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Comment by Dr. Krishna Kumari Challa on December 11, 2020 at 9:24am

How kids’ immune systems evade COVID A growing body of evidence suggests why young children account for only a small percentage of COVID-19 infections: their immune systems seem better equipped to eliminate SARS-CoV-2 t.... Some children who do get infected never test positive for the virus on a standard RNA test, even if they develop symptoms and have antibodies specific to SARS-CoV-2. Their immune system sees the virus “and it just mounts this really quick and effective immune response that shuts it down, before it has a chance to replicate to the point that it comes up positive on the swab diagnostic test”, says immunologist Melanie Neeland. The source of children’s immune advantage is thought to arise from one — or several — of these factors: Children’s T cells are untrained, so they might have a greater capacity to respond to new viruses. Children might have a strong innate immune response from birth, although that raises the question of why it isn’t seen with other viruses that can cause severe disease in children. It could be thanks to the protection of antibodies to seasonal common-cold coronaviruses, which run rampant in children. Kids might receive a smaller dose when exposed to SARS-CoV-2, because their noses contain fewer of the ACE2 receptors that the virus uses to gain access.

Comment by Dr. Krishna Kumari Challa on December 11, 2020 at 8:23am

** The greening of the Earth is approaching its limit

When plants absorb this gas to grow, they remove it from the atmosphere and it is sequestered in their branches, trunk or roots. An article published today in Science shows that this fertilizing effect of CO2 is decreasing worldwide, according to the text co-directed by Professor Josep Peñuelas of the CSIC at CREAF and Professor Yongguan Zhang of the University of Nanjin, with the participation of CREAF researchers Jordi Sardans and Marcos Fernández. The study, carried out by an international team, concludes that the reduction has reached 50% progressively since 1982 due basically to two key factors: the availability of water and nutrients.

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COVID-19 and other pandemics are the effects of our negative impact...

There is increasing awareness that the COVID-19 pandemic is the consequence of environmental and societal crises. A new paper just published in the scientific journal Science of the Total Environment by international research fellows of the Konrad Lorenz Institute for Evolution and Cognition Research (KLI), an Austrian independent center for advanced studies in the life and sustainability sciences, presents an interdisciplinary approach to analyze the COVID-19 pandemic as a phenomenon affecting the diversity of all spheres of the total environment.

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Bad news for fake news: New research helps combat social media misi...

Rice University researchers have discovered a more efficient way for social media companies to keep misinformation from spreading online using probabilistic filters trained with artificial intelligence.

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Researchers shed new light on mysteries behind the light emission o...

A team of researchers from the NYU Abu Dhabi's (NYUAD) Smart Materials Lab (SML) led by Professor of Chemistry Panče Naumov has conducted a thorough review of the scientific literature surrounding the natural production of light, called bioluminescence, and developed conclusions that will help others in the field direct their research to uncover the mysteries behind this fascinating natural phenomenon.

Comment by Dr. Krishna Kumari Challa on December 11, 2020 at 8:19am

Researchers identify the physical mechanism that can kill bacteria with gold nanoparticles

Finding alternatives to antibiotics is one of the biggest challenges facing the research community. Bacteria are increasingly resistant to these drugs, and this resistance leads to the deaths of more than 25,000 around the world. Now, a multidisciplinary team of researchers have discovered that the mechanical deformation of bacteria is a toxic mechanism that can kill bacteria with gold nanoparticles. The results of this research have been published in the journal Advanced Materials and are a breakthrough in researchers' understanding the antibacterial effects of nanoparticles and their efforts to find new materials with bactericide properties.

Since the times of Ancient Egypt, gold has been used in a range of medical applications and, more recently, as for diagnosing and treating diseases such as cancer. This is due to the fact that gold is a chemically inert material, that is, it does not react or change when it comes into contact with an organism. Amongst the scientific community, nanoparticles are known for their ability to make tumors visible and for their applications in nanomedicine.

This new research shows that these chemically inert nanoparticles can kill bacteria thanks to a physical mechanism that deforms the cell wall. To demonstrate this, the researchers have synthesized in the laboratory gold nanoparticles in the shape of an almost perfect sphere and others in the shape of stars, all measuring 100 nanometres (8 times thinner than a hair). The group analyzed how these particle interact with living bacteria. Researchers found that the bacteria become deformed and deflate like a ball that is having the air let out before dying in the presence of these nanoparticles as if the cell wall had spontaneously exploded. 

