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Comment by Dr. Krishna Kumari Challa on July 9, 2021 at 11:58am

More cell phone data use is negatively affecting Wi-Fi performance, study finds

If service becomes slow when you're trying to send a quick email on your smartphone, you might scroll through your network options and discover how many Wi-Fi networks there are. In fact, this plethora of options is itself the problem. These networks are in competition with one another, limiting the speed at which each can operate.

Hidden-nodes in coexisting LAA & Wi-Fi: a measurement study of real deployments. arxiv.org/abs/2103.15591

Comment by Dr. Krishna Kumari Challa on July 9, 2021 at 11:11am

Stem cells can use same method as plants and insects to protect against viruses

Researchers at the Francis Crick Institute have found a vital mechanism, previously thought to have disappeared as mammals evolved, that helps protect mammalian stem cells from RNA viruses such as SARS-CoV-2 and Zika virus. The scientists suggest this could one day be exploited in the development of new antiviral treatments.

On infecting a host, a virus enters cells in order to replicate. For most cells in mammals the first line of protection are proteins, called interferons. Stem cells, however, lack the ability to trigger an interferon response and there has been uncertainty about how they protect themselves.

In their study, published in Science today the scientists analyzed genetic material from mouse stem cells and found it contains instructions to build a protein, named antiviral Dicer (aviD), which cuts up viral RNA and so prevents RNA viruses from replicating. This form of protection is called RNA interference, which is the method also used by cells in plants and invertebrates.

In laboratory experiments which exposed engineered human cells to SARS-CoV-2, the virus infected three times fewer stem cells when aviD was present in the cells compared to when the researchers removed this protein.

An isoform of Dicer protects mammalian stem cells against multiple RNA viruses" Science (2021). science.sciencemag.org/lookup/ … 1126/science.abg2264

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It's fascinating to learn how stem cells protect themselves against RNA viruses. The fact this protection is also what plants and invertebrates use suggests it might be something that goes far back in mammalian history, right up to when the evolutionary tree spilt. For some reason, while all mammalian cells possess the innate ability to trigger this process, it seems to only be relied upon by stem cells.

By learning more about this process, and uncovering the secrets of our immune system we are hoping to open up new possibilities for drug development as we strive to harness our body's natural ability to fight infection

The scientists also grew mini brain organoids from mouse embryonic stem cells and found that, when infected with Zika virus, the organoids with aviD grew more quickly and less viral material was produced than in organoids without this protein. Similarly, when organoids were infected with SARS-CoV-2, there were fewer infected stem cells in the organoids with aviD.

https://phys.org/news/2021-07-stem-cells-method-insects-viruses.htm...

Comment by Dr. Krishna Kumari Challa on July 9, 2021 at 10:46am

Climate changed the size of our bodies 

An interdisciplinary team of researchers has gathered measurements of body and brain size for over 300 fossils from the genus Homo found across the globe. By combining this data with a reconstruction of the world's regional climates over the last million years, they have pinpointed the specific climate experienced by each fossil when it was a living human.

The study reveals that the average body size of humans has fluctuated significantly over the last million years, with larger bodies evolving in colder regions. Larger size is thought to act as a buffer against colder temperatures: less heat is lost from a body when its mass is large relative to its surface area.

Nature Communications (2021). DOI: 10.1038/s41467-021-24290-7

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Our species, Homo sapiens, emerged around 300,000 years ago in Africa. The genus Homo has existed for much longer, and includes the Neanderthals and other extinct, related species such as Homo habilis and Homo erectus.

https://phys.org/news/2021-07-climate-size-bodies-extent-brains.htm...

Comment by Dr. Krishna Kumari Challa on July 9, 2021 at 8:27am

Certain fish skin can be grafted onto burns and diabetic wounds. The material recruits the body's own cells and is converted eventually into living tissue.

Comment by Dr. Krishna Kumari Challa on July 8, 2021 at 11:21am

The shape of nanoparticles in body fluids may reveal the type of ca...

A recent study by scientists from Japanese universities has shown that the shape of cell-derived nanoparticles, known as "extracellular vesicles" (EVs), in body fluids could be a biomarker for identifying types of cancer. In the study, the scientists successfully measured the shape distributions of EVs derived from liver, breast, and colorectal cancer cells, showing that the shape distributions differ from one another. The findings were recently published in the journal Analytical Chemistry.

