Study reveals that methods to infer the connectivity of neural circuits are affected by systematic errors

Researchers  have recently carried out a study investigating the effectiveness of existing methods for algorithmically estimating the wiring of neural networks. Their findings suggest that even the most sophisticated among these methods are biased and tend to infer connections between neurons that are not actually connected, but rather highly correlated.

Because it is difficult to directly measure the wiring diagrams of neural circuits, there has long been an interest in estimating them algorithmically from multicell activity recordings. But this study shows even sophisticated methods, applied to unlimited data from every cell in the circuit, are biased toward inferring connections between unconnected but highly correlated neurons. This failure to 'explain why' connections occurs when there is a mismatch between the true network dynamics and the model used for inference, which is inevitable when modeling the real world.

Abhranil Das et al. Systematic errors in connectivity inferred from activity in strongly recurrent networks, Nature Neuroscience (2020). DOI: 10.1038/s41593-020-0699-2

https://medicalxpress.com/news/2020-10-reveals-methods-infer-neural...

'Universal law of touch' will enable new advances in virtual reality

Seismic waves, commonly associated with earthquakes, have been used by scientists to develop a universal scaling law for the sense of touch.

Rayleigh waves are created by impact between objects and are commonly thought to travel only along surfaces. The team discovered that, when it comes to touch, the waves also travel through layers of skin and bone and are picked up by the body's touch receptor cells.

Using mathematical modelling of these touch receptors the researchers showed how the receptors were located at depths that allowed them to respond to Rayleigh waves. The interaction of these receptors with the Rayleigh waves will vary across species, but the ratio of receptor depth vs wavelength remains the same, enabling the universal law to be defined.

The team also found that the interaction of the waves and receptors remained even when the stiffness of the outermost layer of skin changed. The ability of the receptors to respond to Rayleigh waves remained unchanged despite the many variations in this outer layer caused by, age, gender, profession, or even hydration.

For most mammals, touch is the first sense to develop. They must feel vibrations on the surface of their skin to enable them to respond to various stimuli in their environment, a process called vibrotaction. But how do mammals perceive these vibrations? Through mathematical modeling of the skin and touch receptors, researchers showed that vibrotaction is dominated by “surface” Rayleigh waves traveling cooperatively through all layers of the skin and bone. Applying their model to experimental data, they identified a universal scaling law for the depth of touch receptors across multiple species, indicating an evolutionarily conserved constant in the sensation of vibrations.

 J.W. Andrews el al., "A universal scaling law of mammalian touch," Science Advances (2020). advances.sciencemag.org/lookup … .1126/sciadv.abb6912

https://phys.org/news/2020-10-universal-law-enable-advances-virtual...

**Do cloth masks work? Only if you machine wash them after every single use

A new publication from researchers  advises daily washing of cloth masks to reduce the likelihood of contamination and transmission of viruses like SARS-CoV-2. Cloth masks must be washed daily at high temperatures to be protective against infection, a new analysis shows. It was found that if cloth masks were washed in the hospital laundry, they were as effective as a surgical mask.

It is important to note that given the study was conducted over five years ago, the researchers did not test for SARS-CoV-2—instead, they included common respiratory pathogens such as influenza, rhinoviruses and seasonal coronaviruses in their analysis. It is based on self-reported washing data and was conducted by health workers in high risk wards in a healthcare setting.

"While someone from the general public wearing a cloth mask is unlikely to come into contact with the same amount of pathogens as healthcare worker in a high risk ward, we would still recommended daily washing of cloth masks in the community. COVID-19 is a highly infectious virus, and there is still a lot that we don't know about it, and so it's important that we take every precaution we can to protect against it and ensure masks are effective.

According to the analysis, handwashing the masks did not provide adequate protection. Healthcare workers who self-washed their masks by hand had double the risk of infection compared to those who used the hospital laundry

The WHO recommends machine washing masks with hot water at 60 degrees Celsius and laundry detergent, and the results of our analysis support this recommendation.

Washing machines often have a default temperature of 40 degree or 60 degrees, so do check the setting. At these very hot temperatures, handwashing is not possible. The clear message from this research is that cloth masks do work—but once a cloth mask has been worn, it needs to be washed properly each time before being worn again, otherwise it stops being effective.

There is much research on the design, fabric and construction of masks, but washing is also key for protection.

Chandini Raina MacIntyre et al. Contamination and washing of cloth masks and risk of infection among hospital health workers in Vietnam: a post hoc analysis of a randomized controlled trial, BMJ Open (2020). DOI: 10.1136/bmjopen-2020-042045

https://medicalxpress.com/news/2020-10-masks-machine.html?utm_sourc...

Bacteria-fighting cells in the airways boost infection risk from viruses

Having more bacteria-fighting immune cells in the nose and throat may explain why some people are more likely to be infected by respiratory viruses.

researchers found that volunteers who succumbed to infection from respiratory syncytial virus (RSV) had more specialized white blood cells called neutrophils in their airways before exposure to the virus, compared to those who staved off infection. According to the researchers, this type of neutrophil-driven inflammation in the nose and throat—typically associated with fighting off bacterial infections—may compromise our ability to fight off invading viruses and make us more susceptible to viral infections. The findings could help researchers to understand why people respond differently to the same viral threat, predict who is more at risk of infection, and even lead to preventative treatments to protect against RSV and potentially other respiratory viruses, including influenza and coronaviruses. when they analyzed samples from participants' airways taken before they were exposed to the virus, the team found evidence of neutrophil activation in the nasal mucosa—the cells lining the inside of the nose—in those who became infected with the virus. These immune cells are known to release proteins which help create an antibacterial environment in response to a threat. But the researchers believe this antibacterial immune response may come at a cost, making a host more susceptible to viruses by effectively switching off the early warning system, letting them slip through the net to cause infection.

 Neutrophilic inflammation in the respiratory mucosa predisposes to RSV infection. Science, science.sciencemag.org/cgi/doi … 1126/science.aba9301

https://medicalxpress.com/news/2020-10-bacteria-fighting-cells-airw...

4-D nanoparticles open new perspectives in safer treatment of tumor...

In the context of nanomedicine, nanoparticles are effective because they can be endowed with multiple functions and are able to hit their target without the need for extremely high doses, which are associated with dangerous side effects. However, they tend to remain in the body for an indefinite time, with important risks to the health of patients. Ideally, nanomedicines should behave like a 4-D material, developing nanoparticles for diagnosis (for example by magnetic resonance imaging or CT scan) and cancer therapy that have as their main requirement the ability to biodegrade, not to accumulate in the body, limiting it in this way the side effects.

inorganic nanoparticles based on an alloy of gold and iron, two biocompatible elements, which are therefore particularly suitable for applications in the biomedical field, are able to biodegrade spontaneously in living organisms.

 how the possibility of capturing these "4-D nano-comets" is fundamental in the field of nanomedicine, and especially for the diagnosis and treatment of cancer, showing that metastable gold-iron-based nanoalloys could be ideal candidates for the purpose.

The research, which started with a theoretical-computational investigation, has shown how the atoms of gold and iron, two biocompatible elements that are particularly suitable for applications in the biomedical field, must be arranged inside the nanoparticles so that the latter biodegrade spontaneously in living organisms. The key to the whole study was to find a way to "force" iron and gold to coexist in proportions that are not practicable in nature. For this purpose, laser synthesis techniques in liquid were used to produce bi-metallic Au-Fe nanoparticles capable of biodegradation. These metastable nanoparticles have also been tested in vivo, where they have been shown to leave the organism after a not excessively long period, as opposed to other nanoparticles based only on gold or only on iron oxide, which instead tend to persist for much longer times.

Having a 4-D nanomaterial exploitable as a multimodal imaging agent is particularly important at a clinical level because it allows reducing both the dose administered to the patient and the waiting time before the imaging itself, which are crucial in the treatment of tumors. The next step will be the investigation of the theranostic (i.e., diagnostic and therapeutic) potential of these 4-D nanomedicines.