The scientists thought that a physical mechanism might be responsible for the death of the bacteria. Consequently, they carried out aa numerical simulations to analyze how a homogenous layer of individual nanoparticles could apply sufficient mechanical tension to the cell wall of the bacteria that it ends up breaking seemingly by stretching, like a balloon that is inflated from different points until it exploded.

To confirm this hypothesis, the researchers created an artificial model of a bacterial cell membrane to evaluate its response when it entered into contact with the 100 nm gold nanoparticles. They found that the model spontaneously contracted until it completely collapsed, thus proving the hypothesis that nanoparticles apply a mechanical stretch on the cell membrane of the bacteria.

Denver P. Linklater et al, Antibacterial Action of Nanoparticles by Lethal Stretching of Bacterial Cell Membranes, Advanced Materials (2020). DOI: 10.1002/adma.202005679

https://phys.org/news/2020-12-physical-mechanism-bacteria-gold-nano...

Comment by Dr. Krishna Kumari Challa on December 11, 2020 at 7:14am

Blocking protein restores strength, endurance in old mice, study finds

Muscle loss during aging is known as sarcopenia, and it accounts for billions of dollars of health care expenditures  each year as people lose the ability to care for themselves, experience more falls and become increasingly less mobile. It is due to changes in muscle structure and function: The muscle fibers shrink and the number and function of the cellular powerhouses known as mitochondria dwindle.

Blocking the activity of a single protein in old mice for one month restores mass and strength to the animals' withered muscles and helps them run longer on a treadmill, according to a study by researchers. Conversely, increasing the expression of the protein in young mice causes their muscles to atrophy and weaken.

The improvement is really quite dramatic. The old mice are about 15% to 20% stronger after one month of treatment, and their muscle fibres look like young muscle. Considering that humans lose about 10% of muscle strength per decade after about age 50, this is quite remarkable.

The protein hasn't previously been implicated in aging. The researchers show that the amount of the protein, called 15-PGDH, is elevated in old muscle and is widely expressed in other old tissues. Experiments they conducted in human tissue raise hopes for a future treatment for the muscle weakness that occurs as people age.

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Prostaglandin E2 levels are regulated by 15-PGDH, which breaks down prostaglandin E2. The researchers used a highly sensitive version of mass spectrometry, a method for differentiating closely related molecules, to determine that compared with young mice, the 15-PGDH levels are elevated in the muscles of older animals, and the levels of prostaglandin E2 are lower.

They found a similar pattern of 15-PGDH expression in human muscle tissues, as those from people in their 70s and early 80s expressed higher levels than those from people in their mid-20s.

"We knew from our previous work that prostaglandin E2 was beneficial for regeneration of young muscles.

"Inhibition of prostaglandin-degrading enzyme 15-PGDH rejuvenates aged muscle mass and strength" Science (2020). science.sciencemag.org/lookup/ … 1126/science.abc8059

https://medicalxpress.com/news/2020-12-blocking-protein-strength-mi...

Comment by Dr. Krishna Kumari Challa on December 10, 2020 at 12:02pm

This Teen's Brilliantly Simple Explainer on Quantum Mechanics Just Won a Global Prize

https://www.sciencealert.com/17-year-old-wins-global-science-prize-...

Comment by Dr. Krishna Kumari Challa on December 10, 2020 at 11:31am

Dogs Probably Don't Understand Us as Well as We Think, Brain Scans Reveal

Dogs may never learn that every sound of a word matters

https://www.sciencealert.com/dogs-may-not-actually-understand-us-as...

Comment by Dr. Krishna Kumari Challa on December 10, 2020 at 10:32am

These simple steps can help prevent heat-related fatalities

Comment by Dr. Krishna Kumari Challa on December 10, 2020 at 10:25am

Scientists discover how COVID-19 virus causes multiple organ failure in mice

 Researchers  created a version of COVID-19 in mice that shows how the disease damages organs other than the lungs. Using their model, the scientists discovered that the SARS-CoV-2 virus can shut down energy production in cells of the heart, kidneys, spleen and other organs.

Understanding how this virus can hijack our cells might eventually lead to new ways to prevent or treat the organ failure that can accompany COVID-19 in humans. 

