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Comment by Dr. Krishna Kumari Challa on October 26, 2022 at 11:25am

Purified Sand Particles Have Anti-Obesity Effects, Scientists Confirm

Porous particles of silica made from purified sand could one day play a role in attempts to lose weight.

Past clinical trials have already produced promising results, but the actual weight-lowering mechanism behind the potential treatment has been poorly understood.

To sift out the key variables, researchers have now tested a range of silica sizes and shapes in a simulation of the human gut after a heavy meal.

The results support the idea that porous silica can "impede the digestive processes" that are usually triggered by enzymes breaking down fat, cholesterol, starches, and sugars in the stomach and intestines.

What's more, the size of administered nanoparticles seems to determine how much digestive activity is inhibited.

The authors acknowledge that their model is much too simple to perfectly mimic the complexity of the human gut during digestion, but given the ethics surrounding human clinical trials, gut simulations and animal models are closer than researchers might otherwise get.

Unlike other human gut models, this new one accounts for both fat digestion and carbohydrate digestion. The authors also analyzed the degree to which organic matter might be absorbed within the gastrointestinal tract.

It's possible that porous silica triggers a reduction of weight gain in other ways, too, but the new findings provide additional research with a more solid place to start.

In 2014, researchers found mice on high fat diets put on significantly less weight when fed nanoparticles of porous silica (MSPs). Their total body fat percentage was also reduced. Still, that effect seemed to be based on the relative size of the silica particles used. Larger particles were ultimately more effective.

Follow-up studies on mice supported these results. The right size and shape of porous silica particles seemed to determine the power of mouse digestion in the small intestine.

In 2020, the first clinical data on 10 healthy humans with obesity demonstrated that MSPs can reduce blood glucose levels and blood cholesterol levels, both of which are known risk factors for metabolic and cardiovascular complications.

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Comment by Dr. Krishna Kumari Challa on October 26, 2022 at 9:39am

Hidden 'Oasis of Life' Discovered Deep Under The Ocean in The Maldives

Comment by Dr. Krishna Kumari Challa on October 26, 2022 at 9:19am

Climate change is closing daily temperature gap: Clouds could be th...

Climate change is shrinking the difference between the daily high temperature and the daily low in many parts of the world. The gap between the two, known as the diurnal temperature range (DTR), has a significant effect on growing seasons, crop yields, residential energy consumption and human health issues related to heat stress. But why and where the DTR shrinks with climate change has been something of a mystery.

Comment by Dr. Krishna Kumari Challa on October 26, 2022 at 9:04am

Because hemispherectomies are relatively rare, scientists seldom have access to more than a handful of patients at a time. But the Pitt team found an unexpected silver lining of the COVID-19 pandemic: the normalization of telemedicine services, which made it possible to enroll 40 hemispherectomy patients, an unprecedented number for studies of this kind.

To assess word recognition capacity, researchers presented their participants pairs of words, each differing by only one letter, such as "soap" and "soup" or "tank" and "tack." To test how well the children recognized different faces, scientists showed them pairs of photos of people. Either stimulus appeared on the screen for only a fraction of a second, and the participants had to decide whether the pair of words or the pair of faces were the same or different.

Astoundingly, the single remaining hemisphere supported both of those functions. The capacity for word and face recognition between control subjects and people with hemispherectomies differed, but the differences were less than 10%, and the average accuracy exceeded 80%. In direct comparisons between matching hemispheres in patients and controls, patients' accuracy on both face and word recognition was comparable regardless of the hemisphere removed.

This study showed that  losing half of the brain does not equate to losing half of its functionality. While we can't definitively predict how any given child might be affected by a hemispherectomy, the performance that we see in these patients is encouraging. 

Michael C. Granovetter et al, With childhood hemispherectomy, one hemisphere can support—but is suboptimal for—word and face recognition, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2212936119

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Comment by Dr. Krishna Kumari Challa on October 26, 2022 at 9:03am

Word and face recognition can be adequately supported with half a brain, study finds

A study of brain plasticity and visual perception has found that people who, as children, had undergone surgery removing half of their brain, correctly recognized differences between pairs of words or faces more than 80% of the time. Considering the volume of removed brain tissue, the surprising accuracy highlights the brain's capacity—and its limitations—to rewire itself and adapt to dramatic surgery or traumatic injury.

The findings, published recently in the Proceedings of the National Academy of Sciences (PNAS), is the first-ever attempt to characterize neuroplasticity in humans and understand whether a single brain hemisphere can perform functions typically split between the two sides of the brain.

