubbles into the tumor itself, this latest technology enables the destruction of the tumor in a non-invasive manner.
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Researchers develop a new type of light-sensitive nanoparticle to h...
Oregon State University scientists have produced a proof of concept for a new and better way of caring for women facing the life-threatening situation of ectopic pregnancy, which occurs when a fertilized egg implants somewhere other than the lining of the uterus.
Nov 22, 2022
Dr. Krishna Kumari Challa
Things that make people feel more awake and alert during mornings and afternoons
A team of researchers affiliated with multiple institutions has isolated factors that they think have an impact on how awake and/or alert people feel during the day.
Prior research has shown that more people than ever are complaining of feeling tired, sleepy and unalert during the daytime. Such complaints have been connected to increases in motor vehicle and work accidents and also sloppy job performance. In this new effort, the researchers noted that little research has been conducted looking into the factors that contribute to daytime alertness. To rectify that problem, they conducted a study of their own.
The researchers recruited 833 volunteers (many of whom were either identical or fraternal twins) to undergo testing for two weeks. Each adhered to a prescribed diet and wore a watch that recorded their sleep and physical activity and also their glucose levels. They also recorded the food they ate using a custom phone app, which they also used to record their level of alertness. After the two-week period, the researchers found some patterns. For example, those people who slept longer reported feeling more alert the next day—no surprise there.
But they also found that it was not duration that led to an increase in alertness, but the time that they woke up—waking up later than normal, they found, made the volunteers feel more alert, at least during the morning, even if they did not go to bed late. They also found that the volunteers were more alert on days when they were physically active the day before. And they found that eating a high-carb breakfast, such as muffins, resulted in higher morning alertness.
Drinking pure glucose had them feeling even more alert. A high-protein breakfast, on the other hand, had the volunteers dragging in the morning. The researchers also found four factors that most contributed to daily variances for the volunteers: age, sleep, mood and frequency of eating—eating less often seemed to reduce next-day fatigue.
Raphael Vallat et al, How people wake up is associated with previous night's sleep together with physical activity and food intake, Nature Communications (2022). DOI: 10.1038/s41467-022-34503-2
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Nov 23, 2022
Dr. Krishna Kumari Challa
Scientists unlock nature's secret to super-selective binding
Researchers have discovered that it is not just molecular density, but also pattern and structural rigidity, that control super-selective binding interactions between nanomaterials and protein surfaces. The breakthrough could help optimize existing approaches to virus prevention and cancer detection.
So much of biology comes down to the biophysical process of binding: making a strong connection between one or more groups of atoms—known as ligands—to their corresponding receptor molecule on a surface. A binding event is the first fundamental process that allows a virus to infect a host, or chemotherapy to fight cancer. But binding interactions—at least, our understanding of them—have a "Goldilocks problem": too few ligands on one molecule makes it impossible for it to stably bind with the correct target, while too many can result in undesirable side-effects.
When binding is triggered by a threshold density of target receptors, scientists call this 'super-selective' binding, which is key to preventing random interactions that could dysregulate biological function.
Since nature typically doesn't overcomplicate things, researchers wanted to know the minimum number of binding interactions that would still allow for super-selective binding to occur. They were also interested to know whether the pattern the ligand molecules are arranged in makes a difference in selectivity. As it turns out, it does.
They have recently published a study in the Journal of the American Chemical Society that identifies the optimal ligand number for super-selective binding: six. But they also found, to their excitement, that the arrangement of these ligands—in a line, circle, or triangle, for example—also significantly impacted binding efficacy. They have dubbed the phenomenon "multivalent pattern recognition" or MPR.
After engineering a series of ligand-receptor architectures to explore how density, geometry, and nano-spacing influenced binding super-selectivity, the team realized that rigidity was a key factor. The more flexible, the less precise.
Diagnostics and therapeutics such as chemotherapy could also benefit from super-selectivity, which could allow for more reliable binding with cancer cells, for which certain receptor molecules are known to have a higher density. In this case, healthy cells would remain undetected, drastically reducing side effects.
Finally, such selectivity engineering could offer key insights into complex interactions within the immune system.
Hale Bila et al, Multivalent Pattern Recognition through Control of Nano-Spacing in Low-Valency Super-Selective Materials, Journal of the American Chemical Society (2022). DOI: 10.1021/jacs.2c08529
Nov 23, 2022
Dr. Krishna Kumari Challa
The interplay between epidemics, prevention information, and mass media
When an epidemic strikes, more than just infections spread. As cases mount, information about the disease, how to spot it, and how to prevent it propagates rapidly among people in affected areas as well. Relatively little is known, however, about the interplay between the course of epidemics and this diffusion of information to the public.
A pair of researchers developed a model that examines epidemics through two lenses—the spread of disease and the spread of information—to understand how reliable information can be better disseminated during these events.
They report their two-layered model can predict the effects of mass media and infection prevention information on the epidemic threshold.
To tackle their question, the researchers' model compares the interactions between two layers of information. The first is the transmission of the disease itself, propagated through physical contact between people. The second occupies the information space of social networks, where different voices are sharing the do's and don'ts of infection prevention, called positive and negative information respectively. The model provides a set of equations that can be used to calculate the epidemic threshold using a technique called microscopic Markov chains. Central to this calculation is the time delay between becoming infected and recovering. The longer it takes for patients to recover from an infection, they found, the less likely a patient is cured, leading to a lower recovery rate and making it easier for a disease to break out. Disseminating effective prevention practices and using mass media, however, can increase the epidemic threshold, making it more difficult for the infection to spread. They simulate this by reducing the time delays related to recovery, which boosts recovery rates.
The impact of positive and negative information on SIR-like epidemics in delayed multiplex networks, Chaos An Interdisciplinary Journal of Nonlinear Science (2022). DOI: 10.1063/5.0126799
Nov 23, 2022
Dr. Krishna Kumari Challa
Major discovery about mammalian brains
In a new breakthrough to understand more about the mammalian brain, University of Copenhagen researchers have made an incredible discovery. Namely, a vital enzyme that enables brain signals is switching on and off at random, even taking hours-long "breaks from work". These findings may have a major impact on our understanding of the brain and the development of pharmaceuticals.
