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

https://phys.org/news/2021-09-coronavirus-epidemics-years.html?utm_...

Hormones May Contribute to Asymmetrical Effects of Brain Injury

“Mystery Fever” Claims the Lives of Dozens of Indian Children

So far, more than 50 people have died of a febrile illness, though the cause isn’t clear.

In addition to the ongoing COVID-19 pandemic and an uptick of malaria cases across the country, an unknown disease has killed more than 50 people in the state of Uttar Pradesh, India in the last week; most were children. All of the patients tested negative for COVID-19, and India Today reports it is likely that scrub typhus is to blame, though other possibilities, such as dengue, have not been ruled out.

 The Hindustan Times reports, and monsoon season has brought a greater number of mosquito-borne illnesses. Now, many regions in the state are reporting illness and death due to a mystery fever.

Water-logging, and lack of sanitation and hygiene are the reasons behind the disease spread. The patients, especially children, in hospitals are dying very quickly.

According to multiple news outlets, the hundreds of people hospitalized by the illness have experienced fever, headaches, joint pain, nausea, rashes, and dehydration. A drop in platelet count has also been observed in many fatal cases. Though many of these symptoms can occur in severe dengue cases, The Hindustan Times and others report that the likely culprit is a bacterial disease called scrub typhus.

Scrub typhus can occur after a person is bitten by chiggers infected with Orientia tsutsugamushi bacteria. According to the BBC, these mites live on plants that flourish after the monsoon rains, and they can hitchhike into people’s homes on firewood. The symptoms of O. tsutsugamushi infection largely overlap with what has been seen in the patients.

According to the US Center for Disease Control and Prevention (CDC), there are no vaccinations for scrub typhus and it should be treated with the antibiotic doxycycline. The agency recommends covering exposed skin to prevent chigger bites.

https://www.the-scientist.com/news-opinion/mystery-fever-claims-the...

Biomedical Innovations from Women Less Likely to be Adopted: Study

An analysis of scientists’ networks finds discrepancies in the diffusion of novel ideas through communities.

A study published Monday (August 30) by the National Bureau of Economic Research finds that new ideas in biomedical research are less likely to spread when they are generated by women and minorities than when generated by men.

The authors of the study, which was not peer-reviewed, used a computational technique called natural language processing to scan titles and abstracts in MEDLINE for novel one, two, or three-word phrases originating in biomedical research papers published between 1980 and 2008. The researchers ranked these phrases by the total number of mentions they received in the year when they first appeared and analyzed the top 0.1 percent of phrases for each year to assess whether each represented an actual new idea or scientific innovation.

Ideas generated by teams of mostly male innovators were mentioned just over one percent more frequently in subsequent titles and abstracts than ideas generated by mostly female teams over a period of five years after they were first published.

Why words become harder to remember as we get older

As we get older, we find it increasingly difficult to have the right words ready at the right moment, even though our vocabulary actually grows continuously over the course of our lives. Until now, it was unclear why this is. Researchers  have now found out: It is the networks in the brain that change their communication over time. This makes them more inefficient.

The researchers investigated these connections with the help of two groups - younger study participants between the ages of 20 and 35 and older ones between the ages of 60 and 70. Both groups were asked to name words in the MRI scanner that belong to certain categories, including animals, metals or vehicles.

It became clear that both age groups were good at finding words. However, the younger ones were somewhat faster. The reason for this could be the different brain activities. For one thing, not only were the language areas themselves more active in the younger ones. They also showed a more intensive exchange within two decisive networks: the network for semantic memory, in which factual knowledge is stored, and the executive network, which is responsible for general functions such as attention and memory.

The reverse was true for older people. Here, executive areas showed stronger activity, indicating that the task was more difficult for these individuals overall. In addition, the exchange within the crucial networks was less effective than in the younger people. The older group was most likely to benefit from inter-network exchange, but this is associated with losses. Communication within neuronal networks is more efficient and thus faster than between them.

 Why these activity patterns shift with age has not yet been fully explained. One theory, says Martin, is that as people age, they rely more on the linguistic knowledge they have, so exchanges between networks come into focus, while younger people rely more on their fast working memory and cognitive control processes. On the structural level, the loss of grey matter in the brain could also play a role, which is compensated for by the exchange between networks.

“Age-Dependent Contribution of Domain-General Networks to Semantic C...” by Sandra Martin et al. Cerebral Cortex

https://researchnews.cc/news/8725/Why-words-become-harder-to-rememb...

Robo Pill

Sport science: How do swimmers control their front crawl swimming velocity?

A research team  has reviewed the hydrodynamics literature related to swimming. They identified certain biomechanical aspects, including the relationship between velocity and drag forces, that are not completely understood. This work may help direct future research that could improve the performance of competitive swimmers.

The recent Tokyo Olympics provided impressive feats of speed in the pool, with elite athletes setting many new Olympic and World records. What viewers might not realize, however, is the complexity of the science underlying the sometimes split-second difference between winning a gold medal and going home empty-handed. Biomechanics, the study of motion of the body, and hydrodynamics, the area of physics dealing with fluid flows, contain many questions that remain poorly understood—and swimming fits right at the intersection of these topics. For swimmers who participate in races, even a tiny advance in knowledge can led to a competitive edge.

