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Comment by Dr. Krishna Kumari Challa on April 26, 2024 at 11:48am

Yeast study offers possible answer to why some species are generalists and others specialists

In a landmark study based on one of the most comprehensive genomic datasets ever assembled, a team of scientists offer a possible answer to one of the oldest questions about evolution: why some species are generalists and others specialists.

researchers mapped the genetic blueprints, appetites, and environments of more than 1,000 species of yeasts, building a family tree that illuminates how these single-celled fungi evolved over the past 400 million years.

The results, published in the journal Science, suggest that internal—not external—factors are the primary drivers of variation in the types of carbon yeasts can eat, and the researchers found no evidence that metabolic versatility, or the ability to eat different foods, comes with any trade-offs. In other words, some yeasts are jacks-of-all-trades and masters of each.

Like other organisms, some yeasts have evolved to be specialists—think koalas, which eat nothing but eucalyptus leaves—while others are generalists like raccoons, which eat just about anything.

Scientists have been trying to explain why both generalists and specialists exist almost since Charles Darwin proposed his theory of evolution in 1859.

Part 1

Comment by Dr. Krishna Kumari Challa on April 26, 2024 at 11:43am

Genetic variations may predispose people to Parkinson's disease following long-term pesticide exposure, study finds

A new UCLA Health study has found that certain genetic variants could help explain how long-term pesticide exposure could increase the risk of Parkinson's disease.
While decades of research have linked pesticide exposure and Parkinson's disease risk, researchers have sought to explain why some individuals with high exposure develop the disease while others do not.

One longstanding hypothesis has been that susceptibility to the disease is a combination of both environmental and genetic factors.
The new study, published in the journal npj Parkinson's Disease, used genetic data from nearly 800 Central Valley (California) residents with Parkinson's disease, many of whom had long-term exposure to 10 pesticides used on cotton crops for at least a decade prior to developing the disease, with some patients having been exposed as far back as 1974.

The researchers examined the study participants' genetic makeup for rare variants in genes associated with the function of lysosomes—cellular compartments that break down waste and debris, thought to be associated with the development of Parkinson's disease—and looked for enrichment of variants in patients with high exposure to pesticide use compared to a representative sample of the general population.

Researchers found that variants in these genes were enriched in patients with more severe Parkinson's disease who also had higher exposure to pesticides. These genetic variants also appeared to be deleterious to protein function suggesting that disruption of lysosomal activity may be underling the development of Parkinson's disease combined with pesticide exposure.

 Lysosomal Genes Contribute to Parkinson's Disease near Agriculture with High Intensity Pesticide Use, npj Parkinson's Disease (2024). DOI: 10.1038/s41531-024-00703-4. www.nature.com/articles/s41531-024-00703-4

Comment by Dr. Krishna Kumari Challa on April 26, 2024 at 11:35am

Researchers used advanced statistics to identify 22 distinct gene modules, of which just one was associated with both a high score for depressive symptoms and a low score for cardiovascular health.

The top three genes from this gene module are known to be associated with neurodegenerative diseases, bipolar disorder, and depression. Now they have shown that they are associated with poor cardiovascular health as well.

These genes are involved in biological processes, such as inflammation, that are involved in pathogenesis of both depression and cardiovascular disease. This helps to explain why both diseases often occur together.

Other genes in the shared module have been shown to be involved in brain diseases such as Alzheimer's, Parkinson's, and Huntington's disease.

Researchers and doctors  can use the genes in this module as biomarkers for depression and cardiovascular disease. Ultimately, these biomarkers may facilitate the development of dual-purpose preventative strategies for both the diseases.

Binisha Hamal Mishra et al, Identification of gene networks jointly associated with depressive symptoms and cardiovascular health metrics using whole blood transcriptome in the Young Finns Study, Frontiers in Psychiatry (2024). DOI: 10.3389/fpsyt.2024.1345159

Part 2

Comment by Dr. Krishna Kumari Challa on April 26, 2024 at 11:33am

Link between depression and cardiovascular disease explained: They partly develop from same gene module

Depression and cardiovascular disease (CVD) are serious concerns for public health. Approximately 280 million people worldwide have depression, while 620 million people have CVD.

It has been known since the 1990s that the two diseases are somehow related. For example, people with depression run a greater risk of CVD, while effective early treatment for depression cuts the risk of subsequently developing CVD by half. Conversely, people with CVD tend to have depression as well. For these reasons, the American Heart Association (AHA) advises to monitor teenagers with depression for CVD.