Veronica Torresan et al. 4D Multimodal Nanomedicines Made of Nonequilibrium Au–Fe Alloy Nanoparticles, ACS Nano (2020). DOI: 10.1021/acsnano.0c03614

https://sciencex.com/news/2020-10-d-nanoparticles-perspectives-safe...

Finding the Best Hot Pepper Cures Using SCIENCE

How SARS-CoV-2 disables the human cellular alarm system

https://phys.org/news/2020-10-sars-cov-disables-human-cellular-alar...

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How gut bacteria manipulates your immune system – by mimicking it

Scientists are discovering how microbes ‘speak’ with the body

https://massivesci.com/articles/gut-bacteria-immune-system-protein-...

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What do we really know about the safety of probiotics?

Messing with our gut microbiome could hurt us

https://massivesci.com/articles/probiotics-microbiome-supplements/

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Initiative pushes to make journal abstracts free to read in one place

Cheese Preservative Slows Oral Cancer Spread in Mice: Study

The results add to mounting evidence of microbes’ roles in tumor growth and point to the possibility of impeding malignancies by inhibiting bacteria.

https://www.the-scientist.com/news-opinion/cheese-preservative-slow...

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How media algorithms try to manipulate your decisions and how to overcome them

https://theconversation.com/do-social-media-algorithms-erode-our-ab...

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Astronomers Are Using Black Hole Echoes to Help Map The Universe

https://www.sciencealert.com/echoes-from-black-holes-could-be-the-n...

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Chemists create new crystal form of insecticide, boosting its ability to fight mosquitoes and malaria

https://phys.org/news/2020-10-chemists-crystal-insecticide-boosting...

 Fertiliser use is fuelling climate-warming nitrous oxide emissions: study

https://www.reuters.com/article/us-climate-change-no2-idUSKBN26S35W

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Life in the Clouds

High above our heads, even beyond 120,000 feet up, scientists have found tiny organisms called microbes. These high-flyers were swept up from the ground by winds and storms, or spewed out through volcanic processes. While most of these high-altitude microbes are dead, some are still alive, or have produced material called spores that could activate in the future. David J. Smith, an astrobiologist at NASA’s Ames Research Center, uses airplanes to collect these microbes, analyze them in the laboratory, and expose them to even higher altitudes with balloon experiments to see how they will respond. If microbes can inhabit our clouds, what about other planets? While more research is needed, Smith and others are fascinated by the possibility that airborne microbes could also be found elsewhere in the solar system, and beyond.

Scientists May Be Able to Treat Tinnitus With Electronic Music And Tongue Buzzing

People who experience tinnitus (the perception of noise or ringing in the ears) might finally have some hope for alleviating their symptoms, after an experimental device that stimulates the tongue was found to ease the condition in a sample of 273 volunteers with a chronic case of it.The tongue buzzing is combined with a carefully prepared audio stream fed through headphones, sounding a little like ambient electronic music. The combined treatment caused an improvement in symptoms for 86 percent of the participants, with an average drop of around 14 points on a tinnitus severity ranking scored from 1 to 100. Even better, the improvements lasted for up to a year for many of the individuals involved. These are promising signs for the 10-15 percent of people worldwide who live with the phantom sounds and ringing ears caused by tinnitus.

A  device – called the Lenire – aims to heighten the sensitivity of the brain, effectively crowding out the overactive parts of the brain that would otherwise cause tinnitus symptoms.

https://stm.sciencemag.org/content/12/564/eabb2830

https://www.sciencealert.com/audible-tones-and-tongue-buzzing-could...

New virtual reality software allows scientists to 'walk' inside cells

Virtual reality software which allows researchers to 'walk' inside and analyse individual cells could be used to understand fundamental problems in biology and develop new treatments for disease. The software, called vLUME, was created by scientists. It allows super-resolution microscopy data to be visualised and analysed in virtual reality, and can be used to study everything from individual proteins to entire cells.

Super-resolution microscopy, which was awarded the Nobel Prize for Chemistry in 2014, makes it possible to obtain images at the nanoscale by using clever tricks of physics to get around the limits imposed by light diffraction. This has allowed researchers to observe molecular processes as they happen. However, a problem has been the lack of ways to visualise and analyse this data in three dimensions.

vLUME is revolutionary imaging software that brings humans into the nanoscale. It allows scientists to visualise, question and interact with 3-D biological data, in real time all within a virtual reality environment, to find answers to biological questions faster. It's a new tool for new discoveries. Viewing data in this way can stimulate new initiatives and ideas.

vLUME: 3D virtual reality for single-molecule localization microscopy, Nature Methods (2020). DOI: 10.1038/s41592-020-0962-1

https://techxplore.com/news/2020-10-virtual-reality-software-scient...

Experimental COVID-19 treatment given to Trump found to relieve symptoms in macaques and hamsters

A team of researchers with Regeneron Pharmaceuticals, Inc., working with the Texas Biomedical Research Institute, has found that the antibody cocktail given to President Trump was effective in reducing COVID-19 symptoms in rhesus macaques and golden hamsters. 

The US president had received an experimental antibody cocktail along with doses of vitamin D, zinc and a heartburn medicine. The experimental antibody cocktail he was given was provided courtesy of Regeneron Pharmaceuticals, Inc., a company that has been conducting research into the use of such antibody cocktails as therapies for a host of viral infections, including COVID-19. In this new effort, the researchers tested the antibody cocktail with rhesus macaques and golden hamsters.

In the first part of the study, the researchers administered the cocktail (which they call REGN-COV2) to healthy rhesus macaques. Prior research had shown that they can infected by the SARS-CoV-2 virus, but typically exhibit only mild symptoms. Three days after receiving the cocktail, the monkeys were injected with the SARS-CoV-2 virus and then monitored to see if the treatment had any impact. They found that monkeys who had received the treatment prior to infection exhibited far fewer symptoms than a control group and had a much lower viral load.

The researchers also injected some of the monkeys with the cocktail after they were infected and found that doing so also reduced symptoms and resulted in faster viral clearance. The researchers next repeated the same experiments with golden hamsters. They, too, have been found to be susceptible to COVID-19, but have much more severe symptoms, including major weight loss. They found that giving it to them two days before they were infected with the SARS-CoV-2 virus resulted in greatly reduced symptoms and they did not suffer weight loss. And giving it to the hamsters after an infection had set in also resulted in reduced symptoms and faster viral clearance.

The researchers suggest that REGN-COV2 may offer therapeutic benefits both as a treatment and as a preventative measure for COVID-19.

Alina Baum et al. REGN-COV2 antibodies prevent and treat SARS-CoV-2 infection in rhesus macaques and hamsters, Science (2020). DOI: 10.1126/science.abe2402

https://medicalxpress.com/news/2020-10-experimental-covid-treatment...

Dueling proteins give shape to plants

In an elegant choreography, plants take cues from their environment and channel them into flowers, roots, or branches.

Researchers have been studying two key groups of proteins that influence plant form and timing of developmental transitions. Terminal Flower 1 (TLF1) proteins promote branch formation. When it is repressed, flowers grow. Flowering Locus T (FT) proteins, on the other hand, promote flowering in response to seasonal cues like day length. Strangely enough, the two proteins are almost identical.

These two elements have significance galore. Besides flowering, they're involved in tuberization in potatoes, bulb formation in onions, tendril formation in grapes, growth cessation in trees, lots of things.

Manipulating these genes, some have argued, could lead to the next "green revolution" as one could theoretically "trick" a plant that normally only flowers in the long days of summer to flower quickly, and thus produce fruit or seed, in the short days of winter with a deft genetic edit of TFL1. Or, in an area with a longer growing season, a clever manipulation of growth architecture via FT could encourage increased branching and then a later, and more abundant, flowering and fruit development on the many branches.

Nature Communications (2020). DOI: 10.1038/s41467-020-18782

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Plants have already been bred to have reduced TFL1 activity. Tomato gardeners may know these as determinant plants, which set all their flowers at the same time, as opposed to the indeterminant variety, which continue to branch, flower, and fruit over a period of months. Determinant plants make commercial agriculture more efficient, as fruits can be harvested in one go as opposed to repeated passes.

https://phys.org/news/2020-10-dueling-proteins.html?utm_source=nwle...

