Study identifies nearly 600 genetic loci associated with anti-social behavior, alcohol use, opioid addiction and more

An analysis of data from 1.5 million people has identified 579 locations in the genome associated with a predisposition to different behaviors and disorders related to self-regulation, including addiction and child behavioral problems.

With these findings, researchers have constructed a genetic risk score—a number reflecting a person's overall genetic propensity based on how many risk variants they carry—that predicts a range of behavioral, medical and social outcomes, including education levels, obesity, opioid use disorder, suicide, HIV infections, criminal convictions and unemployment.

[This study] illustrates that genes don't code for a particular disorder or outcome; there are no genes 'for' substance use disorder, or 'for' behavior problems. Instead, genes influence the way our brains are wired, which can make us more at risk for certain outcomes. In this case, we find that there are genes that broadly influence self-control or impulsivity, and that this predisposition then confers risk for a variety of life outcomes.

Multivariate analysis of 1.5 million people identifies genetic associations with traits related to self-regulation and addiction, Nature Neuroscience (2021). DOI: 10.1038/s41593-021-00908-3 , www.nature.com/articles/s41593-021-00908-3

https://medicalxpress.com/news/2021-08-genetic-loci-anti-social-beh...

Plant roots and animals embryos rely on the same chemical for successful development

What do frog eggs have in common with anti-aging creams? Their success depends on a group of chemical compounds called retinoids, which are capable of generating and re-generating tissues. A new study in plants shows that retinoids' tissue-generating capacities are also responsible for the appropriate development of roots.

In a new study, appearing August 26 in the journal Science, a research team led by Alexandra Dickinson, assistant professor at the University of California, San Diego, and Philip Benfey, the Paul Kramer Distinguished Professor of Biology at Duke University, identifies the compound that plays a key role in triggering the development of plants' lateral roots.

The research team had a good suspect: retinal, a type of retinoid, looked like it would fit the bill.

In humans, as well as all vertebrate animals, turning a fertilized egg into an embryo with a little beating heart requires that stem cells differentiate, specialize, and generate specific tissues, such as bones, blood vessels and a nervous system. This process is kickstarted and regulated by retinal. Animals can't produce their own retinal, though, they must ingest it from plants, or from animals that eat plants.

"We know plants have the ability to produce this compound, that it's very important for animal development, and so it was very tempting to check its role in plant development as well.

A plant lipocalin promotes retinal-mediated oscillatory lateral root initiation, Science (2021). DOI: 10.1126/science.abf7461

https://phys.org/news/2021-08-roots-animals-embryos-chemical-succes...

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Migraines protect against diabetes

Migraines protect against diabetes!

People who get migraines are less likely to develop type 2 diabetes, while some people who develop diabetes become less prone to migraines. Today, scientists studying the link between these conditions report how the peptides that cause migraine pain can influence production of insulin in mice, possibly by regulating the amount of secreted insulin or by increasing the number of pancreatic cells that produce it. These findings could improve methods to prevent or treat diabetes.

Researchers already knew that two peptides in the nervous system—calcitonin gene-related peptide (CGRP) and pituitary adenylate cyclase-activating polypeptide (PACAP)—play a major role in causing the pain of migraines. These same peptides, along with the related peptide amylin, are also found in the pancreas. There, they influence release of insulin from beta cells.

Insulin regulates blood sugar levels by helping other cells in the body absorb glucose and either store it or use it for energy. In type 2 diabetes, those other cells become resistant to insulin and less capable of absorbing glucose, leading to high blood sugar levels. The beta cells initially compensate by ramping up insulin production but eventually wear themselves out and die, exacerbating the issue.

Because CGRP and PACAP can seemingly protect against diabetes, researchers worry that the anti-CGRP and anti-PACAP treatments under development or already on the market for migraine could have the unintended consequence of increasing the risk of diabetes. In addition, these peptides are involved in numerous other beneficial functions in the body, such as blood vessel dilation. So scientists are also exploring the potential risks of altering the peptides' activity.

https://www.acs.org/content/acs/en/pressroom/newsreleases/2021/augu...

https://medicalxpress.com/news/2021-08-migraines-diabetes.html?utm_...

Female hummingbirds avoid harassment by looking as flashy as males

Much like in human society, female hummingbirds have taken it into their own hands to avoid harassment. By watching white-necked Jacobin hummingbirds in Panama, researchers discovered that over a quarter of females have the same brightly colored ornamentation as males, which helps them avoid aggressive male behaviors during feeding, such as pecking and body slamming. This paper appears August 26 in the journal Current Biology.

All of the Jacobin  juvenile females  had showy colors. For birds that's really unusual because you usually find that when the males and females are different the juveniles usually look like the adult females, not the adult males, and that's true almost across the board for birds. It was unusual to find one where the juveniles looked like the males. So it was clear something was at play.

Male white-necked Jacobin hummingbirds are known to have bright and flashy colors, with iridescent blue heads, bright white tails, and white bellies. Female Jacobins, on the other hand, tend to be drabber in comparison, with a muted green, gray, or black colors that allow them to blend into their environment. Researchers, however, found that around 20% of adult females have showy colors like males.

As juveniles, all females have the showy colors, but this 20% of females doesn't change to the muted color as they age. It is not clear whether this phenomenon is genetic, by the choice of the hummingbird, or due to environmental factors. However, the researchers found that it is probably the result of the female hummingbirds trying to evade harassment, including detrimental aggression during mating or feeding.

To learn why some female hummingbirds kept their showy colors, the researchers set up a scenario with stuffed hummingbirds on feeders and watched as real hummingbirds interacted with them. They found that hummingbirds harassed mainly the muted colored female hummingbirds, which is in favor of the hypothesis that the showy colors are caused by social selection. Furthermore, most females had showy colors during their juvenile period and not during their reproductive period. This means that the only time they had showy colors is precisely during the period when they're not looking for mates. In combination with other results from the study, this indicates that it is not sexual selection causing the phenomenon.

Current Biology, Falk et al.: "Male-like ornamentation in female hummingbirds results from social harassment rather than sexual selection" www.cell.com/current-biology/f … 0960-9822(21)01033-2 , DOI: 10.1016/j.cub.2021.07.043

https://phys.org/news/2021-08-female-hummingbirds-flashy-males.html...

India’s landfills are home to tiny environmental detoxifiers—bacteria that transform chemical wastes into harmless substances.

While bacteria get a bad rap as disease-causing agents, some of these tiny organisms may just be the rescuers of the environment. An international team found that bacteria from Indian landfills could detoxify chemical wastes called hexabromocyclodecane (HBCD), publishing their study in Chemosphere.

For a long time, industrial production has been a major culprit of environmental pollution, releasing hazardous waste like HBCD. At peak production, HBCD hit scales of 10,000 tons a year as a flame retardant used in textile manufacturing and integrated in plastics for electronic devices.

By the time the chemical was banned worldwide in 2014, the damage had been done. As a long-lived environmental toxin, HBCD had already seeped into sewages, soil and the air—found even in the food chain and consequently, in human blood samples and breast milk.

Given HBCD’s persistence in the surroundings, researchers have been searching for ways to detoxify the chemical pollution from the past to create a cleaner future. Scientists from the University of Delhi and the India Habitat Center, together with collaborators from Sweden, found a solution from nature itself—showing that Sphingobium indicum bacteria inhabiting India’s landfills could digest these chemicals.

The detoxifying abilities of these bacteria come from an enzyme called LinA, which is involved in metabolizing another now-banned insecticide and chemical sibling of HBCD. Known as biological catalysts, enzymes speed up reactions like the breakdown of chemicals.