Now, a team of researchers  has drawn together research on front crawl swimming biomechanics, focusing on propulsive and resistive forces at different swimming velocities, to form a more complete picture of the relationships between the critical variables. New knowledge of swimming energetics and fluid mechanics has improved our understanding of factors that determine swimming performance.

One of the most important relationships to understand is how resistive forces, like drag when moving through the water, depend on the speed of the swimmer. The researchers looked at recent studies that indicated the resistive force increases in proportion to the cube of the velocity. To compensate, swimmers may try to increase their stroke frequency. However, this has limitations. Researchers inferred from experimental and simulation studies that there is a maximum frequency beyond which swimmers cannot further increase swimming velocity due to a change in the angle of attack of the hand that reduces its propulsive force. The different balance of forces at different swimming speeds also means that optimal technique may differ between long-distance and short-distance swimming.

The team also identified conflicting evidence over the effectiveness of kicking for increasing the speed of high-velocity front crawl. This indicates an opportunity to further optimize competitive swimming technique if future research can further unpack the relevant hydrodynamic factors.

The researchers found that certain simplified models of swimming often break down when trying to model more realistic conditions. For example, swimmers are not simply 'pushing' or 'pulling' the water to increase their velocity, as some textbooks frame it. This is because the increase in the negative pressure acting on the dorsal side of the hand is crucial for increasing propulsion. Therefore, teaching the proper technique is important, even for phases considered to be non-propulsive.

Hideki Takagi et al, How do swimmers control their front crawl swimming velocity? Current knowledge and gaps from hydrodynamic perspectives, Sports Biomechanics (2021). DOI: 10.1080/14763141.2021.1959946

https://phys.org/news/2021-09-swimmers-front-velocity.html?utm_sour...

Cavendish Gravity Experiment

A qualitative demonstration of universal gravitation using a torsion balance.

 Fridge-free COVID-19 vaccines  grown in plants and bacteria

Nanoengineers have developed COVID-19 vaccine candidates that can take the heat. Their key ingredients? Viruses from plants or bacteria.

The new fridge-free COVID-19 vaccines are still in the early stage of development. In mice, the vaccine candidates triggered high production of neutralizing antibodies against SARS-CoV-2, the virus that causes COVID-19. If they prove to be safe and effective in people, the vaccines could be a big game changer for global distribution efforts, including those in rural areas or resource-poor communities.

What's exciting about this vaccine technology is that is thermally stable, so it could easily reach places where setting up ultra-low temperature freezers, or having trucks drive around with these freezers, is not going to be possible.

The researchers created two COVID-19 vaccine candidates. One is made from a plant virus, called cowpea mosaic virus. The other is made from a bacterial virus, or bacteriophage, called Q beta.

Both vaccines were made using similar recipes. The researchers used cowpea plants and E. coli bacteria to grow millions of copies of the plant virus and bacteriophage, respectively, in the form of ball-shaped nanoparticles. The researchers harvested these nanoparticles and then attached a small piece of the SARS-CoV-2 spike protein to the surface. The finished products look like an infectious virus so the immune system can recognize them, but they are not infectious in animals and humans. The small piece of the spike protein attached to the surface is what stimulates the body to generate an immune response against the coronavirus.

The researchers note several advantages of using plant viruses and bacteriophages to make their vaccines. For one, they can be easy and inexpensive to produce at large scales.

Another big advantage is that the plant virus and bacteriophage nanoparticles are extremely stable at high temperatures. As a result, the vaccines can be stored and shipped without needing to be kept cold. 

Trivalent subunit vaccine candidates for COVID-19 and their delivery devices, Journal of the American Chemical Society (2021). DOI: 10.1021/jacs.1c06600

https://phys.org/news/2021-09-fridge-free-covid-vaccines-grown-bact...

Why are planets round?

New Mathematical Solutions to An Old Problem in Astronomy

Hundreds of Medical Journals Just United Together to Issue a Brutally Frank Warning

Global warming is already affecting people's health so much that emergency action on climate change cannot be put on hold while the world deals with the COVID-19 pandemic, medical journals across the globe warned on Monday.

Health is already being harmed by global temperature increases and the destruction of the natural world," read an editorial published in more than 220 leading journals ahead of the COP26 climate summit in November.

Since the pre-industrial era, temperatures have risen around 1.1 degrees Celsius.

The editorial, written by the editors-in-chief of over a dozen journals including the Lancet, the East African Medical Journal, Brazil's Revista de Saude Publica and the International Nursing Review, said this had caused a plethora of health problems.

"In the past 20 years, heat-related mortality among people older than 65 years has increased by more than 50 percent," it read.

"Higher temperatures have brought increased dehydration and renal function loss, dermatological malignancies, tropical infections, adverse mental health outcomes, pregnancy complications, allergies, and cardiovascular and pulmonary morbidity and mortality."

It also pointed to the decline in agricultural production, "hampering efforts to reduce undernutrition".

These effects, which hit those most vulnerable like minorities, children, and poorer communities hardest, are just the beginning, it warned.

https://www.bmj.com/content/374/bmj.n1734

NASA Testing Electric 'Air Taxi' Prototype Designed to Carry Passengers in The Sky

NASA is commonly thought of as America's space agency, but its name also emphasizes another research area. The National Aeronautics and Space Administration is also America's civilian aerospace research organization. 