Scientists engineer bacteria-killing molecules from wasp venom

A team led by scientists  has engineered powerful new antimicrobial molecules from toxic proteins found in wasp venom. The team hopes to develop the molecules into new bacteria-killing drugs, an important advancement considering increasing numbers of antibiotic-resistant bacteria which can cause illness such as sepsis and tuberculosis.

The  researchers altered a highly toxic small protein from a common Asian wasp species, Vespula lewisii, the Korean yellow-jacket wasp. The alterations enhanced the molecule's ability to kill bacterial cells while greatly reducing its ability to harm human cells. In animal models, the scientists showed that this family of new antimicrobial molecules made with these alterations could protect mice from otherwise lethal bacterial infections.

 Osmar N. Silva el al., "Repurposing a peptide toxin from wasp venom into antiinfectives with dual antimicrobial and immunomodulatory properties," PNAS (2020). www.pnas.org/cgi/doi/10.1073/pnas.2012379117

https://phys.org/news/2020-10-scientists-bacteria-killing-molecules...

Carnivores living near people feast on human food, threatening ecosystems

Ecologists  have found that carnivores living near people can get more than half of their diets from human food sources, a major lifestyle disruption that could put North America's carnivore-dominated ecosystems at risk. The researchers studied the diets of seven predator species across the Great Lakes region of the U.S. They gathered bone and fur samples for chemical analysis from areas as remote as national parks to major metropolitan regions like Albany, New York. They found that the closer carnivores lived to cities and farms, the more human food they ate.

 Philip J. Manlick el al., "Human disturbance increases trophic niche overlap in terrestrial carnivore communities," PNAS (2020). www.pnas.org/cgi/doi/10.1073/pnas.2012774117

https://phys.org/news/2020-10-carnivores-people-feast-human-food.ht...

**Oral cancer pain predicts likelihood of cancer spreading

 Oral cancer is more likely to spread in patients experiencing high levels of pain, according to a team of researchers at New York University College of Dentistry that found genetic and cellular clues as to why metastatic oral cancers are so painful.

The findings—which appear in Scientific Reports, a journal published by Nature—may ultimately be used to alleviate oral cancer pain and refine surgical decision making when treating oral cancer.

Oral cancer can cause severe pain during everyday activities, including talking and eating. Previous research by Brian L. Schmidt, DDS, MD, PhD, director of the NYU Oral Cancer Center and one of the study’s authors, suggests that patients with metastatic oral cancer—cancer that spreads beyond the mouth—experience more pain than those whose cancer has not spread. The new study helps researchers understand why.

https://researchnews.cc/news/3000/Oral-cancer-pain-predicts-likelih...

New Type of Immunotherapy Helps Mice with Hard-to-Treat Breast Cancer Survive Longer

Where You Sit in a Room Can Influence Your Risk of Catching COVID-19

https://www.sciencealert.com/where-you-sit-in-a-classroom-might-inf...

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Non-Concussive Head Hits Influence the Brain’s Microstructure

Comparing the brain scans of high-impact rugby players with those of athletes in noncontact sports, such as rowing and swimming, revealed tiny, yet significant, differences in the brain’s white matter.

https://www.the-scientist.com/the-literature/non-concussive-head-hi...

Binge drinking may cause Alzheimer's disease—and it might strike younger and in a severe form

Binge drinking may be linked to both the onset and severity of Alzheimer's disease, but scientists have only now embarked on a path to decipher each molecular step involved in how excessive alcohol consumption leads to the most common form of dementia.

Excessive alcohol consumption is toxic to the brain. Binge drinking likely plays an insidious role in the alteration of a normal brain protein  into a biological rogue that is highly prevalent in Alzheimer's disease. The protein is identified by a simplistic monosyllabic name—tau.

In its normal conformation, tau is found in neurons modulating the stability of axonal microtubules. But in its abnormal conformation, tau has long been considered one of the leading hallmarks of Alzheimer's, and makes up the tangles in the notorious "plaques and tangles" pathology. The plaques are deposits of the protein beta amyloid. 

 The main aim of this study is how tau transforms from a normal protein into a neuron-annihilating cause of Alzheimer's under the influence of excessive alcohol. 

The scientists are delving into how tau can become phosphorylated, which means its structural conformation changes and its role in the brain becomes chemically altered under the influence of binge drinking. Studies have shown that frequent and heavy alcohol drinking is linked to earlier onset and increased severity of Alzheimer's disease.

It has been reported that alcohol consumption correlates with Alzheimer's-like cortical atrophy in individuals at high risk of developing the disease as well as younger age of onset.

In addition, chronic alcohol exposure caused neural tau phosphorylation in the hippocampus and memory-impairment in Alzheimer's-predisposed mice.

Archna Sharma et al. Potential Role of Extracellular CIRP in Alcohol-Induced Alzheimer's Disease, Molecular Neurobiology (2020). DOI: 10.1007/s12035-020-02075-1

https://medicalxpress.com/news/2020-10-binge-alzheimer-diseaseand-y...

Covid-19 reinfection casts doubt on virus immunity: study

COVID-19 patients may experience more severe symptoms the second time they are infected, according to research released this week confirming it is possible to catch the potentially deadly disease more than once.

The study charts the first confirmed case of COVID-19 reinfection in the United States. 

The patient, a 25-year-old man, was infected with two distinct variants of SARS-CoV-2, the virus that causes COVID-19, within a 48-day time frame.

The second infection was more severe than the first, resulting in the patient being hospitalised with oxygen support.

The study also reminded us the four other cases of reinfection confirmed globally, with one patient each in Belgium, the Netherlands, Hong Kong and Ecuador. Experts say the prospect of reinfection could have a profound impact on how the world battles through the pandemic. In particular, it could influence the hunt for a vaccine.

Vaccines work by triggering the body's natural immune response to a certain pathogen, arming it with antibodies it to fight off future waves of infection.

But it is not at all clear how long COVID-19 antibodies last.

For some diseases, such as measles, infection confers lifelong immunity. For other pathogens, immunity may be fleeting at best.

The authors said the US patient could have been exposed to a very high dose of the virus the second time around, triggering a more acute reaction.

Alternatively, it may have been a more virulent strain of the virus.

Another hypothesis is a mechanism known as antibody dependent enhancement—that is, when antibodies actually make subsequent infections worse, such as with dengue fever.

The researchers pointed out that reinfection of any kind remains rare, with only a handful of confirmed cases out of tens of millions of COVID-19 infections globally.

However, since many cases are asymptomatic and therefore unlikely to have tested positive initially, it may be impossible to know if a given COVID-19 case is the first or second infection.

https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30764-7/fulltext

https://medicalxpress.com/news/2020-10-covid-reinfection-virus-immu...

Damaged muscles don't just die, they regenerate themselves

Researchers have found that components leaking from broken muscle fibers activate "satellite" muscle stem cells. While attempting to identify the proteins that activate satellite cells, they found that metabolic enzymes, such as GAPDH, rapidly activated dormant satellite cells and accelerated muscle injury regeneration. This is a highly rational and efficient regeneration mechanism in which the damaged muscle itself activates the satellite cells that begin the regeneration process.

Skeletal muscle is made up of bundles of contracting muscle fibers and each muscle fiber is surrounded by satellite cells—muscle stem cells that can produce new muscle fibers. Thanks to the work of these satellite cells, muscle fibers can be regenerated even after being bruised or torn during intense exercise. Satellite cells also play essential roles in muscle growth during developmental stages and muscle hypertrophy during strength training. However, in refractory muscle diseases like muscular dystrophy and age-related muscular fragility (sarcopenia), the number and function of satellite cells decreases. It is therefore important to understand the regulatory mechanism of satellite cells in muscle regeneration therapy.