On the designated binding site, the toxin attaches itself to LinA, similar to a key being inserted into a lock. HBCD rapidly splits up into non-toxic fragments, which are then released to make room for the next chemical to latch onto the enzyme’s binding site.

By genetically modifying the bacteria, the team also altered the structure of the enzymes they produced. While LinA enzymes are highly selective about the molecules they can accept on the binding site, the genetic changes led to a more spacious site for accommodating larger chemicals.

According to the researchers, these experiments highlight the possibility of designing enzymes that can degrade other toxins besides HBCD. Through modifying biological structures, biotransformation may be key to engineering useful bacterial enzymes for remediating heavily polluted environments.

 Heeb et al. (2021) Transformation of ε-HBCD with the Sphingobium indicum Enzymes LinA1, LinA2 and LinATM, a Triple Mutant of LinA2.

https://www.asianscientist.com/2021/08/in-the-lab/bacteria-chemical...

COVID-19, not vaccination, presents biggest blood clot risks: study

Part 1

Researchers from the University of Oxford have recently announced the results of a study into thrombocytopenia (a condition with low platelet counts) and thromboembolic events (blood clots) following vaccination for COVID-19, some of the same events which have led to restricted use of the Oxford-AstraZeneca vaccine in a number of countries.

Writing in the British Medical Journal (BMJ), they detail the findings from over 29 million people vaccinated with first doses of either the ChAdOx1 nCov-19 "Oxford-AstraZeneca" vaccine or the BNT162b2 mRNA "Pfizer-BioNTech' vaccine. They conclude that with both of these vaccines, for short time intervals following the first dose, there are increased risks of some hematological and vascular adverse events leading to hospitalization or death.

However, people should be aware of these increased risks after COVID-19 vaccination and seek medical attention promptly if they develop symptoms, but also be aware that the risks are considerably higher and over longer periods of time if they become infected with SARS-CoV-2.

The authors further note that the risk of these adverse events is substantially higher and for a longer period of time, following infection from the SARS-CoV-2 "coronavirus" than after either vaccine.

All of the coronavirus vaccines currently in use have been tested in randomized clinical trials, which are unlikely to be large enough to detect very rare adverse events. When rare events are uncovered, then regulators perform a risk-benefit analysis of the medicine; to compare the risks of the adverse events if vaccinated versus the benefits of avoidance of the disease—in this case, COVID-19.

part 2

This enormous study, using data on over 29 million vaccinated people, has shown that there is a very small risk of clotting and other blood disorders following first dose COVID-19 vaccination. Though serious, the risk of these same outcomes is much higher following SARS-CoV-2 infection.

Julia Hippisley-Cox et al, Risk of thrombocytopenia and thromboembolism after covid-19 vaccination and SARS-CoV-2 positive testing: self-controlled case series study, BMJ (2021). DOI: 10.1136/bmj.n1931

https://medicalxpress.com/news/2021-08-covid-vaccination-biggest-bl...

part3

Mutation rate of COVID-19 virus is at least 50 percent higher than previously thought

The virus that causes COVID-19 mutates almost once a week—significantly higher than the rate estimated previously—according to a new study by scientists . Their findings indicate that new variants could emerge more quickly than thought previously.

SARS-CoV-2, the virus that causes COVID-19, was previously thought to mutate about once every two weeks. However, new research shows that this estimate overlooked many mutations that happened but were never sequenced.

Viruses regularly mutate, for example when mistakes are made in copying the genomes whilst the virus replicates.

Usually when we consider natural selection, we think about new mutations that have an advantage and so spread, such as the Alpha and Delta variants of COVID-19. This is known as Darwinian selection or positive selection.

However, most mutations are harmful to the virus and reduce its chances of surviving—this is called purifying or negative selection. These negative mutations don't survive in the patient long enough to be sequenced and so are missing from calculations of the mutation rate.

Allowing for these missing mutations, the team estimates that the true mutation rate of the virus is at least 50% higher than previously thought.

The findings, published in Genome Biology and Evolution, reinforce the need to isolate individuals with immune systems that struggle to contain the virus.  These findings mean that if a patient suffers COVID-19 for more than a few weeks, the virus could evolve which could potentially lead to new variants.

The Alpha variant is thought to be the result of evolution of the virus within an individual who was unable to clear the infection.

It's not all bad news because most individuals transmit and clear the virus before it mutates all that much, meaning that the chance of evolution within one patient isn't usually that high. However, this new estimate of the mutation rate indicates that there is more scope for evolution of the virus within such individuals than scientists assumed.

 Atahualpa Castillo Morales et al, Causes and consequences of purifying selection on SARS-CoV-2, Genome Biology and Evolution (2021). DOI: 10.1093/gbe/evab196

https://phys.org/news/2021-08-mutation-covid-virus-percent-higher.h...

Covid-19 not developed as biological weapon: US intelligence community

SARS-CoV-2, the virus that causes Covid-19, was 'not developed' as a biological weapon, the US intelligence community has concluded in a report

SARS-CoV-2, the virus that causes COVID-19, was "not developed" as a biological weapon, the US intelligence community has concluded in a report.

The Director of National Intelligence in a report, prepared at the direction of the president, on Friday said SARS-CoV-2 probably emerged and infected humans through an initial small-scale exposure that occurred no later than November 2019 with the first known cluster of COVID-19 cases arising in Wuhan, China in December 2019.

However, there was no unanimity among the intelligence community (IC) on the origins of the coronavirus.

The virus was not developed as a biological weapon. Most agencies also assess with low confidence that SARS-CoV-2 probably was not genetically engineered; however, two agencies believe there was not sufficient evidence to make an assessment either way, said the unclassified version of the report.

The IC also assesses that China's officials did not have foreknowledge of the virus before the initial outbreak of COVID-19 emerged, it said.

After examining all available intelligence reporting and other information, though, the IC remains divided on the most likely origin of COVID-19. All agencies assess that two hypotheses are plausible: natural exposure to an infected animal and a laboratory-associated incident, the report said.

Four IC elements and the National Intelligence Council assess with low confidence that the initial SARS-CoV-2 infection was most likely caused by natural exposure to an animal infected with it or a close progenitor virus-a virus that probably would be more than 99 per cent similar to SARS-CoV-2.

These analysts give weight to Chinese officials' lack of foreknowledge, the numerous vectors for natural exposure, and other factors, the report said.

part 1

One IC element assesses with moderate confidence that the first human infection with SARS-CoV-2 most likely was the result of a laboratory-associated incident, probably involving experimentation, animal handling, or sampling by the Wuhan Institute of Virology. These analysts give weight to the inherently risky nature of work on coronaviruses, it said.

Analysts at three IC elements remain unable to coalesce around either explanation without additional information, with some analysts favouring natural origin, others a laboratory origin, and some seeing the hypotheses as equally likely. Variations in analytic views largely stem from differences in how agencies weigh intelligence reporting and scientific publications, and intelligence and scientific gaps, the report said.

Press Trust of India

https://www.business-standard.com/article/current-affairs/covid-19-...

https://www.dni.gov/index.php/newsroom/reports-publications/reports...

https://www.nature.com/articles/d41586-021-02366-0

If You See Square Waves, Get Out of the Water!

We Can Make Powerful Nature-Inspired 'Pesticides' Without Poison, Scientists Say

While no one enjoys seeing carefully nurtured crops destroyed by hordes of hungry insects, the most common way to prevent it – the use of insecticides – is causing massive ecological problems.