Electric Vertical Take-Off and Landing Aircraft

The squid and its giant nerve fibre Part 1

Scientists create artificial cells that mimic living cells' ability to capture, process, and expel material

Researchers have developed artificial cell-like structures using inorganic matter that autonomously ingest, process, and push out material—recreating an essential function of living cells.

Their article, published in Nature, provides a blueprint for creating "cell mimics," with potential applications ranging from drug delivery to environmental science.

A fundamental function of living cells is their ability to harvest energy from the environment to pump molecules in and out of their systems. When energy is used to move these molecules from areas of lower concentration to areas of higher concentration, the process is called active transport. Active transport allows cells to take in necessary molecules like glucose or amino acids, store energy, and extract waste.

For decades, researchers have been working to create artificial cells—engineered microscopic structures that emulate the features and behavior of biological cells. But these cell mimics tend to lack the ability to perform complex cellular processes like active transport.

In the Nature study, researchers describe a new, fully synthetic cell mimic that is one step closer to replicating the function of living cells. When deployed in mixtures of different particles, the cell mimics can perform active transport tasks by autonomously capturing, concentrating, storing, and delivering microscopic cargo. These artificial cells are fabricated using minimal ingredients and borrow no materials from biology.

To design the cell mimics, the researchers created a spherical membrane the size of a red blood cell using a polymer, a stand-in for the cellular membrane that controls what goes in and out of a cell. They pierced a microscopic hole into the spherical membrane creating a nano-channel through which matter can be exchanged, imitating a cell's protein channel.

But in order to perform the tasks required for active transport, the cell mimics needed a mechanism to power the cell-like structure to pull in and expel material. In a living cell, mitochondria and ATP provide the necessary energy for active transport. In the cell mimic, the researchers added a chemically reactive component inside the nano-channel that, when activated by light, acts as a pump. When light hits the pump, it triggers a chemical reaction, turning the pump into a tiny vacuum and pulling cargo into the membrane. When the pump is switched off, the cargo is trapped and processed inside the cell mimic. And when the chemical reaction is reversed, the cargo is pushed out on demand.

 Transmembrane transport in inorganic colloidal cell mimics, Nature (2021). DOI: 10.1038/s41586-021-03774-y , www.nature.com/articles/s41586-021-03774-y

https://phys.org/news/2021-09-scientists-artificial-cells-mimic-abi...

Common medications accumulate in gut bacteria, which may reduce drug effectiveness and alter the gut microbiome

Common medications can accumulate in gut bacteria, a new study has found, altering bacterial function and potentially reducing the effectiveness of the drug. These interactions—seen for a variety of medications, such as depression, diabetes, and asthma drugs—could help researchers to better understand individual differences in drug effectiveness and side-effects, according to the study published in Nature.

It is known that bacteria can chemically modify some drugs, a process known as biotransformation. This study is the first to show that certain species of gut bacteria accumulate human drugs.

This could change the effectiveness of the drug both directly, as the accumulation could reduce the availability of the drug to the body, and indirectly, as altered bacterial function and composition could be linked to side-effects.

The human gut naturally contains communities of hundreds of different species of bacteria, which are important in health and disease, called the gut microbiome. The composition of bacterial species varies significantly between people and has previously been shown to be associated with a wide range of conditions including obesity, immune response, and mental health.

In this study, the researchers grew 25 common gut bacteria and studied how they interacted with 15 drugs that are taken orally. The drugs were chosen to represent a range of different types of common drugs, including antidepressant medications, which are known to affect individuals dissimilarly and cause side effects such as gut problems and weight gain.

The researchers tested how each of the 15 drugs interacted with the selected bacterial strains—a total of 375 bacteria-drug tests.

They found 70 interactions between the bacteria and the drugs studied—of which 29 had not been previously reported.

While earlier research has shown bacteria can chemically modify drugs, when the scientists studied these interactions further, they found that for 17 of the 29 new interactions, the drug accumulated within the bacteria without being modified.

 Bioaccumulation of therapeutic drugs by human gut bacteria, Nature (2021). DOI: 10.1038/s41586-021-03891-8 , www.nature.com/articles/s41586-021-03891-8

https://medicalxpress.com/news/2021-09-common-medications-accumulat...

COVID, vaccine misinformation spread by hundreds of websites, analysis finds

More than 500 websites have promoted misinformation about the coronavirus—including debunked claims about vaccines, according to a firm that rates the credibility of websites.

NewsGuard announced Wednesday that, of the more than 6,700 websites it has analyzed, 519 have published false information about COVID-19. Some of the sites publish dubious health information or political conspiracy theories, while others were "created specifically to spread misinformation about COVID-19," the company says on its website.

It's become virtually impossible for people to tell the difference between a generally reliable site and an untrustworthy site. And that is why there is such a big business in publishing this information. They're all hoaxes that have gained traction, and we know that because we see them spreading from website to website. Some of the websites NewsGuard identified have become more popular online than trustworthy sources of information about COVID-19.

https://techxplore.com/news/2021-09-covid-vaccine-misinformation-hu...

Tea made with impure water tastes better

Chemical impurities in tap water can cause a thin film to form on the surface of a cup of tea, and these make it taste better than a drink made with pure water, according to researchers at ETH Zurich in Switzerland.