In mature skeletal muscle, satellite cells are usually present in a dormant state. Upon stimulation after muscle injury, satellite cells are rapidly activated and proliferate repeatedly. During the subsequent myogenesis, they differentiate and regenerate muscle fibers by fusing with existing muscle fibers or with together. Of these three steps (satellite cell activation, proliferation, and muscle differentiation), little is known about how the first step, activation, is induced.

Since satellite cells are activated when muscle fibers are damaged, researchers hypothesized that muscle damage itself could trigger activation

Yoshifumi Tsuchiya et al, Damaged Myofiber-Derived Metabolic Enzymes Act as Activators of Muscle Satellite Cells, Stem Cell Reports (2020). DOI: 10.1016/j.stemcr.2020.08.002

Skeletal muscle development and regeneration mechanisms vary by gender

Researchers at Kumamoto University, Japan, have generated mice lacking the estrogen receptor beta (ERβ) gene, both fiber-specific and muscle stem cell-specific, which resulted in abnormalities in the growth and regeneration of skeletal muscle in female mice. This was not observed in male mice that lacked the ERβ gene, suggesting that estrogen and its downstream signals may be a female-specific mechanism for muscle growth and regeneration.

In humans, skeletal muscle mass generally peaks in the 20s with a gradual decline beginning in the 30s, but it is possible to maintain muscle mass through strength training and a healthy lifestyle. Skeletal muscle can be damaged through excessive exercise or bruising, but it has the ability to regenerate. The muscle stem cells that surround muscle fibers are essential for this regeneration; they also play a part in increasing muscle size (hypertrophy). Muscle stem cell dysfunction is thought to be associated with various muscle weakness, such as age-related sarcopenia and muscular dystrophy. Although basic research on skeletal muscle has progressed rapidly in recent years, most studies were conducted on male animals and gender differences were given much consideration.

Estrogen is a female hormone that maintains the homeostasis of various tissues and organs. A decrease in estrogen levels due to amenorrhea, menopause, or other factors can lead to a disturbance in biological homeostasis. When estrogen binds to estrogen receptors (ERs) in cells, it is transferred into the nucleus and binds to genomic DNA to induce the expression of specific genes as transcription factors. There are two types of ERs, ERα and ERβ. While both ERα and ERβ have high binding capacity to estrogen, their tissue distribution is different, they do not have a common DNA-binding domain, and they may act as antagonists to each other, suggesting that they have different roles. Furthermore, estrogen's effects on cells can be both ER-mediated and non-ER-mediated.

An epidemiological study of pre- and postmenopausal women in their 50s indicated an association between decreased blood estrogen levels and muscle weakness. A research group at Kumamoto University previously showed that estrogen is important for skeletal muscle development and regeneration using an ovariectomized estrogen deficiency mouse model. They also examined the effectiveness of nutritional interventions in estrogen-deficient conditions. However, whether estrogen acts directly on the ER of muscle fibers and muscle stem cells to regulate skeletal muscle growth and regeneration, or whether it acts indirectly through other tissues and organs was unclear. In this study, the researchers generated mice with either myofiber-specific or muscle stem cell-specific ERβ gene deletion and analyzed the function of ERβ in skeletal muscle.

Daiki Seko et al, Estrogen Receptor β Controls Muscle Growth and Regeneration in Young Female Mice, Stem Cell Reports (2020). DOI: 10.1016/j.stemcr.2020.07.017

https://medicalxpress.com/news/2020-10-skeletal-muscle-regeneration...

Physicists successfully carry out controlled transport of stored light

A team of physicists has successfully transported light stored in a quantum memory over a distance of 1.2 millimeters. They have demonstrated that the controlled transport process and its dynamics has only little impact on the properties of the stored light. The researchers used ultra-cold rubidium-87 atoms as a storage medium for the light as to achieve a high level of storage efficiency and a long lifetime.

They stored the light by putting it in a 'suitcase' so to speak, only that in their case the suitcase was made of a cloud of cold atoms. They then moved this suitcase over a short distance and then took the light out again. This is very interesting not only for physics in general, but also for quantum communication, because light is not very easy to 'capture', and if you want to transport it elsewhere in a controlled manner, it usually ends up being lost.

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The controlled manipulation and storage of quantum information as well as the ability to retrieve it are essential prerequisites for achieving advances in quantum communication and for performing corresponding computer operations in the quantum world. Optical quantum memories, which allow for the storage and on-demand retrieval of quantum information carried by light, are essential for scalable quantum communication networks. For instance, they can represent important building blocks of quantum repeaters or tools in linear quantum computing. In recent years, ensembles of atoms have proven to be media well suited for storing and retrieving optical quantum information. Using a technique known as electromagnetically induced transparency (EIT), incident light pulses can be trapped and coherently mapped to create a collective excitation of the storage atoms. Since the process is largely reversible, the light can then be retrieved again with high efficiency.

Wei Li et al, Controlled Transport of Stored Light, Physical Review Letters (2020). DOI: 10.1103/PhysRevLett.125.150501

https://phys.org/news/2020-10-physicists-successfully.html?utm_sour...

How to see what's on the other side of a wormhole without actually traveling through it

Wormholes are incredibly fascinating objects, but also completely hypothetical. We simply don't know if they can truly exist in our universe. But new theoretical insights are showing how we may be able to detect a wormhole—from a spray of high-energy particles emitted at the moment of its formation.

The problem with wormholes - Ask a Spaceman!

O. B. Zaslavskii, New scenario of high-energy particle collisions near wormholes. arXiv:2009.11894 [gr-qc]. arxiv.org/abs/2009.11894

https://phys.org/news/2020-10-side-wormhole.html?utm_source=nwlette...

 it might be possible to find wormholes, and a new paper appearing on the preprint journal arXiv outlines one possible technique.

Here's how it works. Let's say a particle falls into a newly forming wormhole. It can, if it has high enough energy, spontaneously decay into two new particles. One of these particles can escape through the wormhole, while the other can get reflected back through the opening, due to the strange physics operating inside these tunnels.

Then, a new particle enters the wormhole and collides with the reflected particle. The author of the paper found that this collision can reach arbitrarily high energies. This means that what we see on our end of the wormhole could be a shower of high-energy radiation—an unmistakable burst of energy.

Now that we know these kinds of particle showers are possible from opening wormholes, we can look around the universe to see if anything fits the bill… and if we can travel to them.

C-Face: Continuously Reconstructing Facial Expressions by Deep Learning Contours ,UIST 20, SciFi Lab

Multivitamins Don't Necessarily Make You Healthier. Here's Why

Do multivitamins make you healthier?

https://metafact.io/factcheck_answers/2064

https://www.sciencealert.com/multivitamins-don-t-necessarily-make-y...

Pufferfish may be carving mysterious ‘crop circles’ near Australia

The only other known rings are fish nests found 5,500 kilometers away, in Japan

Japan’s white-spotted pufferfish are renowned for producing complex, ringed patterns in the sand. Now, 5,500 kilometers away in Australia, scientists have discovered what appear to be dozens more of these creations.

While conducting a marine life survey out on Australia’s North West Shelf near subsea gas infrastructure with an autonomous underwater vehicle, marine ecologist Todd Bond spotted a striking pattern on the seafloor, more than 100 meters deep.  “Immediately, I knew what it was,” recounts Bond, of the University of Western Australia in Perth. Bond and his colleagues continued the survey, ultimately finding nearly two dozen more.

Until now, these undersea “crop circles” were found only off the coast of Japan. First spotted in the 1990s, it took two decades to solve the mystery of what created them. In 2011, scientists found the sculptors — the diminutive males of what was then a new species of Torquigener pufferfish. The patterns are nests, meticulously plowed over the course of days and decorated with shells to entice females to lay their eggs in the center. 