Millions of neurons are constantly messaging each other to shape thoughts and memories and let us move our bodies at will. When two neurons meet to exchange a message, neurotransmitters are transported from one neuron to another with the aid of a unique enzyme.
This process is crucial for neuronal communication and the survival of all complex organisms. Until now, researchers worldwide thought that these enzymes were active at all times to convey essential signals continuously. But this is far from the case.
Using an innovative method, researchers have closely studied the enzyme and discovered that its activity is switching on and off at random intervals, which contradicts our previous understanding.
This is the first time anyone has studied these mammalian brain enzymes one molecule at a time, and we are awed by the result. Contrary to popular belief, and unlike many other proteins, these enzymes could stop working for minutes to hours. Still, the brains of humans and other mammals are miraculously able to function.
Dimitrios Stamou, Regulation of the mammalian-brain V-ATPase through ultraslow mode-switching, Nature (2022). DOI: 10.1038/s41586-022-05472-9
Nov 24, 2022
Dr. Krishna Kumari Challa
World's heaviest flying bird may be self-medicating on plants used in traditional medicine
Do you think only humans can use plant based medicines based on experience? Then think again. Even animals can do this. Humans aren't the only species that self-medicates.
If you see a great bustard (Otis tarda) in the wild, you're unlikely to forget it. Massive, colorful, and impossible to mistake, they are the heaviest birds living today capable of flight, with the greatest size difference between the sexes. They are also "lek breeders," where males gather at chosen sites to put on an audiovisual show for the visiting females, who choose a mate based on his appearance and the quality of his showbirdship.
But now, a study in Frontiers in Ecology and Evolution suggests that great bustards have another claim to our interest: they actively seek out two plants with compounds that can kill pathogens. They may thus be a rare example of a bird that uses plants against disease—that is, self-medication.
Self-medication in animals is suspected to occur, with a lesser or greater degree of confidence, in animals as diverse as primates, bears, deer, elk, macaws, honeybees, and fruit flies. But it's tricky to prove beyond doubt in wild animals.
We can't compare between control and experimental treatments. And double-blind trials or dose-effect studies, obligatory steps in human or veterinary medicine, are obviously impossible in wild animals.
Great bustards breed on grasslands from western Europe and northwest Africa to central and eastern Asia. Approximately 70% of the world's population live in the Iberian peninsula. Females typically remain faithful to the home range where they hatched for life—10 to 15 years—while after dispersal, males revisit the same lake site year after year. By staying (and importantly, pooping) in the same area for prolonged periods, they risk re-infecting themselves. And males need exceptional stamina during the mating season, which is expected to cause their immune defenses to nose-dive.
In theory, both sexes of great bustards might benefit from seeking out medicinal plants in the mating season when sexually transmitted diseases are common—while males that use plants with compounds active against diseases might appear more healthy, vigorous, and attractive to females.
The research team have studied great bustards since since the early 1980s, mainly in the regions of Madrid and Castille-Leon, Spain. They collected a total of 623 droppings from female and male great bustards, including 178 during the mating season in April. Under a microscope, they counted the abundance of recognizable remains (tissue from stems, leaves, and flowers) of 90 plant species that grow locally and are known to on the bustards' menu.
The results showed that two species are eaten by great bustards more often than expected from their abundance: corn poppies, Papaver rhoeas and purple viper's bugloss, Echium plantagineum.
"Great bustards select corn poppies and purple viper's bugloss mainly in the mating season , in April, when their energy expenditure is greatest. And males, who during these months spend much of their time and energy budgets on sexual display, prefer them more than females.
Part 1
Nov 24, 2022
Dr. Krishna Kumari Challa
Of these two species, the first is avoided by cattle and is used in traditional medicine as a pain reliever, sedative, and immune booster. The second is toxic for humans and cattle if eaten in great quantities. They also have nutritional value: fatty acids abound in corn poppy seeds, while the seeds of purple viper's bugloss are rich in edible oils.
The authors isolated water- and fat-soluble compounds from both species and determined their chemical identity with gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (HPLC-MS). They focused on lipids, volatile essential oils, and alkaloids, produced by many plants as defense against herbivores. For example, they found that corn poppies are rich in bioactive alkaloids like rhoeadine, rhoeagenine, epiberberine, and canadine.
The authors then tested the activity of the isolated molecular fractions against three common parasites of birds: the protozoon Trichomonas gallinae, the nematode (parasitic worm) Meloidogyne javanica, and the fungus Aspergillus niger.
The results show that extracts from both plants are highly effective at inhibiting or killing protozoa and nematodes in vitro, while purple viper's bugloss is also moderately active against fungi.
The authors conclude that great bustards are prime candidates for birds that seek out specific plants to self-medicate. But more research is needed, they caution.The ultimate proof of self-medication requires experimental protocols developed in the biomedical, veterinary, and pharmacological sciences.
Luis M. Bautista-Sopelana et al, Bioactivity of plants eaten by wild birds against laboratory models of parasites and pathogens, Frontiers in Ecology and Evolution (2022). DOI: 10.3389/fevo.2022.1027201
Part 2
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Nov 24, 2022
Dr. Krishna Kumari Challa
Zombie viruses on a hijacking trip: Retroviral gene fragments affect embryonic cells
Ancient, dormant sequences in the genome impact embryonic development in unexpected ways. The mammalian genome contains retroviral sequences that are in an undead but mostly "harmless" state. An international research team recently discovered how some of these retroviral gene fragments affect embryonic cells if they are unleashed. Unexpectedly, not the viral proteins, but rather copies of the genetic material itself generate an imbalance in the cell.
Over thousands of years of evolution, countless viruses have embedded themselves in our genome. A staggering ten percent of mammalian genomes consist of ancient retroviral sequences. These no longer seem to pose any danger, because most of them have mutated beyond recognition. Additionally, these genes have been epigenetically silenced by the cell. But as the silencing of the viral remains fails, they will rise from their graves, causing chaos in the cell.