Pour yourself a cup of tea and leave it to cool slightly, and you may see a film on the surface that cracks like sea ice when you disturb the cup. There are many factors that affect the formation of this film, the researchers say, but the primary one is calcium carbonate in the water. When tap water contains a high amount of minerals such as calcium carbonate, it is called hard water.

“Tap water in many regions comes from limestone aquifers, where calcium carbonate, a harmless compound that can make water taste ‘crisper’, is found.

Other factors that affect the formation of this film include milk, sugar or lemon added to the tea, the brewing temperature, and the concentration of the tea.

The team studied how the strength of the film changed with water hardness by placing a metal device on the surface of the tea and rotating it. “The rotation of that device is carefully controlled, and the resistance to rotation that the film applies is what allows us to determine its strength.

They found that the more calcium carbonate in the water, the stronger the film woul.... “If you were to make a cup of tea in perfectly pure water, it would not form a film at all, but the tea would taste quite bitter

The team’s findings could be useful in industrial settings, where creating conditions to form a strong film could improve the shelf life in packaged tea drinks.

https://aip.scitation.org/doi/10.1063/5.0059760

https://www.sciencefocus.com/science/put-down-the-filter-tea-made-w...

Exposure to traffic noise linked to higher dementia risk

Exposure to noise from traffic on roads and railways over a long period is associated with a higher risk of developing dementia, especially Alzheimer's disease, suggests a study published in The BMJ recently.

The researchers estimate that as many as 1,216 out of the 8,475 cases of dementia registered in Denmark in 2017 could be attributed to these noise exposures, indicating a great potential for dementia prevention through reduction in traffic related noise.

Worldwide, the number of people with dementia is expected to exceed 130 million by 2050, making it a costly and growing global health crisis. Besides well established risk factors, such as cardiovascular diseases and unhealthy lifestyle, environmental exposures may also play a role in the development of dementia.

Transportation noise is considered the second worst environmental risk factor for public health in Europe after air pollution, and around a fifth of the European population is exposed to transportation noise above the recommended level of 55 dB (decibels).

Studies have consistently linked transportation noise to various diseases and health conditions, such as coronary heart disease, obesity, and diabetes. There is, however, little research on transportation noise and dementia and findings are inconsistent.

To address this, researchers investigated the association between long term residential exposure to road traffic and railway noise and risk of dementia among two million adults aged over 60 and living in Denmark between 2004 and 2017.

The researchers estimated road traffic and railway noise at the most and least exposed sides (or façades) of all residential addresses in Denmark.

They then analyzed national health registers to identify cases of all-cause dementia and different types of dementia (Alzheimer's disease, vascular dementia, and Parkinson's disease related dementia) over an average of 8.5 years.

They found 103,500 new cases of dementia during the study period.

After taking account of potentially influential factors related to residents and their neighborhoods, the researchers found that a 10-year average exposure to road traffic and railway noise at the most and least exposed sides of buildings was associated with a higher risk of all-cause dementia.

These associations showed a general pattern of higher risk with higher noise exposure, but with a leveling off or even small declines in risk at higher noise levels.

Further analysis by type of dementia showed both road traffic and railway noise were associated with a higher risk of Alzheimer's disease—up to 27% higher for exposure to road traffic noise of 55 dB and up to 24% higher for exposure to railway noise of 50 dB compared with less than 40 dB.

However, only road traffic noise was associated with an increased risk of vascular dementia, and not railway noise.

 Residential exposure to transportation noise in Denmark and incidence of dementia: national cohort study, BMJ (2021). www.bmj.com/content/374/bmj.n1954

Editorial: Noise exposure and dementia: a rising concern in ageing populations, www.bmj.com/content/374/bmj.n2120

https://medicalxpress.com/news/2021-09-exposure-traffic-noise-linke...

Scientists solve mystery of icy plumes that may foretell deadly supercell storms

The most devastating tornadoes are often preceded by a cloudy plume of ice and water vapor billowing above a severe thunderstorm. New research reveals the mechanism for these plumes could be tied to 'hydraulic jumps' -- a phenomenon Leonardo Da Vinci observed more than 500 years ago.

When a cloudy plume of ice and water vapor billows up above the top of a severe thunderstorm, there's a good chance a violent tornado, high winds or hailstones bigger than golf balls will soon pelt the Earth below.

Supercell storms and exploding turbulence

The thunderstorms that spawn most tornadoes are known as supercells, a rare breed of storm with a rotating updraft that can hurtle skyward at speeds faster than 150 miles an hour, with enough power to punch through the usual lid on Earth's troposphere, the lowest layer of our atmosphere.

In weaker thunderstorms, rising currents of moist air tend to flatten and spread out upon reaching this lid, called the tropopause, forming an anvil-shaped cloud. A supercell thunderstorm's intense updraft presses the tropopause upward into the next layer of the atmosphere, creating what scientists call an overshooting top. "It's like a fountain pushing up against the next layer of our atmosphere," O'Neill said.

As winds in the upper atmosphere race over and around the protruding storm top, they sometimes kick up streams of water vapor and ice, which shoot into the stratosphere to form the tell-tale plume, technically called an Above-Anvil Cirrus Plume, or AACP.

The rising air of the overshooting top soon speeds back toward the troposphere, like a ball that accelerates downward after cresting aloft. At the same time, air is flowing over the dome in the stratosphere and then racing down the sheltered side.