Some are wreaking havoc on bee populations globally, killing birds and piling onto the challenges already faced by endangered species. Thankfully, insecticides are generally only in our food at low levels, but they do harm humans who are highly exposed to them too, like the workers growing our crops. 

They also destroy predatory insect populations, which just makes the problem of crop pests worse in the long term - with fewer pest enemies around to keep their numbers in check.

One alternative that researchers and farmers have been putting to the test is the use of predatory insects to control the problematic plant eaters. However, this approach, known as biological control, has its own challenges.

While insecticides can target multiple pest species, this is a lot harder to achieve when relying on natural predators. Releasing multiple predators could just lead to them preying on each other, or competing with each other for the same pest, as predators may not always target their intended species.

The predators are also very reliant on environmental conditions – temperature and day length can alter their behavior so they may only be effective during certain seasons. This, along with the fact that some pests are invasive and have no native predators means some pesticides may still need to be used, which can then also impact the predators.

part 1

So insect ecologists Jessica Kansman and Sara Hermann are looking into ways of tweaking the use of pest species' natural enemies to make it more practical. They presented results of their progress at this week's meeting of the American Chemical Society.

In a series of trials the researchers let collard-snacking aphids (Myzus persicae) choose between the scent of leaves with predatory ladybugs (Harmonia axyridis) on them or the smell of leaves with no ladybug.

They found exposure to the ladybug scent impacted the aphids' plant choices and even reduced their reproductive rate.

"Our early work has shown that these fear-based responses can change insect behaviors in ways that reduce their damage on these crop plants.

Preliminary field tests using three methoxypyrazine compounds (which we humans would recognize as the smell of ladybugs) isolated from ladybug stink have produced promising results - with aphids avoiding the sprayed collard crops as if ladybugs were present.

"The beauty of these compounds being specific to these insects is that it's an honest cue. The use of natural enemy odor cues is a promising future direction for applied chemical ecology in sustainable pest management

https://scitechdaily.com/using-the-smell-of-fear-to-protect-gardens...

https://www.sciencealert.com/researchers-propose-harnessing-the-ste...

part2

Protecting gardens and crops from insects using the ‘smell of fear’

Combo therapy cuts risk of heart attacks and strokes in half

A combination therapy of aspirin, statins and at least two blood pressure medications given in fixed doses can slash the risk of fatal cardiovascular disease (CVD) by more than half, says an international study.

The fixed-dose combination (FDC) therapies were examined both with and without aspirin versus control groups in a combined analysis of more than 18,000 patients without prior CVD from three large clinical trials. FDCs including aspirin cut the risk of heart attacks by 53 percent, stroke by 51 percent, and deaths from cardiovascular causes by 49 percent.

This combination, either given separately or combined as a polypill, substantially reduces fatal and non-fatal CVD events.

The largest effects are seen with treatments that include blood pressure lowering agents, a statin and aspirin together, which can reduce fatal and non-fatal cardiovascular events by about half.

The benefits are consistent at different blood pressure levels, cholesterol levels and with or without diabetes, but larger benefits may occur in older people.

 Philip Joseph et al, Fixed-dose combination therapies with and without aspirin for primary prevention of cardiovascular disease: an individual participant data meta-analysis, The Lancet (2021). DOI: 10.1016/S0140-6736(21)01827-4

https://medicalxpress.com/news/2021-08-combo-therapy-heart.html?utm...

Faster and Cheaper Ethanol-to-Jet-Fuel

'Charging room' system powers lights, phones, laptops without wires

In a move that could one day free the world's countertops from their snarl of charging cords, researchers have developed a system to safely deliver electricity over the air, potentially turning entire buildings into wireless charging zones.

Detailed in a new study published in Nature Electronics, the technology can deliver 50 watts of power using magnetic fields. In addition to untethering phones and laptops, the technology could also power implanted medical devices and open new possibilities for mobile robotics in homes and manufacturing facilities. The team is also working on implementing the system in spaces that are smaller than room-size, for example a toolbox that charges tools placed inside it.

You could put a computer in anything without ever having to worry about charging or plugging in. There are a lot of clinical applications as well; today's heart implants, for example, require a wire that runs from the pump through the body to an external power supply. This could eliminate that, reducing the risk of infection and improving patients' quality of life.

The system is a major improvement over previous attempts at wireless charging systems, which used potentially harmful microwave radiation or required devices to be placed on dedicated charging pads, the researchers say. Instead, it uses a conductive surface on room walls and a conductive pole to generate magnetic fields.

Devices harness the magnetic field with wire coils, which can be integrated into electronics like cell phones. The researchers say the system could easily be scaled up to larger structures like factories or warehouses while still meeting existing safety guidelines for exposure to electromagnetic fields.

Sasatani, T. et al, Room-scale magnetoquasistatic wireless power transfer using a cavity-based multimode resonator. Nat Electron (2021). doi.org/10.1038/s41928-021-00636-3

https://techxplore.com/news/2021-08-room-powers-laptops-wires.html?...

Synthetic biology enables microbes to build muscle

Would you wear clothing made of muscle fibers? Use them to tie your shoes or even wear them as a belt? It may sound a bit odd, but if those fibers could endure more energy before breaking than cotton, silk, nylon, or even Kevlar, then why not? And this muscle could be produced without harming a single animal.

Researchers have developed a synthetic chemistry approach to polymerize proteins inside of engineered microbes. This enabled the microbes to produce the high molecular weight muscle protein, titin, which was then spun into fibers.

Their research was published Monday, August 30 in the journal Nature Communications.

Microbial production of megadalton titin yields fibers with advantageous mechanical properties, Nature Communications (2021). DOI: 10.1038/s41467-021-25360-6

https://phys.org/news/2021-08-synthetic-biology-enables-microbes-mu...

Female octopuses observed throwing stuff at males harassing them

A team of researchers has found that female octopuses sometimes throw silt at males who are attempting to mate with them. The group has written a paper describing their observations and has posted it on the bioRxiv preprint server.

Earlier researchers recorded instances of octopuses throwing things at other octopuses. At the time, it was not clear if the other octopuses were being intentionally targeted or if it was accidental.

In making more recordings and studying them carefully, the researchers were able to see that the female octopuses engaged in multiple types of object-throwing. In most instances, throwing material such as silt or even shells was simply a means of moving material that was in the way or when building a nest. Less often, they saw what were clearly attempts by females to hurl material at a nearby male—usually, one trying to mate with her.

The researchers found that the hurling was done by grabbing material such as rocks, silt or shells and holding them under the body. Then the material was placed over a siphon that the creature uses for pushing out a jet of water very quickly. Doing so propelled the material ahead of a jet of water, sometimes as far as several body lengths.

In studying the tape, the researchers found multiple instances of females targeting males. And the males duck half of the time!

Peter Godfrey-Smith et al, In the Line of Fire: Debris Throwing by Wild Octopuses, biorxiv (2021). DOI: 10.1101/2021.08.18.456805

https://phys.org/news/2021-08-female-octopuses-males.html?utm_sourc...

Research Finally Reveals Ancient Universal Equation for the Shape of an Egg

Researchers have discovered the universal mathematical formula that can describe any bird’s egg existing in nature, a feat which has been unsuccessful until now.

Egg-shape has long attracted the attention of mathematicians, engineers, and biologists from an analytical point of view. The shape has been highly regarded for its evolution as large enough to incubate an embryo, small enough to exit the body in the most efficient way, not roll away once laid, is structurally sound enough to bear weight and be the beginning of life for 10,500 species that have survived since the dinosaurs. The egg has been called the “perfect shape.”