Researchers found that the messenger copies of some of the viral genes, the RNA, have an important impact on embryonic cells. The viral sequences seem to remember their original mission of hijacking the molecular machinery that ensures the flow of information from DNA to RNA to protein. Interestingly, the messenger RNA itself seems to be responsible.
Scientists described that the RNA of the resurrected viruses exerts attractive forces on the enzymes that read the information from the DNA. The tasks of the embryonic cell—such as reading important embryonic genes—are neglected and a fatal imbalance develops. This unleashed state occurs, for example, in some types of cancer and neurological diseases.
Viruses are cleverly constructed snippets of genetic information. Some of them incorporate themselves into the genome of their hosts and persist there. Thousands of copies of Endogenous Retroviruses (ERVs) have spread throughout mammalian genomes, often in droves of hundreds of repetitive copies.
As retroviruses jump from one section of DNA to the next during their life cycle, they can alter genes and even recombine them. This makes them an important tool for evolution to create new genes. For an individual organism however, uncontrolled gene modification does not bode well, especially during embryonic development.
Part 1
Nov 24, 2022
Dr. Krishna Kumari Challa
This is why the cell will identify ERV sequences and recruit dedicated repressive machinery to their sites and keep them silent. Additionally, the chromosome is getting compacted at these sites.
But what happens if you turn off these protective mechanisms? Chaos!
Vahid Asimi et al, Hijacking of transcriptional condensates by endogenous retroviruses, Nature Genetics (2022). DOI: 10.1038/s41588-022-01132-w
Nov 24, 2022
Dr. Krishna Kumari Challa
Plastic in foraminifera and possible consequences for the environment
Single-celled organisms with calcareous shells, called foraminifera, contribute significantly to the formation of sand deposited on beaches, islands and coastal areas. Researchers have now found for the first time that foraminifera can take up tiny plastic particles and incorporate them into their calcareous shells. The results were published in Scientific Reports and Limnology and Oceanography Letters.
Gleaming white tropical beaches are coveted destinations for many recreation-seekers. But how do we perceive such beaches if we have to fear that they consist to a not inconsiderable extent of micro- and nanoplastics—invisible to our eyes?
Tropical beaches are mainly formed by calcifying marine animals such as corals, mussels and snails. The fact that corals incorporate microplastics into their calcareous skeleton has already been proven in studies. In some regions of the world, however, such as Indonesia, the Philippines and Australia, many beaches consist largely of the calcareous shells of foraminifera. These are single-celled organisms, a few millimeters in size and with a protective calcareous shell, that can be found in warm, shallow coastal areas worldwide.
Foraminifera feed on, among other things, microalgae or organic material particles they find on the seafloor. Micro- and nanoplastic particles have similar sizes and could easily be mistaken for potential food.
In a series of experiments, the team exposed several hundred foraminifera to seawater tanks for several weeks. They fed them partly with tiny micro- or nanoplastic particles, partly with natural food particles or a mixture of both. They observed that while the foraminifera preferred the natural food, when both were available at the same time, they frequently ate plastic pieces.
Using a fluorescence microscope, the researchers were able to observe a large number of yellow glowing nanoplastic particles in the foraminifera. Although some of the unicellular organisms rejected the plastic after the feeding experiments, about half of the foraminifera retained the plastic load inside the cell.
After eight weeks, a scanning electron microscope with 80,000x magnification revealed that many of the single-celled organisms had already encrusted the plastic particles with a layer of calcium carbonate and were apparently in the process of incorporating them into their shell.
So if the plastic particles are small enough, the foraminifera will take them in as food. For the environment, this could have advantages and disadvantages. For example, the trillions of foraminifera on the seafloor could be a sink for nanoplastics, a system that removes plastic from the ocean.
One problem the researcher sees, however, is potential impacts on the health of the foraminifera. On beaches and in shallow marine areas, the shells of foraminifera are often deposited at high densities of more than 1 kg per m2. However, if the protozoa interchange plastic particles with their natural food and incorporate them into their calcareous shells, their fitness, shell formation and stability could be disrupted—with consequences for their population as a whole.
Part 1
Nov 24, 2022
Dr. Krishna Kumari Challa
This, in turn, could have a long-term impact on coasts and islands, which are already suffering greatly under the weight of sea-level rise and erosion from increasingly frequent and powerful storm surges.
Marlena Joppien et al, Nanoplastic incorporation into an organismal skeleton, Scientific Reports (2022). DOI: 10.1038/s41598-022-18547-4
Marlena Joppien et al, Microplastics alter feeding strategies of a coral reef organism, Limnology and Oceanography Letters (2022). DOI: 10.1002/lol2.10237
Part2
Nov 24, 2022
Dr. Krishna Kumari Challa
Researchers suggest that wormholes may look almost identical to black holes
A group of researchers has found evidence that suggests the reason that a wormhole has never been observed is that they appear almost identical to black holes.
They describe studying theoretical linear polarization from an accretion disk that would be situated around a class of static traversable wormholes and compared the findings to images of black holes.
For many years, scientists and science fiction writers have considered the theoretical possibility of a wormhole. Such an object, theory suggests, would take the form of a tunnel of sorts that connects two different parts of the universe. Moving through the tunnel would allow for travel to distant destinations in ways not available to spaceships incapable of moving faster than the speed of light—by taking a shortcut.
Unfortunately, no one has ever observed a worm hole or even any physical evidence that they actually exist. Still, because the theory for their existence is so strong, astrophysicists assume they do exist. The problem is that we either lack the technology to see them, or we have not been looking for them in the right way.
In this new effort, the researchers suggest that the latter is the problem. They have found evidence, via theory, that suggests that they might be sitting out there in the night sky in plain sight, and that the reason we are not seeing them is because we are mistaking them for black holes.
The work involved studying wormhole theories and then applying findings to the creation of simulations, with an emphasis on the polarity of the light that would be emitted by such an object—and by also taking account of the characteristics of an assumed disk surrounding its mouth. They then created both direct and indirect images to depict what a wormhole would look like and compared them to black holes; they found them to look remarkably similar.
