Comment

Comment by Dr. Krishna Kumari Challa on October 16, 2020 at 5:44am

When feeling the pinch, nuclei instigate cells to escape crowded spaces

The threat of serious deformation triggers a rapid escape reflex that enables cells to move away and squeeze out from tight spaces or crowded tissues.

In a new study  researchers reveal that squeezing a cell to the point where its nucleus starts to stretch triggers the activation of motor proteins which in turn transform the cell's cytoskeleton so that it can flee a packed environment.

Each cell has a nucleus, and each nucleus has a membrane that separates the chromosomes from the rest of the cell. At a rest state, the nuclear membrane is saggy, akin to a loose shopping bag. Now researchers have found that when the nuclear membrane  is squeezed, the wrinkles on its surface iron themselves out, instigating a cascade of events that transform the cytoskeleton and eventually aid the cell in escaping its crowded environment.

The nucleus measures shape changes for cellular proprioception to control dynamic cell behavior, Science (2020). DOI: 10.1126/science.aba2644

Study finds how body cells move within a tissue

https://phys.org/news/2020-10-nuclei-instigate-cells-crowded-spaces...

Comment by Dr. Krishna Kumari Challa on October 15, 2020 at 1:09pm

Science Pinpoints Global Metal Deposit Locations

Miners can find new deposits with less effort

--

** 

Decoy Cells Trick SARS-CoV-2, Reduce Cytokines In Vitro

Genetically engineered cells that overproduce ACE2, the receptor the novel coronavirus uses to enter cells, neutralize infection in vitro and mop up inflammatory cytokines in mice.

https://www.the-scientist.com/news-opinion/decoy-cells-trick-sars-c...

Comment by Dr. Krishna Kumari Challa on October 15, 2020 at 1:05pm

Electric and Magnetic Field Treatments Lower Mouse Blood Sugar

**The effects seem to be mediated by a reactive oxygen species in the animals’ livers.

https://www.the-scientist.com/news-opinion/electric-and-magnetic-fi...

Comment by Dr. Krishna Kumari Challa on October 15, 2020 at 7:55am

New areas at risk of drinking water arsenic exposure in India

An international team involving researchers based in Manchester (UK), Patna (India) and Zurich (Switzerland) has found new areas of arsenic contamination in drinking water in India. Their country-specific, country-wide model for well water arsenic in India has recently been published in the International Journal for Environmental Research and Public Health.

Their model confirms the known high probability of finding hazardous high arsenic well waters in northern India in the river basins of the Ganges and Brahmaputra. What is new and particularly concerning, is that the model also finds an elevated probability of high arsenic well waters in other Indian areas, where previously arsenic hazard was generally not considered to be a major concern—so much so that in many of these areas well water arsenic is not routinely checked.

These areas include parts of south-west and central India and are mostly areas underlain by sediments and sedimentary rocks.

The study suggests follow up to help better define specific areas in which action is required to reduce adverse public health outcomes from drinking high arsenic well waters. The study also highlights the importance of systematic testing of hazards, not just in known high hazard areas, but also through random sampling of all wells used for drinking water.

Joel Podgorski et al. Groundwater Arsenic Distribution in India by Machine Learning Geospatial Modeling, International Journal of Environmental Research and Public Health (2020). DOI: 10.3390/ijerph17197119

https://phys.org/news/2020-10-areas-arsenic-exposure-india.html?utm...

Comment by Dr. Krishna Kumari Challa on October 15, 2020 at 7:40am

The Great Barrier Reef has lost half its corals

A new study of the Great Barrier Reef shows populations of its small, medium and large corals have all declined in the past three decades. Scientists  found the number of small, medium and large corals on the Great Barrier Reef has declined by more than 50 percent since the 1990s.

The decline occurred in both shallow and deeper water, and across virtually all species—but especially in branching and table-shaped corals. These were the worst affected by record-breaking temperatures that triggered mass bleaching in 2016 and 2017.

Climate change is driving an increase in the frequency of reef disturbances such as marine heatwaves. 'There is no time to lose—we must sharply decrease greenhouse gas emissions ASAP if we want to protect them from more degradation and total loss', the researchers conclude.

Andreas Dietzel et al, Long-term shifts in the colony size structure of coral populations along the Great Barrier Reef, Proceedings of the Royal Society B: Biological Sciences (2020). DOI: 10.1098/rspb.2020.1432

https://phys.org/news/2020-10-great-barrier-reef-lost-corals.html?u...

