Virus that causes COVID-19 is widespread in wildlife

SARS-CoV-2, the virus responsible for COVID-19, is widespread among wildlife species, according to  new research published July 29, 2024 in Nature Communications. The virus was detected in six common backyard species, and antibodies indicating prior exposure to the virus were found in five species, with rates of exposure ranging from 40 to 60% depending on the species.

Genetic tracking in wild animals confirmed both the presence of SARS-CoV-2 and the existence of unique viral mutations with lineages closely matching variants circulating in humans at the time, further supporting human-to-animal transmission, the study found.

The highest exposure to SARS CoV-2 was found in animals near hiking trails and high-traffic public areas, suggesting the virus passed from humans to wildlife, according to scientists.

The findings highlight the identification of novel mutations in SARS-CoV-2 in wildlife and the need for broad surveillance, researchers say. These mutations could be more harmful and transmissible, creating challenges for vaccine development.

The scientists stressed, however, that they found no evidence of the virus being transmitted from animals to humans, and people should not fear typical interactions with wildlife.

Widespread exposure to SARS-CoV-2 in wildlife communities, Nature Communications (2024). DOI: 10.1038/s41467-024-49891-w

Losing a loved one may speed up aging, study finds

Losing someone close, like a family member, can make you age faster, says a new study.

The study found that people who lost a parent, partner, sibling, or child, showed signs of older biological age compared to those who hadn't experienced such losses. The research was published in JAMA Network Open.

Biological aging is the gradual decline in how well your cells, tissues, and organs function, leading to a higher risk of chronic diseases. Scientists measure this type of aging using DNA markers known as epigenetic clocks.

The study suggests that the impact of loss on aging can be seen long before middle age and may contribute to health differences among racial and ethnic groups.

The study also confirmed that people who experienced two or more losses had older biological ages according to several epigenetic clocks. Experiencing two or more losses in adulthood was more strongly linked to biological aging than one loss and significantly more so than no losses.

Losing a parent or sibling early in life can be very traumatic, often leading to mental health issues, cognitive problems, higher risks of heart disease, and a greater chance of dying earlier. Losing a close family member at any age poses health risks, and repeated losses can increase the risks of heart disease, mortality, and dementia; and impacts may persist or become apparent long after the event.

Familial Loss of a Loved One and Biological Aging, JAMA Network Open (2024).

 https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2821615

Origins of matter in the early universe

The early universe was 250,000 times hotter than the core of our sun. That's far too hot to form the protons and neutrons that make up everyday matter. Scientists recreate the conditions of the early universe in particle accelerators by smashing atoms together at nearly the speed of light.

Measuring the resulting shower of particles allows scientists to understand how matter formed. The particles that scientists measure can form in various ways: from the original soup of quarks and gluons or from later reactions.

These later reactions began 0.000001 seconds after the Big Bang, when the composite particles made of quarks began to interact with each other.

A new calculation determined that as much as 70% of some measured particles are from these later reactions, not from reactions similar to those of the early universe. The research is published in the journal Physics Letters B.

This finding improves scientific understanding of the origins of matter. It helps identify how much of the matter around us formed in the first few fractions of a second after the Big Bang, versus how much matter formed from later reactions as the universe expanded.

This result implies large amounts of the matter around us formed later than expected. To understand the results of collider experiments, scientists must discount the particles formed in the later reactions.

Only those formed in the subatomic soup reveal the early conditions of the universe. This new calculation shows that the number of measured particles formed in reactions is much higher than expected.

Joseph Dominicus Lap et al, Hadronic J/ψ regeneration in Pb+Pb collisions, Physics Letters B (2023). DOI: 10.1016/j.physletb.2023.138246

Don't close your borders: Countries need to cooperate on migration as climate crisis worsens

Humanity must rethink migration as the climate crisis drives rapid global changes, researchers say.

With significant migration expected—and border policies hardening—the researchers say the "time is ripe to highlight the benefits of collaboration between nations and regions."

By promoting the benefits of migration, especially in an era of aging populations, global leaders could ensure a better future for people and societies.

The paper, titled "Anticipating the global redistribution of people and property" and published in the journal One Earth, comes from an international team of climate and social scientists. 

Millions of people are projected to be displaced by sea-level rise in the next decades, and 2 billion could be exposed to extreme heat beyond their experience by the end of the century.

Ignoring or downplaying the inevitable global redistribution of people would lead to geo-political instability, and a polarized and fractured world.

"Instead, the international community must come together to rethink mobility and cultural integration to ensure a benign transition to this new world."

So far, most migration with significant climate dimensions has happened within countries, with people leaving areas affected by long-term decline in agricultural productivity or escaping conditions such as coastal erosion or extreme events.

While some large nations have different climate zones that can accommodate this, small countries do not.

The paper also warns that a "skewed distribution of wealth and associated power" makes it difficult for people to move, both within and between states.

Global warming exacerbates existing inequalities, making habitability a major political challenge of this century.

"Concrete cooperation is now needed to match migrant flows with demand for labor, to the benefit of the Global South and the developed world alike.

The paper says major reform of the food system, supported by movement of workers, could increase production while conserving nature.

Migration can therefore be a win–win for people and the climate, but leaders must make a positive case for economic benefits and effective integration. "Playing up the social costs of migration appeals to national identity motivations, but fails to overcome problems from aging populations.

Instead, leaders should focus on the economic and social benefits of new populations and effective integration, which benefits newcomers and original inhabitants alike.

"Every corner of the world needs to anticipate the coming climate crisis and promote the safe and beneficial movement of people as conditions change.

It is the question of survival and you can't stop people from moving when their very existence is under threat. 

Marten Scheffer et al, Anticipating the global redistribution of people and property, One Earth (2024). DOI: 10.1016/j.oneear.2024.06.008

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Why the solar corona is so much hotter than sun's surface

In a new study published in The Astrophysical Journal,  researchers explore critical aspects of a phenomenon called kinetic Alfvén waves (KAWs) to provide fresh insights into an age-old heliophysics mystery.

They examined the potentially pivotal role of KAWs in heating the solar corona, moving science one step closer to solving the puzzle of why the corona is many times hotter than the surface of the sun itself.

For decades, Alfvén waves have been proven to be the best candidates for transporting energy from one place to another. 

This paper utilizes a novel approach to model energetic particles in space plasmas, as observed by satellites like Viking and Freja, to answer how the electromagnetic energy of the waves, interacting with particles, transforms into heat during the damping process as the waves move through space.

The corona, or solar atmosphere, is an enigmatic region surrounding our home star that extends far beyond the visible disk of the sun, stretching some 8 million kilometers above the sun's surface. Yet, the corona is also characterized by extraordinarily high temperatures, a mystery that has captivated astrophysicists for nearly seventy years.

This new work  offers important insights into the critical problem of how energy in a magnetic field is transformed to heat a plasma comprising charged particles like protons and electrons.

Kinetic Alfvén waves—abundant throughout the plasma universe—are oscillations of the ions and magnetic field as they move through the solar plasma. The waves are formed by motions in the photosphere, the sun's outer shell that radiates visible light.