Analysis of all egg shapes used four geometric figures: sphere, ellipsoid, ovoid, and pyriform (conical), with a mathematical formula for the pyriform yet to be derived.

To rectify this, researchers introduced an additional function into the ovoid formula, developing a mathematical model to fit a completely novel geometric shape characterized as the last stage in the evolution of the sphere-ellipsoid, which it is applicable to any egg geometry.

This new universal mathematical formula for egg shape is based on four parameters: egg length, maximum breadth, shift of the vertical axis, and the diameter at one quarter of the egg length.

This long sought-for universal formula is a significant step in understanding not only the egg shape itself, but also how and why it evolved, thus making widespread biological and technological applications possible.

Mathematical descriptions of all basic egg shapes have already found applications in food research, mechanical engineering, agriculture, biosciences, architecture, and aeronautics. As an example, this formula can be applied to engineering construction of thin walled vessels of an egg shape, which should be stronger than typical spherical ones.

“Egg and math: introducing a universal formula for egg shape” by Valeriy G. Narushin, Michael N. Romanov and Darren K. Griffin, 23 August 2021, Annals of the New York Academy of Sciences.
DOI: 10.1111/nyas.14680

https://scitechdaily.com/the-perfect-shape-research-finally-reveals...

Making 1 Simple Substitution For Table Salt Could Save Millions of Lives, Study Shows

Effect of Salt Substitution on Cardiovascular Events and Death

too much salt is bad for you. More specifically, too much sodium is bad for you, and sodium is one of the two primary elements that make up salt (aka the chemical compound sodium chloride).

At the same time, other studies have plotted the health impacts of insufficient potassium in people's diets, which also has a negative effect on blood pressure.

As it happens, one product – commonly available in many supermarkets – can mitigate both these problems at the same time: salt substitutes that are designed to taste just like salt, but feature reduced levels of sodium and added amounts of potassium.

Despite the promise of salt substitutes, however, there's been a lack of large clinical trials measuring their impact on stroke, heart disease, and death, so questions remain about how effective they are.

Now, a giant study conducted in China seems to suggest pretty much everybody would benefit from making the switch.

https://www.nejm.org/doi/10.1056/NEJMoa2105675

https://www.sciencealert.com/making-1-simple-substitution-for-table...

**

Genes can respond to coded information in signals—or filter them out entirely

New research demonstrates that genes are capable of identifying and responding to coded information in light signals, as well as filtering out some signals entirely. The study shows how a single mechanism can trigger different behaviours from the same gene—and has applications in the biotechnology sector.

The fundamental idea here is that you can encode information in the dynamics of a signal that a gene is receiving. So, rather than a signal simply being present or absent, the way in which the signal is being presented matters.

For this study, researchers modified a yeast cell so that it has a gene that produces fluorescent proteins when the cell is exposed to blue light.

Here's how that works. A region of the gene called the promoter is responsible for controlling the gene's activity. In the modified yeast cells, a specific protein binds to the promoter region of the gene. When researchers shine blue light on that protein, it becomes receptive to a second protein. When the second protein binds to the first protein, the gene becomes active. And that's easy to detect, since the activated gene produces proteins that glow in the dark.

The researchers then exposed these yeast cells to 119 different light patterns. Each light pattern differed in terms of the intensity of the light, how long each pulse of light was, and how frequently the pulses occurred. The researchers then mapped out the amount of fluorescent protein that the cells produced in response to each light pattern.

People talk about genes being turned on or off, but it's less like a light switch and more like a dimmer switch—a gene can be activated a little bit, a lot, or anywhere in between. If a given light pattern led to the production of a lot of fluorescent protein, that means the light pattern made the gene very active. If the light pattern led to the production of just a little fluorescent protein, that means the pattern only triggered mild activity of the gene.

The researchers found that different light patterns can produce very different outcomes in terms of gene activity, that all three light pattern variables—intensity of the light, frequency of the light pulses, and how long each pulse lasted—could influence gene activity, but found that controlling the frequency of light pulses gave them the most precise control over gene activity.

Mapping the Dynamic Transfer Functions of Eukaryotic Gene Regulation, Cell Systems (2021).

1. Jessica B. Lee et al. Mapping the dynamic transfer functions of eukaryotic gene regulation. Cell Systems, 2021 DOI: 10.1016/j.cels.2021.08.003

https://phys.org/news/2021-08-genes-coded-signalsor-filter.html?utm...

High virus count in the lungs drives COVID-19 deaths

A buildup of coronavirus in the lungs is likely behind the steep mortality rates seen in the pandemic, a new study finds. The results contrast with previous suspicions that simultaneous infections, such as bacterial pneumonia or overreaction of the body's immune defense system, played major roles in heightened risk of death, the investigators say.

the new study showed that people who died of COVID-19 had on average 10 times the amount of virus, or viral load, in their lower airways as did severely ill patients who survived their illness. Meanwhile, the investigators found no evidence implicating a secondary bacterial infection as the cause of the deaths, although they cautioned that this may be due to the frequent course of antibiotics given to critically ill patients.

These findings suggest that the body's failure to cope with the large numbers of virus infecting the lungs is largely responsible for COVID-19 deaths in the pandemic.

Despite previous concerns that the virus may prompt the immune system to attack the body's own lung tissue and lead to dangerous levels of inflammation, the investigators found no evidence that this was a major contributor to COVID-19 deaths in the group studied. In fact,  this study notes that the strength of the immune response appeared proportionate to the amount of virus in the lungs.

The new study, publishing online Aug. 31 in the journal Nature Microbiology, was designed to clarify the role of secondary infections, viral load, and immune cell populations in COVID-19 mortality.

1. Imran Sulaiman, Matthew Chung, Luis Angel, Jun-Chieh J. Tsay, Benjamin G. Wu, Stephen T. Yeung, Kelsey Krolikowski, Yonghua Li, Ralf Duerr, Rosemary Schluger, Sara A. Thannickal, Akiko Koide, Samaan Rafeq, Clea Barnett, Radu Postelnicu, Chang Wang, Stephanie Banakis, Lizzette Pérez-Pérez, Guomiao Shen, George Jour, Peter Meyn, Joseph Carpenito, Xiuxiu Liu, Kun Ji, Destiny Collazo, Anthony Labarbiera, Nancy Amoroso, Shari Brosnahan, Vikramjit Mukherjee, David Kaufman, Jan Bakker, Anthony Lubinsky, Deepak Pradhan, Daniel H. Sterman, Michael Weiden, Adriana Heguy, Laura Evans, Timothy M. Uyeki, Jose C. Clemente, Emmie de Wit, Ann Marie Schmidt, Bo Shopsin, Ludovic Desvignes, Chan Wang, Huilin Li, Bin Zhang, Christian V. Forst, Shohei Koide, Kenneth A. Stapleford, Kamal M. Khanna, Elodie Ghedin, Leopoldo N. Segal. Microbial signatures in the lower airways of mechanically ventilated COVID-19 patients associated with poor clinical outcome. Nature Microbiology, 2021; DOI: 10.1038/s41564-021-00961-5

https://medicalxpress.com/news/2021-08-high-virus-lungs-covid-death...

The right mixture of salts to get life started

In modern organisms, the hereditary material DNA encodes the instructions for the synthesis of proteins—the versatile nanomachines that enable modern cells to function and replicate. But how was this functional linkage between DNA and proteins established? According to the "RNA world" hypothesis, primordial living systems were based on self-replicating RNA molecules. Chemically speaking, RNA is closely related to DNA. However, in addition to storing information, RNA can fold into complex structures that have catalytic activity, similar to the protein nanomachines that catalyze chemical reactions in cells. These properties suggest that RNA molecules should be capable of catalyzing the replication of other RNA strands, and initiating self-sustaining evolutionary processes. Hence, RNA is of particular interest in the context of the origin of life as a promising candidate for the first functional biopolymer.

