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Comment by Dr. Krishna Kumari Challa on April 20, 2021 at 8:49am

Earth's biggest mass extinction took ten times longer on land than in the water

Our planet's worst mass extinction event happened 252 million years ago when massive volcanic eruptions caused catastrophic climate change. The vast majority of animal species went extinct, and when the dust settled, the planet entered the early days of the Age of Dinosaurs. Scientists are still learning about the patterns of which animals went extinct and which ones survived, and why. In a new study in PNAS, researchers found that while extinctions happened rapidly in the oceans, life on land underwent a longer, more drawn-out period of extinctions.

Pia A. Viglietti el al., "Evidence from South Africa for a protracted end-Permian extinction on land," PNAS (2021). www.pnas.org/cgi/doi/10.1073/pnas.2017045118

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Part of why scientists had looked to the marine extinctions for clues as to what happened on land is that there's a more complete fossil record of life underwater. If you want to become a fossil, dying by water, where your body will rapidly get covered by sediment, is a good way to make that happen. As a result, paleontologists have known for a while that 252 million years ago a mass extinction hit at the end of the Permian period, and within 100,000 years, more than 85% of the species living in the ocean went extinct. And while that seems like a long time to us, that's very quick in geologic time. The marine version of the end-Permian extinction took up 100,000 years out of the entire 3,800,000,000 years that life has existed—the equivalent to 14 minutes out of a whole year.

https://phys.org/news/2021-04-earth-biggest-mass-extinction-ten.htm...

Comment by Dr. Krishna Kumari Challa on April 19, 2021 at 8:35am

Researchers create light waves that can penetrate even opaque materials

Why is sugar not transparent? Because light that penetrates a piece of sugar is scattered, altered and deflected in a highly complicated way. However, as a research team from TU Wien (Vienna) and Utrecht University (Netherlands) has now been able to show, there is a class of very special light waves for which this does not apply: for any specific disordered medium—such as the sugar cube you may just have put in your coffee—tailor-made light beams can be constructed that are practically not changed by this medium, but only attenuated. The light beam penetrates the medium, and a light pattern arrives on the other side that has the same shape as if the medium were not there at all.

This idea of "scattering-invariant modes of light" can also be used to specifically examine the interior of objects. The results have now been published in the journal Nature Photonics.

This method of finding light patterns that penetrate an object largely undisturbed could  be used for imaging procedures. "In hospitals, X-rays are used to look inside the body—they have a shorter wavelength and can therefore penetrate our skin. But the way a light wave penetrates an object depends not only on the wavelength, but also on the waveform.

Pritam Pai et al. Scattering invariant modes of light in complex media, Nature Photonics (2021). DOI: 10.1038/s41566-021-00789-9

https://phys.org/news/2021-04-penetrate-opaque-materials.html?utm_s...

Comment by Dr. Krishna Kumari Challa on April 17, 2021 at 9:55am

New hydrogel can repair tears in human tissue

Scientists have developed an injectable gel that can attach to various kinds of soft internal tissues and repair tears resulting from an accident or trauma.

Comment by Dr. Krishna Kumari Challa on April 17, 2021 at 9:40am

Streams and rivers emit more carbon dioxide at night than day

Streams and rivers emit large amounts of carbon dioxide into the atmosphere, but a new study published in Nature Geoscience led by researchers at the universities in Umeå and Lausanne shows that the flux may be greater than previously thought.

Current estimates of carbon dioxide emissions from running water are based on manual samples, where a person goes to the river, takes a sample and analyzes the content of carbon dioxide in the water. But by doing this, we had previously assumed that concentrations are stable over time. In the last decade, there has been a revolution in sensor technology and now we can measure water parameters continuously in the water and know how variable are over time.

In the current study, an international research team led by Lluis Gomez-Gener at the École polytechnique fédérale de Lausanne, Gerard Rocher-Ros and Ryan Sponseller at Umeå University has used the power of sensors to measure carbon dioxide in rivers and streams at a high-resolution. They found that carbon dioxide emissions during the night were greater than during the day.

These results are of great importance for our understanding of the role of rivers and streams in the global carbon cycle, as previous estimates, based on manual samples during the day, underestimated the actual flux.

Lluís Gómez-Gener et al. Global carbon dioxide efflux from rivers enhanced by high nocturnal emissions, Nature Geoscience (2021). DOI: 10.1038/s41561-021-00722-3

https://phys.org/news/2021-04-streams-rivers-emit-carbon-dioxide.ht...

Comment by Dr. Krishna Kumari Challa on April 17, 2021 at 8:57am

Fit matters most when double masking to protect yourself from COVID-19

A study published today in JAMA Internal Medicine shows that wearing two face coverings can nearly double the effectiveness of filtering out SARS-CoV-2-sized particles, preventing them from reaching the wearer's nose and mouth and causing COVID-19. The reason for the enhanced filtration isn't so much adding layers of cloth, but eliminating any gaps or poor-fitting areas of a mask.

The medical procedure masks are designed to have very good filtration potential based on their material, but the way they fit our faces isn't perfect.

According to their findings, the baseline fitted filtration efficiency (FFE) of a mask differs person to person, due to each person's unique face and mask fit. But generally, a procedure mask without altering the fit, is about 40-60% effective at keeping COVID-19-sized particles out. A cloth mask is about 40% effective.