Part 1

The researchers focused on the heating and energy exchange facilitated by KAWs. The reason for the great interest in these waves lies in their ability to transport energy. Observational data from numerous spacecraft and theoretical investigations have consistently demonstrated that KAWs dissipate and contribute to solar coronal heating during their propagation in space.
Because of these unique properties, the waves provide a critical mechanism for transferring energy, important to understanding the energy exchange between electromagnetic fields and plasma particles.
KAWs operate on small kinetic scales and are capable of supporting parallel electric and magnetic field fluctuations, enabling an energy transfer between the wave field and plasma particles through a phenomenon called Landau interactions.
The present work utilized and explores the Landau damping mechanism, which occurs when particles moving parallel to a wave have velocities comparable to the wave's phase velocity.
Landau damping is an exponential decrease as a function of time of particular waves in plasma. "When particles interact with the wave, they receive/lose energy—a term called 'resonant condition.
Part 2

This can result in the wave either delivering its energy to the particles or gaining energy from them, causing the particles to either damp or grow.
This new research work finds that KAWs rapidly dissipate, completely transferring their energy to plasma particles in the form of heating. This energy transfer accelerates the particles over longer spatial distances, significantly impacting the dynamics of the plasma.
The analytical insights gleaned from this study will find practical application in understanding phenomena within the solar atmosphere, particularly shedding light on the significant role played by non-thermal particles in the heating processes.

 Syed Ayaz et al, Solar Coronal Heating by Kinetic Alfvén Waves, The Astrophysical Journal (2024). DOI: 10.3847/1538-4357/ad5bdc

Part 3

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 Chimpanzees  are capable of speech

Axel G. Ekström et al, Chimpanzee utterances refute purported missing links for novel vocalizations and syllabic speech, Scientific Reports (2024). DOI: 10.1038/s41598-024-67005-w

How to cope with increasingly hot summers

• Use an electric fan, a particularly effective method in humid climates like Quebec's. But remember: using a fan can be counter-productive in very low humidity or above 40° C temperatures.
• Sponge yourself regularly with cool water.
• Soak your feet in cold water.
• Stay socially connected (especially important for seniors and the socially isolated).
• Set your air conditioner to 25° C instead of 20° C to build up your tolerance to higher temperatures (and reduce energy consumption).

Confirmed link between maternal asthma and child allergies

For the first time, researchers  have confirmed maternal asthma increases risks of child allergies.

In a systematic review of more than 20,000 sources, the researchers discovered children whose mothers have asthma are 76% more likely to have the condition themselves.

The review is the first time anyone has brought together the data on how severity and control of asthma during pregnancy affects allergy and asthma outcomes in children. It also found that better asthma control during pregnancy reduces the risk in children.

They found found maternal asthma is associated with an increased risk of wheeze (59%), food allergy (32%), eczema (17%) and hay fever (18%),

The findings are published in the BJOG: An International Journal of Obstetrics & Gynaecology.

Associations between maternal asthma and risks of progeny asthma were similar when the exposure was maternal asthma during the index pregnancy or as a history of asthma, consistent with the chronic nature of asthma.

Uncontrolled and more severe maternal asthma during the index pregnancy were also associated with increased risk of progeny asthma.

Andrea J. Roff et al, Maternal asthma during pregnancy and risks of allergy and asthma in progeny: A systematic review and meta‐analysis, BJOG: An International Journal of Obstetrics & Gynaecology (2024). DOI: 10.1111/1471-0528.17900

Blocking One Protein Extends Lifespan in Mice by Up to 25%

A protein called interleukin 11 (IL-11) appears to play a crucial role in aging, with scientists extending the lifespans of mice by up to 25 percent simply by blocking the molecule's effects.

Researchers  used genetic engineering to turn off IL-11 production in a sample of mice, while injecting other mice with an anti-IL-11 drug.

Deaths from cancer and tumorous growths were reduced in both groups, while health conditions related to the effects of aging – including chronic inflammation and poor metabolism – were also less common.

The treated mice had fewer cancers, and were free from the usual signs of aging and frailty, but researchers also saw reduced muscle wasting and improvement in muscle strength. In other words, the old mice receiving anti-IL-11 were healthier.

Interleukin 11 has been of interest to scientists studying the aging process for several years. We know that it builds up in the body as we get older, and it's linked to increasing levels of inflammation, scar tissue, and overall frailty.

https://www.nature.com/articles/s41586-024-07701-9

First, keep your head back with your ears submerged to keep your airways open. Resist the urge to panic, try to relax and breathe normally. Gently move your hands paddling them as this will aid in keeping afloat. Don't fret if your legs sink, everyone's buoyancy is different. Finally, spread your arms and legs as this really helps maintain your stability in the water.

More women are ending pregnancies on their own, a new study suggests. Some resort to unsafe methods

A growing number of women said they've tried to end their pregnancies on their own by doing things like taking herbs, drinking alcohol or even hitting themselves in the belly, a new study suggests.

Researchers surveyed reproductive-age women in the U.S. before and after the Supreme Court overturned Roe v. Wade in June 2022. The proportion who reported trying to end pregnancies by themselves rose from 2.4% to 3.3%.

A lot of people are taking things into their own hands.

Study authors acknowledged that the increase is small. But the data suggests that it could number in the hundreds of thousands of women.

Researchers surveyed about 7,000 women six months before the Supreme Court decision, and then another group of 7,100 a year after the decision. They asked whether participants had ever taken or done something on their own to end a pregnancy. Those who said yes were asked follow-up questions about their experiences.

The data show that making abortion more difficult to access is not going to mean that people want or need an abortion less frequently.

Women gave various reasons for handling their own abortions, such as wanting an extra measure of privacy, being concerned about the cost of clinic procedures and preferring to try to end their pregnancies by themselves first.

They reported using a range of methods. Some took medications—including emergency contraception and the abortion pills misoprostol and mifepristone obtained outside the medical system and without a prescription. Others drank alcohol or used drugs. Some resorted to potentially harmful physical methods such as hitting themselves in the abdomen, lifting heavy things or inserting objects into their bodies.

Some respondents said they suffered complications like bleeding and pain and had to seek medical care afterward. Some said they later had an abortion at a clinic. Some said their pregnancies ended after their attempts or from a later miscarriage, while others said they wound up continuing their pregnancies when the method didn't work.

Respondents may be under-reporting their abortions because researchers are asking them about "a sensitive and potentially criminalized behaviour."

 The study's findings confirm the statement : If you make it hard to get (an abortion) in a formal setting, people will just do it informally.

Lauren Ralph et al, Self-Managed Abortion Attempts Before vs After Changes in Federal Abortion Protections in the US, JAMA Network Open (2024). DOI: 10.1001/jamanetworkopen.2024.24310

Study finds working from home stifles innovation

Remote and hybrid working may be great for employees' work-life balance, but it may be stifling innovation, according to new research.

The study found that staff who worked in a hybrid model were less likely to come up with innovative ideas than colleagues who always worked in the office. And staff working from home tended to produce lower quality innovative ideas than those who always worked in the office. 

Innovation in the workplace can occur through random, spontaneous 'watercooler' conversations between employees. However, these 'productive accidents' are less likely to occur when employees work from home. This  research work has found that innovation is suffering as a result.

Michael Gibbs et al, Employee innovation during office work, work from home and hybrid work, Scientific Reports (2024). DOI: 10.1038/s41598-024-67122-6

Scientists 'Mind Controlled' Mice Remotely 

At the mere flick of a magnetic field, mice engineered with nanoparticle-activated 'switches' inside their brains were driven to feed, socialize, and act like clucky new mothers in an experiment designed to test an innovative research tool.

