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Comment by Dr. Krishna Kumari Challa on November 14, 2024 at 10:34am

Human induced evolution

A native New Zealand insect that once mimicked its toxic neighbor has changed color in deforested areas, in a striking example of human-induced evolution.

The long-tailed stonefly, Zelandoperla, had a clever strategy to avoid predation from birds: it mimicked the appearance of a uniquely toxic stonefly, Austroperla, a forest dweller that deters predators by producing cyanide.

Researchers  have found that in deforested areas without Austroperla in the picture, and with fewer bird predators, some Zelandoperla have given up their guise.
The findings highlight "the possibility for populations to adapt rapidly in the wake of sudden environmental change," the team writes in their published paper.

While the long-tailed stonefly has no toxins of its own, it has managed to pull off a convincing impersonation of Austroperla using its genetic toolkit, which colored some of the insects a dark shade of ebony.

The disguise worked to deter their feathered predators, which, unable to tell the difference, steered clear of both the toxic stonefly and its mimic.

But Austroperla is a forest creature: it lives in streams where it feeds on leaves and woody debris. In deforested areas, its preferred food sources are lacking, and Austroperla has become less common.

The removal of forests since humans arrived has removed the poisonous species. 
As a result, in deforested regions the mimicking species has abandoned this strategy – as there is nothing to mimic – instead evolving into a different colour.

The scientists used a combination of field observations, predation experiments, and gene map analysis to show the insect's response to human-driven change.

https://www.science.org/doi/10.1126/science.ado5331

Comment by Dr. Krishna Kumari Challa on November 14, 2024 at 10:05am

The numbers from the United States are far more disturbing, with a 2020 report showing that between 2013 and 2017, younger-onset dementia in 30- to 44-year-olds had spiked by 373%.

All age groups recorded an increase, with a 311% rise in the 45–54 age group, and a 143% rise for 55–64s, but it was the Millennials and Gen Xers who were the hardest hit.

Some people cite the improvement in diagnostic techniques as being behind this change, but if that were the case, we would be seeing a similar increase across all ages. We aren't.
The report did not speculate on the cause for this dramatic increase in younger-onset dementia. Still, there is nothing else that has happened in the past 10 years that can explain this change apart from the global rise to dominance of the smartphone from about 2012.

We know that people with lower cognitive capacity are more susceptible to dementia.

We know overusing smartphones can result in lower cognitive capacity.

We may argue that correlation is not causation, but the correlation between lead in water and problems with children's brain development seen across the world from the mid-20th century was enough for governments to spend the equivalent of millions of dollars to replace all our water pipes.

Younger-onset dementia rates have risen at the same time as smartphones have taken over every part of our lives, and dismissing this as a coincidence will not address the problem.

Screen use may or may not be the original cause of the problem, but the fact that excessive and ongoing screen use leads to changes in the brain means there is a relationship that warrants urgent further investigation.

https://lighthouse.mq.edu.au/article/november-2024/opinion-we-need-...

Part 2

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Comment by Dr. Krishna Kumari Challa on November 14, 2024 at 10:04am

We need to talk about what smartphones are doing to kids' brains, say experts

We know there are links between young people overusing devices and a decline in cognitive abilities, as well as problems with attention, focus and memory.

Researchers  recently published a review and meta-analysis of 34 studies looking at neuropsychological deficits in children and teenagers who had screen-use disorders—basically what can be classified as screen addictions.

Their findings showed strong evidence of impacts on attention, focus and executive functioning in these young people, but also changes in their brains that were visible on scans, with the loss of gray and white matter in areas of the frontal lobe that are associated with learning and memory.

Yes, you read that correctly.

Overuse can result in young people losing brain capacity.

These studies relate to the roughly 3% of teenagers who are classified as having a clinical screen overuse disorder, but the latest figures show the average Australian teenager is spending four to six hours a day on social media, and a total of up to eight hours a day using screens for leisure.

Recent research from the University of North Carolina shows brain changes related to habitual checking of social media in Grade 6 and 7 students over three years. A third of the children—those who were frequently checking their feeds—showed significant changes in brain areas involved in emotion, motivation and cognition.

Brains are very much a use-it-or-lose-it organ: if you challenge yourself through thinking, problem-solving and learning, you develop new connections in your brain. If you don't challenge yourself, not only do new connections not form, but the old ones start to die off.