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New options for sustainable antibiotic therapy

Public health is coming under increasing pressure worldwide due to the antibiotic crisis: the rapid increase in resistance of bacterial pathogens could mean that in the near future bacterial infections that are usually harmless will be difficult or impossible to treat. The spread of antibiotic resistance is based on the ability of pathogens to adapt quickly to the drugs. In principle, evolutionary theory assumes that this adaptation is more difficult when environmental conditions change rapidly. Sequential antibiotic therapy, which involves switching between different antibiotics in a short time, could therefore lead to a reduction in the spread of resistance. This therapeutic approach is usually not considered in medical treatment and is also hardly investigated in basic research—despite the possible long-term benefits.

Researchers take step toward using cellular motion to help wound healing

With a technique that overcomes cells' innate social behaviors, researchers have taken an important step in directing skin cells to migrate en masse to close wounds—"literally making skin crawl".

In a new study, the researchers overcame the inertia typical of mature skin tissue by breaking the molecular connections between cells, applying an electrical field to direct their migration and then rebuilding the connections. This novel approach improves the controllability of tissues and may one day help optimize wound healing through electrical stimulation.

Research showed that cells in the body can sense and follow an electric field, a process called electrotaxis. Electric fields generated in the body promote healing by directing cells to move toward the wound and are also vital for growth and development.

Despite promising clinical evidence from decades of use in patients, scientists have yet to work out how cells detect and respond to electric fields or how electrical stimulation can best be applied therapeutically. "It's kind of a black box

 Gawoon Shim et al, Overriding native cell coordination enhances external programming of collective cell migration, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2101352118

part1

In their previous work, Cohen's group used electric fields to program thousands of individual cells to move in circles and around corners. Their new study used a model of more mature skin—a single layer of mouse skin cells all latched together—which is harder to control. Instead of moving with the speed and precision of a marching band in response to an electric current, the mature skin cells inched along like a crowd of people holding hands with their neighbors.

The mature skin also posed another problem: Once the leading edge of cells advanced, it would peel away from the petri dish and die. "If you apply a command that differs from what the cells naturally 'want' to do, you get a tug-of-war. The result was the tissues ripped themselves apart.

Cohen and Shim suspected that the "handshakes" between cells prevented the tissue from fluidly following the electrical commands. These handshakes are proteins called cadherins that anchor neighboring cells together. They make tissues cohesive so they can move together but can also create traffic jams when cells don't have space to move.

 Gawoon Shim et al, Overriding native cell coordination enhances external programming of collective cell migration, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2101352118

https://phys.org/news/2021-08-cellular-motion-wound.html?utm_source...

part 2

Cadherins need calcium ions to complete their connections, so Shim grew the cells with different amounts of calcium and measured their response to electrical stimulation. She saw that the less calcium the cells had, the more fluid they became and the quicker they moved. "It goes really fast.

Calcium has many effects on living tissues, however, so Shim had to confirm that the handshakes were to blame for the slow movement. She grew cells with an antibody that attaches to cadherins. With blocked handshakes, these cells moved more quickly.

After working out the ground rules of cell adhesiveness, the researchers developed a solution to their sticky cell problem. Shim grew a layer of skin cells in a high calcium solution so they made their normal connections. Then she treated the cells with a chemical that grabs up calcium ions to break up the cellular handshakes. When Shim lowered the calcium level and applied the electric field, the cells moved on command. Finally, she restored the high calcium level to reinstate the handshakes, resulting in a healthy and cohesive layer of skin cells.

To demonstrate that this approach has the potential to accelerate healing, Shim performed the above experiment using an electrobioreactor developed in the Cohen lab that mimics the closing of a wound. Unlike other models of electrotaxis where the electric field moves cells in one direction, their new system exposes cells to an electric field focused on the center of the injury. Shim showed that the stimulated tissues successfully came together while the unstimulated ones remained largely separate. Cohen's group described their electrobioreactor in a new paper in Biosensors and Bioelectronics.

part3

Model of SARS-CoV-2 dynamics reveals opportunity to prevent COVID-19 transmission

Scientists have simulated the transition of the SARS-CoV-2 spike protein structure from when it recognizes the host cell to when it gains entry, according to a study published today in eLife.

The team was particularly interested in the role of sugar molecules on the spike protein, which are called glycans. To see whether the number, type and position of glycans play a role in the membrane fusion stage of viral cell entry by mediating these intermediate spike formations, they performed thousands of simulations using an all-atom structure-based model. Such models allow prediction of the trajectory of atoms over time, taking into account steric forces—that is, how neighboring atoms affect the movement of others.

The simulations revealed that glycans form a "cage" that traps the "head" of the S2 subunit, causing it to pause in an intermediate form between when it detaches from the S1 subunit and when the viral and cell membranes are fused. When the glycans were not there, the S2 subunit spent much less time in this conformation.

The simulations also suggest that holding the S2 head in a particular position helps the S2 subunit recruit human host cells and fuse with their membranes, by allowing the extension of short proteins called fusion peptides from the virus. Indeed, glycosylation of S2 significantly increased the likelihood that a fusion peptide would extend to the host cell membrane, whereas when glycans were absent, there was only a marginal possibility that this would occur.

 simulations indicate that glycans can induce a pause during the spike protein transition. This provides a critical opportunity for the fusion peptides to capture the host cell.

In the absence of glycans, the viral particle would likely fail to enter the host. Our study reveals how sugars can control infectivity, and it provides a foundation for experimentally investigating factors that influence the dynamics of this pervasive and deadly pathogen.

Esteban Dodero-Rojas et al, Sterically confined rearrangements of SARS-CoV-2 Spike protein control cell invasion, eLife (2021). DOI: 10.7554/eLife.70362

https://phys.org/news/2021-08-sars-cov-dynamics-reveals-opportunity...

part 2 **

 Winners from the Wellcome Photography Prize 2021: 

Fighting Infections

Scientists  discover a rare, aggressive form of Alzheimer's that begins in the early 40s

A newly discovered gene mutation linked to early onset Alzheimer's disease has been discovered by an international team of scientists, who traced the DNA flaw through multiple members of a single family.

Alzheimer's has long been known as a mind-robbing disease that that wipes out memories and destroys one's sense of self. Most cases of arise sporadically, emerging after age of 65—transmuting one's golden years into a nightmare marked by an incurable brain disease.

Aside from Alzheimer's dementia that begins sporadically in old age, are insidious familial forms that begin years to decades earlier. Early onset refers Alzheimer's that begins before age 65.

Now, an international team of scientists—led by neurobiologists in Sweden—have identified an extraordinarily rare form of the disease that so far has been found only in one family. This form of Alzheimer's is aggressive, rapid and steals its victims' most productive years along their cognitive functions.

Researchers in Sweden have named this form of Alzheimer's—the Uppsala APP deletion—after the family that's endowed with this notorious DNA miscue. It invariably causes descent into dementia at a young age.

Affected individuals have an age at symptom onset  in their early forties, and suffer from a rapidly progressing disease course.

Researchers found that the mutation accelerates the formation of brain-damaging protein plaques, known as amyloid beta, or more simply as Aβ. The gooey plaques destroy neurons and, as a result, annihilate the executive functions of the brain itself. Neuroscientists basically define executive functions as working memory, mental flexibility and self control.

