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Comment by Dr. Krishna Kumari Challa on October 21, 2022 at 9:37am

Metallic water prepared for first time under terrestrial conditions

Inside a vacuum chamber, the researchers expose a drop of sodium-potassium alloy to a small amount of water vapor, which begins to condense on its surface. The electrons liberated from the alkali metal dissolve in the layer of water on the surface faster than the chemical reaction that results in the explosion. There are a sufficient number of them to overcome the critical limit for the formation of a conduction band and thus give rise to a metallic water solution.

https://www.sciencealert.com/scientists-transformed-pure-water-into...

Comment by Dr. Krishna Kumari Challa on October 21, 2022 at 8:58am

Alligators exposed to PFAS show autoimmune effects

A recent study of alligators  found the animals had elevated levels of 14 different per- and polyfluoroalkyl (PFAS) chemicals in their blood serum, as well as clinical and genetic indicators of immune system effects. The work adds to the body of evidence connecting PFAS exposure with adverse immune system effects.

Researchers took blood samples and did health evaluations on 49 alligators living along the Cape Fear River between 2018 and 2019. They compared these results to a reference population of 26 alligators from Lake Waccamaw, located in the adjoining Lumber River basin.

They  looked at 23 different PFAS and saw clear differences between both types and levels of PFAS in the two populations. The most unusual observation the team made was that alligators in the Cape Fear River which had high concentration of PFAS also had a number of unhealed or infected lesions.

Alligators rarely suffer from infections. They do get wounds, but they normally heal quickly. Seeing infected lesions that weren't healing properly was concerning and led the scientists  to look more closely at the connections between PFAS exposure and changes in the immune systems of the alligators.

A qRT-PCR genetic analysis revealed significantly elevated levels of interferon-alpha (INF-α) responsive genes in the Cape Fear River alligators: their levels were 400 times higher than those of the low level PFAS containing alligators, 

INF-α is a secreted immune protein involved in stimulating immune response.The set of INF-α responsive genes we analyzed are normally involved with viral infections. In humans, chronic (or long-term) high expression of this set of genes is an important indicator of autoimmune diseases, especially lupus. Additionally, some PFAS exposures in humans are linked with chronic autoimmune disorders like ulcerative colitis and thyroid disease. 

The elevated expression of INF-α in these alligators tells us that something in these alligators' immune responses is being disrupted.

Blood Concentrations of Per- and Polyfluoroalkyl Substances are Associated with Autoimmune-like Effects in American Alligators from Wilmington, North Carolina, Frontiers in Toxicology (2022). DOI: 10.3389/ftox.2022.1010185

Comment by Dr. Krishna Kumari Challa on October 21, 2022 at 8:10am

Injecting extracellular vesicles from young mice into older mice found to reduce some signs of aging

A team of researchers has found that injecting older mice with extracellular vesicles (EVs) from young mice reduced some signs of aging. 

EVs, which are also known as exosomes, are structures produced in eukaryotic cells that are involved in signaling between cells and also used for transporting mRNA. Suspecting that aspects of the aging process might be related to degeneration in communication between cells, the researchers wondered what would happen if they injected older mice with EVs. To find out, they extracted stem cells from fatty tissue in young test mice. Next, they collected EVs that were produced by the cells they had collected. They then injected the EVs into the tails of older mice—once at the outset of the test and again a week later.

The researchers then began studying the mice to see what impact the injections might have. They found that after just two weeks, the mice showed improvements in physical strength, suggesting reductions in age-related muscle degeneration. They also found the mice tired less easily and tended to be better coordinated—and their fur grew back more quickly. The team noted that the improvements peaked at approximately 30 days after the initial injection and disappeared after approximately 60 days.

The researchers also dissected some of the test mice and found reductions in degeneration of kidney tissue and an increase in cell production. They also found reductions in inflammatory biomarkers and that some tissue appeared to be epigenetically younger.

Jorge Sanz-Ros et al, Small extracellular vesicles from young adipose-derived stem cells prevent frailty, improve health span, and decrease epigenetic age in old mice, Science Advances (2022). DOI: 10.1126/sciadv.abq2226

Comment by Dr. Krishna Kumari Challa on October 20, 2022 at 6:06am

Analysis shows women who publish physics papers are cited less often than men

A team of researchers affiliated with multiple institutions in the U.S. has found that women who publish physics papers are cited less often than are men. In their paper published in the journal Nature Physics, the group describes their analysis of more than 1 million published papers in multiple journals.

Prior research and anecdotal evidence have suggested that women are greatly underrepresented in the sciences, particularly chemistry, physics and math. Prior research has also shown that there are a number of reasons for the differences, among them, simple discrimination. In this new effort, the researchers looked at one type of discrimination—underciting papers based on gender—that could play a role in the underrepresentation of women in physics.