Neuroplasticity is a process that allows the brain to change its activity and rewire itself, either structurally or functionally, in response to changes in the environment. And even though brain plasticity peaks early in development, our brains continue to change well into adulthood.

As humans age, the two halves of our brains, called hemispheres, become increasingly specialized. Even though this division of labor is not absolute, the two hemispheres adopt distinct chief responsibilities: The left hemisphere matures into the primary place for reading printed words, and the right hemisphere matures into the primary place for recognizing faces.

But neuroplasticity has limitations, and this hemispheric preference becomes more rigid over time. In some cases, adults who develop a brain lesion because of stroke or a tumor might experience a reading impairment or become face blind, depending on whether the left or right hemisphere of the brain is affected.

But what happens when the brain is forced to change and adapt while it is still highly plastic? To answer this question, researchers looked at a special group of patients who had undergone a complete hemispherectomy—or a surgical removal of one hemisphere to control epileptic seizures—during childhood.

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Comment by Dr. Krishna Kumari Challa on October 26, 2022 at 8:41am

Combined, this electron-hole pair is an electrically neutral quasiparticle called an exciton. A quasiparticle is a particle-like entity that does not count as one of the 17 elementary particles of the standard model of particle physics, but that can still have elementary-particle properties like charge and spin. The exciton quasiparticle can also be described as an exotic atom because it is in effect a hydrogen atom that has had its single positive proton replaced by a single positive hole.

Electron-hole systems have been used to create other phases of matter such as electron-hole plasma and even exciton liquid droplets. The researchers wanted to see if they could make a BEC out of excitons.

Direct observation of an exciton condensate in a three-dimensional semiconductor has been highly sought after since it was first theoretically proposed in 1962. Nobody knew whether quasiparticles could undergo Bose-Einstein condensation in the same way as real particles

 Yusuke Morita et al, Observation of Bose-Einstein condensates of excitons in a bulk semiconductor, Nature Communications (2022). DOI: 10.1038/s41467-022-33103-4

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Comment by Dr. Krishna Kumari Challa on October 26, 2022 at 8:39am

Researchers create first quasiparticle Bose-Einstein condensate

Physicists have created the first Bose-Einstein condensate—the mysterious fifth state of matter—made from quasiparticles, entities that do not count as elementary particles but that can still have elementary-particle properties like charge and spin. For decades, it was unknown whether they could undergo Bose-Einstein condensation in the same way as real particles, and it now appears that they can. The finding is set to have a significant impact on the development of quantum technologies including quantum computing.

Bose-Einstein condensates are sometimes described as the fifth state of matter, alongside solids, liquids, gases and plasmas. Theoretically predicted in the early 20th century, Bose-Einstein condensates, or BECs, were only created in a lab as recently as 1995. They are also perhaps the oddest state of matter, with a great deal about them remaining unknown to science.

BECs occur when a group of atoms is cooled to within billionths of a degree above absolute zero. Researchers commonly use lasers and magnet traps to steadily reduce the temperature of a gas, typically composed of rubidium atoms. At this ultracool temperature, the atoms barely move and begin to exhibit very strange behaviour.

They experience the same quantum state—almost like coherent photons in a laser—and start to clump together, occupying the same volume as one indistinguishable super atom. The collection of atoms essentially behaves as a single particle.

Most BECs are fabricated from dilute gases of ordinary atoms. But until now, a BEC made out of exotic atoms has never been achieved. Exotic atoms are atoms in which one subatomic particle, such as an electron or a proton, is replaced by another subatomic particle that has the same charge. Positronium, for example, is an exotic atom made of an electron and its positively charged anti-particle, a positron. An exciton is another such example. When light hits a semiconductor, the energy is sufficient to excite electrons to jump up from the valence level of an atom to its conduction level. These excited electrons then flow freely in an electric current—in essence transforming light energy into electrical energy. When the negatively charged electron performs this jump, the space left behind, or hole, can be treated as if it were a positively charged particle. The negative electron and positive hole are attracted and thus bound together.

Part 1

Comment by Dr. Krishna Kumari Challa on October 25, 2022 at 11:52am

Why eLife Is Doing Away with Rejections

The peer-reviewed journal eLife announced recently (October 20) that it will be doing away with the long-held practice of accepting or rejecting scientific manuscripts that are submitted for publication. Last year, the journal began exclusively reviewing papers that had already been posted as preprints. Now, eLife will post submitted preprints regardless of their quality, alongside commentary from peer reviewers and anassessment from the journal itself that details the reviewers’ and editors’ thoughts on the significance of the research and the strength of the evidence supporting the paper’s conclusions. Authors will have the option to revise the papers and resubmit, or simply ask that the manuscript be published as-is on the eLife site.