Dementia might be thought of as an old person's disease, but younger people can also be affected. Early onset dementia usually affects adults aged between 30 and 65, but there are rare cases of people being diagnosed in their 20s. In the past, the majority of cases of younger-onset dementia were believed to be inherited.

Part 1

Comment by Dr. Krishna Kumari Challa on November 14, 2024 at 9:35am

Toxic smog smothering India's capital smashes WHO limit

Residents of India's capital New Delhi choked in a blanketing toxic smog this week as worsening air pollution surged past 50 times the World Health Organization's recommended daily maximum.

Many in the city cannot afford air filters, nor do they have homes they can effectively seal from the misery of foul smelling air blamed for thousands of premature deaths.

Cooler temperatures and slow-moving winds trap deadly pollutants each winter, stretching from mid-October until at least January.

At dawn on Wednesday, "hazardous" pollutant levels in parts of the sprawling urban area of more than 30 million people topped 806 micrograms per cubic meter, according to monitoring firm IQAir.

That is more than 53 times the World Health Organization recommended daily maximum of fine particulate matter—dangerous cancer-causing microparticles known as PM2.5 pollutants that enter the bloodstream through the lungs.

By midday, when air usually is at its best, it eased to about 25-35 times above danger levels, depending on different districts.

Now breathing in Delhi has become  like "smoking cigarettes". Older people have difficulties breathing. It is particularly punishing for babies, children and the elderly.

The city is blanketed in acrid smog each year, primarily blamed on stubble burning by farmers in neighboring regions to clear their fields for plowing, as well as factories, Diwali fire works and traffic fumes.

But a report by The New York Times this month, based on air and soil samples it collected over five years, revealed the dangerous fumes also spewing from a power plant incinerating the city's landfill garbage mountains.

Experts the newspaper spoke to said that the levels of heavy metals found were "alarming".

Swirling white clouds of smog also delayed several flights across northern India.

The India Meteorological Department said that at least 18 regional airports had a visibility lower than 1,000 meters (1,093 yards)—dropping below 500 meters in Delhi.

India's Supreme Court last month ruled that clean air was a fundamental human right, ordering both the central government and state-level authorities to take action.

But politicians are accused of not wanting to anger key figures in their constituencies, particularly powerful farming groups and industrialists.

City authorities have launched some initiatives to tackle pollution, which have done little in practice.

The choking carbon smog across Delhi came as researchers warned that planet-warming fossil fuel emissions would hit a record high this year, according to new findings from an international network of scientists at the Global Carbon Project.

Researchers said increases in CO₂ emissions from India—as well as growth in international aviation—drove emissions up.

It found no sign the world was moving away from fossil fuels as planned.

Source: News agencies

Comment by Dr. Krishna Kumari Challa on November 14, 2024 at 9:08am

These results support the importance of early identification of individuals exhibiting accelerated brain atrophy and certain unfavorable biomarkers. By recognizing when higher risk is present, preventive intervention strategies can be optimized to delay or hopefully even prevent the onset of MCI.

Yuto Uchida et al, Acceleration of Brain Atrophy and Progression From Normal Cognition to Mild Cognitive Impairment, JAMA Network Open (2024). DOI: 10.1001/jamanetworkopen.2024.41505

 Shohei Fujita, Optimizing Strategies to Prevent Cognitive Decline With 20-Year Brain Imaging, JAMA Network Open (2024). DOI: 10.1001/jamanetworkopen.2024.41466

Part 2

Comment by Dr. Krishna Kumari Challa on November 14, 2024 at 9:07am

Indicators of an aging brain

Researchers, working with the Biomarkers for Older Controls at Risk for Dementia (BIOCARD) cohort, have found that certain factors are linked to faster brain shrinkage and quicker progression from normal thinking abilities to mild cognitive impairment (MCI). People with type 2 diabetes and low levels of specific proteins in their cerebrospinal fluid showed more rapid brain changes and developed MCI sooner than others.

Long-term studies tracking brain changes over many years are rare but valuable. Previous research mostly provided snapshots in time, which can't show how individual brains change over the years. By following participants for up to 27 years (20-year median), this study offers new insights into how health conditions might speed up brain aging.

In a study, "Acceleration of Brain Atrophy and Progression From Normal Cognition to Mild Cognitive Impairment," published in JAMA Network Open, researchers used the BIOCARD cohort to examine risk factors associated with the acceleration of brain atrophy and progression from normal cognition to MCI. An Invited Commentary is also available.