While 'mind control' animal experiments are far from new, they have generally relied on cumbersome electrodes tethering the subject to an external system, which not only requires invasive surgery but also sets limits on how freely the test subject can move about.
In what is claimed to be a breakthrough in neurology, researchershave developed a method for targeting pathways in the brain using a combination of genetics, nanoparticles, and magnetic fields.

They call the technology Nano-MIND, an acronym for Magnetogenetic Interface for NeuroDynamics. And while mind-control is a coarse but relatively accurate way of describing it, the system in its current form is intended to provide researchers with a means of remotely activating neural circuits for a range of research applications.

This is the world's first technology to freely control specific brain regions using magnetic fields. Magnetic stimulation is an emerging field of research in neurology, where washing the brain with pulses of electromagnetism broadly massages whole regions into subtly changing their behavior. 

To target specific circuits, the researchers took a leaf out of another field of research called optogenetics, which genetically engineers mechanisms into cells that can be readily activated by a light source. In this case, the team integrated ion channels into targeted populations of brain cells in mice. Instead of delivering light through a localized fiber, as in optogenetics, the ion channels could be switched on magnetically with a twist of a tiny actuator. All that's required is a surrounding field that's strong enough to pull at the nanoparticle.

https://www.nature.com/articles/s41565-024-01694-2

43% of cocoa products exceed lead safety levels, study finds

When our friends, relatives and colleagues come from the US they bring lots of chocolates  and we consume them very fondly. But this new information is alarming ....

A new study  found a disquieting percentage of cocoa products in the U.S. contain heavy metals that exceed guidelines, including higher concentrations in organic products.

The study, "A Multi-Year Heavy Metal Analysis of 72 Dark Chocolate and Cocoa Pr... was published on July 31, 2024 in Frontiers in Nutrition.

Researchers analyzed 72 consumer cocoa products, including dark chocolate, every other year over an eight year period for contamination with lead, cadmium, and arsenic, heavy metals that pose a significant health hazard in sufficient amounts.

We all love chocolate but it's important to indulge with moderation, as with other foods that contain heavy metals, including large fish like tuna and unwashed brown rice. While it's not practical to avoid heavy metals in your food entirely, you must be cautious of what you are eating and how much.

The researchers used a threshold of maximum allowable dose levels to assess the extent of heavy metal contamination in an array of chocolate products, found on grocery store shelves.

Key findings:

43% of the products studied exceeded the maximum allowable dose level for lead. 35% of the products studied exceeded the maximum allowable dose level for cadmium.

None of the products exceeded the maximum allowable dose level for arsenic. Surprisingly, organic labeled products showed higher levels of both lead and cadmium compared to non-organic products.

For the average consumer, consuming a single serving of these cocoa products may not pose significant health risks based on the median concentrations found. However, consuming multiple servings or combining consumption with other sources of heavy metals could lead to exposures that exceed the maximum allowable dose level.

Foods with high lead levels may include animal foods that can bioaccumulate heavy metals (shellfish, organ meats) and foods or herbal supplements grown in contaminated soil and/or imported from countries with less regulation.  For cadmium, the main concerns are the same with the addition of some seaweeds.

Consumers should be aware of potential cumulative exposure risks, particularly with cocoa products labeled organic, as they may have higher heavy metal concentrations. A serving size of dark chocolate is typically one ounce and has been generally suggested to have health benefits including cardiovascular health, cognitive performance, and chronic inflammation.

 Study Finds Many Cocoa Products Contaminated by Heavy Metals, Frontiers in Nutrition (2024). DOI: 10.3389/fnut.2024.1366231 , www.frontiersin.org/journals/n … 024.1366231/abstract

Incidence of heart attacks and strokes was lower after COVID-19 vaccination, finds study of 46 million adults

A new study, published recently in Nature Communications and involving nearly the whole adult population of England, has found that the incidence of heart attacks and strokes was lower after COVID-19 vaccination than before or without vaccination.

Researchers analyzed de-identified health records from 46 million adults in England between 8 December 2020 and 23 January 2022. Data scientists compared the incidence of cardiovascular diseases after vaccination with the incidence before or without vaccination, during the first two years of the vaccination program.

The study showed that the incidence of arterial thromboses, such as heart attacks and strokes, was up to 10% lower in the 13 to 24 weeks after the first dose of a COVID-19 vaccine. Following a second dose, the incidence was up to 27% lower after receiving the AstraZeneca vaccine and up to 20% lower after the Pfizer/Biotech vaccine. The incidence of common venous thrombotic events—mainly pulmonary embolism and lower limb deep venous thrombosis—followed a similar pattern.

This research further supports the large body of evidence on the effectiveness of the COVID-19 vaccination program, which has been shown to provide protection against severe COVID-19 and saved millions of lives worldwide. It did not identify new adverse cardiovascular conditions associated with COVID-19 vaccination and offers further reassurance that the benefits of vaccination outweigh the risks.

The incidence of cardiovascular disease is higher after COVID-19, especially in severe cases. This may explain why the incidence of heart attacks and strokes is lower in vaccinated people compared with unvaccinated people.

Cohort study of cardiovascular safety of different COVID-19 vaccination doses among 46 million adults in England, Nature Communications (2024). DOI: 10.1038/s41467-024-49634-x

AI predicts male infertility risk with blood test, no semen needed

According to a World Health Organization (WHO) study (2017), about half of all infertility is due to men. Semen analysis is considered essential for diagnosis of male infertility, but is not readily available at medical institutions other than those specializing in infertility treatment, and there is a high threshold for receiving it.

In a new study, researchers developed an AI model that can predict the risk of male infertility without the need for semen analysis by only measuring hormone levels in a blood test. AI creation software that requires no programming was used for the model, and the study was reported in Scientific Reports.

The AI prediction model was based on data from 3,662 patients and had an accuracy rate of approximately 74%. In particular, it was 100% correct in predicting non-obstructive azoospermia, the most severe form of male infertility.

The current study collected clinical data from 3,662 men who underwent semen and hormone testing for male infertility between 2011 and 2020. Semen volume, sperm concentration, and sperm motility were measured in the semen tests, and LH, FSH, PRL, testosterone, and E2 were measured in the hormone tests. T/E2 was also added. Total motile sperm count (semen volume X sperm concentration X sperm motility rate) was calculated from the semen test results.

Based on the reference values for semen testing in the WHO laboratory manual for the examination and processing of human semen, 6th edition (2021), a total motile sperm count of 9.408 X 10⁶ (1.4 mL X 16 X 10⁶/mL X 42%) was defined as the lower limit of normal, assigning a value of "0" if the total motility sperm count for an individual patient was above 9.408 X 10⁶ and a value of "1" when it was below. The accuracy of the AI model was approximately 74%.

A New Model for Determining Risk of Male Infertility from Serum Hormone Levels, without Semen Analysis, Scientific Reports (2024).

Next, the AI model was validated using data from 2021 and 2022 for which both semen and hormone tests were available. Using the data of 188 patients in 2021, the accuracy was about 58%, while accuracy using the data for 166 patients in 2022 was about 68%. However, non-obstructive azoospermia could be predicted with a 100% accuracy rate in both 2021 and 2022.

Who needs males? Female sharks make babies alone

 Researchers have noted the first case of "virgin birth", or reproduction without fertilization, in an endangered shark species, a scientific journal reported this week.