The peer-reviewed journal eLife announced recently (October 20) that it will be doing away with the long-held practice of accepting or rejecting scientific manuscripts that are submitted for publication. Last year, the journal began exclusively reviewing papers that had already been posted as preprints. Now, eLife will post submitted preprints regardless of their quality, alongside commentary from peer reviewers and an assessment from the journal itself that details the reviewers’ and editors’ thoughts on the significance of the research and the strength of the evidence supporting the paper’s conclusions. Authors will have the option to revise the papers and resubmit, or simply ask that the manuscript be published as-is on the eLife site. It’s all about moving from the assessment being based on where you publish [to being] based on what you publish.

The executive director of eLife says: 

For every paper that we review, we will post a reviewed preprint that is a rerendering of the of the original preprint on the eLife website. It will feature the peer reviews that we’ve received and an editorial assessment—we’re calling it an eLife assessment. And that is a brief summary of the reviews that give a description of the strength of evidence and also the significance of the research. . . . Rather than having published in eLife being the primary . . . indicator of quality, we’re replacing that with something which is much more nuanced, which essentially focuses on the actual research itself and highlights the strength of the paper itself.

https://www.the-scientist.com/news-opinion/q-a-why-elife-is-doing-a...

https://elifesciences.org/articles/83889?utm_source=content_alert&a...

Comment by Dr. Krishna Kumari Challa on October 25, 2022 at 11:41am

The other natural suspects—volcanoes and cosmic rays—had even less influence during the last 150 years of warming, scientists conclude.

The other way to show that it is carbon dioxide causing warming is by building what Vecchi calls "a causal chain."

National Oceanic and Atmospheric Administration records measured on a Hawaiian volcano show rising carbon dioxide levels as do ice records that go back thousands of years. But the key is what type of carbon dioxide.

There are three types of carbon-containing material. Some contain light carbon, or carbon-12. Some contain heavy carbon or carbon-13 and still others contain radioactive carbon-14.

Over the last century or so, there's more carbon-12 in the atmosphere compared to carbon-13 and less carbon-14 in recent decades, according to NOAA. Carbon-12 is essentially fossil carbon from long ago, as in fossil fuels. So the change in the ratio of carbon-12 to carbon-13 tells scientists the carbon in the air is more from burning fossil fuels than natural carbon, Vecchi said.

That's the fingerprint of burning coal, oil and natural gas.

https://phys.org/news/2022-10-climate-humans-triggered.html?utm_sou...

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Comment by Dr. Krishna Kumari Challa on October 25, 2022 at 11:41am

Climate Questions: How do we know humans triggered warming?

Call it Law and Order: Climate Change. Scientists used detective work to pinpoint the prime suspect in Earth's warming: us.

They proved it couldn't be anything but carbon dioxide and other greenhouse gases from the burning of fossil fuels.
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For more than 30 years top scientists from across the globe have worked together every several years to draft a report on climate change and what causes it and with each report—and increases in global temperatures—they have become more and more certain that climate change is caused by human activities. In the latest version of their report they said: "It is unequivocal that human influence has warmed the atmosphere, ...

Scientists—including the late Ralph Cicerone, the former president of the National Academy of Scientists—have told The Associated Press their confidence in climate change being a human caused problem is equivalent to their certainty in understanding that cigarettes are deadly.

Scientists can calculate how much heat different suspects trap, using a complex understanding of chemistry and physics and feeding that into computer simulations that have been generally accurate in portraying climate, past and future. They measure what they call radiative forcing in watts per meter squared.

The first and most frequent natural suspect is the sun. The sun is what warms Earth in general providing about 1,361 watts per meter squared of heat, year in year out. That's the baseline, the delicate balance that makes Earth livable. Changes in energy coming from the sun have been minimal, about one-tenth of a watt per meter squared, scientists calculate.

But carbon dioxide from the burning of fossil fuels is now trapping heat to the level of 2.07 watts per meter squared, more than 20 times that of the changes in the sun, according to the U.S. Environmental Protection Agency. Methane, another powerful heat-trapping gas, is at 0.5 watts per meter square.

The sun's 11-year cycle goes through regular but small ups and downs, but that doesn't seem to change Earth's temperature. And if anything the ever so slight changes in 11-year-average solar irradiance have been shifting downward, according to NASA calculations, with the space agency concluding "it is therefore extremely unlikely that the Sun has caused the observed global temperature warming trend over the past century."

In other words, the sun had an alibi.

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