‘Great Adaptations’ unravels mysteries of amazing animal abilities

Tales of unusual animals — and unusual science — make for an entertaining read

the mystery behind the mole’s wiggly star-shaped appendage (it helps the subterranean animal sense prey without using sight)

how “hangry” water shrews execute the fastest documented predatory attack by a mammal and how cockroaches resist becoming zombies during parasitoid wasp attacks (SN: 10/31/18).

the notion that a tentacled snake (Erpeton tentaculatum) might use the short appendages close to itsmouth to lure in nearby fish, just like snapping turtles dowith their tongues, turned out to be wrong. Instead, the tentacleshelp a snake sense a fish’s position in the water andknow when to attack. What’s more, the snakes have hackedtheir prey’s natural escape reflexes. In a fatal mistake, fishflee in the wrong direction — straight toward a snake’smouth — when duped by a twitch of the snake’s neck rightbefore the predator strikes.

 Tentacled snakes are born knowing how to strike at prey rather than learning through failure you can’t “find enough superlatives to sum up these results.” A fight between a parasitoid wasp and a cockroach is like an “insect rodeo.” The wasp attacks a cockroach’s head in an attempt to lay an egg, but in defense the roach “bucks, jumps, and flails with all its might.”

https://www.sciencenews.org/article/book-great-adaptations-unravels...

You can check   Great Adaptations on Amazon.com.

Restoring 30% of the world's ecosystems in priority areas could stave off extinctions and absorb CO2

Returning specific ecosystems that have been replaced by farming to their natural state in all continents worldwide would rescue the majority of land-based species of mammals, amphibians and birds under threat of extinction. Such measures would also soak up more than 465 billion tons of carbon dioxide, according to a new report released today. Protecting 30% of the priority areas identified in the study, together with protecting ecosystems still in their natural form, would reduce carbon emissions equivalent to 49% of all the carbon that has built up in our atmosphere over the last two centuries. Some 27 researchers from 12 countries contributed to the report, which assesses forests, grasslands, shrublands, wetlands and arid ecosystems.

By identifying precisely which destroyed ecosystems worldwide should be restored to deliver biodiversity and climate benefits at a low cost without impact on agricultural production, the study is the first of its kind to provide global evidence that where restoration takes place has the most profound impact on the achievement of biodiversity, climate and food security goals. According to the study, restoration can be 13 times more cost-effective when it takes place in the highest priority locations.

Global priority areas for ecosystem restoration, Nature (2020). DOI: 10.1038/s41586-020-2784-9

https://phys.org/news/2020-10-world-ecosystems-priority-areas-stave...

Scientists home in on the mechanism that protects cells from premature aging

Molecules that accumulate at the tip of chromosomes are known to play a key role in preventing damage to our DNA. Now, researchers  have unraveled how these molecules home in on specific sections of chromosomes—a finding that could help to better understand the processes that regulate cell survival in aging and cancer.

Much like the aglet of a shoelace prevents the end of the lace from fraying, stretches of DNA called telomeres form protective caps at the ends of chromosomes. But as cells divide, telomeres become shorter, making the protective cap less effective. Once telomeres get too short, the cell stops dividing. Telomere shortening and malfunction have been linked to cell aging and age-related diseases, including cancer.

Scientists have known that RNA species called TERRA help to regulate the length and function of telomeres. Discovered in 2007  TERRA belongs to a class of molecules called noncoding RNAs, which are not translated into proteins but function as structural components of chromosomes. TERRA accumulates at chromosome ends, signaling that telomeres should be elongated or repaired.

However, it was unclear how TERRA got to the tip of chromosomes and remained there. "The telomere  makes up only a tiny bit of the total chromosomal DNA, so the question is 'how does this RNA find its home. By visualizing TERRA molecules under a microscope, the researchers found that a short stretch of the RNA is crucial to bring it to telomeres. Further experiments showed that once TERRA reaches the tip of chromosomes, several proteins regulate its association with telomeres. Among these proteins, one called RAD51 plays a particularly important role. RAD51 is a well-known enzyme that is involved in the repair of broken DNA molecules. The protein also seems to help TERRA stick to telomeric DNA to form a so-called "RNA-DNA hybrid molecule". Scientists thought this type of reaction, which leads to the formation of a three-stranded nucleic acid structure, mainly happened during DNA repair. The new study shows that it can also happen at chromosome ends when TERRA binds to telomeres. The researchers also found that short telomeres recruit TERRA much more efficiently than long telomeres. Although the mechanism behind this phenomenon is unclear, the researchers hypothesize that when telomeres get too short, either due to DNA damage or because the cell has divided too many times, they recruit TERRA molecules. This recruitment is mediated by RAD51, which also promotes the elongation and repair of telomeres. "TERRA and RAD51 help to prevent accidental loss or shortening of telomeres. That's an important function."

Given the role of telomeres in health and disease, it will be important to see how the newly discovered mechanism—which was deduced from observations in living cells and reproduced in test tubes—is regulated in the very complex cellular environment.

RAD51-dependent recruitment of TERRA long noncoding RNA to telomeres through R-loops, Nature (2020). DOI: 10.1038/s41586-020-2815-6

https://phys.org/news/2020-10-scientists-home-mechanism-cells-prema...

The Great Barrier Reef has lost half its corals

A new study of the Great Barrier Reef shows populations of its small, medium and large corals have all declined in the past three decades. Scientists  found the number of small, medium and large corals on the Great Barrier Reef has declined by more than 50 percent since the 1990s.

The decline occurred in both shallow and deeper water, and across virtually all species—but especially in branching and table-shaped corals. These were the worst affected by record-breaking temperatures that triggered mass bleaching in 2016 and 2017.

Climate change is driving an increase in the frequency of reef disturbances such as marine heatwaves. 'There is no time to lose—we must sharply decrease greenhouse gas emissions ASAP if we want to protect them from more degradation and total loss', the researchers conclude.

Andreas Dietzel et al, Long-term shifts in the colony size structure of coral populations along the Great Barrier Reef, Proceedings of the Royal Society B: Biological Sciences (2020). DOI: 10.1098/rspb.2020.1432

https://phys.org/news/2020-10-great-barrier-reef-lost-corals.html?u...

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Scientists shed new light on viruses' role in coral bleaching

Scientists  have shown that viral infection is involved in coral bleaching—the breakdown of the symbiotic relationship between corals and the algae they rely on for energy.

After analyzing the viral metagenomes they found that bleached corals had a higher abundance of eukaryotic viral sequences, and non-bleached corals had a higher abundance of bacteriophage sequences. This gave the researchers the first quantitative evidence of a shift in viral assemblages between coral bleaching states.
Bacteriophage viruses infect and replicate within bacteria. Eukaryotic viruses infect non-bacterial organisms like animals.
In addition to having a greater presence of eukaryotic viruses in general, bleached corals displayed an abundance of what are called giant viruses. Known scientifically as nucleocytoplasmic large DNA viruses, or NCLDV, they are complex, double-stranded DNA viruses that can be parasitic to organisms ranging from the single-celled to large animals, including humans.
Giant viruses have been implicated in coral bleaching. Now scientists were able to generate the first draft genome of a giant virus that might be a factor in bleaching.

Adriana Messyasz et al, Coral Bleaching Phenotypes Associated With Differential Abundances of Nucleocytoplasmic Large DNA Viruses, Frontiers in Marine Science (2020). DOI: 10.3389/fmars.2020.555474

https://phys.org/news/2020-10-scientists-viruses-role-coral.html?ut...

New areas at risk of drinking water arsenic exposure in India

An international team involving researchers based in Manchester (UK), Patna (India) and Zurich (Switzerland) has found new areas of arsenic contamination in drinking water in India. Their country-specific, country-wide model for well water arsenic in India has recently been published in the International Journal for Environmental Research and Public Health.

Their model confirms the known high probability of finding hazardous high arsenic well waters in northern India in the river basins of the Ganges and Brahmaputra. What is new and particularly concerning, is that the model also finds an elevated probability of high arsenic well waters in other Indian areas, where previously arsenic hazard was generally not considered to be a major concern—so much so that in many of these areas well water arsenic is not routinely checked.

These areas include parts of south-west and central India and are mostly areas underlain by sediments and sedimentary rocks.

The study suggests follow up to help better define specific areas in which action is required to reduce adverse public health outcomes from drinking high arsenic well waters. The study also highlights the importance of systematic testing of hazards, not just in known high hazard areas, but also through random sampling of all wells used for drinking water.