The findings published in Scientific Reports concern the first case of the phenomenon in the common smooth-hound shark, Mustelus mustelus, a species threatened by illegal fishing that inhabits the Mediterranean and other warm waters.

Researchers found that two female M. mustelus sharks under observation in captivity had exhibited parthenogenesis—in which a female can reproduce asexually without the need of sperm to fertilize the egg—each year since 2020.

The two 18-year-old sharks have been at the Cala Gonone Aquarium in Sardinia since 2010.

Remarkably, this finding reveals that parthenogenesis can occur annually in these sharks, alternating between two females, and conclusively excludes long-term sperm storage as a cause.

Cycling parthenogenesis, in which progeny can be born either from fertilized eggs or asexually with unfertilized eggs, occurs in over 15,000 species, yet is not fully understood.

Parthenogenesis,  is more common in invertebrates than vertebrates. Reptiles and some sharks, rays and skates are able to "modify their adaptive strategy according to the surrounding circumstances".

Although the mechanisms driving parthenogenesis remain unclear, it is suggested that male population reduction could be a pivotal factor.

Giuseppe Esposito et al, First report of recurrent parthenogenesis as an adaptive reproductive strategy in the endangered common smooth-hound shark Mustelus mustelus, Scientific Reports (2024). DOI: 10.1038/s41598-024-67804-1

Why men and women feel touch differently

Why women generally seem to have a more acute sense of touch than men?

 Women are better than men at touch discrimination—although not because they have smaller fingers, but because in general they have softer fingers. 

But demonstrating the "why" behind the gender difference, first published in November 2023 in the Journal of Physiology, continues to be a cited topic of interest. The insight could be useful as engineers develop softer sensor materials for wearable technology, improve prosthetics with a sense of touch, or design better interfaces for surgical robots.

The experimental design combined novel 3D imaging and biomechanical observations of skin and how it deforms when pressed, statistical analysis and machine learning, and experiments to test how the participants used touch to perceive objects.
They found that softer skin resulted in greater rates of change in surface contact with objects, which correlated with a greater ability to distinguish small changes in the objects' stiffness.

"The mechanism seems to be that attributes of surface contact control the recruitment of sensory nerve fibers in the skin".

For those who'd like to improve their touch perception, the researchers said, apply hyaluronic acid, an effective skin moisturizer and softener.

Bingxu Li et al, An individual's skin stiffness predicts their tactile discrimination of compliance, The Journal of Physiology (2023). DOI: 10.1113/JP285271

Engineered microbes found to repel mosquitoes

Genetically-engineered human skin bacteria can make mice less attractive to mosquitoes for 11 days. Mosquitoes transmit a host of deadly diseases, including malaria, West Nile, dengue, yellow fever, and Zika. Female mosquitoes on the hunt for a blood meal tune into scents released by skin microbes that live on their targets.

Researchers engineered versions of the common human  skin commensals Staphylococcus epidermidis and Corynebacterium amycolatum to produce much less of a form of lactic acid known to attract mosquitoes. The work is published in the journal PNAS Nexus.

The authors tested the microbes alone and found the engineered version of S. epidermidis attracted about half as many Aedes aegypti and Anopheles gambiae mosquitoes and about 22% fewer Culex quinquefasciatus as the wildtype versions of the microbes.

The authors also tried the engineered microbes on mice. Painting the mice with wildtype S. epidermidis attracted mosquitos. However, painting the mice with engineered S. epidermidis reduced mosquito attraction by up to 64.4%, compared with wildtype, starting three days after the microbe was applied.

The effect lasted for 11 days. Trials with engineered C. amycolatum had similar results. In addition, a smaller proportion of mosquitoes that landed on mice painted with engineered microbes bit the mice. According to the authors, the results suggest the feasibility of creating a living and long-lasting engineered microbiome-based mosquito repellent.

 Feng Liu et al, Engineered skin microbiome reduces mosquito attraction to mice, PNAS Nexus (2024). DOI: 10.1093/pnasnexus/pgae267

Study uncovers unique brain plasticity in people born blind

A study by neuroscientists reveals that the part of the brain that receives and processes visual information in sighted people develops a unique connectivity pattern in people born blind. They say this pattern in the primary visual cortex is unique to each person—akin to a fingerprint.

The findings, described July 30, 2024, in PNAS, have profound implications for understanding brain development and could help launch personalized rehabilitation and sight restoration strategies.

For decades, scientists have known that the visual cortex in people born blind responds to a myriad of stimuli, including touch, smell, sound localization, memory recall and response to language. However, the lack of a common thread linking the tasks that activate primary areas in the visual cortex has perplexed researchers.

The new study offers a compelling explanation: differences in how each individual's brain organizes itself.

We don't see this level of variation in the visual cortex connectivity among individuals who can see—the connectivity of the visual cortex is usually fairly consistent, say the researchers.

The connectivity pattern in people born blind is more different across people, like an individual fingerprint, and is stable over time—so much so that the individual person can be identified from the connectivity pattern.

Lénia Amaral et al, Longitudinal stability of individual brain plasticity patterns in blindness, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2320251121

Study links TB strain infectivity to shared geographic background

For some forms of tuberculosis, the chances that an exposed person will become infected depend on whether the individual and the bacteria share a hometown, according to a new study comparing how different strains move through mixed populations in cosmopolitan cities.

Results of the research, led by Harvard Medical School scientists and published in Nature Microbiology, provide the first hard evidence of long-standing observations that have led scientists to suspect that pathogen, place, and human host collide in a distinctive interplay that influences infection risk and fuels differences in susceptibility to infection.

The study strengthens the case for a long-standing hypothesis in the field that specific bacteria and their human hosts likely co-evolved over hundreds or thousands of years, the researchers said.

The findings may also help inform new prevention and treatment approaches for tuberculosis, a wily pathogen that sickens more than 10 million people and causes more than a million deaths worldwide each year, according to the World Health Organization.

In the current analysis, believed to be the first controlled comparison of TB strains' infectivity in populations of mixed geographic origins, the researchers custom built a study cohort by combining case files from patients with TB in New York City, Amsterdam, and Hamburg. Doing so gave them enough data to power their models.

The analysis showed that close household contacts of people diagnosed with a strain of TB from a geographically restricted lineage had a 14% lower rate of infection and a 45% lower rate of developing active TB disease compared with those exposed to a strain belonging to a widespread lineage.

The study also showed that strains with narrow geographic ranges are much more likely to infect people with roots in the bacteria's native geographic region than people from outside the region.

The researchers found that the odds of infection dropped by 38% when a contact is exposed to a restricted pathogen from a geographic region that doesn't match the person's background, compared with when a person is exposed to a geographically restricted microbe from a region that does match their home country. This was true for people who had lived in the region themselves and for people whose two parents could each trace their heritage to the region.

This pathogen-host affinity points to a shared evolution between humans and microbes with certain biological features rendering both more compatible and fueling the risk for infection, the researchers said.

Part 1

the new study showed that for geographically restricted strains, whether a person has ancestors who lived where the strain is common was an even bigger predictor of infection risk than bacterial load in the sputum. In the cases analyzed in the study, this risk of common ancestry even outweighed the risk stemming from having diabetes and other chronic diseases previously shown to render people more susceptible to infection.

The findings add to a growing body of evidence of the importance of paying attention to the wide variation between different lineages of tuberculosis and to the details of how different lineages of tuberculosis interact with different host populations.