María Pagnon de la Vega et al, The Uppsala APP deletion causes early onset autosomal dominant Alzheimer's disease by altering APP processing and increasing amyloid β fibril formation, Science Translational Medicine (2021). DOI: 10.1126/scitranslmed.abc6184

https://medicalxpress.com/news/2021-09-scientists-sweden-rare-aggre...

Do genetics control who our friends are? It seems so with mice

Have you ever met someone you instantly liked, or at other times, someone who you knew immediately that you did not want to be friends with, although you did not know why?

Some people speculated that "unconscious" part of the brain enables us to process information spontaneously, when, for example, meeting someone for the first time, interviewing someone for a job, or faced with making a decision quickly under stress.

Now, a new study from the University of Maryland School of Medicine (UMSOM) suggests that there may be a biological basis behind this instantaneous compatibility reaction. A team of researchers showed that variations of an enzyme found in a part of the brain that regulates mood and motivation seems to control which mice want to socially interact with other mice—with the genetically similar mice preferring each other.

These findings may indicate that similar factors could contribute to the social choices people make. Understanding what factors drive these social preferences may help us to better recognize what goes awry in diseases associated with social withdrawal, such as schizophrenia or autism, so that better therapies can be developed.

The study was published on July 28 in Molecular Psychiatry, a Nature publication.

But, let us wait till these results are reproduced several times before coming to a conclusion.

 Abigail J. Smith et al, A genetic basis for friendship? Homophily for membrane-associated PDE11A-cAMP-CREB signaling in CA1 of hippocampus dictates mutual social preference in male and female mice, Molecular Psychiatry (2021). DOI: 10.1038/s41380-021-01237-4

https://medicalxpress.com/news/2021-09-genetics-friends-mice.html?u...

Hidden bacterial hairs power nature's 'electric grid'

A hair-like protein hidden inside bacteria serves as a sort of on-off switch for nature's "electric grid," a global web of bacteria-generated nanowires that permeates all oxygen-less soil and deep ocean beds,  researchers report in the journal Nature.

The ground beneath our feet, the entire globe, is electrically wired. These previously hidden bacterial hairs are the molecular switch controlling the release of nanowires that make up nature's electrical grid.

Almost all living things breathe oxygen to get rid of excess electrons when converting nutrients into energy. Without access to oxygen, however, soil bacteria living deep under oceans or buried underground over billions of years have developed a way to respire by "breathing minerals," like snorkeling, through tiny protein filaments called nanowires.

Scientists had thought that the nanowires are made up of a protein called "pili" ("hair" in Latin) that many bacteria show on their surface. This work has reveal that this pili structure is made up of two proteins And instead of serving as nanowires themselves, pili remain hidden inside the bacteria and act like pistons, thrusting the nanowires into the environment. Previously nobody had suspected such a structure.

Just how these soil bacteria use nanowires to exhale electricity, however, has remained a mystery. Now that mystery has been solved.

Understanding how bacteria create nanowires will allow scientists to tailor bacteria to perform a host of functions—from combatting pathogenic infections or biohazard waste to creating living electrical circuits, the authors say. It will also assist scientists seeking to use bacteria to generate electricity, create biofuels, and even develop self-repairing electronics.

Structure of Geobacter pili reveals secretory rather than nanowire behaviour, Nature (2021). DOI: 10.1038/s41586-021-03857-w , www.nature.com/articles/s41586-021-03857-w

https://phys.org/news/2021-09-hidden-bacterial-hairs-power-nature.h...

Ultrasonic social distancing

Social distancing has been a critical component of the world's response to the COVID-19 pandemic. The idea being that keeping physical apart from other people will reduce the risk of a person spreading the respiratory virus to someone else. It is just one component of our response, which also includes wearing face coverings, frequent hand sanitisation, and obtaining a vaccine against the virus.

New research in the International Journal of Sensor Networks discusses the potential of ultrasonic sensors to help people keep a safe distance from others when social distancing is deemed necessary in a pandemic situation.

Mohit Ghai and Ruchi Gupta of the Department of Electrical and Electronics Engineering at ADGITM, IP University in Delhi, India, describe a small, portable sensor-alarm device based on an Arduino system. Arduino is an open-source hardware and software system that can be used to quickly build single-board microcontrollers and microcontroller kits with a variety of inexpensive applications. There is scope to add Wi-Fi capability and other networking functionality to a device too.

The team's Arduino device has an ultrasonic sensor that continuously probes the space around a person and is triggered when another person enters one's personal space within a pre-determined threshold distance set according to social distancing rules. The system is not dissimilar to the parking sensors with which many vehicles are fitted and so could give a timely indication to the user that they have moved too close to another person unwittingly or alert them when another person moves nearer to them in a shopping queue or other setting, for instance.

Given how often people misjudge distances between themselves and others especially in busy environments, a portable alarm system of this sort could be a boon to those hoping to ensure social distancing is maintained to help reduce the risk of spreading infection.

Mohit Ghai et al, Ultrasonic sensor based social distancing device, International Journal of Sensor Networks (2021). DOI: 10.1504/IJSNET.2021.117227

https://techxplore.com/news/2021-09-ultrasonic-social-distancing.ht...

Scientific breakthrough in the battle against cancer: First 3D printing of glioblastoma cancer tumor

Biologists Just Got Closer to The DNA Secrets That Stop Species From Interbreeding

We think of DNA as the vitally important molecules that carry genetic instructions for most living things, including ourselves. But not all DNA actually codes proteins; now, we're finding more and more functions involving the non-coding DNA scientists used to think of as 'junk'.

A new study suggests that satellite DNA – a type of non-coding DNA arranged in long, repetitive, apparently nonsensical strings of genetic material – may be the reason why different species can't successfully breed with each other.

It appears that satellite DNA plays an essential role in keeping all of a cell's individual chromosomes together in a single nucleus, through the work of cellular proteins.

According to biologists Madhav Jagannathan and Yukiko Yamashita who authored the new study, that important role is managed differently in each species, leading to genetic incompatibility. The clash of the different strategies between species may be what causes chromosomes to scatter outside of the nucleus, at least in part, preventing reproduction.

"We propose a unifying framework that explains how the widely observed satellite DNA divergence between closely related species can cause reproductive isolation," they write in their paper.

This "satellite DNA divergence" has been well established in previous research, leading to suspicions about its role in speciation. In the case of the chimpanzee genome and the human genome, for example, the protein-coding DNA is almost identical, while the 'junk' DNA is almost entirely different.

https://academic.oup.com/mbe/advance-article/doi/10.1093/molbev/msa...

https://www.sciencealert.com/junk-dna-could-be-why-different-specie...

Study explores the influence of the X-chromosome on brain anatomy

Past neuroscience research suggests that common differences in people's genetic profiles can explain a significant proportion of variations in people's brain anatomy. In more specific terms, they found that neuroanatomical variation is partly explained by genetic variation.

Scientists have hypothesized that the X-chromosome has a particularly crucial influence on the brain, as it is known to be associated with the expression of many genes. In addition, several types of intellectual disabilities have been found to be related with mutations of genes on the X chromosome.

All existing studies investigating the role of genetics on brain anatomy excluded the X-chromosome, which accounts for about 5% of our genomes. it would be important to address this gap because—beyond the basic need to complete the missing analysis—there were lot of existing hints that the X-chromosome might actually have a special capacity to explain variation in brain anatomy.

So  if a common genetic variation explains 30% of variation in total brain volume, then a chromosome which represents 10% of the genome would explain 3% of variation in total brain volume.