The researchers noted that it should be possible to tell wormholes and black holes apart by noting subtle differences between them, such as polarization patterns and intensities and also their radii.
Valentin Deliyski et al, Polarized image of equatorial emission in horizonless spacetimes: Traversable wormholes, Physical Review D (2022). DOI: 10.1103/PhysRevD.106.104024
Nov 25, 2022
Dr. Krishna Kumari Challa
New CRISPR-based tool inserts large DNA sequences at desired sites in cells
Building on the CRISPR gene-editing system, researchers have designed a new tool that can snip out faulty genes and replace them with new ones, in a safer and more efficient way.
Using this system, the researchers showed that they could deliver genes as long as 36,000 DNA base pairs to several types of human cells, as well as to liver cells in mice. The new technique, known as PASTE, could hold promise for treating diseases that are caused by defective genes with a large number of mutations, such as cystic fibrosis.
The new tool combines the precise targeting of CRISPR-Cas9, a set of molecules originally derived from bacterial defense systems, with enzymes called integrases, which viruses use to insert their own genetic material into a bacterial genome.
Just like CRISPR, these integrases come from the ongoing battle between bacteria and the viruses that infect them.
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The CRISPR-Cas9 gene editing system consists of a DNA-cutting enzyme called Cas9 and a short RNA strand that guides the enzyme to a specific area of the genome, directing Cas9 where to make its cut. When Cas9 and the guide RNA targeting a disease gene are delivered into cells, a specific cut is made in the genome, and the cells' DNA repair processes glue the cut back together, often deleting a small portion of the genome.
If a DNA template is also delivered, the cells can incorporate a corrected copy into their genomes during the repair process. However, this process requires cells to make double-stranded breaks in their DNA, which can cause chromosomal deletions or rearrangements that are harmful to cells. Another limitation is that it only works in cells that are dividing, as nondividing cells don't have active DNA repair processes.
This new work deals with a tool that could cut out a defective gene and replace it with a new one without inducing any double-stranded DNA breaks. To achieve this goal, they turned to a family of enzymes called integrases, which viruses called bacteriophages use to insert themselves into bacterial genomes.
For this study, the researchers focused on serine integrases, which can insert huge chunks of DNA, as large as 50,000 base pairs. These enzymes target specific genome sequences known as attachment sites, which function as "landing pads." When they find the correct landing pad in the host genome, they bind to it and integrate their DNA payload. Combining these enzymes with a CRISPR-Cas9 system that inserts the correct landing site would enable easy reprogramming of the powerful insertion system.
The new tool, PASTE (Programmable Addition via Site-specific Targeting Elements), includes a Cas9 enzyme that cuts at a specific genomic site, guided by a strand of RNA that binds to that site. This allows them to target any site in the genome for insertion of the landing site, which contains 46 DNA base pairs. This insertion can be done without introducing any double-stranded breaks by adding one DNA strand first via a fused reverse transcriptase, then its complementary strand.
Once the landing site is incorporated, the integrase can come along and insert its much larger DNA payload into the genome at that site.
Omar Abudayyeh, Drag-and-drop genome insertion of large sequences without double-strand DNA cleavage using CRISPR-directed integrases, Nature Biotechnology (2022). DOI: 10.1038/s41587-022-01527-4. www.nature.com/articles/s41587-022-01527-4
Nov 25, 2022
Dr. Krishna Kumari Challa
Scientists reveal first close-up look at bats' immune response to live infection
In a world first, scientists have sequenced the response to viral infection in colony-bred cave nectar bats (Eonycteris spelaea) at single-cell resolution. Published in the journal Immunity, the findings contribute to insights into bat immunity that could be harnessed to protect human health.
Bats harbor many types of viruses. Even when they are infected with viruses deadly to humans, they show no notable signs or symptoms of disease. By understanding how bats' immune responses protect them from infections, we may find clues that will help humans to better combat viral infections.
And knowing how to better fight viral infections can aid in the development of treatments that will help us to be more bat-like—by falling sick less and aging better.
In this study, the scientists investigated bat immune responses to Malacca virus, a double-stranded RNA virus that uses bats as its natural reservoir. This virus also causes mild respiratory disease in humans.
The team used single-cell transcriptome sequencing to study lung immune responses to infections at the cellular level, identifying the different types of immune cells in bats—some of which are different from those in other mammals, including humans—and uncovering what they do in response to such viral infections.
They found that a type of white blood cell, called neutrophils, showed a very high expression of a gene called IDO1, which is known to play a role in mediating immune suppression in humans. The scientists think that IDO1 expression in cave nectar bats could play an important role in limiting inflammation following infection.
Researchers also found marked anti-viral gene signatures in white blood cells known as monocytes and alveolar macrophages, which—in a sense—consume viral particles and then teach T cells how to recognize the virus. This observation is interesting as it shows that bats clearly activate an immune response following infection despite showing few outward symptoms or pathology. The team also identified an unusual diversity and abundance of T cells and natural killer cells—named for their ability to kill tumor cells and cells infected with a virus—in the cave nectar bat, which are broadly activated to respond to the infection.
Akshamal M. Gamage et al, Single-cell transcriptome analysis of the in vivo response to viral infection in the cave nectar bat Eonycteris spelaea, Immunity (2022). DOI: 10.1016/j.immuni.2022.10.008
Nov 25, 2022
Dr. Krishna Kumari Challa
Bacteria that break down nicotine found in the guts of mice
A team of researchers, has isolated a type of bacteria in the guts of mice that break down nicotine. In their paper published in the journal Nature, the group describes how they isolated the bacteria and why their finding could reduce incidences of fatty liver disease in humans.
Prior research has shown that smoking cigarettes is the leading cause of preventable deaths around the world. In addition to its association with lung disease, smoking cigarettes has also been linked to fatty liver disease. In this new effort, the researchers have found that a certain kind of bacteria breaks down nicotine in the guts of mice (due to forced smoking), and thereby reduces the likelihood of developing fatty liver disease.
