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Comment by Dr. Krishna Kumari Challa on August 28, 2021 at 9:13am

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...

Comment by Dr. Krishna Kumari Challa on August 28, 2021 at 8:55am

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

Comment by Dr. Krishna Kumari Challa on August 28, 2021 at 8:54am

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

Comment by Dr. Krishna Kumari Challa on August 28, 2021 at 8:48am

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

Part 1

Comment by Dr. Krishna Kumari Challa on August 27, 2021 at 1:46pm

Breaking Bad Chemicals With Bacterial Detoxifiers

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...

Comment by Dr. Krishna Kumari Challa on August 27, 2021 at 12:14pm

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...

Comment by Dr. Krishna Kumari Challa on August 27, 2021 at 11:59am

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_...

Comment by Dr. Krishna Kumari Challa on August 27, 2021 at 11:53am

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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Comment by Dr. Krishna Kumari Challa on August 27, 2021 at 11:43am

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...

Comment by Dr. Krishna Kumari Challa on August 27, 2021 at 10:38am

 researchers to identify a new class of planets, Hycean planets, with massive planet-wide oceans beneath hydrogen-rich atmospheres. Hycean planets can be up to 2.6 times larger than Earth and have atmospheric temperatures up to nearly 200 degrees Celsius, but their oceanic conditions could be similar to those conducive for microbial life in Earth's oceans. Such planets also include tidally locked 'dark' Hycean worlds that may have habitable conditions only on their permanent night sides, and 'cold' Hycean worlds that receive little radiation from their stars.

Planets of this size dominate the known exoplanet population, although they have not been studied in nearly as much detail as super-Earths. Hycean worlds are likely quite common, meaning that the most promising places to look for life elsewhere in the Galaxy may have been hiding in plain sight.

However, size alone is not enough to confirm whether a planet is Hycean: other aspects such as mass, temperature and atmospheric properties are required for confirmation.

https://phys.org/news/2021-08-class-habitable-exoplanets-big-life.h...

part 2

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