Using computer simulations of idealized supercell thunderstorms, O'Neill and colleagues discovered that this excites a downslope windstorm at the tropopause, where wind speeds exceed 240 miles per hour. "Dry air descending from the stratosphere and moist air rising from the troposphere join in this very narrow, crazy-fast jet. The jet becomes unstable and the whole thing mixes and explodes in turbulence," O'Neill said. "These speeds at the storm top have never been observed or hypothesized before."

part2

We Asked a NASA Scientist – Do Aliens Exist?

COVID advances win Breakthrough prizes

Techniques that have helped scientists to understand COVID-19 have scooped two out of five of the most lucrative awards in science and.... “These two awards are for research that has had such an impact on the world that they elevate the stature of the Breakthrough Prize,” says chemical biologist Yamuna Krishnan. “They have been saving lives by the millions.” This year’s US$3-million Breakthrough prizes went to:

• Biochemists Katalin Karikó and Drew Weissman, who discovered how to smuggle genetic material called messenger RNA into cells, leading to the development of a new class of vaccine. Karikó recalls the scepticism surrounding her work in the 1990s that led to numerous grant-proposal and paper rejections (including the 2005 paper for which she is now being recognized), and forced her to take a demotion and a pay cut.
• Chemists Shankar Balasubramanian, David Klenerman and Pascal Mayer, who developed the next-generation sequencing technique that has been used to rapidly track variants of the SARS-CoV-2 coronavirus.
• Chemical biologist Jeffrey Kelly, for working out the part that protein misfolding plays in amyloidosis, a disease that can affect the heart and other organs and cause neurodegeneration — and for developing an effective treatment.
• Optical physicists Hidetoshi Katori and Jun Ye, for inventing the optical lattice clock — a device that would lose less than one second over 15 billion years, improving the precision of time measurements by 10,000 times.
• Mathematician Takuro Mochizuki, for extending the understanding of algebraic structures called ‘holonomic D-modules’ — which are related to certain types of differential equation — to deal with points at which the equations under study are not well defined.

https://www.nature.com/articles/d41586-021-02449-y?utm_source=Natur...

Sim shows how COVID virus infects cells

How Volcanic Eruptions Can Cool Earth? -- Explained!

Climate change includes both global warming driven by human-induced emissions of greenhouse gases and the resulting large-scale shifts in weather patterns.

Research on beards, wads of gum wins 2021 Ig Nobel prizes

Beards aren't just cool and trendy—they might also be an evolutionary development to help protect a man's delicate facial bones from a punch to the face.

That's the conclusion of a trio of scientists from the University of Utah who are among the winners of this year's Ig Nobel prizes, the Nobel Prize spoofs that honor—or maybe dishonor, depending on your point of view—strange scientific discoveries.

The winners of the 31st annual Ig Nobels being announced Thursday included researchers who figured out how to better control cockroaches on U.S. Navy submarines; animal scientists who looked at whether it's safer to transport an airborne rhinoceros upside-down; and a team that figured out just how disgusting that discarded gum stuck to your shoe is.

These sound like  silly studies, but as usual, there was some method to the madness. These findings have implications for a wide range of disciplines, including forensics, contagious disease control, or bioremediation of wasted chewing gum residues.

https://www.improbable.com/2021-ceremony/winners/

https://phys.org/news/2021-09-beards-wads-gum-ig-nobel.html?utm_sou...

New programmable gene editing proteins found outside of CRISPR systems

Within the last decade, scientists have adapted CRISPR systems from microbes into gene editing technology, a precise and programmable system for modifying DNA. Now, scientists at MIT's McGovern Institute and the Broad Institute of MIT and Harvard have discovered a new class of programmable DNA modifying systems called OMEGAs (Obligate Mobile Element Guided Activity), which may naturally be involved in shuffling small bits of DNA throughout bacterial genomes.

These ancient DNA-cutting enzymes are guided to their targets by small pieces of RNA. While they originated in bacteria, they have now been engineered to work in human cells, suggesting they could be useful in the development of gene editing therapies, particularly as they are small (~30% the size of Cas9), making them easier to deliver to cells than bulkier enzymes. The discovery, reported in the journal Science, provides evidence that natural RNA-guided enzymes are among the most abundant proteins on earth, pointing toward a vast new area of biology that is poised to drive the next revolution in genome editing technology.

Han Altae-Tran et al, The widespread IS200/605 transposon family encodes diverse programmable RNA-guided endonucleases, Science (2021). DOI: 10.1126/science.abj6856

https://phys.org/news/2021-09-programmable-gene-proteins-crispr.htm...

New technology designed to genetically control disease-spreading mosquitoes

Leveraging advancements in CRISPR-based genetic engineering, researchers have created a new system that restrains populations of mosquitoes that infect millions each year with debilitating diseases.

