Comment

Comment by Dr. Krishna Kumari Challa on July 1, 2023 at 9:45am

Use of vertebrates by humans and other predators. a Number and percent of vertebrate species with documented human use, and b number for which use is considered a threat, including the subset facing extinction (Vulnerable, Endangered, or Critically Endangered status on the IUCN Red list). c Prey diversity (number of species; logarithmic scale) of humans and comparable predators (i.e., those that prey on vertebrates for which range-wide data were available) across equivalent geographic ranges, with percentages indicating human prey overlap with each predator. Credit: Communications Biology (2023). DOI: 10.1038/s42003-023-04940-w

Part 2

Comment by Dr. Krishna Kumari Challa on July 1, 2023 at 9:44am

Humans found to prey on approximately one-third of all vertebrate species

An international team of ecologists, life scientists, conservationists and biologists has found that humans prey on approximately one-third of all vertebrate species in existence. In their study, reported in the journal Communications Biology, the group analyzed data collected by members of the International Union for Conservation of Nature (IUCN).

Prior research has shown that humans are the ultimate apex predator. Our species not only catches and eats prey, but domesticates certain animals to collect their milk, to make leather from their hides or to keep them as pets. In this new effort, the research team wondered just how many vertebrate species humans prey on—in their study, they defined predatory behavior as acts that remove animals from their natural environment, either dead or alive, and use them for a source of food or as a harvesting or trade resource.

To find their answer, they turned to the IUCN, an organization made up of both civil and governmental organizations engaged in monitoring, protecting, and conserving natural resources. Its 1,400 members have become a well-known resource for natural resource status reports.

In this effort, the researchers focused only on the 47,665 vertebrate species tracked by the organization. In looking at the data, the researchers found that humans prey on approximately 14,663 species, which is approximately a third of those known to the IUCN. They also found that nearly 40% of the species preyed upon by humans are listed as threatened. More specifically, they found that approximately 55% of these species are eaten. And they found that more than half of all the terrestrial species preyed on by humans are part of the pet trade. Also, humans hunt approximately 358 species of finned fish for sport and 452 species of birds—and 207 species of mammals and fish are used for clothing. They also found that 192 mammal species and 82 amphibian species are used for medical purposes.

The research team notes that such large numbers make humans far and away the biggest predator on the planet—summing it up, they found that humans prey on other species at a rate 300 times that of any other predator when accounting for the size of predation areas.

 Chris T. Darimont et al, Humanity's diverse predatory niche and its ecological consequences, Communications Biology (2023). DOI: 10.1038/s42003-023-04940-w

Part 1

Comment by Dr. Krishna Kumari Challa on July 1, 2023 at 9:24am

Static electricity attracts ticks to hosts, scientists find

Ticks carry a lot of nasty diseases, including Lyme disease, that make many people's and animal's lives miserable, and can even cause death. Therefore there is a huge social and economic benefit to trying to reduce the ability of ticks to attach onto people and the animals humans rely upon.

Ticks can be attracted across air gaps several times larger than themselves by the static electricity that their hosts naturally accumulate, researchers have discovered.

This likely greatly increases their efficiency at finding hosts to parasitize because ticks are not capable of jumping, and therefore this is the only mechanism by which they would be able to make contact with hosts that are beyond the reach of their tiny legs.

Findings of the study, titled "Static electricity passively attracts ticks onto hosts," published in Current Biology, are the first known example of static electricity being implicated in the attachment of an animal to another animal.

Static electricity attracting tick

Until now, we had no idea that an animal could benefit from static electricity in this way, and it really opens up one's imagination as to how many invisible forces like this could be helping animals and plants live their lives.

Sam J. England, Static electricity passively attracts ticks onto hosts, Current Biology (2023). DOI: 10.1016/j.cub.2023.06.021. www.cell.com/current-biology/f … 0960-9822(23)00772-8

Comment by Dr. Krishna Kumari Challa on June 30, 2023 at 12:17pm

Science can help to end extreme poverty

Ending poverty starts with agreeing on how to measure what it means, argues a Nature editorial in the second of a series of articles on how science can help to support the teetering United Nations Sustainable Development Goals. The COVID-19 pandemic, Russia’s invasion of Ukraine, ongoing conflicts and the effects of climate change have all played a part in reversing a decades-long decline in poverty. More than 700 million people now live under the extreme-poverty line, defined as a daily income of less than US$2.15. Economic expansion and basic social and health-care protections could help to address the problem. More fundamentally, a rethink of how to measure poverty is needed. The global figure calculated using an index that includes housing, child mortality, clean water, sanitation and electricity is nearly double that calculated on the basis of income.

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Antacids in the ocean to try to gobble CO₂

The first commercial experiments are underway to see whether ocean alkalinity enhancement — essentially using antacids to help the ocean digest CO₂ — could slow global warming. The idea is to speed up a natural geochemical weathering process that ultimately transfers carbon dioxide from the atmosphere into the deep ocean. Quantifying the technology’s real-world impact remains the biggest challenge. The newly alkaline seawater needs to remain at the surface for carbon sequestration to occur. “If it gets drawn down into the ocean, then we might not get the benefit for another 1,000 years,” explains oceanographer Katja Fennel.