 Recent findings on doubling of face masks, shows that when a cloth mask is placed over a surgical mask, the FFE improved by about 20%, and improved even more with a snug-fitting, sleeve-type mask, such as a gaiter. When layered over procedure masks, cloth masks improve fit by eliminating gaps and holding the procedure mask closer to the face, consistently covering the nose and mouth. When a procedure mask is worn over a cloth mask, FFE improved by 16%.

 recent findings on doubling of face masks, shows that when a cloth mask is placed over a surgical mask, the FFE improved by about 20%, and improved even more with a snug-fitting, sleeve-type mask, such as a gaiter. When layered over procedure masks, cloth masks improve fit by eliminating gaps and holding the procedure mask closer to the face, consistently covering the nose and mouth. When a procedure mask is worn over a cloth mask, FFE improved by 16%.

It was found that wearing two loosely fitted masks will not give you the filtration benefit that one, snug-fitting procedure mask will.

JAMA Internal Medicine (2021). DOI: 10.1001/jamainternmed.2021.2033

https://medicalxpress.com/news/2021-04-masking-covid-.html?utm_sour...

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Comment by Dr. Krishna Kumari Challa on April 17, 2021 at 8:42am

New understanding of the deleterious immune response in rheumatoid arthritis

Researchers have made a breakthrough in understanding the role played by high-risk immune genes associated with the development of rheumatoid arthritis (RA).

J.J. Lim el al., "The shared susceptibility epitope of HLA-DR4 binds citrullinated self-antigens and the TCR," Science Immunology (2021). immunology.sciencemag.org/look … 6/sciimmunol.abe0896

https://medicalxpress.com/news/2021-04-deleterious-immune-response-...

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Comment by Dr. Krishna Kumari Challa on April 17, 2021 at 8:36am

Sweat sensor could alert doctors, patients to looming COVID cytokine storm

Early in the COVID-19 pandemic, doctors recognized that patients who developed a "cytokine storm"—a surge of pro-inflammatory immune proteins—were often the sickest and at highest risk of dying. But a cytokine storm can also occur in other illnesses, such as influenza. Today, scientists report preliminary results on a sweat sensor that acts as an early warning system for an impending cytokine storm, which could help doctors more effectively treat patients.

COVID Sweat Sensor Catches Your Immune System Before It Goes Berserk

Abstract Title [American Chemical Society (ACS)].: SWEATSENSER DX an enabling technology for on demand profiling of cytokines on passively expressed eccrine sweat

https://medicalxpress.com/news/2021-04-sensor-doctors-patients-loom...

Comment by Dr. Krishna Kumari Challa on April 17, 2021 at 7:18am

https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)00869-2/fulltext

Corona is an airborne disease: evidence

Comment by Dr. Krishna Kumari Challa on April 16, 2021 at 3:07pm

what happens when you turn off a light in a room made completely out of mirrors!

Comment by Dr. Krishna Kumari Challa on April 16, 2021 at 1:39pm

Is a calorie always a calorie? Not when it comes to almonds,  researchers find

Researchers have found that a calorie labelled is not the same as a calorie digested and absorbed when the food source is almonds.

The findings, published in the journal Mayo Clinic Proceedings, should help alleviate concerns that almonds contribute to weight gain, which persist despite the widely recognized benefits of nuts as a plant-based source of protein, vitamins and minerals.

Nuts have generally been thought of as healthy the last two decades, but the messaging around nuts has often come with a disclaimer that they are high in fat and energy. We still see that caveat in the media and on the internet today, and it has been part of many clinical guidelines, although that is changing.

Other researchers have shown that there is a bioaccessibility issue with nuts – that a calorie labelled may not be a calorie absorbed. This study quantifies that effect with almonds in a relevant population.

The researchers found that after digestion, about 20 per cent of calories derived largely from fat in almonds remained unabsorbed, which they observed in stool samples. That translated to about two per cent less energy absorbed from the diet overall among study participants.

A person eating the same amount of almonds in a daily diet of 2,000 to 3,000 calories would absorb 40 to 60 calories less than would be predicted by Atwater factors, on which many food labels are based. That could result in weight loss up to 2.9 kilograms, or 6.3 pounds, over a year, assuming no compensation in the form of increased intake or decreased energy expenditure.

Participants in the study did not gain weight, which is consistent with the majority of high-quality trials that measure nut consumption and weight gain – some of which show an association with weight loss.

The researchers used a randomized crossover trial to study 22 women and men with high cholesterol who underwent a series of three, month-long dietary interventions separated by a week-long washout period.

All study participants consumed an NCEP Step-2 diet (low in saturated fat and cholesterol, part of the U.S. National Cholesterol Education Program). The three dietary interventions were full-dose almonds (75 grams per day or three quarters of a cup); half-dose almonds plus half-dose muffins; and full-dose muffins as a study control. The nutritional makeup of the muffins matched the almonds in amount of protein, fibre and fats.

One unique aspect of this study is that it assessed people with high cholesterol, who are at greater risk for cardiovascular disease.

https://researchnews.cc/news/6171/Is-a-calorie-always-a-calorie--No...

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