What wasn't yet known is what causes this apparent relatedness between the two diseases. Part of the answer probably lies in lifestyle factors common in patients with depression and which increase the risk of CVD, such as smoking, alcohol abuse, lack of exercise, and a poor diet. But it's also possible that both diseases might be related at a deeper level, through shared developmental pathways.

Now, scientists have shown that depression and CVD do indeed share part of their developmental programs, having at least one functional gene module in common. This result, published in Frontiers in Psychiatry, provides new markers for depression and CVD, and could ultimately help researchers to find drugs to target both diseases.

Part 1

Comment by Dr. Krishna Kumari Challa on April 26, 2024 at 11:11am

Study explores why human-inspired machines can be perceived as eerie

Artificial intelligence (AI) algorithms and robots are becoming increasingly advanced, exhibiting capabilities that vaguely resemble those of humans. The growing similarities between AIs and humans could ultimately bring users to attribute human feelings, experiences, thoughts, and sensations to these systems, which some people perceive as eerie and uncanny.

A  recent paper, published in Computers in Human Behavior: Artificial Humans, reviews past studies and reports the findings of an experiment testing a recent theory known as "mind perception," which proposes that people feel eeriness when exposed to robots that closely resemble humans because they ascribe minds to these robots.

For many people, the idea of a machine with conscious experience is unsettling. This discomfort extends to inanimate objects as well.

Overall, the results of the meta-analysis and experiment run by these researchers suggest that past studies backing mind perception theory could be flawed. In fact, the researcher gathered opposite results, suggesting that individuals who attribute sentience to robots do not necessarily find them eerier due to their human resemblance.

Although attributions of mind are not the main cause of the uncanny valley, they are part of the story. They can be relevant in some contexts and situations, yet that attributing mind to a machine that looks human is creepy. Instead, perceiving a mind in a machine that already looks creepy makes it creepier. However, perceiving a mind in a machine that has risen out of the uncanny valley and looks nearly human makes it less creepy.

Exploring whether there is strong support for this speculation is an area for future research, which would involve using more varied and numerous stimuli.

Karl F. MacDorman, Does mind perception explain the uncanny valley? A meta-regression analysis and (de)humanization experiment, Computers in Human Behavior: Artificial Humans (2024). DOI: 10.1016/j.chbah.2024.100065

Comment by Dr. Krishna Kumari Challa on April 25, 2024 at 12:26pm

Disease Ecology Butterfly Effect
When their preferred trees to chew on were cut down for the tobacco trade, chimpanzees in Uganda began consuming bat guano instead. Researchers recorded videos in the Budongo Forest Reserve between 2017 and 2019 and observed 839 instances of guano consumption, not only by chimpanzees but also by black-and-white colobus monkeys and red duikers, a type of forest antelope. The guano provides the chimps with essential minerals like sodium, potassium, magnesium and phosphorus that they would normally have gotten from the felled trees.

Why this matters: In addition to essential nutrients, the bat guano contained 27 unique viruses, including a novel coronavirus, the researchers found. Illnesses transmitted from animals to humans, called zoonotic diseases, account for about three quarters of new infectious diseases around the world. Those pathogens have a higher chance of jumping from an animal to a human when people encroach on ecosystems and disrupt relationships among species.

 “This is the butterfly effect of infectious disease ecology,” says senior study author Tony Goldberg, a wildlife epidemiologist at the University of Wisconsin–Madison. “Far-flung events like demand for tobacco can have crazy, unintended consequences for disease emergence that follow pathways that we rarely see and can’t predict.”

Comment by Dr. Krishna Kumari Challa on April 25, 2024 at 12:19pm

WHO redefines airborne transmission

The World Health Organization (WHO) has changed how it classifies airborne pathogens. It has removed the distinction between transmission by smaller virus-containing ‘aerosol’ particles and spread through larger ‘droplets’. The division, which some researchers argue was unscientific, justified WHO’s March 2020 assertion that SARS-CoV-2, the virus behind the COVID-19 pandemic, was not airborne. Under the new definition, SARS-CoV-2 would be recognized as spreading ‘through the air’ — although some scientists feel this term is less clear than ‘airborne’. “I'm not saying everybody is happy, and not everybody agrees on every word in the document, but at least people have agreed this is a baseline terminology,” says WHO chief scientist Jeremy Farrar.

https://www.who.int/publications/m/item/global-technical-consultati...