Previous studies have shown that some genetic groups of TB are more prone to developing drug resistance and that TB vaccines appear to work better in some places than others. There is also evidence that some treatment regimens might be better suited to some strains of TB than others.

"These findings emphasize how important it is to understand what makes different strains of TB behave so differently from one another, and why some strains have such a close affinity for specific, related groups of people.

In addition to the analysis of clinical, genomic, and public health data, the researchers also tested the ability of different strains of TB to infect human macrophages, a type of immune cell that TB hijacks to cause infection and disease. The researchers grew cells from donors from different regions. Once again, cell lines from people with ancestry that matched the native habitat of a restricted strain of tuberculosis bacteria were more susceptible to the germs than cells from people from outside the area, mirroring the results of their epidemiologic study.

Differential rates of Mycobacterium tuberculosis transmission associate with host–pathogen sympatry, Nature Microbiology (2024). DOI: 10.1038/s41564-024-01758-y

Part 2

Warming breaks down symbiosis

Hotter conditions prevent two tiny organisms working together for mutual benefit, new research shows.

Scientists studied a single-celled organism (Paramecium bursaria) which can absorb and host algae (Chlorella spp). This pairing is common in freshwater worldwide, and their symbiotic relationship provides benefits including trading of nutrients and protection for the algae.

But when scientists made the water 5°C warmer, the partnership stopped working—and the results suggest the algae may even become parasitic.

The breakdown of such relationships could have a major impact on ecosystems.

The paper, published in the journal Aquatic Biology, is titled "One year of warming leads to the total loss of productivity in a widespread photosymbiosis."

This kind of relationship—called photosymbiosis—is an important part of freshwater and ocean ecosystems.

To illustrate their importance, these relationships provide around half of all marine photosynthesis.

A well-known example is found in coral reefs—where the reef-building corals host resident photosynthetic partners. In recent years, we have seen many high-profile 'bleaching' events—when corals expel these partners, often due to high temperatures, leaving them at risk of stress and mortality.

B Makin et al, One year of warming leads to the total loss of productivity in a widespread photosymbiosis, Aquatic Biology (2024). DOI: 10.3354/ab00769

Study finds regular aspirin use associated with greatest reduction in colorectal cancer among those most at risk

Regular aspirin may help lower risk of colorectal cancer in people with greater lifestyle-related risk factors for the disease, according to a study by researchers. 

 The study, published in JAMA Oncology, could encourage a more nuanced approach to preventive aspirin use.

The U.S. Preventive Services Task Force previously recommended daily low-dose aspirin to prevent cardiovascular events and colorectal cancer in all adults ages 50 to 59 (the highest risk age group for colorectal cancer). In 2016, they withdrew the recommendation in part due to concerns about aspirin increasing the risk of gastrointestinal bleeding.

For the study, researchers analyzed the health data from 107,655 participants from the Nurses' Health Study and Health Professionals Follow-Up Study. They compared the colorectal cancer rates in those who took aspirin regularly with those who did not take aspirin regularly. Regular aspirin use was defined as either two or more standard dose (325 mg) tablets per week or daily low-dose (81 mg) aspirin.

Study participants were followed starting from an average age of 49.4 years. Those who regularly took aspirin had a colorectal cancer 10-year cumulative incidence of 1.98%, compared to 2.95% among those who did not take aspirin.

The benefit of aspirin was largest among those with the unhealthiest lifestyles. Those with the lowest healthy lifestyle scores (unhealthiest) had a 3.4% chance of getting colorectal cancer if they did not take regular aspirin and a 2.12% chance of getting colorectal cancer if they took aspirin regularly.

By contrast, in those with the highest healthy lifestyle scores (healthiest), the colorectal cancer rates were 1.5% in regular aspirin-taking group and 1.6% in the non-regular aspirin group. This means that in the least healthy group, treating 78 patients with aspirin would prevent one case of colorectal cancer over a 10-year period, while it would take treating 909 patients to prevent one case for the healthiest group.

Lifestyle scores were calculated based on  body mass index, frequency of cigarette and alcohol use, physical activity, and adherence to a high-quality diet.

These results show that aspirin can proportionally lower the markedly elevated risk in those with multiple risk factors for colorectal cancer.

In contrast, those with a healthier lifestyle have a lower baseline risk of colorectal cancer, and, therefore, their benefit from aspirin was still evident, albeit less pronounced.

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One outcome of the study could be that "health care providers might more strongly consider recommending aspirin to patients who have less healthy lifestyles.
Previous studies have found evidence to suggest aspirin can reduce the production of pro-inflammatory proteins, known as prostaglandins, that can promote the development of cancer. Aspirin may also block signaling pathways that cause cells to grow out of control, influence the immune response against cancer cells, and block the development of blood vessels that supply nutrients to cancer cells.

Aspirin likely prevents colorectal cancer through multiple mechanisms.
The study did not assess potential side effects of daily aspirin use, such as bleeding. In addition, while the study tried to control for a wide range of risk factors for colorectal cancer, in comparing non-aspirin and aspirin-taking groups with the same level of risk factors, because this was an observational study, it is possible there may have been additional factors that influenced the findings.

 Aspirin Use and Incidence of Colorectal Cancer According to Lifestyle Risk, JAMA Oncology (2024). DOI: 10.1001/jamaoncol.2024.2503

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Paper cut physics: the physics behind why some paper is more prone to cut fingers

We all know what it’s like to pick up a sheet of paper, only to get a painful paper cut. The injury is usually small and shallow, but it can really hurt!
Your body has hundreds of nerves. These nerves are spread throughout your body, from head to toe.
In your hands and fingers, though, the nerve endings are densely packed together. So, they’re more sensitive than other areas, like your back or arm.
This explains why paper cuts hurt so much. They commonly affect the hands and fingers, which have a higher density of nerve endings.
But what about all the blood? Well, the capillaries in your hands and fingers are closely packed together. This means paper cuts can cause a lot of bleeding because of how concentrated blood can be in your hands.

In experiments with a gelatin replica of human tissue, researchers found that a thin sheet of paper tended to buckle before it could cut. Thick paper typically indented the material but didn’t pierce it: Like a dull knife blade, it didn’t concentrate force into a small enough area. A thickness of around 65 micrometers was a paper cut sweet spot — or sore spot — physicist Kaare Jensen and colleagues report in a paper to appear in Physical Review E.

That makes dot matrix printer paper the most treacherous, the researchers say. (That paper is seldom used today ). Paper from various magazines was a close second in the scientists’ tests. 

The angle of slicing also played a role. Paper pressed straight down into the gelatin was less likely to cut than paper that cleaved across and down.

S.F. Arnbjerg-Nielsen, M.D. Biviano and K.H. Jensen. Competition between slicing and buckling underlies the erratic natu.... Physical Review E, in press, 2024.

Almost Half of Dementia Cases Avoidable by Addressing 14 Risk Factors, Major Study Finds

Millions of cases of dementia could be prevented or delayed by reducing a range of risk factors according to a major new study, though outside experts warn that such measures can only go so far.

The debilitating condition, which progressively robs people of their memories, cognitive abilities, language and independence, currently affects more than 55 million people across the world. Dementia is caused by a range of diseases, the most common of which is Alzheimer's.

A huge review of the available evidence published in The Lancet journal on Wednesday said that the "potential for prevention is high" in the fight against dementia.

At the time, the international team of researchers estimated that 40 percent of dementia cases were linked to 12 risk factors.