----

Scientists shed new light on viruses' role in coral bleaching

Scientists  have shown that viral infection is involved in coral bleaching—the breakdown of the symbiotic relationship between corals and the algae they rely on for energy.

After analyzing the viral metagenomes they found that bleached corals had a higher abundance of eukaryotic viral sequences, and non-bleached corals had a higher abundance of bacteriophage sequences. This gave the researchers the first quantitative evidence of a shift in viral assemblages between coral bleaching states.
Bacteriophage viruses infect and replicate within bacteria. Eukaryotic viruses infect non-bacterial organisms like animals.
In addition to having a greater presence of eukaryotic viruses in general, bleached corals displayed an abundance of what are called giant viruses. Known scientifically as nucleocytoplasmic large DNA viruses, or NCLDV, they are complex, double-stranded DNA viruses that can be parasitic to organisms ranging from the single-celled to large animals, including humans.
Giant viruses have been implicated in coral bleaching. Now scientists were able to generate the first draft genome of a giant virus that might be a factor in bleaching.

Adriana Messyasz et al, Coral Bleaching Phenotypes Associated With Differential Abundances of Nucleocytoplasmic Large DNA Viruses, Frontiers in Marine Science (2020). DOI: 10.3389/fmars.2020.555474

https://phys.org/news/2020-10-scientists-viruses-role-coral.html?ut...

Comment by Dr. Krishna Kumari Challa on October 15, 2020 at 7:34am

Scientists home in on the mechanism that protects cells from premature aging

Molecules that accumulate at the tip of chromosomes are known to play a key role in preventing damage to our DNA. Now, researchers  have unraveled how these molecules home in on specific sections of chromosomes—a finding that could help to better understand the processes that regulate cell survival in aging and cancer.

Much like the aglet of a shoelace prevents the end of the lace from fraying, stretches of DNA called telomeres form protective caps at the ends of chromosomes. But as cells divide, telomeres become shorter, making the protective cap less effective. Once telomeres get too short, the cell stops dividing. Telomere shortening and malfunction have been linked to cell aging and age-related diseases, including cancer.

Scientists have known that RNA species called TERRA help to regulate the length and function of telomeres. Discovered in 2007  TERRA belongs to a class of molecules called noncoding RNAs, which are not translated into proteins but function as structural components of chromosomes. TERRA accumulates at chromosome ends, signaling that telomeres should be elongated or repaired.

However, it was unclear how TERRA got to the tip of chromosomes and remained there. "The telomere  makes up only a tiny bit of the total chromosomal DNA, so the question is 'how does this RNA find its home. By visualizing TERRA molecules under a microscope, the researchers found that a short stretch of the RNA is crucial to bring it to telomeres. Further experiments showed that once TERRA reaches the tip of chromosomes, several proteins regulate its association with telomeres. Among these proteins, one called RAD51 plays a particularly important role. RAD51 is a well-known enzyme that is involved in the repair of broken DNA molecules. The protein also seems to help TERRA stick to telomeric DNA to form a so-called "RNA-DNA hybrid molecule". Scientists thought this type of reaction, which leads to the formation of a three-stranded nucleic acid structure, mainly happened during DNA repair. The new study shows that it can also happen at chromosome ends when TERRA binds to telomeres. The researchers also found that short telomeres recruit TERRA much more efficiently than long telomeres. Although the mechanism behind this phenomenon is unclear, the researchers hypothesize that when telomeres get too short, either due to DNA damage or because the cell has divided too many times, they recruit TERRA molecules. This recruitment is mediated by RAD51, which also promotes the elongation and repair of telomeres. "TERRA and RAD51 help to prevent accidental loss or shortening of telomeres. That's an important function."

Given the role of telomeres in health and disease, it will be important to see how the newly discovered mechanism—which was deduced from observations in living cells and reproduced in test tubes—is regulated in the very complex cellular environment.

RAD51-dependent recruitment of TERRA long noncoding RNA to telomeres through R-loops, Nature (2020). DOI: 10.1038/s41586-020-2815-6

https://phys.org/news/2020-10-scientists-home-mechanism-cells-prema...

Comment by Dr. Krishna Kumari Challa on October 15, 2020 at 7:08am

Restoring 30% of the world's ecosystems in priority areas could stave off extinctions and absorb CO2

Returning specific ecosystems that have been replaced by farming to their natural state in all continents worldwide would rescue the majority of land-based species of mammals, amphibians and birds under threat of extinction. Such measures would also soak up more than 465 billion tons of carbon dioxide, according to a new report released today. Protecting 30% of the priority areas identified in the study, together with protecting ecosystems still in their natural form, would reduce carbon emissions equivalent to 49% of all the carbon that has built up in our atmosphere over the last two centuries. Some 27 researchers from 12 countries contributed to the report, which assesses forests, grasslands, shrublands, wetlands and arid ecosystems.