Comment by Dr. Krishna Kumari Challa on July 7, 2021 at 11:41am

New species of ‘fairy lantern’ from Malaysian rainforests

Comment by Dr. Krishna Kumari Challa on July 4, 2021 at 9:29am

Antimicrobial Resistance, HAIs and the Environment!

Comment by Dr. Krishna Kumari Challa on July 4, 2021 at 9:17am

Proving The Impossible

Comment by Dr. Krishna Kumari Challa on July 3, 2021 at 10:20am

Microbes in cow stomachs can break down plastic

Plastic is notoriously hard to break down, but researchers  have found that bacteria from a cow's rumen—one of the four compartments of its stomach—can digest certain types of the ubiquitous material, representing a sustainable way to reduce plastic litter.

The scientists suspected such bacteria might be useful since cow diets already contain natural plant polyesters.

Thye  looked at three kinds of polyesters. One, polyethylene terephthalate, commonly known as PET, is a synthetic polymer commonly used in textiles and packaging. The other two consisted of a biodegradable plastic often used in compostable plastic bags (polybutylene adipate terephthalate, PBAT), and a biobased material (Polyethylene furanoate, PEF) made from renewable resources.

They obtained rumen liquid from a slaughterhouse in Austria to get the microorganisms they were testing. They then incubated that liquid with the three types of plastics they were testing (which were tested in both powder and film form) in order to understand how effectively the plastic would break down.

According to their results, which were recently published in Frontiers in Bioengineering and Biotechnology, all three plastics could be broken down by the microorganisms from cow stomachs, with the plastic powders breaking down quicker than plastic film. 

Frontiers in Bioengineering and Biotechnology, DOI: 10.3389/fbioe.2021.684459a , www.frontiersin.org/articles/1 … ioe.2021.684459/full

https://phys.org/news/2021-07-microbes-cow-stomachs-plastic.html?ut...

Comment by Dr. Krishna Kumari Challa on July 3, 2021 at 9:54am

Groundbreaking methane synthesis discovery

An interdisciplinary team of scientists recently published research casting new light on a previously unknown element of the carbon cycle, thanks to data collected from Yellowstone National Park over more than a decade.

The study is the subject of a new paper published this week in the journal Proceedings of the National Academy of Science titled "Aerobic Bacterial Methane Synthesis."

They began studying the microbiology of Yellowstone Lake in 2007. While collecting data to analyze the lake's chemistry and the interaction of various microbes in the lake with the park's underlying thermal features, they noticed something seemed off. They came across some lake water gas chemistries that didn't make  sense.

That discrepancy illustrated what has been termed the "methane paradox." For years, scientists have understood that when microorganisms produce methane, they do it anaerobically, meaning they don't use oxygen. But in the surface waters of the lake where the team was seeing methane, none of those organisms were found.

Methane is a naturally occurring gas made up of carbon and hydrogen atoms. It is the byproduct of a number of biological processes, though human activities like mining coal and refining natural gas also produce methane. It is a greenhouse gas known to be much more potent when trapping heat in the atmosphere than carbon dioxide, which is why many researchers are interested in identifying where in the biosphere it is created and where it goes.

When they did the DNA extraction from the lake water, they couldn't find the anaerobic organisms that are usually responsible for the presence of methane. Instead, they discovered aerobic bacteria were involved, isolating a bacterium called Acidovorax, which then allowed them to begin understanding this process.

Thye used analytical equipment to identify the presence of methylamine and glycine betaine in the lake water, biochemicals the team hypothesized to be key in the process of methane production. To test the theory, they narrowed down which gene the Acidovorax bacteria needed to convert methylamine or glycine betaine into methane.

They could break this down to a basic discovery about methylamine conversion to methane under aerobic conditions

Through a series of microbial experiments and extensive analysis of the wider biological community present in the lake samples, scientists identified a known gene that encodes aspartate aminotransferase, or AAT, that seemed to be catalyzing the methane synthesis.

This is a fundamentally different process from anaerobic methane synthesis

Qian Wang et al, Aerobic bacterial methane synthesis, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2019229118

https://phys.org/news/2021-07-team-publishes-groundbreaking-methane...

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