The new precision-guided sterile insect technique, or pgSIT, alters genes linked to male fertility—creating sterile offspring—and female flight in Aedes aegypti, the mosquito species responsible for spreading wide-ranging diseases including dengue fever, chikungunya and Zika.

pgSIT is a new scalable genetic control system that uses a CRISPR-based approach to engineer deployable mosquitoes that can suppress populations. Males don't transmit diseases so the idea is that as you release more and more sterile males, you can suppress the population without relying on harmful chemicals and insecticides.

pgSIT differs from "gene drive" systems that could suppress disease vectors by passing desired genetic alterations indefinitely from one generation to the next. Instead, pgSIT uses CRISPR to sterilize male mosquitoes and render female mosquitoes, which spread disease, as flightless. The system is self-limiting and is not predicted to persist or spread in the environment, two important safety features that should enable acceptance for this technology.

Suppressing mosquito populations with precision guided sterile males, Nature Communications (2021). DOI: 10.1038/s41467-021-25421-w

https://phys.org/news/2021-09-technology-genetically-disease-spread...

Study: AI can make better clinical decisions than humans

There's no harm in getting a second opinion. But what if that second opinion could be generated by a computer, using artificial intelligence? Would it come up with better treatment recommendations than your professional proposes?

Medical and educational professionals frequently disagree on the effectiveness of behavioral interventions, which may cause people to receive inadequate treatment.

To find a better way, researchers compiled simulated data from 1,024 individuals receiving treatment for behavioral issues. The researchers then compared the treatment conclusions drawn in each case by five doctoral-level behavior analysts with those produced by a computer model the two academics developed using machine learning.

The five professionals only came to the same conclusions approximately 75 percent of the time. More importantly, machine learning produced fewer decision-making errors than did all the professionals.

Given these very positive results, the next step would be to "integrate these models in an app that could automatically make decisions or provide feedback about how treatment is progressing". 

The goal, the researchers think, should be to use machine learning to facilitate the work of professionals, not actually replace them, while also making treatment decisions more consistent and predictable.

 Marc J. Lanovaz et al, Machine learning to analyze single‐case graphs: A comparison to visual inspection, Journal of Applied Behavior Analysis (2021). DOI: 10.1002/jaba.863

https://techxplore.com/news/2021-09-ai-clinical-decisions-humans.ht...

Drugs that mimic effects of cigarette smoke reduce SARS-CoV-2's ability to enter cells

Researchers have identified a potential reason why lower numbers of COVID cases have appeared amongst smokers compared to non-smokers, even as other reports suggest smoking increases severity of the disease.

Researchers have identified two drugs that mimic the effect of chemicals in cigarette smoke to bind to a receptor in mammalian cells that inhibits production of ACE2 proteins, a process that appears to reduce the ability of the SARS-CoV-2 virus to enter the cell.

The findings appear in the journal Scientific Reports on 17 August.

Something of a paradox exists with respect to smoking cigarettes and COVID-19. Active smoking is associated with increased severity of disease, but at the same time, many reports have suggested lower numbers of COVID cases amongst smokers than amongst non-smokers.

Something strange was going on here. We must stress the presence of strong evidence showing that smoking increases the severity of COVID-19. But the mechanism now discovered  is worth further investigation as a potential tool to fight SARS-CoV-2 infections.

--

It is known that cigarette smoke contains polycyclic aromatic hydrocarbons (PAHs). These can bind to and activate aryl hydrocarbon receptors (AHRs). A receptor is any structure of the surface or inside of a cell that is shaped to receive and bind to a particular substance. AHRs are a type of receptor inside of mammalian cells that is in turn a transcription factor—something that can induce a wide range of cellular activities through its ability to increase or decrease the expression of certain genes.

Knowing this about the relationship between PAHs and AHRs, the researchers wanted to investigate the effect of drugs that activate AHR on expression of the genes that control production of the ACE2 protein—the infamous receptor protein on the surface of many cells types that works like a lock that the SARS-CoV-2 virus is able to pick. After binding the virus to the ACE2 protein, it can then enter and infect the cell.

Part 1

First, the scientists investigated various cell lines to examine their gene expression levels of ACE2. They found that those cells originating in the oral cavity, lungs and liver had the highest ACE2 expression.

These high-ACE2-expression cells were then subjected to various doses of cigarette-smoke extract (CSE) for 24 hours. After this, the rate of expression of the CYP1A1 gene, which is known to be inducible by CSE, was evaluated. The CSE treatment had induced increased expression of CYP1A1 gene in liver and lung cells in a dose-dependent manner—the greater the dose, the greater the effect. However, this effect was not as pronounced in oral cavity cells. In other words, greater activity of the CYP1A1, less production of the ACE2 receptors—the route that the virus is able to enter cells.

In order to explain why this was happening in the presence of cigarette smoke, the researchers then used RNA sequencing analysis to investigate what was happening with gene expression more comprehensively. They found that CSE increased the expressions of genes related to a number of key signaling processes within the cell that are regulated by AHR.

To more directly observe this mechanism by which AHR acts on ACE2 expression, the effects of two drugs that can activate AHR were evaluated on the liver cells. The first, 6‑formylindolo(3,2‑b)carbazole (FICZ) is derivative of the amino acid tryptophan, and the second, omeprazole (OMP), is a medication already widely used in the treatment of acid reflux and peptic ulcers.

RNA sequencing data suggested that the CYP1A1 gene was strongly induced in liver cells by these AHR activators, and expression of the ACE2 gene was strongly inhibited, again in a dose-dependent manner.

In other words, the cigarette smoke extract and these two drugs—all of which act as activators of AHR—are able to suppress the expression of ACE2 in mammalian cells, and by doing so, reduce the ability of the SARS-CoV-2 virus to enter the cell.