Joel Podgorski et al. Groundwater Arsenic Distribution in India by Machine Learning Geospatial Modeling, International Journal of Environmental Research and Public Health (2020). DOI: 10.3390/ijerph17197119

https://phys.org/news/2020-10-areas-arsenic-exposure-india.html?utm...

Electric and Magnetic Field Treatments Lower Mouse Blood Sugar

**The effects seem to be mediated by a reactive oxygen species in the animals’ livers.

https://www.the-scientist.com/news-opinion/electric-and-magnetic-fi...

Science Pinpoints Global Metal Deposit Locations

Miners can find new deposits with less effort

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Decoy Cells Trick SARS-CoV-2, Reduce Cytokines In Vitro

Genetically engineered cells that overproduce ACE2, the receptor the novel coronavirus uses to enter cells, neutralize infection in vitro and mop up inflammatory cytokines in mice.

https://www.the-scientist.com/news-opinion/decoy-cells-trick-sars-c...

When feeling the pinch, nuclei instigate cells to escape crowded spaces

The threat of serious deformation triggers a rapid escape reflex that enables cells to move away and squeeze out from tight spaces or crowded tissues.

In a new study  researchers reveal that squeezing a cell to the point where its nucleus starts to stretch triggers the activation of motor proteins which in turn transform the cell's cytoskeleton so that it can flee a packed environment.

Each cell has a nucleus, and each nucleus has a membrane that separates the chromosomes from the rest of the cell. At a rest state, the nuclear membrane is saggy, akin to a loose shopping bag. Now researchers have found that when the nuclear membrane  is squeezed, the wrinkles on its surface iron themselves out, instigating a cascade of events that transform the cytoskeleton and eventually aid the cell in escaping its crowded environment.

The nucleus measures shape changes for cellular proprioception to control dynamic cell behavior, Science (2020). DOI: 10.1126/science.aba2644

Study finds how body cells move within a tissue

https://phys.org/news/2020-10-nuclei-instigate-cells-crowded-spaces...

Symptoms all in your head—or in your gut? Maybe a little of both.

Anyone who has ever experienced "butterflies in the stomach" before giving a big presentation won't be surprised to learn there is an actual physical connection between their gut and their brain. Neuroscientists and medical professionals call this the "gut-brain-axis" (GBA). A better understanding of the GBA could lead to treatments and cures for neurological mood disorders like depression and anxiety, as well as for a range of chronic auto-immune inflammatory diseases like irritable bowel syndrome (IBS) and rheumatoid arthritis (RA).

Scientists suspect the chemical neurotransmitter serotonin is the biomarker for a range of GBA disorders. Serotonin spurs the nervous system into action via the vagus nerve, the physical connector between the brain and the colon. Generated deep within the lining of the gut, serotonin ultimately influences everything from mood and emotions to sleep, digestion and the secretion of hormones. Its production is in some way affected by the bacterial "microbiome" present in this environment. Researchers hope that creating tools to analyze serotonin's production and dysfunction in the gut microbiome will help unlock the mysteries of GBA-related disorders.

Three new published papers detail the progress in detecting serotonin, assessing its neurological effects, and sensing minute changes to the gut epithelium.

 Pradeep Ramiah Rajasekaran et al, 3D-Printed electrochemical sensor-integrated transwell systems, Microsystems & Nanoengineering (2020). DOI: 10.1038/s41378-020-00208-z

Ashley A. Chapin et al. Electrochemical measurement of serotonin by Au-CNT electrodes fabricated on microporous cell culture membranes, Microsystems & Nanoengineering (2020). DOI: 10.1038/s41378-020-00184-4 A.

A. Chapin, J. Han, T. -W. Ho, J. Herberholz and R. Ghodssi, "A Hybrid Biomonitoring System for Gut-Neuron Communication," in Journal of Microelectromechanical Systems, vol. 29, no. 5, pp. 727-733, Oct. 2020, DOI: 10.1109/JMEMS.2020.3000392.

Pradeep Ramiah Rajasekaran et al. 3D-Printed electrochemical sensor-integrated transwell systems, Microsystems & Nanoengineering (2020). DOI: 10.1038/s41378-020-00208-z

https://phys.org/news/2020-10-symptoms-heador-gut.html?utm_source=n...

Scientists discovered hidden colours created by a new mechanism

Scientists have stumbled across an unusual way to observe colour that had previously gone unnoticed.

To create the effect, researchers attached a very thin film of one material to another, larger sample. The electric field (an invisible force created by the attraction and repulsion of electrical charges) is very strong where the two materials are connected.

When combined with 'optical interference' (the interaction of different waves of light), a scattering process occurs from the surface of the material, creating bright colors when viewed under different lighting conditions.

Most materials in the world around us appear a certain color because they only absorb part of solar spectrum. For example, leaves on a tree look green to us because they absorb red and blue light.

However, some objects, animals and materials create color a different way, because of the properties they contain. These are known as structural colors.

Structural colors are usually created by diffraction, which happens when rays of light interfere with each other as they reflect off surfaces. Rainbows and colorful oil slicks on top of water are examples of structural color, and the effect is also responsible for the amazing vivid hues of peacock feathers and butterfly wings.

While those phenomena are well established, an unexpected new mechanism for creating similar effects has been uncovered.

The effect is an example of structural color forming because of frequency-selective scattering of light, in which the strength of the electric field and the type of material used is a key factor.

Scientists using  a light microscope to observe gold nanoparticles  unexpectedly noticed that the entire sample was creating a vivid colour visible to the naked eye from all directions.

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To understand it properly, they created thin films which could scatter light and at the same time create diffraction or interference. The system was made using silicon nitride coatings on larger metallic aluminum samples.

Different colors were visible by changing the lighting conditions. Under normal light, the samples looked like a mirror, reflecting back almost all visible light. But turning the overhead lights off and using only one beam of light to illuminate the sample produces vivid, iridescent colors.

Explaining how to easily observe this phenomenon, Eser said: "If you use a flashlight, while in a dark room, to illuminate the sample, the reflected light beam travels away from you to the other side of the room.

"The reflected light never reaches your eyes, only the scattered light can reach your eyes. Whereas when the room light is on, light comes from everywhere on to the sample and therefore you will always see reflected light traveling into your eyes.

"The effect is a previously completely unrecognized curiosity that results in us seeing color. It's fundamentally something different."

 Eser Metin Akinoglu et al. Concealed Structural Colors Uncovered by Light Scattering, Advanced Optical Materials (2020). DOI: 10.1002/adom.202001307

https://phys.org/news/2020-10-dont-hidden-colours-coincidence.html?...

The Lancet: Herd immunity approaches to COVID-19 control are a 'dangerous fallacy', say authors of open letter

A group of 80 researchers warn that a so-called herd immunity approach to managing COVID-19 by allowing immunity to develop in low-risk populations while protecting the most vulnerable is "a dangerous fallacy unsupported by the scientific evidence".

The open letter, referred to by its authors as the John Snow Memorandum, is published today by The Lancet. It is signed by 80 international researchers (as of publication) with expertise spanning public health, epidemiology, medicine, paediatrics, sociology, virology, infectious disease, health systems, psychology, psychiatry, health policy, and mathematical modelling [1]. The letter will also be launched during the 16th World Congress on Public Health programme 2020.

https://www.eurekalert.org/pub_releases/2020-10/tl-pss101420.php

A hydrogel that could help repair damaged nerves
Injuries to peripheral nerves –– tissues that transmit bioelectrical signals from the brain to the rest of the body –– often result in chronic pain, neurologic disorders, paralysis or disability. Now, researchers have developed a stretchable conductive hydrogel that could someday be used to repair these types of nerves when there’s damage.

Injuries in which a peripheral nerve has been completely severed, such as a deep cut from an accident, are difficult to treat. A common strategy, called autologous nerve transplantation, involves removing a section of peripheral nerve from elsewhere in the body and sewing it onto the ends of the severed one. However, the surgery does not always restore function, and multiple follow-up surgeries are sometimes needed. Artificial nerve grafts, in combination with supporting cells, have also been used, but it often takes a long time for nerves to fully recover.