One of the ways that scientists measure prestige in their field is by the number of times their publications are cited. A high number of citations for a given paper also suggests that the work was both insightful and impactful on the field in which a paper has been published. Thus, a dearth of citations by a given scientist or paper could suggest that the work did little to advance the science involved. But it could also suggest that a bias exists in the science community that makes it more difficult for some members to collect citations.

The researchers 

studied approximately 1.07 million physics papers published over the years 1995 to 2020 in 35 well-established journals. Their effort involved counting the number of citations made for all of the papers and noting whether the authors of the paper were male or female (as determined by their forename).

The researchers found that papers published by men (where the first and last authors listed were male) were on average 4.23% more likely to be cited. This, they contend, shows that there is a gender bias that favors citing male colleagues over those who are female. They conclude by suggesting ways to reduce this bias, such as having researchers sign diversity statements or holding publishers more accountable.

 Erin G. Teich et al, Citation inequity and gendered citation practices in contemporary physics, Nature Physics (2022). DOI: 10.1038/s41567-022-01770-1

Comment by Dr. Krishna Kumari Challa on October 20, 2022 at 5:53am

When a macrophage encounters a bacterium, it chops it into pieces for them to be presented to other immune cells signaling that there's an infection. Having the functional version of the gene, appears to create an advantage, likely by enhancing the ability of our immune system to sense the invading pathogen. By the researchers' estimate, possessing two copies of the rs2549794 variant would have make a person about 40% more likely to survive the Black Death than those who had two copies of the non-functional variant.

The team even went so far as to test how the rs2549794 variant affected the ability of living human cells to help fight the plague, determining that macrophages expressing two copies of the variant were more efficient at neutralizing Y. pestis compared to those without it.

Examining the effects of the ERAP2 variants in vitro allowed teh scientists to functionally test how the different variants affect the behavior of immune cells from modern humans when challenged with living Yersinia pestis.

Luis Barreiro, Evolution of immune genes is associated with the Black Death, Nature (2022). DOI: 10.1038/s41586-022-05349-x. www.nature.com/articles/s41586-022-05349-x

Selection of human immune-related genes was driven by the Black Death

The Black Death shaped the evolution of immunity genes

Part 2**

Comment by Dr. Krishna Kumari Challa on October 20, 2022 at 5:49am

Selection of human immune-related genes was driven by the Black Death

The Black Death was the single greatest mortality event in recorded history, killing up to 50% of the European population in less than five years. New research has found evidence that one of the darkest periods in recorded human history placed a significant selective pressure on the human population, changing the frequency of certain immune-related genetic variants and affecting our susceptibility to disease today.

Caused by the bacterium Yersinia pestis, the global pandemic of the bubonic plague wiped out 30% to 60% of people in cities across North Africa, Europe, and Asia, with massive repercussions for the human race—and, apparently, our genome.

In the study, thanks to recent advances in sequencing technology, the scientists examined ancient DNA samples from the bones of over 200 individuals from London and Denmark who died before, during, and after the Black Death plague swept through the region in the late 1340s. Using targeted sequencing for a set of 300 immune-related genes, they identified four genes that, depending on the variant, either protected against or increased susceptibility to Y. pestis.

The research team zeroed in on one gene with a particularly strong association to susceptibility: ERAP2. Individuals who possessed two copies of one specific genetic variant, dubbed rs2549794, were able to produce full length copies of the ERAP2 transcript, therefore producing more of the functional protein, compared to another variant that led to a truncated and non-functional version of the transcript. Functional ERAP2 plays a role in helping the immune system recognize the presence of an infection.

Part 1

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Comment by Dr. Krishna Kumari Challa on October 19, 2022 at 9:21am

Chemical Hair Straighteners Linked to Uterine Cancer

Rare and aggressive uterine cancers are rapidly raising and a new study suggests chemical straighteners might be partly to blame.

For almost 11 years, researchers at the US National Institute of Environmental Health Sciences (NIEHS) followed 33,947 adults who had a uterus upon enrollment in the study. During this time, 378 uterine cancer cases were identified.

Those who had used a chemical straightening product more than four times in the 12 months prior to being surveyed were 155 percent more likely to later be diagnosed with uterine cancer, compared with those who had never received a straightening treatment.

To put it in perspective, those who never used hair straightening products would have a 1.64 percent chance of being diagnosed with uterine cancer by their 70th birthday. That number creeps up to 4.05 percent among those who frequently straighten their hair chemically – a still small, but appreciably higher risk.

Hair dyes, meanwhile, were not linked to uterine cancer.

These findings are the first epidemiologic evidence of association between use of straightening products and uterine cancer.