The X-chromosome consists of approximately 5% of the total genome. Taking this into consideration, researchers calculated the proportion of anatomical variation that could be explained by the X-chromosome. They found that given its known size and the percentage of the human genome it represents, the proportion they calculated differed significantly from the expected proportion.

The main take-aways from our studies are that the X-chromosome does indeed 'punch above its weight' in its capacity to explain differences in brain anatomy and that this phenomenon seems to be concentrated in particular brain systems important for complex thinking, decision making and action.

In terms of practical implications— this finding tells us that we really do need to put an end to exclusion of the X-chromosome from genetic analyses of the brain and related traits such as cognition and behavior.

The findings gathered by this team of researchers significantly enrich the current understanding of the X-chromosome's role in human neurodevelopment.

X-chromosome influences on neuroanatomical variation in humans. Nature Neuroscience(2021). DOI: 10.1038/s41593-021-00890-w

https://medicalxpress.com/news/2021-09-explores-x-chromosome-brain-...

**

A gecko-inspired robot's crash-landing correction

Birds and mammals evolve faster if their home is rising

The rise and fall of Earth's land surface over the last three million years shaped the evolution of birds and mammals, a new study has found, with new species evolving at higher rates where the land has risen most.

Researchers at the University of Cambridge have combined reconstructions of the Earth's changing surface elevations over the past three million years with data on climate change over this timeframe, and with bird and mammal species' locations. Their results reveal how species evolved into new ones as land elevation changed—and disentangle the effects of elevation from the effects of climate.

The study found that the effect of elevation increase is greater 

than that of historical climate change, and of present-day elevation and temperature, in driving the formation of new species – 'or speciation'.

In contrast to areas where land elevation is increasing, elevation loss was not found to be an important predictor of where speciation happens. Instead, present-day temperature is a better indicator of speciation in these areas.

The results are published today in the journal Nature Ecology and Evolution.

 Global topographic uplift has elevated speciation in mammals and birds over the last 3 million years, Nature Ecology and Evolution (2021). DOI: 10.1038/s41559-021-01545-6 , www.nature.com/articles/s41559-021-01545-6

https://phys.org/news/2021-09-birds-mammals-evolve-faster-home.html...

Nano 'camera' made using molecular glue allows real-time monitoring of chemical reactions

Researchers have made a tiny camera, held together with 'molecular glue' that allows them to observe chemical reactions in real time.

The device, made by a team from the University of Cambridge, combines tiny semiconductor nanocrystals called quantum dots and gold nanoparticles using molecular glue called cucurbituril (CB). When added to water with the molecule to be studied, the components self-assemble in seconds into a stable, powerful tool that allows the real-time monitoring of chemical reactions.

The camera harvests light within the semiconductors, inducing electron transfer processes like those that occur in photosynthesis, which can be monitored using incorporated gold nanoparticle sensors and spectroscopic techniques. They were able to use the camera to observe chemical species which had been previously theorized but not directly observed.

The platform could be used to study a wide range of molecules for a variety of potential applications, such as the improvement of photocatalysis and photovoltaics for renewable energy. The results are reported in the journal Nature Nanotechnology.

Földes, T. et al, Nanoparticle surfactants for kinetically arrested photoactive assemblies to track light-induced electron transfer, Nat. Nanotechnol. (2021). DOI: 10.1038/s41565-021-00949-6 , www.nature.com/articles/s41565-021-00949-6

https://phys.org/news/2021-09-nano-camera-molecular-real-time-chemi...

Decaying forest wood releases 10.9 billion tons of carbon yearly, which will increase with climate change

If you've wandered through a forest, you've probably dodged dead, rotting branches or stumps scattered on the ground. This is "deadwood," and it plays several vital roles in forest ecosystems.

It provides habitat for small mammals, birds, amphibians and insects. And as deadwood decomposes it contributes to the ecosystem's cycle of nutrients, which is important for plant growth.

But there's another important role we have little understanding of on a global scale: the carbon deadwood releases as it decomposes, with part of it going into the soil and part into the atmosphere. Insects, such as termites and wood borers, can accelerate this process.

The world's deadwood currently stores 73 billion tons of carbon. Our new research in Nature has, for the first time, calculated that 10.9 billion tons of this (around 15%) is released into the atmosphere and soil each year—a little more than the world's emissions from burning fossil fuels.

But this amount can change depending on insect activity, and will likely increase under climate change. It's vital deadwood is considered explicitly in all future climate change projections.

Sebastian Seibold et al, The contribution of insects to global forest deadwood decomposition, Nature (2021). DOI: 10.1038/s41586-021-03740-8

https://phys.org/news/2021-09-forest-wood-billion-tons-carbon.html?...

**

How harmful is methane?

Methane contributes to global warming; it is therefore a greenhouse gas. Of all the methane produced in some developed countries, 70% comes from livestock farming. A substantial percentage. But how harmful is it? Because, unlike other greenhouse gasses, methane breaks down relatively quickly in the atmosphere. 

Greenhouse gasses are important. They form a blanket around the earth. Without greenhouse gasses, it would be unbearably cold on earth. The problem with the greenhouses gasses is that we too much of them. The blanket becomes so thick, that the earth's temperature rises. This causes periods of drought and in other places too much precipitation, the polar caps melt, and so on.

there are three greenhouse gasses: carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O). Roughly speaking, you can say that all three are created during the breakdown or combustion of organic substances. CO₂ (and NO_x) are mainly created through the combustion of diesel, lignite or gasoline. Not only in transport and traffic, but also in production processes. From the concrete in your house to the staples in your furniture, almost everything in our lives produces CO₂ during its production.

Methane is released during the breakdown of organic substances. For example, in the gastrointestinal tract of animals. Ruminants (cows, goats, sheep) in particular produce a lot of methane. Methane is also 34 times more powerful than carbon dioxide. So, the earth warms up extra fast when there is more methane in the atmosphere. N₂O is created in processes where nitrogen compounds play a role: in manure storage and manure application."

part 1

CO₂ stays in the atmosphere for a very, very long time. Many thousands of years. So that greenhouse gas accumulates, and the 'blanket' around the earth thickens. The unique thing about methane is that it halves in the atmosphere in just over 8 years. The other half becomes CO₂. So if you emit 100 kilos of methane today, in 8.5 years there will be 50 kilos left, and after another 8.5 years only 25 kilos, and so on," Vellinga explains. "That CO₂ has gone through what is known as the short carbon cycle: it was converted by grass, corn, etc. into plant material, which the cow converts back into CO₂ and CH₄. And that CH₄ becomes CO₂ again pretty quickly. Nothing to worry about, you might say."

"But be careful not to make the problem too small. Before you know it, it seems as if there is nothing wrong with methane. On the contrary. As long as methane is in the atmosphere, it contributes very strongly to warming. Over the lifetime of methane, this is as much as 80 to 100 times more than CO₂.

But the advantage is that it disappears quickly. Reducing methane emissions can cause the concentration of methane in the atmosphere to drop and therefore even reduce the greenhouse effect. When reducing CO₂, the current greenhouse effect remains the same and only does not increase. So reducing methane is more effective than reducing CO₂. But it has to be done both ways."

https://phys.org/news/2021-09-fact-methane.html?utm_source=nwletter...

Part 2

**

How Do Ants Tunnel So Well?

Drug cocktail reduces aging-associated disc degeneration

Chronic back pain affects  millions of  adults in the world. Degeneration of the discs that cushion and support vertebrae, a common occurrence of aging, is a major contributor to low back pain. Although a widespread condition, few treatments are available.