Now researchers prepared a tough but stretchable conductive hydrogel containing polyaniline and polyacrylamide. The crosslinked polymer had a 3D microporous network that, once implanted, allowed nerve cells to enter and adhere, helping restore lost tissue. They showed that the material could conduct bioelectrical signals through a damaged sciatic nerve removed from a toad. Then, they implanted the hydrogel into rats with sciatic nerve injuries. Two weeks later, the rats’ nerves recovered their bioelectrical properties, and their walking improved compared with untreated rats. Because the electricity-conducting properties of the material improve with irradiation by near-infrared light, which can penetrate tissues, it could be possible to further enhance nerve conduction and recovery in this way, the researchers say.

https://www.acs.org/content/acs/en/pressroom/newsreleases/2020/octo...

https://researchnews.cc/news/3043/A-hydrogel-that-could-help-repair...

Reviving cells after a heart attack

Researchers unravel the healing mechanisms of extracellular vesicles and demonstrate their healing power on a heart-on-a-chip

How the brain quenches the thirst in different ways ....

After eating a bag of salty potato chips, you probably feel thirsty. And after a long period of exercise, you also probably feel thirsty. However, these two types of thirst are not the same.

In the first example, you would likely reach for water. This is because after eating chips, the concentration of salts and minerals in your blood becomes elevated, which induces a state called osmotic thirst. On the other hand, after exercising, you are likely to reach for Gatorade or some other fluid that can both rehydrate you and replenish electrolytes, minerals that are important for the body functions. This thirst, called hypovolemic thirst, occurs when the volume of your blood is reduced due to fluid loss from sweating.

Now researchers have discovered unique populations of neurons in the mouse brain that separately drive osmotic thirst and hypovolemic thirst. The research exploited a high-throughput and robust technique for mapping neurons that are activated by a specific behaviour or stimulus.

Two brain regions are known to be important in drinking behaviors in mammals, the subfornical organ (SFO) and the organum vasculosum laminae terminalis (OVLT). The Oka laboratory previously demonstrated that each of these regions contains two general categories of neurons: some that induce drinking behavior and others that inhibit it.

The mice were then genetically modified so that the team could activate the osmolality- and hypovolemia-sensitive neurons with pulses of light, through a technique called optogenetics. The researchers showed that the activation of the osmolality-sensitive neurons drove the mice to drink pure water and to avoid salty water. In contrast, when hypovolemia-sensitive neurons were activated, the mice showed an appetite for mineral-rich liquids.
The results show that thirst is a multimodal sensation caused by distinct stimuli. This is an exciting finding because it illustrates how our brain senses internal states using a very similar strategy as peripheral sensory systems such as taste and olfaction

https://www.caltech.edu/about/news/brain-quenches-thirst-different-...

https://researchnews.cc/news/3054/The-brain-quenches-thirst-in-diff...

** Need to be in two places at once? It may be possible

https://researchnews.cc/news/3052/Need-to-be-in-two-places-at-once-...

Glowing blue helps shield this tardigrade from harmful ultraviolet light

Fluorescence may allow water bears to survive in especially sunny regions

When blasted with ultraviolet radiation, a newly discovered species of tardigrade protects itself by glowing blue.

Tardigrades, microscopic animals also known as water bears or moss piglets, are nature’s ultimate survivor. They’re game for temperatures below –270° Celsius and up to 150° C and can withstand the vacuum of space, and some are especially resistant to harmful UV radiation .   One tardigrade ( belonging to the genus Paramacrobiotus)shields itself from that UV radiation with glowing pigments, a new study suggests. It’s the first experimental evidence of fluorescent molecules protecting animals from radiation

H.R. Suma, S. Prakash and S.M. Eswarappa. Naturally occurring fluorescence protects the eutardigrade Paramacrobiotus sp. from ultraviolet radiation. Biology Letters. Published online October 14, 2020. doi: 10.1098/rsbl.2020.0391.

https://www.sciencenews.org/article/tardigrade-water-bear-glow-blue...

**Groundbreaking discovery finally proves rain really can move mountains

A pioneering technique that captures precisely how mountains bend to the will of raindrops has helped to solve a long-standing scientific enigma.

The dramatic effect rainfall has on the evolution of mountainous landscapes is widely debated among geologists, but new research led by the University of Bristol and published today in Science Advances, clearly calculates its impact, furthering our understanding of how peaks and valleys have developed over millions of years. Its findings, which focused on the mightiest of mountain ranges—the Himalaya—also pave the way for forecasting the possible impact of climate change on landscapes and, in turn, human life.

It may seem intuitive that more rain can shape mountains by making rivers cut down into rocks faster. But scientists have also thought rain can erode a landscape quickly enough to essentially 'suck' the rocks out of the Earth, effectively pulling mountains up very quickly. Both these theories have been debated for decades because the measurements required to prove them are so painstakingly complicated. That's what makes this discovery such an exciting breakthrough, as it strongly supports the notion that atmospheric and solid earth processes are intimately connected.

When a cosmic particle from outer space reaches Earth, it is likely to hit sand grains on hillslopes as they are transported toward rivers. When this happens, some atoms within each grain of sand can transform into a rare element. By counting how many atoms of this element are present in a bag of sand, we can calculate how long the sand has been there, and therefore how quickly the landscape has been eroding. Once we have erosion rates from all over the mountain range, we can compare them with variations in river steepness and rainfall. However, such a comparison is hugely problematic because each data point is very difficult to produce and the statistical interpretation of all the data together is complicated.

The new model  allows us for the first time to quantify how rainfall affects erosion rates in rugged terrain. Their findings  show how critical it is to account for rainfall when assessing patterns of tectonic activity using topography, and also provide an essential step forward in addressing how much the slip rate on tectonic faults may be controlled by climate-driven erosion at the surface. The study findings also carry important implications for land use management, infrastructure maintenance, and hazards in the Himalaya.

Climate controls on erosion in tectonically active landscapes, Science Advances (2020). advances.sciencemag.org/lookup … .1126/sciadv.aaz3166

https://phys.org/news/2020-10-groundbreaking-discovery-mountains.ht...

Calcium bursts kill drug-resistant tumour cells

Multidrug resistance (MDR)—a process in which tumors become resistant to multiple medicines—is the main cause of failure of cancer chemotherapy. Tumor cells often acquire MDR by boosting their production of proteins that pump drugs out of the cell, rendering the chemotherapies ineffective. Now, researchers reporting in ACS' Nano Letters have developed nanoparticles that release bursts of calcium inside tumor cells, inhibiting drug pumps and reversing MDR.

A pump protein called P-glycoprotein (P-gp) often plays a key role in MDR. P-gp is in the cell membrane, where it uses energy in the form of adenosine triphosphate (ATP) to pump drugs out of tumor cells. Scientists have tried to block P-gp in various ways, such as with small-molecule inhibitors or by depleting ATP. However, the strategies used so far can cause side effects, or they are unstable in the body. Some of the treatments can be difficult to prepare. Kaixiang Zhang, Zhenzhong Zhang, Jinjin Shi and colleagues wanted to block P-gp using a different approach. Previous research suggested that overloading tumor cells with calcium ions could both decrease production of P-gp and reduce ATP levels. But the team needed to find a way to deliver bursts of calcium, along with a chemotherapy drug, inside cancer cells.

The researchers made a "calcium ion nanogenerator" (TCaNG) by loading calcium phosphate nanoparticles with the chemotherapy drug doxorubicin and then coating them with molecules that would allow TCaNG to target and enter cancer cells. Once inside cells, TCaNGs entered an acidic compartment, where the TCaNGs disintegrated, releasing both doxorubicin and bursts of calcium ions. When the team tested TCaNG on cancer cells in a petri dish in the lab, both ATP and P-gp production decreased, which allowed doxorubicin to kill the previously resistant tumor cells. When tested in tumor-bearing mice, TCaNG-treated mice showed significantly smaller tumors after 21 days of treatment than control mice, with no apparent side effects.