The factors included people having a lower level of education, hearing problems, high blood pressure, smoking, obesity,  depression physical inactivity,  diabetes, excessive drinking, traumatic brain injury, air pollution and social isolation.

The latest update adds two more risk factors: vision loss and high cholesterol.

Added Sugar in Your Diet May Speed Up Your Body's Biological Aging

Eating large amounts of food with added sugar could have a hyperactive effect on the body's ticking biological clock, even when the rest of a person's diet remains otherwise healthy.

A new study among 342 Black and White middle-aged women (please note that the sample size is very low) has found those who eat high quantities of added sugar have 'older-looking' cells.

The findings could help explain why some people seem to age faster or slower than others who have lived the same number of years. Sugar intake could be an important, overlooked factor.

Along with the occasional mutation, our DNA can accumulate less permanent edits over time. These so-called epigenetic changes often act like chemical padlocks, deactivating genes and altering how the body's genetic code is expressed for a time.
A collection of transient edits is referred to as an epigenetic clock, and can be a useful way to guess at a person's true biological age. Epigenetic changes can be read by scientists to better understand how old a cell is and what damages or stresses it has experienced.

Diet, lifestyle, genetics, and disease are all known to affect how quickly a person's epigenetic clock ticks, but this is one of the first studies to examine how sugar specifically plays a role. It also includes a diverse cohort.

The findings suggest that added sugar can alter epigenetic switches related to aging more quickly than healthier foods can turn them off, regardless of whether healthy nutrients are also present.

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Female participants who ate a diet rich in vitamins, minerals, and antioxidants, for instance, had cells with the 'youngest'-looking epigenetic age. Those on the Mediterranean diet were observed to have the slowest epigenetic clocks.

Still, the more added sugar a person consumed each day, the older their salivary DNA appeared to scientists, even when their meals were rich in foods that maintain and repair DNA.

This was true even when accounting for education, lifestyle factors, and the current health of participants.

On average, women in the study ate just over 60 grams of sugar a day, although some ate more than 300 grams a day.
The findings suggest that added sugar can significantly accelerate cellular aging, but it is important to note that this study is only based on food records collected over three non-consecutive days, and one salivary swab.

Previous studies have suggested that cells can appear epigenetically 'younger' or 'older' depending on when in the day their DNA was sampled, so longer term studies among both sexes are needed before further conclusions can be drawn.

https://jamanetwork.com/journals/jamanetworkopen/article-abstract/2...

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A bio-inspired vision sensor that can detect spectrally distinctive features

The ability to detect objects in settings with unfavorable lighting, for example at night, in shadowed locations or in foggy conditions, could greatly improve the reliability of autonomous vehicles and mobile robotic systems. Most widely employed computer vision methods, however, have been found to perform under poor lighting.

Researchers  recently introduced a new bio-inspired vision sensor that can adapt to the spectral features of the environments it captures, thus successfully detecting objects in a wider range of lighting conditions. This newly developed sensor, introduced in a paper published in Nature Electronics, is based on an array of photodiodes arranged back-to-back.

The primary objective of this recent work was to design a vision sensor that is better than other sensors at recognizing objects in an environment marked by strong light interference and when there is smoke or fog in the air. The sensor they planned to develop would also collect data with minimal time latency, consuming very little power.

Bangsen Ouyang et al, Bioinspired in-sensor spectral adaptation for perceiving spectrally distinctive features, Nature Electronics (2024). DOI: 10.1038/s41928-024-01208-x.

Brain activity associated with specific words is mirrored between speaker and listener during a conversation

When two people interact, their brain activity becomes synchronized, but it was unclear until now to what extent this "brain-to-brain coupling" is due to linguistic information or other factors, such as body language or tone of voice.

Researchers report August 2 in the journal Neuron that brain-to-brain coupling during conversation can be modeled by considering the words used during that conversation, and the context in which they are used.

Researchers could see linguistic content emerge word-by-word in the speaker's brain before they actually articulate what they're trying to say, and the same linguistic content rapidly reemerges in the listener's brain after they hear it.

To communicate verbally, we must agree on the definitions of different words, but these definitions can change depending on the context. For example, without context, it would be impossible to know whether the word "cold" refers to temperature, a personality trait, or a respiratory infection.

The contextual meaning of words as they occur in a particular sentence, or in a particular conversation, is really important for the way that we understand each other.

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To examine the role of context in driving brain coupling, the team collected brain activity data and conversation transcripts from pairs of epilepsy patients during natural conversations.

The patients were undergoing intracranial monitoring using electrocorticography for unrelated clinical purposes at the New York University School of Medicine Comprehensive Epilepsy Center. Compared to less invasive methods like fMRI, electrocorticography records extremely high-resolution brain activity because electrodes are placed in direct contact with the surface of the brain.

Next, the researchers used the large language model GPT-2 to extract the context surrounding each of the words used in the conversations, and then used this information to train a model to predict how brain activity changes as information flows from speaker to listener during conversation.

Using the model, the researchers were able to observe brain activity associated with the context-specific meaning of words in the brains of both speaker and listener.

They showed that word-specific brain activity peaked in the speaker's brain around 250 ms before they spoke each word, and corresponding spikes in brain activity associated with the same words appeared in the listener's brain approximately 250 ms after they heard them.

Compared to previous work on speaker–listener brain coupling, the team's context-based approach model was better able to predict shared patterns in brain activity. This shows just how important context is, because it best explains the brain data. Large language models take all these different elements of linguistics like syntax and semantics and represent them in a single high-dimensional vector. This work shows that this type of unified model is able to outperform other hand-engineered models from linguistics.

A shared model-based linguistic space for transmitting our thoughts from brain to brain in natural conversations, Neuron (2024). DOI: 10.1016/j.neuron.2024.06.025. www.cell.com/neuron/fulltext/S0896-6273(24)00460-4

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Scientists pin down the origins of the moon's tenuous atmosphere

While the moon lacks any breathable air, it does host a barely-there atmosphere. Since the 1980s, astronomers have observed a very thin layer of atoms bouncing over the moon's surface. This delicate atmosphere—technically known as an "exosphere"—is likely a product of some kind of space weathering. But exactly what those processes might be has been difficult to understand with any certainty.

Now, scientists  say they have identified the main process that formed the moon's atmosphere and continues to sustain it today. In a study appearing in Science Advances, the team reports that the lunar atmosphere is primarily a product of "impact vaporization."

In their study, the researchers analyzed samples of lunar soil collected by astronauts during NASA's Apollo missions.

Their analysis suggests that over the moon's 4.5-billion-year history its surface has been continuously bombarded, first by massive meteorites, then more recently, by smaller, dust-sized "micrometeoroids."

These constant impacts have kicked up the lunar soil, vaporizing certain atoms on contact and lofting the particles into the air. Some atoms are ejected into space, while others remain suspended over the moon, forming a tenuous atmosphere that is constantly replenished as meteorites continue to pelt the surface.

The researchers found that impact vaporization is the main process by which the moon has generated and sustained its extremely thin atmosphere over billions of years.

Nicole Nie, Lunar Soil Record of Atmosphere Loss over Eons, Science Advances (2024). DOI: 10.1126/sciadv.adm7074. www.science.org/doi/10.1126/sciadv.adm7074

Researchers demonstrate mechanism that may have stabilized the first RNA molecules

The origins of life remain a major mystery. How were complex molecules able to form and remain intact for prolonged periods without disintegrating? A team at ORIGINS, a Munich-based Cluster of Excellence, has demonstrated a mechanism that could have enabled the first RNA molecules to stabilize in the primordial soup.