The worrisome results are the latest from a recent string of studies on widely-used chemicals that disrupt the endocrine system; messenger chemicals in our bodies that connect hormones to their target organs.

Excess hormones like estrogen and progesterone have been tied to uterine cancer in the past, and many hair products can mimic these natural hormones and bind to their receptors.

In 2018, researchers found endocrine-disrupting chemicals in 18 tested hair products. What's more, 84 percent of the chemicals identified were not listed on product labels.

In 2019, a study funded by the NIH found permanent hair dye and straightening chemicals are associated with a higher risk of breast cancer.

In 2021, a follow-up study found permanent hair dye and straightening chemicals are also associated with a higher risk of ovarian cancer.

Now, uterine cancer can be added to the list as well.

https://academic.oup.com/jnci/advance-article/doi/10.1093/jnci/djac...

Comment by Dr. Krishna Kumari Challa on October 19, 2022 at 6:21am

Simulations show major forest fires can increase intensity of distant storms

A team of researchers has found, via simulation, that major forest fires in western parts of the United States can increase the intensity of thunderstorms hundreds or even thousands of miles downwind. The study is published in Proceedings of the National Academy of Sciences.

Prior research has shown that wildfires or forest fires can have a major impact on local weather systems. Heat and soot can lead to the formation of major thunderstorms. In this new effort, the researchers found evidence of a similar phenomenon involving downwind systems far away from the fire.

To learn more about large-scale weather impacts of forest fires, the researchers pored over weather data for the continental U.S. for the years 2010 to 2020. They looked for major storm events that occurred not long after, or during major fires in the west. The researchers found several examples of major storms breaking out after major fires. But they also note that fire season in the west does not coincide with storm season farther east; thus, the impact of the fires on the storms is difficult to associate.

To gain a better understanding of what may occur during and after a major fire, the researchers turned to an established weather model that allowed for adjusting paraments such as heat and smoke to observe the impacts. The simulation showed that big fires can increase the intensity of storm systems hundreds or even thousands of miles away. The researchers also found that they can contribute to creation of larger hailstones.

More specifically, the simulations showed that large fires can increase air flowing across the continent, pushing moist air ahead of it. That can lead to increasing storm strength. The simulations also showed that the soot from a big fire can be carried for long distances, contributing to increases in hail size.

The researchers sum up by suggesting that global warming, which is making western parts of the U.S. both hotter and drier, is likely to lead to bigger and stronger storms across the U.S. due in part to the impact of the increase in forest fires.

Yuwei Zhang et al, Notable impact of wildfires in the western United States on weather hazards in the central United States, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2207329119

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Comment by Dr. Krishna Kumari Challa on October 18, 2022 at 9:42am

Fatty tissue surrounding intestinal tracts of mice found to help eject gut-infesting worms

A team of researchers has found that fatty tissue surrounding the intestinal tracts of mice help to eject gut-infesting worms. Their paper is published in the journal Science Immunology.

Prior research has shown that mesenteric adipose tissue aids the immune system in responding to pathogens and also certain types of cancer. In this new effort, the researchers found that it also assists with combating parasitic infections.

The work began when the researchers inadvertently noticed that mesenteric adipose tissue (fatty tissue that surrounds the intestinal tract) stiffened when a mouse was infected with helminths, a type of worm. Such stiffening, the team noted, helped to eject the worms.

In taking a closer look at how fatty tissue might recognize and respond to a parasitic infection, the researchers found that a type of T cell found in such tissue, called Th2, communicated with stromal cells, which play a role in differentiating cells that grow into different types of structural support cells. They then conducted flow cytometry, histology, cell culture and single-cell RNA sequencing on the fatty tissue to learn more about how it stiffened in response to an infection.

They discovered that Th2 cells infiltrated fat tissue even though the parasite did not infect such tissue. They also found that the Th2 cells released both Amphiregulin and cytokine TGFβ. Additionally, the stromal cells became more active when in the presence of Amphiregulin and cytokine TGFβ and thus produced more cytokines. And finally, they found that the stromal and Th2 cells were combining in interstitial spaces in the fatty tissue, forcing them to become enlarged and to secrete collagen, which resulted in tissue stiffening.

The researchers also found that the stiffening lasted up to a year before tissue returned to normal, rather than progressing to fibrosis. This allowed the mice to respond more quickly to a secondary infection.

Agnieszka M. Kabat et al, Resident T H 2 cells orchestrate adipose tissue remodeling at a site adjacent to infection, Science Immunology (2022). DOI: 10.1126/sciimmunol.add3263

Comment by Dr. Krishna Kumari Challa on October 16, 2022 at 8:51am

Inner structure of the body during physical rehab

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