Comment by Dr. Krishna Kumari Challa on April 25, 2024 at 12:17pm

Lethal mpox strain appears to spread via sex
A virulent strain of the monkeypox virus might have gained the ability to spread through sexual contact. The strain, called clade Ib, has caused a cluster of infections in a conflict-ridden region of the Democratic Republic of the Congo (DRC). This isn’t the first time scientists have warned that the monkeypox virus could become sexually transmissible: similar warnings during a 2017 outbreak in Nigeria were largely ignored. The strain responsible, clade II, is less lethal than clade Ib, but ultimately caused an ongoing global outbreak that has infected more than 94,000 people and killed more than 180.

https://www.medrxiv.org/content/10.1101/2024.04.12.24305195v2.full....

https://www.nature.com/articles/d41586-024-01167-5?utm_source=Live+...

Comment by Dr. Krishna Kumari Challa on April 25, 2024 at 12:14pm

Scientists study lipids cell by cell, making new cancer research possible

Imagine being able to look inside a single cancer cell and see how it communicates with its neighbors. Scientists are celebrating a new technique that lets them study the fatty contents of cancer cells, one by one.

A study has sampled single live cancer cells and measured the fatty lipid compounds inside them. Working with partners at GSK and UCL, and developing new equipment with Yokogawa, the team saw how those cells transformed in response to changes in their environment.
The work appears in Analytical Chemistry.
The trouble with cancer cells is that no two are alike. That makes it harder to design good treatment, because some cells will always resist treatment more than others. Yet it has always proven tricky to study live cells after they have been removed from their natural environment, in enough detail to truly understand their makeup. That is why it is so exciting to be able to sample live cells under a microscope and study their fatty contents one by one.
Individual pancreatic cancer cells were lifted from a glass culture dish using Yokogawa's Single Cellome System SS2000. This extracts single live cells using tiny tubes 10 µm across—about half the diameter of the thinnest human hair.

By staining the cells with fluorescent dye, the researchers could monitor lipid droplets (stores of fatty molecules inside cells, thought to play an important role in cancer) throughout the experiment.

Then, working with partners at Sciex, researchers developed a new method using a mass spectrometer to fragment the lipids in the cells. This told them about their composition.

The researchers demonstrated that different cells had very different lipid profiles. They also saw how lipids in the cells changed in response to what was going on around them.

Untargeted single-cell lipidomics using liquid chromatography and data-dependent acquisition after live cell selection, Analytical Chemistry (2024). DOI: 10.1021/acs.analchem.3c05677

Comment by Dr. Krishna Kumari Challa on April 25, 2024 at 11:35am

Octocorals are one of the oldest groups of animals on the planet known to bioluminescence. "So, the question 's when did they develop this ability?"
Researchers had completed an extremely detailed, well-supported evolutionary tree of the octocorals in 2022. They created this map of evolutionary relationships, or phylogeny, using genetic data from 185 species of octocorals.

With this evolutionary tree grounded in genetic evidence, DeLeo and Quattrini then situated two octocoral fossils of known ages within the tree according to their physical features. The scientists were able to use the fossils' ages and their respective positions in the octocoral evolutionary tree to date to figure out roughly when octocoral lineages split apart to become two or more branches.

Next, the team mapped out the branches of the phylogeny that featured living bioluminescent species.

With the evolutionary tree dated and the branches that contained luminous species labeled, the team then used a series of statistical techniques to perform an analysis called ancestral state reconstruction.
If we know these species of octocorals living today are bioluminescent, we can use statistics to infer whether their ancestors were highly probable to be bioluminescent or not. The more living species with the shared trait, the higher the probability that as you move back in time that those ancestors likely had that trait as well.
The researchers used numerous different statistical methods for their ancestral state reconstruction, but all arrived at the same result: Some 540 million years ago, the common ancestor of all octocorals were very likely bioluminescent. That is 273 million years earlier than the glowing ostracod crustaceans that previously held the title of earliest evolution of bioluminescence in animals.
The octocorals' thousands of living representatives and relatively high incidence of bioluminescence suggests the trait has played a role in the group's evolutionary success. While this further begs the question of what exactly octocorals are using bioluminescence for, the researchers said the fact that it has been retained for so long highlights how important this form of communication has become for their fitness and survival.

Evolution of bioluminescence in Anthozoa with emphasis on Octocorallia, Proceedings of the Royal Society B: Biological Sciences (2024). DOI: 10.1098/rspb.2023.2626. royalsocietypublishing.org/doi … .1098/rspb.2023.2626

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