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Comment by Dr. Krishna Kumari Challa on October 29, 2023 at 12:06pm

Scientists Caught Sperm Defying One of The Major Laws of Physics

With their whip-like tails, human sperm propel themselves through viscous fluids, seemingly in defiance of Newton's third law of motion, according to a new study that characterizes the motion of these sex cells and single-celled algae.

Scientists investigated these non-reciprocal interactions in sperm and other microscopic biological swimmers, to figure out how they slither through substances that should, in theory, resist their movement.

When Newton conceived his now-famed laws of motion in 1686, he sought to explain the relationship between a physical object and the forces acting upon it with a few neat principles that, it turns out, don't necessarily apply to microscopic cells wriggling through sticky fluids.

Newton's third law can be summed up as "for every action, there is an equal and opposite reaction". It signifies a particular symmetry in nature where opposing forces act against each other. In the simplest example, two equal-sized marbles colliding as they roll along the ground will transfer their force and rebound based on this law.

However, nature is chaotic, and not all physical systems are bound by these symmetries. So-called non-reciprocal interactions show up in unruly systems made up of flocking birds, particles in fluid – and swimming sperm.

These motile agents move in ways that display asymmetric interactions with the animals behind them or the fluids that surround them, forming a loophole for equal and opposite forces to skirt Newton's third law.
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Part 1

Comment by Dr. Krishna Kumari Challa on October 29, 2023 at 11:44am

Scientists Unveil World-First Experimental Cocaine Addiction Vaccine

Scientists  have announced the development of an innovative new treatment for addiction to the drug and its powerful derivative crack: a vaccine.

Dubbed "Calixcoca," the test vaccine, which has shown promising results in trials on animals, triggers an immune response that blocks cocaine and crack from reaching the brain, which researchers hope will help users break the cycle of addiction.

Put simply, addicts would no longer get high from the drug.

​If the treatment gets regulatory approval, it would be the first time cocaine addiction is treated using a vaccine.

​The vaccine works by triggering patients' immune systems to produce antibodies that bind to cocaine molecules in the bloodstream, making them too large to pass into the brain's mesolimbic system, or "reward center," where the drug normally stimulates high levels of pleasure-inducing dopamine.

​It also protected rat fetuses against cocaine, researchers found, suggesting it could be used in humans to protect the unborn babies of pregnant addicts.

​The vaccine is now set to enter the final stage of trials: testing on humans.

​The vaccine is made with chemical compounds designed in the lab, rather than biological ingredients, meaning it would be less expensive to produce than many vaccines and would not have to be stored at cold temperatures.​

Source: AFP

Comment by Dr. Krishna Kumari Challa on October 28, 2023 at 9:50am

Microgravity Can Permanently Mutate Bacteria And Make Them Faster Breeders

Certain types of bacteria can mutate to reproduce more quickly when exposed to microgravity, and that's not great news for our space tourist dreams, seeing as we humans are teeming with bacteria. It's not clear why these bacteria respond so positively to microgravity, but researchers are figuring out ways to protect astronauts out in space, as well as mitigating the damage should a space-modified colony ever find its way back to Earth. In a study published in 2017, researchers from the University of Houston monitored Escherichia coli cells through 1,000 generations of growth in simulated microgravity conditions, finding that it spread significantly faster than a control sample of unaltered bacteria. The E. coli cells also picked up at least 16 different genetic mutations along the way, though it's not clear how these mutations affect growth rates, either individually or as a group. The adapted cells grew about three times as many colonies as the unmodified E. coli, the tests showed. Even when the supercharged bacteria were removed from microgravity conditions up to 30 generations before testing, 72 percent of the growth advantage was retained, showing that some changes prompted by space travel could be permanent. Certain strains have previously been shown to grow 60 percent more quickly in microgravity, so there seems to be something about that weightless environment that these microorganisms really like. Even now, astronauts on board the ISS are having to deal with thick biofilms of bacteria on their equipment that are growing faster than normal.

https://www.nature.com/articles/s41526-017-0020-1

Comment by Dr. Krishna Kumari Challa on October 28, 2023 at 9:24am

Inside CERN’s ‘antimatter factory’ creating antihydrogen

Comment by Dr. Krishna Kumari Challa on October 27, 2023 at 7:34am

Mimics human tissue, fights bacteria: new biomaterial

Scientists have created a new material that could change the way human tissue can be grown in the lab and used in medical procedures.

The new material belongs to a family of substances called hydrogels, the essence of life’s ‘squishy’ substances found in all living things, such as cartilage in animals and in plants like seaweed. The properties of hydrogels make them very useful in biomedical research because they can mimic human tissue, allowing cells to grow in a laboratory.