Research in humans has suggested that SARS-CoV-2 can circulate through the bloodstream to reach multiple organs. So in the UCLA experiment, the researchers first engineered mice to have the human version of ACE2 in the heart and other vital organs. Then, they infected half of the animals by injecting SARS-CoV-2 into their bloodstreams. Over the following days, the researchers tracked the animals’ overall health and analyzed how levels of certain genes and proteins in their bodies changed.

Within seven days, all of the mice with COVID-19 had stopped eating and were completely inactive, and had lost, on average, about 20% of their body weight. Animals that had been engineered to carry the human ACE2 protein but had not been infected with the virus, on the other hand, did not lose a significant amount of weight.

Moreover, the COVID-19 infected animals had altered levels of immune cells, swelling of the heart tissue and wasting away of the spleen — all symptoms that have been observed in people who are critically ill with COVID-19.

The research team also looked at which genes were turned on and off in the mice infected with SARS-CoV-2, and they discovered other signs of disease. Common molecular processes that help cells generate energy — through mechanisms known as the tricarboxylic acid cycle, or TCA cycle, and electron transport chain — were shut off in the heart, kidney, spleen and lungs.

If a virus snuffs out the energy-generating pathways in multiple organs of the body, that’s going to really wreak havoc.

The study also revealed that some changes were long-lasting throughout the organs in mice with COVID-19. In addition to temporarily altering which genes were turned on and off in some cells, the virus made epigenetic changes — chemical alterations to the structure of DNA that cause more lasting effects. This could explain why, in some people with COVID-19, symptoms persist for weeks or months after their bodies are rid of the virus.

https://newsroom.ucla.edu/releases/covid-19-multiple-organ-failure-...

https://researchnews.cc/news/4027/Scientists-discover-how-COVID-19-...

Comment by Dr. Krishna Kumari Challa on December 10, 2020 at 10:16am

Pesticides in contact with plastic mulch take longer to degrade

The use of plastic mulch (plastic covering on crop lines) is a widespread technique used in agricultural regions in order to increase the profitability of the crops. According to the European Commission, 100,000 tons of plastic mulch was used per year in the European Union in 2016. Taking these figures into account and the fact that after the harvest some plastic usually remains in the soil, the accumulation of plastic in territories of intensive agriculture is an environmental problem that is of concern in the sector and also for public administration.

Comment by Dr. Krishna Kumari Challa on December 10, 2020 at 10:10am

Why did Mount Everest's height change?

The world's highest mountain is now officially a little higher. China and Nepal presented a new official figure of 8,848.86 meters (29,031.69 feet) above sea level. 

China and Nepal agreed this week on a new standard height for Mount Everest. Geological changes, the complicated business of measuring a mountain and varying criteria for determining the world's highest peak will likely ensure the question isn't settled for good.

The mountain's height changes. The movement of tectonic plates can lift it up ever so gradually, while earthquakes can bring it down.

The countervailing forces may help maintain a degree of stability over time.

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There's more than one way to measure a mountain.

Last year, a Nepalese team set up a satellite navigation marker on Everest's peak to gauge its exact position via GPS satellites. A Chinese team undertook a similar mission this spring, though it used the Chinese-made Beidou constellation of navigation satellites, along with other equipment.

At the same time, Nepalese crews took measurements with modern, laser-equipped versions of instruments called theodolites, first used to gauge the mountain's height in 1856 by measuring angles using trigonometry.

The Nepalese team also used ground penetrating radar to measure the amount of snow and ice that sits on top of its highest rock.

The new height is 0.86 meters (more than 2 feet) above the higher of the countries' two previous figures, that given by Nepal. The two had diverged for year over the mountain's actual height.

Measuring the height above sea level has always been tricky because ocean levels vary considerably depending on tides, magnetism and other factors. Rising sea levels are creating another factor for future measurements.

How high above sea level is just one way of measuring a mountain's height. One reason Everest wins the prize is that its base sits high up on already lofty foothills.

As measured from the Earth's core, Ecuador's Mount Chimborazo is the world's highest, standing more than 2,072 meters (6,800 feet) above Everest. Because the Earth bulges in the middle, mountains along the equator are farther from the core.

Measuring from the foot of the mountain to the peak, Hawaii's Mauna Kea is the tallest. Most of it, however, is under the sea.

https://phys.org/news/2020-12-mount-everest-height.html?utm_source=...

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