Comment by Dr. Krishna Kumari Challa on June 30, 2023 at 12:05pm

Researchers observe rubber-like elasticity in liquid glycerol for the first time

Simple molecular liquids such as water or glycerol are of great importance for technical applications, in biology or even for understanding properties in the liquid state. Researchers  have now succeeded in observing liquid glycerol in a completely unexpected rubbery state.

In their article published in Proceedings of the National Academy of Sciences, the researchers report how they created rapidly expanding bubbles on the surface of the liquid in vacuum using a pulsed laser. However, the thin, micrometers-thick liquid envelope of the bubble did not behave like a viscous liquid dissipating deformation energy as expected, but like the elastic envelope of a rubber toy balloon, which can store and release elastic energy.

It is the first time an elasticity dominating the flow behavior in a Newtonian liquid like glycerol has been observed. Its existence is difficult to reconcile with common ideas about the interactions in liquid glycerol and motivates the search for more comprehensive descriptions. Surprisingly, the elasticity persists over such long timescales of several microseconds that it could be important for very rapid engineering applications such as micrometer-confined flows under high pressure. Yet, the question remains unsettled whether this behavior is a specific property of liquid glycerol, or rather a phenomenon that occurs in many molecular liquids under similar conditions but has not been observed so far.

 Meghanad Kayanattil et al, Rubber-like elasticity in laser-driven free surface flow of a Newtonian fluid, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2301956120

Comment by Dr. Krishna Kumari Challa on June 30, 2023 at 11:58am

A Star Fit For Life

Comment by Dr. Krishna Kumari Challa on June 30, 2023 at 11:08am

The NANOGrav 15-year Data Set: Evidence for a Gravitational-Wave Background, The Astrophysical Journal Letters (2023). DOI: 10.3847/2041-8213/acdac6

Gabriella Agazie et al, The NANOGrav 15 yr Data Set: Observations and Timing of 68 Millisecond Pulsars, The Astrophysical Journal Letters (2023). DOI: 10.3847/2041-8213/acda9a

Gabriella Agazie et al, The NANOGrav 15 yr Data Set: Detector Characterization and Noise Budget, The Astrophysical Journal Letters (2023). DOI: 10.3847/2041-8213/acda88

Adeela Afzal et al, The NANOGrav 15 yr Data Set: Search for Signals from New Physics, The Astrophysical Journal Letters (2023). DOI: 10.3847/2041-8213/acdc91

Astrophysical Interpretation of a Gravitational Wave Background from Massive Black Hold Binaries (accepted for publication in ApJL)

Bayesian Limits on GWs from Individual SMBHBs (accepted for publication in ApJL)

Part 2

Comment by Dr. Krishna Kumari Challa on June 30, 2023 at 11:08am

Clamor of gravitational waves from universe's merging supermassive black holes 'heard' for first time

Following 15 years of data collection in a galaxy-sized experiment, scientists have "heard" the perpetual chorus of gravitational waves rippling through our universe for the first time—and it's louder than expected.

The groundbreaking discovery was made by scientists with the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) who closely observed stars called pulsars that act as celestial metronomes. The newly detected gravitational waves—ripples in the fabric of space-time—are by far the most powerful ever measured: They carry roughly a million times as much energy as the one-off bursts of gravitational waves from black hole and neutron star mergers detected by experiments such as LIGO and Virgo.

Most of the gigantean gravitational waves are probably produced by pairs of supermassive black holes spiraling toward cataclysmic collisions throughout the cosmos, the NANOGrav scientists report in a series of new papers appearing today in The Astrophysical Journal Letters.

This is the first-ever evidence for the gravitational wave background. We've opened a new window of observation on the universe."

The existence and composition of the gravitational wave background—long theorized but never before heard—presents a treasure trove of new insights into long-standing questions, from the fate of supermassive black hole pairs to the frequency of galaxy mergers.

For now, NANOGrav can only measure the overall gravitational wave background rather than radiation from the individual "singers." 

The gravitational wave background is about twice as loud as what scientists expected. It's really at the upper end of what our models can create from just supermassive black holes.

The deafening volume may result from experimental limitations or heavier and more abundant supermassive black holes. But there's also the possibility that something else is generating powerful gravitational waves.

Part 1

Comment by Dr. Krishna Kumari Challa on June 28, 2023 at 11:54am

What BMI doesn't tell you about your health

Comment by Dr. Krishna Kumari Challa on June 27, 2023 at 10:27am

Liver fibrosis linked to reduced cognitive ability and brain volume

Researchers have found that liver fibrosis — scarring of the liver tissue that occurs in many chronic liver diseases — is associated with reduce cognitive ability and, in certain regions of the brain, reduced brain volume. And this connection may be mediated in part by inflammation.

The researchers evaluated data on liver fibrosis, cognitive function — such as working memory, the ability to solve new problems, and processing speed — and gray matter volume in different regions of the brain. They found that, compared with healthy participants, those with liver fibrosis tended to have reduced cognitive ability and reduced gray matter volume in several brain regions, including the hippocampus, thalamus, striatum, and brain stem.

With this type of study, the researchers could not establish cause and effect; they could only evaluate correlations.

A growing body of scientific evidence is revealing that brain health and body health are interconnected, such that one often affects the other. 
More and more, people are starting to realize that there’s not this split between brain-based disorders and other types of physical health. We’re starting to understand that liver disease, heart disease, and other diseases will have impacts on the brain, and brain disorders have impacts on the body

https://www.sciencedirect.com/science/article/pii/S235239642300244X

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