When people (or mice) smoke cigarettes, it has been found, some of the nicotine makes its way into the gut, leading to an increased risk of fatty liver disease, associated with scarring, and in some cases, liver cancer.
In this new work, the researchers measured the amount of nicotine that makes its way to the gut by comparing stool samples of 30 human smokers and 30 nonsmokers. They then did the same with mice and found the results to be similar.
Next, they sterilized the guts of several lab mice and ran the nicotine experiment again. They found that the mice with the sterilized guts had more nicotine in their systems, indicating that at least one type of gut bacteria was breaking down the nicotine. Then, by process of elimination, they were able to track down the bacteria (Bacteroides xylanisolvens) that was responsible for the breakdown—it was producing a type of enzyme that breaks down nicotine.
Prior research has shown that B xylanisolven also live in the human gut. The researchers next plan to study it and the enzymes it produces to find out if the enzyme can be produced commercially and given to smokers to reduce their chances of developing fatty liver disease and by extension, liver cancer.
Nov 25, 2022
Dr. Krishna Kumari Challa
To stop new viruses jumping across to humans, we must protect and r...
Bats have lived with coronaviruses for millennia. Details are still hazy about how one of these viruses evolved into SARS-CoV-2, which causes COVID in humans. Did it go directly from bats to humans or via another animal species? When? And why? If we can't answer these questions for this now-infamous virus, we have little hope of preventing the next pandemic.
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Researchers explain how lipids can control immune response
When we consume fats (also called lipids) in our diet, they can be metabolized or stored to provide energy for the body. But they are also involved in regulating the genes expressed within—and the signaling between—cells. Lipids influence how our cells behave and function, which affects many processes in the body including the immune system.
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Artificial sweeteners found to kill off antibiotic-resistant bacteria
Sugar substitutes found in many supermarket foods have been shown to kill off antibiotic-resistant bacteria that cause pneumonia and sepsis. Three artificial sweeteners used in products such as diet drinks, yogurts and desserts dramatically halt the growth of multidrug-resistant priority pathogens.
Nov 25, 2022
Dr. Krishna Kumari Challa
To stop new viruses jumping across to humans, we must protect and restore bat habitat
Bats have lived with coronaviruses for millennia. Details are still hazy about how one of these viruses evolved into SARS-CoV-2, which causes COVID in humans. Did it go directly from bats to humans or via another animal species? When? And why? If we can't answer these questions for this now-infamous virus, we have little hope of preventing the next pandemic.
Some bat species are hosts for other viruses lethal to humans, from rabies to Nipah to Hendra. But their supercharged immune systems allow them to co-exist with these viruses without appearing sick.
So what can we do to prevent these viruses emerging in the first place? Researchers found one surprisingly simple answer in their new research on flying foxes in Australia: protect and restore native bat habitat to boost natural protection.
When we destroy native forests, we force nectar-eating flying foxes into survival mode. They shift from primarily nomadic animals following eucalypt flowering and forming large roosts to less mobile animals living in a large number of small roosts near agricultural land where they may come in contact with horses.
Hendra virus is carried by bats and can spill over to horses. It doesn't often spread from horses to humans, but when it does, it's extremely dangerous.
Now we know how habitat destruction and spillover are linked, we can act. Protecting the eucalyptus species flying foxes rely on will reduce the risk of the virus spreading to horses and then humans. The data scientists gathered also makes it possible to predict times of heightened Hendra virus risk—up to two years in advance.
By restoring and protecting the natural barriers which for so long kept us safe from bat-borne viruses. It is far better to prevent viruses from spilling over in the first place than to scramble to stop a possible pandemic once it's begun.
Planting trees can help stop dangerous new viruses reaching us. It really is as simple as that.
Peggy Eby et al, Pathogen spillover driven by rapid changes in bat ecology, Nature (2022). DOI: 10.1038/s41586-022-05506-2
https://phys.org/news/2022-11-viruses-humans-habitat.html?utm_sourc...
Nov 25, 2022
Dr. Krishna Kumari Challa
Honeypot ants
Bees aren’t the only insects to make honey, some ants can make the sweet treat too.
The honeypot ant, Camponotus inflatus, lives in the deserts of Australia where worker bees harvest nectar from the flowers of the mulga tree. The bees carry it underground and feed it to specialised workers known as ‘rotunds’ whose job it is to dangle upside down and eat.
Indeed, the tubby little insects are fed so much nectar that their abdomens swell up to the size of a small grape, and the abdomen wall is stretched so thin that the honey can be seen inside.
The rotunds form roughly 50 per cent of the colony, and live in cool, underground galleries. They are highly prized by Indigenous Australians who have been excavating and eating them for thousands of years. In the 1990 documentary, Trials Of Life, David Attenborough was filmed quaffing one.
The honey is said to be runnier and less sweet than the better-known bee alternative, but remains rich in antioxidants.
These literal honeypots are an insurance policy against hard times. When the regular workers run out of food, they stroke the rotunds’ antennae, causing the ants to regurgitate the stored honey. They also groom and clean the honeypots to keep the living larders in good condition.
Nov 25, 2022
Dr. Krishna Kumari Challa
Wolves infected with a common parasite may be much more likely to become pack leaders
A team of researchers with the Yellowstone Wolf Project at the Yellowstone Center for Resources, in Yellowstone National Park, in Wyoming, has found that wolves in the park who become infected with Toxoplasma gondii, a common parasite, are much more likely to become leaders of their pack. In their study, reported in the journal Communications Biology, the group analyzed data from studies of the wolves in the park over a 26-year period.
T. gondii is an obligate parasite that infects the protozoa in cells of infected animals. Such infections are known as toxoplasmosis, and they occur in almost all warm-blooded animals, including humans. Prior research has shown that in most cases, symptoms are few, through there is some evidence that suggests that they can lead to an increase in erratic or aggressive behaviour.
In this new effort, the researchers wondered what sort of impact of T. gondii infections might have on wild wolves. To find out, they conducted an extensive study of wolves living in Yellowstone National Park.