When two RNA strands combine, their stability and lifespan increase significantly. The work is published in the journal Nature Chemistry.

In all likelihood, life on Earth began in water, perhaps in a tide pool that was cut off from seawater at low tide but flooded by waves at high tide. Over billions of years, complex molecules like DNA, RNA and proteins formed in this setting before, ultimately, the first cells emerged. 

RNA is a fascinating molecule. It can store information and also catalyze biochemical reactions. Scientists therefore think that RNA must have been the first of all complex molecules to form.

The problem, however, is that active RNA molecules are composed of hundreds or even thousands of bases and are very unstable. When immersed in water, RNA strands quickly break down into their constituent parts—a process known as hydrolysis. So, how could RNA have survived in the primordial soup?

In laboratory testing, the researchers from TUM and LMU used a model system of RNA bases that join together more easily than naturally occurring bases in our cells today.

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The researchers added these fast-joining RNA bases into a watery solution, provided an energy source and examined the length of the RNA molecules that formed. Their findings were sobering, as the resulting strands of up to five base pairs only survived for a matter of minutes.

The results were different, however, when the researchers started by adding short strands of pre-formed RNA. The free complementary bases quickly joined with this RNA in a process called hybridization. Double strands of three to five base pairs in length formed and remained stable for several hours.

The exciting part is that double strands lead to RNA folding, which can make the RNA catalytically active.

Double-stranded RNA therefore has two advantages: it has an extended lifespan in the primordial soup and serves as the basis for catalytically active RNA.

Another characteristic of double-stranded RNA could have helped bring about the origin of life. It is firstly important to note that RNA molecules can also form protocells. These are tiny droplets with an interior fully separated from the outside world. Yet, these protocells do not have a stable cell membrane and so easily merge with other protocells, which causes their contents to mix.

This is not conducive to evolution because it prevents individual protocells from developing a unique identity. However, if the borders of these protocells are composed of double-stranded DNA, the cells become more stable and merging is inhibited.

Christine M. E. Kriebisch et al, Template-based copying in chemically fuelled dynamic combinatorial libraries, Nature Chemistry (2024). DOI: 10.1038/s41557-024-01570-5

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Coinfecting viruses obstruct each other's cell invasion

The process by which phages—viruses that infect and replicate within bacteria—enter cells has been studied for over 50 years. In a new study, researchers  have used cutting-edge techniques to look at this process at the level of a single cell.

The field of phage biology has seen an explosion over the last decade because more researchers are realizing the significance of phages in ecology, evolution, and biotechnology. 

This new work is unique because we looked at phage infection at the level of individual bacterial cells.

The process of phage infection involves the attachment of the virus to the surface of a bacterium. Following this, the virus injects its genetic material into the cell. After entering, a phage can either force the cell to produce more phages and eventually explode, a process called cell lysis, or the phage can integrate its genome into the bacterial one and remain dormant, a process called lysogeny. The outcome depends on how many phages are simultaneously infecting the cell. A single phage causes lysis, while infection by multiple phages results in lysogeny.

In the current study, the researchers wanted to ask whether the number of infecting phages that bind to the bacterial surface corresponds to the amount of viral genetic material that is injected into the cell. To do so, they fluorescently labeled both the protein shell of the phages and the genetic material inside. They then grew Escherichia coli, used different concentrations of infecting phages, and tracked how many of them were able to inject their genetic material into E. coli.

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Scientists have known since the 70s that when multiple phages infect the same cell, it impacts the outcome of the infection. In this paper, they were able to take precise measurements.
The researchers were surprised to find that the entry of a phage's genetic material could be impeded by the other coinfecting phages. They found that when there were more phages attached to the surface of the cell, relatively fewer of them were able to enter.
Their data shows that the first stage of infection, phage entry, is an important step that was previously underappreciated. The researchers found that the coinfecting phages were impeding each other's entry by perturbing the electrophysiology of the cell.
The outermost layer of bacteria is constantly dealing with the movement of electrons and ions that are crucial for energy generation and transmitting signals in and out of the cell. Over the past decade, researchers have started realizing the importance of this electrophysiology in other bacterial phenomena, including antibiotic resistance. This paper opens a new avenue for research in bacterial electrophysiology—its role in phage biology.
By influencing how many phages actually enter, these perturbations affect the choice between lysis and lysogeny. This study also shows that entry can be impacted by environmental conditions such as the concentration of various ions.

 Thu Vu Phuc Nguyen et al, Coinfecting phages impede each other's entry into the cell, Current Biology (2024). DOI: 10.1016/j.cub.2024.05.032

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Researchers use vibrations from traffic to measure underground soil moisture

Researchers have developed a new method to measure soil moisture in the shallow subterranean region between the surface and underground aquifers. This region, called the vadose zone, is crucial for plants and crops to obtain water through their roots.

However, measuring how this underground moisture fluctuates over time and between geographical regions has traditionally relied on satellite imaging, which only gives low-resolution averages and cannot penetrate below the surface. Additionally, moisture within the vadose zone changes rapidly—a thunderstorm can saturate a region that dries out a few days later.

The new method relies upon seismic technology that normally measures how the ground shakes during earthquakes. However, it can also detect the vibrations of human activity, like traffic. As these vibrations pass through the ground, they are slowed down by the presence of water—the more moisture, the slower the vibration moves. The new study measures the water content in the vadose zone through seismic rumblings from everyday traffic.

The new method is based on a technique pioneered in the  lab, called distributed acoustic sensing (DAS). With this technique, lasers are pointed into unused underground fiber-optic cables (like the kind that provides the internet).

As a seismic wave, or any kind of vibration, passes through the cable, the laser light bends and refracts. Measuring the wiggles in this laser light gives researchers information about the passing wave, making the 10-kilometer cable equivalent to a line of thousands of conventional seismic sensors.

The ability to measure vadose zone moisture in real time is crucial for managing water use and conservation efforts. 

Fiber-optic seismic sensing of vadose zone soil moisture dynamics, Nature Communications (2024).

Streetlights running all night makes leaves so tough that insects can't eat them, threatening the food chain

Light pollution disrupts circadian rhythms and ecosystems worldwide—but for plants, dependent on light for photosynthesis, its effects could be profound. Now scientists writing in Frontiers in Plant Science have found that exposure to high levels of artificial light at night makes tree leaves grow tougher and harder for insects to eat, threatening urban food chains.

Compared to natural ecosystems, tree leaves in most urban ecosystems generally show little sign of insect damage. Scientists were curious as to why. Their observations show that   in two of the most common tree species in Beijing, artificial light at night led to increased leaf toughness and decreased levels of leaf herbivory.

Artificial light has increased levels of night-time brightness by almost 10%: most of the world's population experiences light pollution every night. Because plant properties affect their interactions with other plants and animals, any changes to plants caused by artificial light could have a significant impact on the ecosystem.

Leaves that are free of insect damage may bring comfort to people, but not insects. Herbivory is a natural ecological process that maintains the biodiversity of insects.

The scientists suspected that plants experiencing high levels of artificial light would focus on defense rather than growth, producing tougher leaves with more chemical defense compounds. 

In their experiments,  they  found that the more intense the light, the more frequently they encountered leaves that showed no signs at all of herbivory.