With age, every tissue in the body accumulates senescent cells. Senescent cells secrete destructive enzymes and inflammatory proteins that affect nearby healthy cells. Senolytic drugs remove these deteriorating cells, leaving room for new cells to replace them. The idea is that removing senescent cells from a tissue will improve the tissue's function.

New research has shown  that treating mice with a drug cocktail that removes aging cells reduces disc degeneration. The findings, reported in Nature Communications on September 3rd, show how a novel approach to preventing age-related disc degeneration may pave the way for treating chronic back pain.

The findings show that senolytic drugs—ones already approved for use in clinical trials—can mitigate disc degeneration that occurs with aging.

Just because the drugs work in one tissue doesn't mean they will also work in another. Every tissue is different and should be treated differently.

Young and middle-aged mice given the senolytic cocktail showed less disc degeneration and fewer senescent cells by the time they reached an advanced age compared to mice given a placebo.

"Long-term treatment with senolytic drugs Dasatinib and Quercetin ameliorates age-dependent intervertebral disc degeneration in mice." Nature Communications (2021) , DOI: 10.1038/s41467-021-25453-2

https://medicalxpress.com/news/2021-09-drug-cocktail-aging-associat...

The first cells might have used temperature to divide

A simple mechanism could underlie the growth and self-replication of protocells—putative ancestors of modern living cells—suggests a study publishing September 3 in Biophysical Journal. Protocells are vesicles bounded by a membrane bilayer and are potentially similar to the first unicellular common ancestor (FUCA). On the basis of relatively simple mathematical principles, the proposed model suggests that the main force driving protocell growth and reproduction is the temperature difference that occurs between the inside and outside of the cylindrical protocell as a result of inner chemical activity.

The purpose of this study was to identify the main forces driving cell division. This is important because cancer is characterized by uncontrolled cell division. This is also important to understand the origin of life.

The splitting of a cell to form two daughter cells requires the synchronization of numerous biochemical and mechanical processes involving cytoskeletal structures inside the cell. But in the history of life, such complex structures are a high-tech luxury and must have appeared much later than the ability to split. Protocells must have used a simple splitting mechanism to ensure their reproduction, before the appearance of genes, RNA, enzymes, and all the complex organelles present today, even in the most rudimentary forms of autonomous life.

In the new study, researchers proposed a model based on the idea that the early forms of life were simple vesicles containing a particular network of chemical reactions—a precursor of modern cellular metabolism. The main hypothesis is that molecules composing the membrane bilayer are synthesized inside the protocell through globally exothermic, or energy-releasing, chemical reactions.

The slow increase of the inner temperature forces the hottest molecules to move from the inner leaflet to the outer leaflet of the bilayer. This asymmetric movement makes the outer leaflet grow faster than the inner leaflet. This differential growth increases the mean curvature and amplifies any local shrinking of the protocell until it splits in two. The cut occurs near the hottest zone, around the middle.

The scenario described can be viewed as the ancestor of mitosis. Having no biological archives as old as 4 billion years, we don't know exactly what FUCA contained, but it was probably a vesicle bounded by a lipid bilayer encapsulating some exothermic chemical reactions.

Although purely theoretical, the model could be tested experimentally.

Biophysical Journal, Attal and Schwartz: "Thermally driven fission of protocells" www.cell.com/biophysical-journ … 0006-3495(21)00686-X  , DOI: 10.1016/j.bpj.2021.08.020

https://phys.org/news/2021-09-cells-temperature.html?utm_source=nwl...

**

Unified theory explains how materials transform from solids to liquids

A new study unveils a unified mathematical expression that defines how soft-yet-rigid materials transition from a solid into a liquid flow when they exceed their specific stress threshold.

This study has shown   that these physical states—solid and liquid—can exist together in the same material, and we can explain it using one mathematical expression.

To develop this model, the team performed numerous studies that subjected a variety of different soft materials to stress while measuring the individual solidlike and liquidlike strain responses using a device called a rheometer.

The researchers were able to observe a material's behavior and see a continuous transition between the solid and liquid states and were able to resolve two distinct behaviors that reflect energy dissipation via solid and fluid mechanisms.

Krutarth Kamani et al, Unification of the Rheological Physics of Yield Stress Fluids, Physical Review Letters (2021). DOI: 10.1103/PhysRevLett.126.218002

https://phys.org/news/2021-09-theory-materials-solids-liquids.html?...

Fish eyes grown in a petri dish from embryonic stem cells

A research team has demonstrated that complex retinal tissue can be cultured in a Petri dish from embryonic stem cells of bony fish. Until now, stem cells from mammals, including humans, have been used in organoid research. For the first time, researchers have demonstrated that stem cells from medaka and zebrafish can also form highly organized neural structures under controlled laboratory conditions. Among other things, the researchers expect to gain new insights into the basic mechanisms of retinal development.

Organoids are bits of tissue that are grown from stem cells and resemble actual organs. They are used in basic research to gain new information on cell organization and organ development, to investigate the origin of disease, and to develop and test new medications. The major advantage of fish organoids is that they are highly reproducible, unlike organoids from mammalian stem cells. They develop reliably and very quickly and enable a direct comparison with living embryos that in fish grow outside of the womb.

Researchers are  now able to manipulate the molecular and genetic mechanisms of retina  formation.

  Researchers used pluripotent stem cells  from medaka and zebrafish embryos. Such cells have not yet differentiated and can potentially develop into many different cell types. All the cells taken from a single embryo independently aggregated into one large retina within 24 hours. In a matter of a few days, it then formed layers of different cell types that are also found in the fish eye, including photoreceptor cells, bipolar cells, amacrine cells, and ganglion cells. The growth process proved to be incredibly efficient. Hundreds of small retina organoids could be generated within a day. The high throughput allowed the researchers to precisely isolate the conditions in which structures resembling a head with two eyes, including both brain and retina, are formed.

Lucie Zilova et al, Fish primary embryonic pluripotent cells assemble into retinal tissue mirroring in vivo early eye development, eLife (2021). DOI: 10.7554/eLife.66998

https://phys.org/news/2021-09-fish-eyes-grown-petri-dish.html?utm_s...

Coronavirus epidemics first hit more than 21,000 years ago

Sarbecoviruses have crossed into humans twice in the last decade, leading to the deadly SARS-CoV-1 outbreak in 2002-04 and the current COVID-19 pandemic, caused by the SARS-CoV-2 virus. A new Oxford University study, published today, shows that the most recent common ancestor of these viruses existed more than 21,000 years ago, nearly 30 times older than previous estimates.

Despite having a very rapid rate of evolution over short timescales, to survive, viruses must remain highly adapted to their hosts—this imposes severe restrictions on their freedom to accumulate mutations without reducing their fitness. This causes the apparent rate of evolution of viruses to slow down over time. The new research, for the first time, successfully recreates the patterns of this observed rate decay in viruses.

The study also demonstrates that while existing evolutionary models have often failed to measure the divergence between virus species over periods—from a few hundred to a few thousands of years—the evolutionary framework developed in this study will enable the reliable estimation of virus divergence across vast timescales, potentially over the entire course of animal and plant evolution.

The new model enables us to not only reconstruct the evolutionary history of viruses related to SARS-CoV-2, but also a much wider range of RNA and DNA viruses during more remote periods in the past.

Mahan Ghafari et al, A mechanistic evolutionary model explains the time-dependent pattern of substitution rates in viruses, Current Biology (2021). DOI: 10.1016/j.cub.2021.08.020

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