There are also human-made hydrogels that are used in a broad range of commodity products ranging from food and cosmetics to contact lenses and absorbent materials, and more recently in medical research to seal wounds and replace damaged tissue. While they might function adequately as space fillers that encourage tissue growth, synthetic hydrogels fall short in recreating the complex properties of real human tissue.

But in a research paper published today in Nature Communications, scientists describe how a new lab-made hydrogel behaves like natural tissue, with a number of surprising qualities that have implications for medical, food and manufacturing technology.

The hydrogel material is made from very simple, short peptides, which are the building blocks of proteins. The material is bioactive, which means that encapsulated cells behave as if they are living in natural tissue. At the same time, the material is antimicrobial, meaning that it will prevent bacterial infections. This combination lands it in the sweet spot for materials that might be useful in medicine. The material is also self-healing, which means that it will reform after being squished, fractured, or after being expelled from a syringe. This makes it ideal for 3D bioprinting, or as an injectable material for medicine.

https://www.nature.com/articles/s41467-023-41907-1

Comment by Dr. Krishna Kumari Challa on October 25, 2023 at 10:01am

Biological fingerprints in soil show where diamond-containing ore is buried

Researchers have identified buried kimberlite, the rocky home of diamonds, by testing the DNA of microbes in the surface soil.

These "biological fingerprints" can reveal which minerals are buried tens of meters below Earth's surface without having to drill. The researchers believe it is the first use of modern DNA sequencing of microbial communities in the search for buried minerals.

The research published in Communications Earth and Environment represents a new tool for mineral exploration, where a full toolbox could save prospectors time and a lot of money.

When ore interacts with soil, it changes the communities of microbes in the soil. The researchers tested this in the lab, introducing kimberlite to soil microbes and watching how they changed in number and species.

Using these "indicator" microbes and their DNA sequences, the team tested the surface soil at an exploration site in the Northwest Territories where kimberlite had previously been confirmed through drilling. They found 59 of the 65 indicators were present in the soil, with 19 present in high numbers directly above the buried ore. They also identified new indicator microbes to add to their set.

Using this set, they tested the surface soil at a second site in the Northwest Territories where they suspected kimberlite was present, and precisely located the topological outline and location of kimberlite buried tens of meters beneath the Earth's surface. This showed that indicators from one site could predict the location at another site. In future, exploration teams could build up a database of indicator species and test an unknown site to find out if kimberlite deposits are buried beneath the soil.

The researchers evaluated their technique against another technique known as geochemical analysis, which involves testing elements in the soil to identify the minerals beneath. The microbes were more precise when it came to identifying the location of buried ore.

Rachel L. Simister et al, DNA sequencing, microbial indicators, and the discovery of buried kimberlites, Communications Earth & Environment (2023). DOI: 10.1038/s43247-023-01020-z

Comment by Dr. Krishna Kumari Challa on October 23, 2023 at 10:04am

Comment by Dr. Krishna Kumari Challa on October 23, 2023 at 9:30am

Two probiotics identified as promising hypertension treatments

An estimated 40% of the global adult population have high blood pressure, or hypertension, which puts people at risk of cardiovascular disease and other dangerous health conditions. Recent studies suggest that probiotics may offer a protective effect, but researchers have a limited understanding of why shaping the gut microbiota can regulate blood pressure.

A study published in mSystems adds two new strains to the list of potential antihypertensive probiotics.

In experiments on hypertensive mice, treatment with the two probiotics, Bifidobacterium lactis and Lactobacillus rhamnosus, returned blood pressure to normal levels. The researchers also tracked how those probiotics altered the animals' gut microbial mix over 16 weeks, identifying specific microbes and metabolic pathways that may help explain the protective effect.

Accumulated evidence supports an antihypertensive effect of probiotics and probiotic fermented foods in both in vitro and in vivo experiments

Previous studies have connected the rising rates of hypertension worldwide to increasing consumption of sugar. It likely boosts blood pressure through many mechanisms—increased insulin resistance or salt retention, for example—but in recent years researchers have investigated sugar's effect on the gut microbiome, as well.

In the new study, the researchers tested the two probiotic strains on mice that developed high blood pressure after consuming water mixed with fructose. Over 16 weeks, they measured the animals' blood pressures every four weeks. They found that fructose-fed mice that received either probiotic showed significantly lower blood pressures than those fed a high fructose diet and not treated with probiotics.