Keiji Tanimoto et al, Inhibiting SARS-CoV-2 infection in vitro by suppressing its receptor, angiotensin-converting enzyme 2, via aryl-hydrocarbon receptor signal, Scientific Reports (2021). DOI: 10.1038/s41598-021-96109-w

https://medicalxpress.com/news/2021-09-drugs-mimic-effects-cigarett...

Part 2

A new gold standard for detecting cancer mutations

An international research collaboration has identified a new gold standard for detecting cancer mutations using genomic pathology.

This research set out to understand why there has been a history of low reproducibility of genomic testing results between different labs when detecting cancers.

Scientists found factors like sample and library preparation, differing sequencing technology and bioinformatic tools were affecting the reproducibility and performance of the genomic analytical techniques.

The research team have now developed a set recommendations and guidelines on how to improve the reproducibility and precision of the tumor mutation detection in clinical practice.

All stages of mutation detection are interdependent and this dependency is complex.

There is no 'one way' to detect cancerous tumor mutations. For example, the amount of DNA sequencing needed to detect a cancer mutation will vary based on the amount of tumor content.

Every person is different and should be treated differently. And our research provides a new tool to improve precision medicine.

Wenming Xiao et al, Toward best practice in cancer mutation detection with whole-genome and whole-exome sequencing, Nature Biotechnology (2021). DOI: 10.1038/s41587-021-00994-5

https://medicalxpress.com/news/2021-09-gold-standard-cancer-mutatio...

 Study reveals that immune cells cooperate to trap and kill bacteria

Like a spider trapping its prey, our immune system cells cooperate to capture and "eat" bacteria.

The newly identified antibacterial mechanism, reported Sept. 10 in Science Advances, could inspire novel strategies for combating Staphylococcus aureus (staph) and other extracellular bacterial pathogens.

It was known that neutrophils—first responder immune cells that migrate to sites of infection—can self-destruct and release their protein and DNA contents to generate neutrophil extracellular traps (NETs). Now, Vanderbilt researchers led by postdoctoral fellow Andrew Monteith, Ph.D., have discovered that NETs boost the bacterial killing power of another type of immune cell: macrophages.

Neutrophils produce the spider webs that immobilize the bacteria, and macrophages are the spiders that engulf and kill the bacteria. Neutrophils and macrophages are both phagocytic cells known for ingesting bacteria and producing antimicrobial peptides, reactive oxygen species and other enzymes to fight infection. NET generation (NETosis), thought to be a form of programmed cell death, is a more recently discovered neutrophil antibacterial strategy. The released neutrophil DNA creates a sticky trap that is also studded with antimicrobial peptides.

The macrophages end up with not only their own antibacterial arsenal, but also the neutrophils' antibacterial arsenal, all in the same compartment killing the bacteria.

 Neutrophil extracellular traps enhance macrophage killing of bacterial pathogens, Science Advances (2021). DOI: 10.1126/sciadv.abj2101

https://phys.org/news/2021-09-caught-web-reveals-immune-cells.html?...

Why do some plants track the sun?

Heliotropism,  literally means moving in relation to the sun.

Sunflowers track the course of the sun spectacularly on warm and sunny, spring or summer days. Sometimes they move through an arc of almost 180⁰ from morning to evening.

A number flowering species display heliotropism, including alpine buttercups, arctic poppies, alfalfa, soybean and many of the daisy-type species. So why do they do it?

Flowers are really in the advertising game and will do anything they can to attract a suitable pollinator, as effectively and as efficiently as they can. There are several possible reasons why tracking the sun might have evolved to achieve more successful pollination.

By tracking the sun, flowers absorb more solar radiation and so remain warmer. The warmer temperature suits or even rewards insect pollinators that are more active when they have a higher body temperature.

Optimum flower warmth may also boost pollen development and germination, leading to a higher fertilization rate and more seeds.

So, the flowers are clearly moving. But how?

For many heliotropic flowering species, there's a special layer of cells called the pulvinus just under the flower heads. These cells pump water across their cell membranes in a controlled way, so that cells can be fully pumped up like a balloon or become empty and flaccid. Changes in these cells allow the flower head to move.

When potassium from neighboring plant cells is moved into the cells of the pulvinus, water follows and the cells inflate. When they move potassium out of the cells, they become flaccid.

These potassium pumps are involved in many other aspects of plant movement, too. This includes the opening and closing of stomata (tiny regulated leaf apertures), the rapid movement of mimosa leaves, or the closing of a fly trap.

In 2016, scientists discovered that the pin-up example of heliotropism—the sunflower—had a different way of moving.

They found sunflower movement is due to significantly different growth rates on opposite sides of the flowering stem.

On the east-facing side, the cells grow and elongate quickly during the day, which slowly pushes the flower to face west as the daylight hours go by—following the sun. At night the west-side cells grow and elongate more rapidly, which pushes the flower back toward the east over night.

Everything is then set for the whole process to begin again at dawn next day, which is repeated daily until the flower stops growing and movement ceases.

While many people are aware of heliotropism in flowers, heliotropic movement of leaves is less commonly noticed or known. Plants with heliotropic flowers don't necessarily have heliotropic leaves, and vice versa.