By identifying precisely which destroyed ecosystems worldwide should be restored to deliver biodiversity and climate benefits at a low cost without impact on agricultural production, the study is the first of its kind to provide global evidence that where restoration takes place has the most profound impact on the achievement of biodiversity, climate and food security goals. According to the study, restoration can be 13 times more cost-effective when it takes place in the highest priority locations.

Global priority areas for ecosystem restoration, Nature (2020). DOI: 10.1038/s41586-020-2784-9

https://phys.org/news/2020-10-world-ecosystems-priority-areas-stave...

Comment by Dr. Krishna Kumari Challa on October 14, 2020 at 8:04am

‘Great Adaptations’ unravels mysteries of amazing animal abilities

Tales of unusual animals — and unusual science — make for an entertaining read

the mystery behind the mole’s wiggly star-shaped appendage (it helps the subterranean animal sense prey without using sight)

how “hangry” water shrews execute the fastest documented predatory attack by a mammal and how cockroaches resist becoming zombies during parasitoid wasp attacks (SN: 10/31/18).

the notion that a tentacled snake (Erpeton tentaculatum) might use the short appendages close to itsmouth to lure in nearby fish, just like snapping turtles dowith their tongues, turned out to be wrong. Instead, the tentacleshelp a snake sense a fish’s position in the water andknow when to attack. What’s more, the snakes have hackedtheir prey’s natural escape reflexes. In a fatal mistake, fishflee in the wrong direction — straight toward a snake’smouth — when duped by a twitch of the snake’s neck rightbefore the predator strikes.

 Tentacled snakes are born knowing how to strike at prey rather than learning through failure you can’t “find enough superlatives to sum up these results.” A fight between a parasitoid wasp and a cockroach is like an “insect rodeo.” The wasp attacks a cockroach’s head in an attempt to lay an egg, but in defense the roach “bucks, jumps, and flails with all its might.”

https://www.sciencenews.org/article/book-great-adaptations-unravels...

You can check   Great Adaptations on Amazon.com.

Comment by Dr. Krishna Kumari Challa on October 14, 2020 at 8:00am

Pufferfish may be carving mysterious ‘crop circles’ near Australia

The only other known rings are fish nests found 5,500 kilometers away, in Japan

Japan’s white-spotted pufferfish are renowned for producing complex, ringed patterns in the sand. Now, 5,500 kilometers away in Australia, scientists have discovered what appear to be dozens more of these creations.

While conducting a marine life survey out on Australia’s North West Shelf near subsea gas infrastructure with an autonomous underwater vehicle, marine ecologist Todd Bond spotted a striking pattern on the seafloor, more than 100 meters deep.  “Immediately, I knew what it was,” recounts Bond, of the University of Western Australia in Perth. Bond and his colleagues continued the survey, ultimately finding nearly two dozen more.

Until now, these undersea “crop circles” were found only off the coast of Japan. First spotted in the 1990s, it took two decades to solve the mystery of what created them. In 2011, scientists found the sculptors — the diminutive males of what was then a new species of Torquigener pufferfish. The patterns are nests, meticulously plowed over the course of days and decorated with shells to entice females to lay their eggs in the center. 

https://www.sciencenews.org/article/pufferfish-mysterious-crop-circ...

Comment by Dr. Krishna Kumari Challa on October 14, 2020 at 7:48am

Multivitamins Don't Necessarily Make You Healthier. Here's Why

Do multivitamins make you healthier?

Some peopel take multivitamins daily on the idea that they help improve overall health and potentially lower disease. Is their any science behind the health benefits of taking multivitamin supplements?

 Multivitamins have their use for people with vitamin and mineral deficiencies, but they don't appear to offer many health benefits for the general population.

If you feel that you could be lacking in certain nutrients, it may be better to look at changing your diet rather than reaching for supplements. If you need help, see your doctor or a dietitian. 

https://metafact.io/factcheck_answers/2064

https://www.sciencealert.com/multivitamins-don-t-necessarily-make-y...

• ‹ Previous
• 1
• …
• 741
• 742
• 743
• 744
• 745
• …
• 1083
• Next ›
• Page