The work involved studying data from blood samples taken from over 200 wolves living in the park over the years 1995–2020, while looking for evidence of infection. The researchers also looked at the notes made by research observers to learn more about any behavior changes that might have been evident in the wolves.
The researchers found that young, infected wolves tended to leave their packs earlier than those uninfected. Infected males were 50% more likely to leave their pack as early as six months after birth. Males normally stay for up to 21 months. And infected females were 25% more likely to leave their pack at 30 months, rather than the normal 48.
The researchers also found that infected males were more than 46 times more likely to become pack leaders than uninfected males. The researchers also found that infection rates were higher in wolves that mingled with cougars. The researchers suggest the differences in behavior were likely due to the impact of the parasite on the brains of wolves, making them bolder and less likely to back down when challenged by others.
Connor J. Meyer et al, Parasitic infection increases risk-taking in a social, intermediate host carnivore, Communications Biology (2022). DOI: 10.1038/s42003-022-04122-0
Nov 26, 2022
Dr. Krishna Kumari Challa
'SuperGPS' Technology Accurately Pinpoints Your Position Within Inches
Many of us rely on GPS (Global Positioning System) to estimate travel times, find our way to new places, avoid traffic congestion, keep track of the kids, and generally avoid getting lost.
But it's not always the most reliable of systems, especially in built-up areas where it's difficult to get a straight line of sight to and from a satellite.
Now researchers have come up with a new and improved technology that could eventually replace GPS in some scenarios. Called SuperGPS, it's accurate within 10 centimeters (or 3.9 inches) and doesn't rely on navigation satellite systems.
The new approach makes use of networks similar to cell networks, but instead of streaming data to our phones the network gets a precise fix on the device.
A combination of radio transmitters and fiber-optic networks form the foundation of the system, with some smart tweaks on top.
In a test site with six radio transmitters, the researchers were able to demonstrate their system in action across an area of 660 square meters (7,104 square feet). The timings of the transmitted radio signals can be measured and interpreted to gauge distance, which then reveals the position of individual devices.
One of the key components of the new network positioing system is a synchronized atomic clock: perfect timing means more precise positioning. Essentially, the fiber optic cables act as connections that keep everything in sync, and accurate to one billionth of a second. The system also deploys a radio signal bandwidth that's much larger than normal.
Developers used several small bandwidth radio signals combined together to form a larger virtual bandwidth for the network communication.
This additional bandwidth overcomes one of the biggest problems with standard GPS, which is that radio signals get reflected off buildings and can quickly become confused.
"This can make GPS unreliable in urban settings, for instance, which is a problem if we ever want to use automated vehicles.As well as automated vehicles, the new system could be useful in planning quantum communication networks and next-generation networks for mobile devices, according to the researchers who developed it.
https://www.nature.com/articles/s41586-022-05315-7
Nov 27, 2022
Dr. Krishna Kumari Challa
Mars Sample Return: Bringing Mars Rock Samples Back to Earth
NASA and the European Space Agency are developing plans for one of the most ambitious campaigns ever attempted in space: bringing the first samples of Mars material safely back to Earth for detailed study. The diverse set of scientifically curated samples now being collected by NASA’s Mars Perseverance rover could help scientists answer the question of whether ancient life ever arose on the Red Planet. Bringing samples of Mars to Earth for future study would happen in several steps with multiple spacecraft, and in some ways, in a synchronized manner. This short animation features key moments of the Mars Sample Return campaign: from landing on Mars and securing the sample tubes to launching them off the surface and ferrying them back to Earth.
Nov 27, 2022
Dr. Krishna Kumari Challa
Researchers recreate the adrenal gland in a petri dish
Sitting atop the kidneys, the adrenal gland plays a pivotal role in maintaining a healthy body. Responding to signals from the brain, the gland secretes hormones that support critical functions like blood pressure, metabolism, and fertility.
People with adrenal gland disorders—such as primary adrenal insufficiency, in which the gland does not release sufficient hormones—can suffer fatigue, dangerously low blood pressure, coma, and even death if untreated. No cure for primary adrenal insufficiency exists, and the lifelong hormone-replacement therapy used to treat it carries significant side effects.
A preferable alternative would be a regenerative medicine approach, regrowing a functional adrenal gland capable of synthesizing hormones and appropriately releasing them in tune with the brain's feedback. In a new study in the journal Developmental Cell, researchers have coaxed stem cells in a petri dish to divide, mature, and take on some of the functions of a human fetal adrenal gland, bringing that goal one step closer.
To begin, the researchers used what's known as an "organoid culture" system, in which cells grow first as a floating aggregate for three weeks, then on a membrane exposed to air on one side, promoting better survival and allowing them to proliferate in three dimensions. Utilizing a carefully selected growth medium, they prompted the iPSCs to elicit an intermediate tissue type in the adrenal development process, the posterior intermediate mesoderm (PIM).
After verifying they had cultured PIM-like cells, the researchers embarked on directing those cells to transition to the next stage, adrenocortical progenitor-like cells, during which cells turn on markers indicating they have "committed" to becoming adrenal gland cells.
Molecular assays to check for adrenal markers, as well as transmission electron microscope analyses, all told the researchers they were on the right track to recreating a tissue that resembled the early adrenal gland.
The process we developed was highly efficient, with around 50% of cells in organoids acquiring adrenocortical cell fate. They also showed that the cells they grew could respond to what's known as the hypothalamic-pituitary-adrenal axis, a feedback loop that governs communication from the brain to the adrenal gland and back again.
Yuka Sakata, Keren Cheng, Michinori Mayama, Yasunari Seita, Andrea J. Detlefsen, Clementina A. Mesaros, Trevor M. Penning, Kyosuke Shishikura, Wenli Yang, Richard J. Auchus, Jerome F. Strauss, Kotaro Sasaki. Reconstitution of human adrenocortical specification and steroidogenesis using induced pluripotent stem cells. Developmental Cell, 2022; 57 (22): 2566 DOI: 10.1016/j.devcel.2022.10.010
Nov 27, 2022
Dr. Krishna Kumari Challa
Study shows prestigious institutions produce more published manuscripts because they have a bigger labour pool
A quartet of researchers has found that the reason more prestigious universities are able to publish more scientific papers than lesser institutions is that they have a larger pool of undergrads, fellows and postdocs to assist with such efforts.
