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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

Comment by Dr. Krishna Kumari Challa on June 27, 2023 at 9:57am

A Hole in the World
There’s a hole under the Indian Ocean. Spanning more than three million square kilometers, the gouge is centered about 1,200 km southwest of the southern tip of India. Because of a low pull of gravity there, combined with higher gravity in surrounding areas, the sea level over the hole is 106 meters lower than the global average, according to a new study.

Why this is cool: Earth is not perfectly round. Rather, it is flatter at the poles and bulges around the equator, with other irregular peaks and valleys caused by different regions’ mass exerting different gravitational pulls. The hole under the Indian Ocean is the planet's most prominent gravitational anomaly.

What the experts say: Slabs of the floor of an ancient sea called the Tethys Ocean which existed 200 million years ago sank into the mantle, creating plumes of molten rock. The hole under the Indian Ocean probably took its present shape about 20 million years ago, when the plumes started to spread within the upper mantle, says Debanjan Pal, a doctoral student at the Indian Institute of Science in Bangalore, and lead author of the new study.

https://eos.org/science-updates/seismologists-search-for-the-indian...

https://www.scientificamerican.com/article/giant-gravity-hole-in-th...

Comment by Dr. Krishna Kumari Challa on June 26, 2023 at 12:54pm

In fact, as far back as 1995, researchers were arguing that babies born with both 'true' and 'pseudo' tails should undergo neuroimaging as well as surgery to make sure their development was tracking like it should.

So why have vestigial tails been reported in case studies since as though they were innocent, undisputed consequences of our genetic heritage?

Part of the problem is that it is not yet known if a true tail is directly derived from the embryonic tail, as some scientists have suggested. There simply isn't enough research on where the congenital abnormality lies – partly because of how rare these case studies are.

Regardless of where a baby's tail came form, however, evidence strongly suggests it is the result of a congenital issue and is not a harmless vestigial trait.

For the life and health of these children, that's an important message that needs to be cleared up once and for all.

Part 3

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https://www.sciencealert.com/some-babies-are-born-with-tails-but-no...

Comment by Dr. Krishna Kumari Challa on June 26, 2023 at 12:53pm

As it turns out, both rare appendages probably represent an incomplete fusion of the spinal column, or what's known as a spinal dysraphism. This suggests their formation is not a harmless 'regression' in the evolutionary process but a concerning disturbance in an embryo's growth most likely resulting from a mix of genetic and environmental factors.

When a human embryo reaches about five weeks of development, it sprouts a tail-like structure composed of a neural tube and notochord, which is kind of like an early spinal cord.

By the eighth week of development, this tail is typically reabsorbed back into the embryo's body. If it sticks around until birth, it could indicate the presence of a larger birth defect.

In fact, human babies that are born with tails tend to have serious associated neurological defects. In 2008, for instance, a paper argued that "true vestigial tails are not benign" because they may be associated with underlying dysraphism.

Roughly half of the cases reviewed were associated with either meningocele or spina bifida occulta.

This suggests babies born with tails need greater medical attention than a simple surgery. And it strongly disagrees with the 1985 paper that argued "the true human tail is a benign condition not associated with any underlying [spinal] cord malformation."

Part 2

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