Part1

Heliotropism evolves in response to highly specific environmental conditions, and factors affecting flowers can be different from those impacting leaves.

For example, flowers are all about pollination and seed production. For leaves, it's for maximizing photosynthesis, avoiding over-heating on a hot day or even reducing water loss in harsh and arid conditions.

Some species, such as the Queensland box, arrange their leaves so they're somewhat horizontal in the morning, capturing the full value of the available sunlight. But there are also instances where leaves align vertically to the sun in the middle of the day to minimize the risks of heat damage.

It's easy to think of plants as static organisms. But of course, they are forever changing, responding to their environments and growing. They are dynamic in their own way, and we tend to assume that when they do change, it will be at a very slow and steady pace.

Heliotropism shows us this is not necessarily the case. Plants changing daily can be a little unsettling in that we sense a change but may not be aware of what is causing our unease.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

https://phys.org/news/2021-09-daily-tracking-sun-fascinating.html?u...

Part2

What happens when two very different respiratory viruses infect the same cell

We know that several viruses infect us. A recent study from the University of Glasgow has discovered what happens when you get infected with some of these viruses at the same time, and it has implications for how they make us sick and how we protect ourselves from them.

For many reasons, respiratory viruses are often found during winter in the temperate regions of the world, or the rainy season of equatorial regions. During these periods, you'll probably be infected with more than one virus at any one time in a situation called a "co-infection."

Research shows that up to 30% of infections may harbor more than one virus. What this means is that, at some point two different viruses are infecting the cells that line your nose or lungs.

We know that co-infection can be important if we look at a process called "antigenic shift" in influenza viruses, which is basically caused by virus "sex." This sometimes occurs when two different influenza strains meet up inside the same cell and exchange genes, allowing a new variant to emerge.

Co-infection can create a predicament for viruses when you consider that they need to compete for the same resource: you. Some viruses appear to block other viruses, while some viruses seem to like each other. What is driving these positive and negative interactions during co-infections is unknown, but animal studies suggest that it could be critical in determining how sick you get.

The University of Glasgow study investigated what happens when you infect cells in a dish with two human respiratory viruses. For their experiments, they chose IAV and RSV, which are both common and cause lots of disease and death each year. The researchers looked at what happens to each virus using high-resolution imaging techniques, such as cryo-electron microscopy, that their labs have perfected over the years.

They found that some of the human lung cells in the dish contained both viruses. And, by looking closely at those co-infected cells, they found that the viruses that were emerging from the cell had structural characteristics of both IAV and RSV. The new "chimeric" virus particles had proteins of both viruses on their surface and some even contained genes from the other. This is the first evidence of this occurring from co-infection of distinct respiratory viruses.

Follow-up experiments in the same paper showed that these new chimeric viruses were fully functional and could even infect cells that were rendered resistant to influenza, presumably gaining access using the RSV proteins could even get into a broader range of human cells than either virus alone could. Potentially, this could be happening during natural co-infections during the winter.

https://www.biorxiv.org/content/10.1101/2021.08.16.456460v2

https://theconversation.com/heres-what-happens-when-two-very-differ...

Animals shape shifting as climate warms

Some animals are "shape-shifting" and have developed bigger tails, beaks and ears to regulate their body temperatures as the planet warms, according to a new study. From Australian parrots to European rabbits, researchers found evidence that a host of warm-blooded animals have evolved bigger body parts, which could allow them to lose body heat more effectively. Climate change is heaping "a whole lot of pressure" on animals. It's high time we recognised that animals also have to adapt to these changes, but this is occurring over a far shorter timescale than would have occurred through most of evolutionary time. The study, published on recently  in the journal Trends in Ecology and Evolution, reviewed previous research "where climatic warming is a potential hidden explanatory variable for the occurrence of shape-shifting" and found trends particularly noticeable in birds.

The Australian parrot, for example, had shown an average 4-10 percent increase in the size of its bill since 1871 and the authors said this positively correlated with the summer temperature each year.

Other birds, like North American dark-eyed juncos, thrushes and Galapagos finches also saw bill size increases.

Meanwhile, the wings of the great roundleaf bat grew, the European rabbit developed bigger ears, while the tails and legs of masked shrews were found to be larger.

Shape-shifting does not mean that animals are coping with climate change and that all is 'fine'. It just means they are evolving to survive it -- but we're not sure what the other ecological consequences of these changes are, or indeed that all species are capable of changing and surviving.

It's well known that animals use their appendages to regulate their internal temperature. African elephants, for example, pump warm blood to their large ears, which they then flap to disperse heat.

The beaks of birds perform a similar function – blood flow can be diverted to the bill when the bird is hot. This heat-dispersing function shows the beak is warmer than the rest of the body. All this means there are advantages to bigger appendages in warmer environments.

warm-blooded animals – also known as endotherms – tended to have smaller appendages while those in warmer climates tend to have larger ones.

This pattern became known as Allen's rule, which has since been supported by studies of birds  and mammals.

Biological patterns such as Allen's rule can also help make predictions about how animals will evolve as the climate warms.

https://www.cell.com/trends/ecology-evolution/fulltext/S0169-5347(21)00197-X?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS016953472100197X%3Fshowall%3Dtrue

https://researchnews.cc/news/8818/Animals--shape-shifting--as-clima...