In their paper, published in the journal Science Advances, Sam Zhang, Hunter Wapman, Daniel Larremore and Aaron Clauset describe analyzing massive amounts of data in the Web of Science database to learn more about publishing by institutions in the U.S.
Most of the prestigious science paper publishing institutions in the U.S. are college- or university-based. Some of the most well known are MIT, Harvard, Stanford and the University of California. Researchers at these institutions conduct a lot of science research and publish a corresponding number of science-research based papers in peer-reviewed journals.
In this new effort, the research group sought to better understand the factors underlying the tendency of prestigious institutions to produce more published manuscripts than other, less-prestigious institutions.
The work involved sifting data from the Web of Science database, which is actually a portal to several other databases, all of which contain massive amounts of data related to science research efforts. In their effort, the researchers included data from 1.6 million published articles, written by 78,802 authors, all of whom were either tenured or on a tenure track.
The data involved research efforts at 26 U.S. universities that grant Ph.Ds. The researchers focused on data describing productivity of both the authors involved in research efforts and publishing groups as a whole.
The researchers found a pattern—more prestigious schools tend to produce more papers because they have more people available to work on research teams. They noted that neither the senior- nor junior-level people working on the papers were more productive than others working at less-prestigious institutions; it was just more people working and getting more done.
The researchers suggest the possibility that less-prestigious institutions could increase their publication rates if they chose to increase the number of qualified people available to work on research and publishing efforts.
Sam Zhang et al, Labor advantages drive the greater productivity of faculty at elite universities, Science Advances (2022). DOI: 10.1126/sciadv.abq7056
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Nov 29, 2022
Dr. Krishna Kumari Challa
New kind of tropical cyclone identified in the Indian Ocean
Oceanography experts have described a new kind of cyclone in the Indian Ocean near Sumatra after observing satellite surface winds in the region.
The experts' search for the trigger mechanisms of the Indian Ocean Dipole has led to the discovery of the new type of atmospheric tropical cyclone forming in the South-East Tropical Indian Ocean (SETIO) that they call SETIO Cyclone.
The Indian Ocean Dipole (IOD) is a coupled atmosphere-ocean interaction in the tropical Indian Ocean that strongly affects the climate and rainfall variability of surrounding countries including Australia.
Researchers found that SETIO cyclones are short-lived weather-like events that develop frequently during austral winter/spring and operate to maintain a warm surface ocean in the region.
Dramatic changes happen in some years when SETIO cyclones fail to develop, and ambient winds trigger the appearance of cold seawater in a vast area strongly disturbing both winds and rainfall patterns over the Indian Ocean.
In the natural sciences, it is of uttermost importance to identify so-called trigger processes, such as SETIO cyclones, that link the cause to an effect.
This is a rare new discovery that sheds new light into the functioning of the IOD.
Ankit Kavi et al, Synoptic-scale atmospheric cyclones in the South-East Tropical Indian Ocean (SETIO) and their relation to IOD variability, Journal of Southern Hemisphere Earth Systems Science (2022). DOI: 10.1071/ES22020
Nov 29, 2022
Dr. Krishna Kumari Challa
The largest source of abiotic methane gas on Earth
Methane (CH4), the chief constituent of natural gas, is one of the most widely used "clean" fuels. Although methane is usually considered to originate from organic matter, recently, more and more evidence shows that methane can be produced by abiotic processes.
Researchers demonstrated that large amounts of methane gas can form during prograde metamorphism in a cold subduction zone, evidenced by the massive CH4-rich fluid inclusions in eclogites from Western Tianshan, China.
Based on their calculation, the potential CH4 flux from worldwide modern subduction zones is estimated to be as much as ~10.8 Mt/y. Consequently, the subducted cold oceanic crust may produce the largest amount of abiotic methane, along with other abiotic methane sources such as that from mid-ocean ridges or that from by high-pressure serpentinization.
Massive CH4-rich fluid inclusions have been found in garnet and omphcite, which are the main constituent minerals of eclogite in the West Tianshan subduction zone (eclogite is the most important high grade metamorphic rock during cold subduction). Isotopic analyses and petrological studies both demonstrated that this methane was of abiotic origin and formed by water-rocks reactions during the prograde high-pressure to ultrahigh-pressure metamorphism.
Lijuan Zhang et al, Massive abiotic methane production in eclogite during cold subduction, National Science Review (2022). DOI: 10.1093/nsr/nwac207
Nov 29, 2022
Dr. Krishna Kumari Challa
Blood Thinner Ineffective for COVID-19 Patients: Study
A clinical trial finds that the anticoagulant apixaban, which has been prescribed to help COVID-19 patients recover, is ineffective and in rare instances dangerous.
N
ew data from a clinical trial suggest that apixaban, an anticoagulant that’s widely been prescribed to promote recovery in patients with severe cases of COVID-19, doesn’t offer any discernable benefit for people with the disease.
The UK-wide trial, which is run by Addenbrooke’s Hospital and the University of Cambridge, involved more than 1,000 hospitalized COVID-19 patients and compared the outcomes of those who had been randomly assigned to receive apixaban to those who had not, according to Financial Times. It found that 29.1 percent of those who received the blood thinner either ended up back in the hospital or died within a year, compared to 30.8 percent of people who weren’t given the drug. That finding doesn’t support apixaban as an effective treatment for COVID-19, and the researchers conclude that doctors ought to stop prescribing it to their coronavirus patients. Meanwhile, BBC News reports that a “small number” of the 402 patients who took apixaban had to discontinue treatment due to severe bleeding.
The trial will continue with other drugs thought to help against COVID-19, according to BBC News, including a statin called atorvastatin that may help lessen the inflammatory response launched by COVID-19 patients’ immune systems and so prevent tissue damage.
https://clinicaltrials.gov/ct2/show/NCT04801940
https://www.the-scientist.com/news-opinion/blood-thinner-ineffectiv...