The researchers used shotgun metagenomic sequencing to probe connections between the altered gut microbiota and the change in blood pressure. They found that a high-fructose diet in the mice led to an increase in Bacteroidetes and a decrease in Firmicutes bacteria; however, treatment with probiotics returned those populations to those found in the control group. In addition, the analysis identified new microbial signatures associated with blood pressure: Increased levels of Lawsonia and Pyrolobus bacteria, and reduced levels of Alistipes and Alloprevotella, were associated with lower blood pressure.

 mSystems (2023). journals.asm.org/doi/10.1128/msystems.00331-23

Comment by Dr. Krishna Kumari Challa on October 22, 2023 at 9:03am

The encounter between Neanderthals and Homo sapiens as told by their genomes

 About 40,000 years ago, Neanderthals, who had lived for hundreds of thousands of years in the western part of the Eurasian continent, gave way to Homo sapiens, who had arrived from Africa. This replacement was not sudden, and the two species coexisted for a few millennia, resulting in the integration of Neanderthal DNA into the genome of Homo sapiens.

Researchers  have analyzed the distribution of the portion of DNA inherited from Neanderthals in the genomes of humans (Homo sapiens) over the last 40,000 years. These statistical analyses revealed subtle variations in time and geographical space. This work, published in the journal Science Advances, helps us to understand the common history of these two species.

Thanks to genome sequencing and comparative analysis, it is established that Neanderthals and Homo sapiens interbred and that these encounters were sometimes fruitful, leading to the presence of about 2% of DNA of Neanderthal origin in present-day Eurasians. However, this percentage varies slightly between regions of Eurasia, since DNA from Neanderthals is somewhat more abundant in the genomes of Asian populations than in those of European populations.

One hypothesis to explain this difference is that natural selection would not have had the same effect on genes of Neanderthal origin in Asian and European populations.

Another new theory suggests that such differences could be explained by migratory flows: when a migrant population hybridizes with a local population, in their area of cohabitation, the proportion of DNA of the local population tends to increase with distance from the point of departure of the migrant population.

In the case of Homo sapiens and Neanderthals, the hypothesis is that the further one moves away from Africa, Homo sapiens' point of origin, the greater the proportion of DNA from Neanderthal, a population mainly located in Europe. To test this hypothesis, the authors used a database made available by Harvard Medical School that includes more than 4,000 genomes from individuals who have lived in Eurasia over the past 40 millennia.

Statistical analyses revealed that, in the period following the dispersal of Homo sapiens from Africa, the genomes of Paleolithic hunter-gatherers who lived in Europe contained a slightly higher proportion of DNA of Neanderthal origin than the genomes of those who lived in Asia. This result is contrary to the current situation but in agreement with paleontological data, since the presence of Neanderthals was mainly reported in western Eurasia (no Neanderthal bones have been discovered further east than the Altai region of Siberia).

Subsequently, during the transition to the Neolithic, i.e. the transition from the hunter-gatherer lifestyle to the farmer lifestyle, 10,000 to 5,000 years ago, the study shows a decline in the proportion of DNA of Neanderthal origin in the genomes of European populations, resulting in a slightly lower percentage than that of Asian populations (as currently observed).

This study shows that the analysis of ancient genomes, coupled with archaeological data, makes it possible to trace different stages in the history of hybridized species.

Claudio S. Quilodrán, Jérémy Rio, Alexandros Tsoupas, Mathias Currat. Past human expansions shaped the spatial pattern of Neanderthal ancestry. Science Advances, 2023; 9 (42) DOI: 10.1126/sciadv.adg9817

Comment by Dr. Krishna Kumari Challa on October 21, 2023 at 11:47am

The researchers demonstrated that there were considerable differences in gene expression in the intestine, brain and placenta of the fetuses of germ-free and normal mouse dams.

In the gut, genes associated with the immune system and host–microbe interactions were less active in the fetuses of germ-free dams. There were significant differences in the expression of genes in the brain associated with the development and functioning of the nervous system. In the placenta, there were differences in the expression of several important genes that regulate pregnancy.

The differences were more extensive in male fetuses, indicating that they may be more sensitive to the effects of the maternal microbiota, at least in mice.

The researchers discovered that the expression of many important genes was associated with the concentration of metabolites likely to be modulated by the maternal microbiota. These metabolites were absent in the fetuses of germ-free dams, or occurred at least at significantly lower concentrations.

Aleksi Husso et al, Impacts of maternal microbiota and microbial metabolites on fetal intestine, brain, and placenta, BMC Biology (2023). DOI: 10.1186/s12915-023-01709-9

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