It is possible that trees exposed to artificial light at night may extend their photosynthesis duration. Additionally, these leaves might allocate a greater proportion of resources to structural compounds, such as fibers, which could lead to an increase in leaf toughness.

Lower levels of herbivory imply lower abundances of herbivorous insects, which could in turn result in lower abundances of predatory insects, insect-eating birds, and so on. 

If there 're less pollinating insects, that would also affect the fruit yield.

 Artificial light at night decreases leaf herbivory in typical urban areas, Frontiers in Plant Science (2024). DOI: 10.3389/fpls.2024.1392262

New biomaterial regrows damaged cartilage in joints

scientists have developed a new bioactive material that successfully regenerated high-quality cartilage in the knee joints of a large-animal model.

Although it looks like a rubbery goo, the material is actually a complex network of molecular components, which work together to mimic cartilage's natural environment in the body.

In the new study, the researchers applied the material to damaged cartilage in the animals' knee joints. Within just six months, the researchers observed evidence of enhanced repair, including the growth of new cartilage containing the natural biopolymers (collagen II and proteoglycans), which enable pain-free mechanical resilience in joints.

Stupp, Samuel I., A bioactive supramolecular and covalent polymer scaffold for cartilage repair in a sheep model, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2405454121

Sometimes mental effort is associated with unpleasant feelings, study says

If somebody complains that it hurts to think, they may be onto something, as mental exertion appears to be associated with unpleasant feelings in many situations, according to research published in the journal Psychological Bulletin.

Managers often encourage employees, and teachers often encourage students to exert mental effort. On the surface, this seems to work well: Employees and students do often opt for mentally challenging activities. From this, you may be tempted to conclude that employees and students tend to enjoy thinking hard. But the study results suggest that this conclusion would be false: In general, people really dislike mental effort.

Researchers conducted a meta-analysis of 170 studies, published between 2019 and 2020 and comprising 4,670 participants, to examine how people generally experience mental effort. They did so by testing whether mental effort is associated with unpleasant feelings and whether that association depends on the task or the population involved.

The studies used a variety of participants (e.g., health care employees, military employees, amateur athletes, college students) from 29 countries and involved 358 different cognitive tasks (e.g., learning a new technology, finding one's way around an unfamiliar environment, practicing golf swings, playing a virtual reality game).

In all studies analyzed, participants reported the level of effort they exerted as well as the extent to which they experienced unpleasant feelings such as frustration, irritation, stress or annoyance.

Across all populations and tasks, the greater the mental effort, the greater the unpleasantness experienced by participants.

These findings show that mental effort feels unpleasant across a wide range of populations and tasks.

This is important for professionals, such as engineers and educators, to keep in mind when designing tasks, tools, interfaces, apps, materials or instructions. When people are required to exert substantial mental effort, you need to make sure to support or reward them for their effort, say the researchers.

One interesting finding, according to them, was that while the association between mental effort and adverse feelings was still significant, it was less pronounced in studies conducted in Asian countries compared with those in Europe or North America!

This fits with the general idea that the aversiveness of mental effort may depend on people's learning history. High school students in Asian countries tend to spend more time on schoolwork than their European or North American counterparts and may therefore learn to withstand higher levels of mental exertion early on in their lives.

More important is the real-world observation that, despite the aversive nature of mentally challenging tasks, people still voluntarily engage in them.

The Unpleasantness of Thinking: A Meta-Analytic Review of the Association Between Mental Effort and Negative Affect, Psychological Bulletin (2024). DOI: 10.1037/bul0000443

Physicists develop new method to combine conventional internet with the quantum internet

Researchers  have developed a new transmitter-receiver concept for transmitting entangled photons over an optical fiber. This breakthrough could enable the next generation of telecommunications technology, the quantum internet, to be routed via optical fibers. The quantum internet promises eavesdropping-proof encryption methods that even future quantum computers cannot decrypt, ensuring the security of critical infrastructure.

In their experiment, the researchers demonstrated that the entanglement of photons is maintained even when they are sent together with a laser pulse. The research results were published in Science Advances.

The physicists could change the colour of a laser pulse with a high-speed electrical signal so that it matches the colour of the entangled photons. This effect enables them to combine laser pulses and entangled photons of the same colour in an optical fiber and separate them again.

This effect could integrate the conventional internet with the quantum internet.

Their experiment shows how the practical implementation of hybrid networks can succeed.

 Philip Rübeling et al, Quantum and coherent signal transmission on a single-frequency channel via the electro-optic serrodyne technique, Science Advances (2024). DOI: 10.1126/sciadv.adn8907

Excessive use of botanicals like turmeric, green tea are harming  livers

Botanicals like turmeric, green tea and black cohosh may seem benign, but their overuse is being increasingly linked to liver injury.

New research suggests that thousands are using at least one of the several leading botanicals. Many are ending up in hospitals for liver toxicity, researchers report.

Because there's almost no  regulatory oversight over botanicals, chemical tests of products linked to liver crises show frequent discrepancies between product labels and detected ingredients.

The researchers focused on the use of six of the most popular botanicals: Turmeric, green tea extract, the Garcinia cambodgia plant, black cohosh, red yeast rice and ashwagandha.

Millions of adults regularly take turmeric supplements, often with the notion that it can ease pain or arthritis. Unfortunately, "multiple randomized clinical trials have failed to demonstrate any efficacy of turmeric-containing products in osteoarthritis," and overdoing it on turmeric has been linked to serious liver toxicity, the researchers said.

Likewise, millions of  adults are estimated to be taking another potential liver toxin, green tea extract, usually to help boost energy and aid in weight loss.

But again, "multiple studies have failed to demonstrate any objective evidence of weight loss and sustained improvement in mood or energy levels" with products containing the active ingredients in green tea extract, the research  team noted.

Other claims, many unfounded, are made for other botanicals: Garcinia cambodgia is touted for weight loss, black cohosh for easing hot flashes and ashwagandha to help build muscle. But scientists noted that consumers may be overdosing on botanicals, or getting misled by labels that don't reflect the actual ingredients in their supplements. That may be leading to more users ending up in the ER.

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According to a US national database, cases of liver toxicity linked to botanical use, some severe or even fatal, nearly tripled between 2004 and 2014—from 7% of cases to 20%. Use of turmeric, green tea extract, Garcinia cambodgia were often implicated. Another study found such cases rising from 12.5% of liver toxicity cases in 2007 to 21.1% by 2015.
Who's using these botanicals? According to the new study, the most common consumer is an older (average age about 52) white (75% of users) female (57%), who was typically well-off.

People taking botanicals were more likely to be battling some kind of chronic illness, such as arthritis, thyroid disorders or cancer, compared to folks not using the supplements.
In two-thirds of cases, people took a botanical while also taking a prescription medicine, the study found. Because of the danger of drug interactions and the threat to liver health, it's crucial that botanical users inform their doctors, the research group said.
When botanicals are overused, the damage to the liver "can not only be severe, leading to hepatocellular [liver] injury with jaundice, but also fatal, leading to death or liver transplantation," the research team warned.

A prior study found that the number of liver transplants required due to botanical overuse jumped by 70% between 2009 and 2020.

 Alisa Likhitsup et al, Estimated Exposure to 6 Potentially Hepatotoxic Botanicals in US Adults, JAMA Network Open (2024). DOI: 10.1001/jamanetworkopen.2024.25822

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