Nov 30, 2022
Dr. Krishna Kumari Challa
A secret of developing life: In some instances the fetus helps repair a ruptured amniotic sac
Premature rupture of the amniotic sac can have devastating consequences, but scientists are studying instances when the damaged sac repairs itself—a phenomenon that requires cooperation of the developing fetus.
A new investigation of the amnion, the innermost layer of epithelial cells in the amniotic sac reveals a cascade of cellular events that result in sac repair. The new research helps lay the groundwork for a keener understanding of both healthy pregnancies and when things go awry.
Aware that premature rupture of the amniotic membranes can lead to premature birth, researchers are asking what causes the sac to reseal. Producing a definitive answer to that question may ultimately lead to interventions that prevent premature birth for those whose membranes don't reseal. The biggest potential benefit down the road is guarding against the sometimes lethal outcomes when babies are born too small, too soon.
The premature rupture of the amniotic sac, a condition referred to as a preterm prelabour rupture of membranes (pPROM) is a leading cause of preterm birth. In some cases, these ruptured membranes heal spontaneously. Researchers investigated repair mechanisms of the amnion, a layer of epithelial cells in the amniotic sac closest to the fetus.
Amniotic membranes normally remain intact until the onset of active labor or within 24 hours before labor starts. pPROM may not be easy to detect. For some women, fluid leaks slowly and may be mistaken for urine. Obstetricians say it's important to note that amniotic fluid usually has no color and doesn't smell like urine. They also underscore that premature membrane rupture can occur for a variety of reasons.
In some women the amnion can rupture early for reasons ranging from infections of the uterus, cervix, or vagina to too much stretching of the amniotic sac. The latter may occur as a direct result of too much fluid in the sac, or more than one baby putting pressure on the membranes. Other causes of membrane rupture include conditions such as malnutrition, or intrauterine bleeding. Smoking is another factor that can cause rupture.
In this new study the research team found that fetal macrophages are recruited to rupture sites in both the human and mouse amnion and assist in the repair of torn membranes.
Macrophages migrated to and resided at rupture sites in both human and mouse amnion. A process called epithelial-mesenchymal transition, in which epithelial cells acquire a mesenchymal phenotype and which is implicated in tissue repair, was observed at rupture sites.
In short, epithelial cells took on the role of mesenchymal cells and helped begin the process of resealing. None of the cascade of biological events would have occurred without macrophages first migrating to and taking up residence at the rupture site. This shows that ruptures are reversible with repairs
The membrane repair is highly reliant on signaling molecules: in this case, transformation growth factor-β/Smad—TGF-β/Smad—signaling. TGF-β/Smad was prominent in both mouse and human samples.
This study's findings could potentially inform research into treatments for preterm membrane ruptures to prevent preterm birth.
Yosuke Kawamura et al, Fetal macrophages assist in the repair of ruptured amnion through the induction of epithelial-mesenchymal transition, Science Signaling (2022). DOI: 10.1126/scisignal.abi5453
Nov 30, 2022
Dr. Krishna Kumari Challa
The effects of climate change on body size evolution
The Northern Treeshrew, a small, bushy-tailed mammal native to South and Southeast Asia, defies two of the most widely tested ecological "rules" of body size variation within species, according to a new study.
The unexpected finding, researchers say, may be attributable to climate change—the body size rules reversed in Northern Treeshrews as average temperatures climbed—and likely exists in other species.
The first-of-its-kind study, published Nov. 29 in the journal Scientific Reports, found that the Northern Treeshrew (Tupaia belangeri) breaks both Bergmann's rule and the island rule. The former describes a common pattern wherein individuals of a warm-blooded species inhabiting colder climates—generally located at higher latitudes—have larger average body sizes than those in warmer climates, which are usually at lower latitudes. The latter predicts that small mammal species evolve larger body sizes on islands than their mainland counterparts, whereas island-bound large mammals evolve smaller body sizes.
Although both rules have been repeatedly tested from a strictly geographic standpoint, how they interact—and possibly even change over shorter timescales amidst rapid climate change—has never been rigorously examined.
In the first published study to do so, researchers analyzed 839 museum specimens of adult Northern Treeshrews collected over 130 years from across their entire geographic range, including mainland and island populations, along with historical climate data.
They found that, contrary to Bergmann's rule, body size of the Northern Treeshrew increased in warmer climates closer to the equator. More importantly—and quite unexpectedly—they discovered that both rules have reversed over a remarkably brief period between the late 19th and 20th centuries, with the reversal accelerating as average temperatures rose.
This study highlights that body size is linked to complex, dynamic and potentially interdependent ecological factors. This is the first time a rule reversal like this has been found in any species. The study also found that the two rules are intertwined.
Maya M. Juman et al, Recent and rapid ecogeographical rule reversals in Northern Treeshrews, Scientific Reports (2022). DOI: 10.1038/s41598-022-23774-w
Nov 30, 2022
Dr. Krishna Kumari Challa
Time slows down on crowded train!
Testing time perception in an unusually lifelike setting—a virtual reality ride on a New York City subway train—an interdisciplinary Cornell research team found that crowding makes time seem to pass more slowly.
As a result, rush-hour commutes on public transit may feel significantly longer than other rides that objectively take the same amount of time.
The research adds to evidence that social context and subjective feelings distort our sense of the passage of time, and may have practical implications for people's willingness to use public transit, particularly after the pandemic.
It's a new way of thinking about social crowding, showing that it changes how we perceive time. Crowding creates stressful feelings, and that makes a trip feel longer.
: Saeedeh Sadeghi et al, Affective experience in a virtual crowd regulates perceived travel time, Virtual Reality (2022). DOI: 10.1007/s10055-022-00713-8 Saeedeh
Saeedeh Sadeghi et al, Crowding and Perceived Travel Time in Public Transit: Virtual Reality Compared With Stated Choice Surveys, Transportation Research Record: Journal of the Transportation Research Board (2022). DOI: 10.1177/03611981221130346
Nov 30, 2022