Junjie Liu et al, Nanoenabled Intracellular Calcium Bursting for Safe and Efficient Reversal of Drug Resistance in Tumor Cells, Nano Letters (2020). DOI: 10.1021/acs.nanolett.0c03042

https://phys.org/news/2020-10-calcium-drug-resistant-tumor-cells.ht...

Ultrafast camera films 3-D movies at 100 billion frames per second

In his quest to bring ever-faster cameras to the world researchers  have developed technology that can reach blistering speeds of 70 trillion frames per second, fast enough to see light travel. Just like the camera in your cell phone, though, it can only produce flat images.

Now, they have gone a step further to create a camera that not only records video at incredibly fast speeds but does so in three dimensions.

The new camera, which uses the same underlying technology as other compressed ultrafast photography (CUP) cameras, is capable of taking up to 100 billion frames per second. That is fast enough to take 10 billion pictures, more images than the entire human population of the world, in the time it takes you to blink your eye.

Single-shot stereo-polarimetric compressed ultrafast photography for light-speed observation of high-dimensional optical transients with picosecond resolution, Nature Communications (2020).

https://www.nature.com/articles/s41467-020-19065-5

https://phys.org/news/2020-10-ultrafast-camera-d-movies-billion.htm...

Zeptoseconds: New world record in short time measurement

In 1999,  chemist Ahmed Zewail received the Nobel Prize for measuring the speed at which molecules change their shape. He founded femtochemistry using ultrashort laser flashes: the formation and breakup of chemical bonds occurs in the realm of femtoseconds.

Now, atomic physicists have for the first time studied a process that is shorter than femtoseconds by magnitudes. They measured how long it takes for a photon to cross a hydrogen molecule: about 247 zeptoseconds for the average bond length of the molecule. This is the shortest timespan that has been successfully measured to date.

The scientists carried out the time measurement on a hydrogen molecule (H₂) which they irradiated with X-rays from the X-ray laser source PETRA III at the Hamburg accelerator facility DESY. The researchers set the energy of the X-rays so that one photon was sufficient to eject both electrons out of the hydrogen molecule.

Zeptosecond Birth Time Delay in Molecular Photoionization, Science (2020). DOI: 10.1126/science.abb9318

https://phys.org/news/2020-10-zeptoseconds-world-short.html?utm_sou...

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Electrons behave like particles and waves simultaneously, and therefore the ejection of the first electron resulted in electron waves launched first in the one, and then in the second hydrogen molecule atom in quick succession, with the waves merging.

The photon behaved here much like a flat pebble that is skimmed twice across the water: when a wave trough meets a wave crest, the waves of the first and second water contact cancel each other, resulting in what is called an interference pattern.

The scientists measured the interference pattern of the first ejected electron using the COLTRIMS reaction microscope, an apparatus that Dörner helped develop and which makes ultrafast reaction processes in atoms and molecules visible. Simultaneously with the interference pattern, the COLTRIMS reactions microscope also allowed the determination of the orientation of the hydrogen molecule. The researchers here took advantage of the fact that the second electron also left the hydrogen molecule, so that the remaining hydrogen nuclei flew apart and were detected.

Slowing light in an optical cavity with mechanical resonators and mirrors

Theoretical physicists  have shown that a position-dependent mass optomechanical system involving a cavity between two mirrors, one attached to a resonator, can enhance induced transparency and reduce the speed of light.

We are all taught at high school that the speed of light through a vacuum is about 300000km/s, which means that a beam from Earth takes about 2.5 seconds to reach the Moon. It naturally moves more slowly through transparent objects, however, and scientists have found ways to slow it dramatically. Optomechanics, or the interaction of electromagnetic radiation with mechanical systems, is a relatively new and effective way of approaching this. Theoretical physicists have now demonstrated how light is slowed in a position-based mass optomechanical system. This work has been published in EPJ D.

They describe cavity optomechanics, which involves optical modes set up in a cavity between mirrors. The cavity mode, which is driven by a strong field and probed by a weak field, provides a 'playground' for investigating phenomena including slow light and optomechanically induced transparency (OMIT). The latter is a quantum effect in which the optical response of atoms and molecules is controlled by an electromagnetic field. In this work, the physicists studied a cavity system comprising a fixed mirror and a movable one. The moving mirror oscillates along the axis of the cavity with a single harmonic frequency. By considering the total mass of the resonator as dependent on its position, and calculating the effective Hamiltonian of the whole system (which describes its total energy), the physicists showed how the system can enhance OMIT and slow light. As the mass is position-dependent, the system is non-linear and the nature and magnitude of the quantum effects observed depend strongly on the value of a non-linear parameter, alpha.

 Kamran Ullah et al. Enhanced optomechanically induced transparency and slow/fast light in a position-dependent mass optomechanics, The European Physical Journal D (2020). DOI: 10.1140/epjd/e2020-10286-1

https://phys.org/news/2020-10-optical-cavity-mechanical-resonators-...

New feature found in energy spectrum of universe's most powerful particles

Particles smaller than an atom hurtle through the universe nearly at the speed of light, blasted into space from something, somewhere, in the cosmos.

A scientific collaboration of the Pierre Auger Observatory, including researchers from the University of Delaware, has measured the most powerful of these particles—ultra-high-energy cosmic rays—with unprecedented precision. In doing so, they have found a "kink" in the energy spectrum that is shining more light on the possible origins of these subatomic space travelers.

The team's findings are based on the analysis of 215,030 cosmic ray events with energies above 2.5 quintillion electron volts (eV), recorded over the past decade by the Pierre Auger Observatory in Argentina. It is the largest observatory in the world for studying cosmic rays.

The new spectral feature, a kink in the cosmic-ray energy spectrum at about 13 quintillion electron volts, represents more than points plotted on a graph. It brings humanity a step closer to solving the mysteries of the most energetic particles in nature. Through this latest analysis, we can further corroborate our earlier indications that ultra-high-energy cosmic rays are not just protons of hydrogen, but also a mix of nuclei from heavier elements, and this composition changes with energy.

A. Aab et al. Features of the Energy Spectrum of Cosmic Rays above 2.5×1018 eV Using the Pierre Auger Observatory, Physical Review Letters (2020). DOI: 10.1103/PhysRevLett.125.121106

A. Aab et al. Measurement of the cosmic-ray energy spectrum above 2.5×1018 eV using the Pierre Auger Observatory, Physical Review D (2020). DOI: 10.1103/PhysRevD.102.062005

https://phys.org/news/2020-10-feature-energy-spectrum-universe-powe...

Research shows Krebs cycle possible without metals or enzyme catalysts, offers new clues to life's origins

This is a new study  that may fundamentally alter humanity's understanding of the origin of life.

The study describes how organic chemical reactions could have started inorganically for the first time billions of years ago, according to a research discovery . One of those elemental metabolic processes is called the Krebs cycle, also known as the citric acid cycle. 

This study represents the first time the Krebs cycle has been replicated synthetically.

They started with some small molecules and figured out how to make the Krebs cycle run, and it runs without enzymes in water at mild pH. These discoveries have potential applications in understanding how life started on Earth, and where else in the universe it may emerge.

What's in living cells?" Stubbs asked. "What are some of those core components that must have existed very early on? The answer is the citric acid cycle. This is one of the processes that turns food into energy. It doesn't matter whether you're human, plant, lizard, whatever … So it's likely this cycle existed near the origins of life, and that's what this paper is all about—how could simpler versions of this cycle, which now requires complex biological machinery to operate, have operated from the beginning without any of that evolved hardware?

This discovery also led to novel ways to chemically synthesize biological diagnostic agents used in an emerging cancer and bacterial infection detection diagnostic method called metabolic flux analysis.

 R. Trent Stubbs et al. A plausible metal-free ancestral analogue of the Krebs cycle composed entirely of α-ketoacids, Nature Chemistry (2020). DOI: 10.1038/s41557-020-00560-7

https://phys.org/news/2020-10-krebs-metals-enzyme-catalysts-clues.h...