 A total of 185 participants, averaging 55 years old at the start and all cognitively normal, were selected. They underwent brain scans and tests of their cerebrospinal fluid over 20 years, measuring changes in brain structures and levels of proteins associated with Alzheimer's disease.

Findings showed that high rates of white matter shrinkage and enlargement of the brain's ventricles (fluid-filled spaces) were significant predictors of earlier MCI onset. Specifically, white matter atrophy was associated with an 86% higher risk and ventricular enlargement with a 71% higher risk of progressing to MCI.

Individuals with diabetes showed an average 41% higher risk of progressing from normal cognition to MCI compared to individuals without.
A low ratio of amyloid β peptides Aβ42 to Aβ40 in cerebrospinal fluid was associated with a 48% higher risk of developing MCI. This ratio acts as a biomarker for Alzheimer's disease, where an imbalance between these two forms of amyloid beta proteins is linked to the formation of harmful plaques in the brain.

When participants had both diabetes and a low Aβ42 to Aβ40 ratio, their risk of progressing to MCI increased by 55%, demonstrating that these two factors together significantly heighten the likelihood of cognitive decline.

Part 1

Comment by Dr. Krishna Kumari Challa on November 14, 2024 at 9:01am

Experiment supports existence of a new type of superconductor

A research team has found the strongest evidence yet of a novel type of superconducting material, a fundamental science breakthrough that may open the door to coaxing superconductivity—the flow of electric current without a loss of energy—in a new way.

The discovery also lends tangible support to a long-held theory about superconductivity—that it could be based upon electronic nematicity, a phase of matter in which particles break their rotational symmetry.

Here is what that means. In iron selenide crystals mixed with sulfur, iron atoms are positioned in a grid. At room temperature, an electron in an iron atom cannot distinguish between horizontal and vertical directions. But at lower temperatures, the electron may enter a "nematic" phase, where it begins to prefer moving in one direction or the other.

In some instances, the electron may start to fluctuate between preferring one direction, then the other. This is called nematic fluctuation.

For decades, physicists have attempted to prove the existence of superconductivity due to nematic fluctuations, with little success. But the new study, a multi-institutional effort led by Yale's Eduardo H. da Silva Neto, offers promise.

The findings appear in the journal Nature Physics.

Pranab Kumar Nag et al, Highly anisotropic superconducting gap near the nematic quantum critical point of FeSe1−xSx, Nature Physics (2024). DOI: 10.1038/s41567-024-02683-x

Comment by Dr. Krishna Kumari Challa on November 14, 2024 at 8:58am

Dr. Drake's equation was more of a guide for scientists on how to go about searching for life, rather than an estimating tool or serious attempt to determine an accurate result.

Its parameters included the rate of yearly star formation in the Milky Way, the fraction of stars with planets orbiting them and the number of worlds that could potentially support life.

By comparison, the new model connects the rate of yearly star formation in the universe with its fundamental ingredients, such as the aforementioned dark energy density.

 Daniele Sorini et al, The impact of the cosmological constant on past and future star formation, Monthly Notices of the Royal Astronomical Society (2024). DOI: 10.1093/mnras/stae2236. academic.oup.com/mnras/article … .1093/mnras/stae2236

Part 3

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Comment by Dr. Krishna Kumari Challa on November 14, 2024 at 8:57am

It concludes that a typical observer would expect to experience a substantially larger density of dark energy than is seen in our own universe—suggesting the ingredients it possesses make it a rare and unusual case in the multiverse.

The approach presented in the paper involves calculating the fraction of ordinary matter converted into stars over the entire history of the universe, for different dark energy densities.

The model predicts this fraction would be approximately 27% in a universe that is most efficient at forming stars, compared to 23% in our own universe.

This means we don't live in the hypothetical universe with the highest odds of forming intelligent life forms. Or in other words, the value of dark energy density we observe in our universe is not the one that would maximize the chances of life, according to the model.
Understanding dark energy and the impact on our universe is one of the biggest challenges in cosmology and fundamental physics.

The parameters that govern our universe, including the density of dark energy, could explain our own existence.
Surprisingly, though, researchers found that even a significantly higher dark energy density would still be compatible with life, suggesting we may not live in the most likely of universes.
The new model could allow scientists to understand the effects of differing densities of dark energy on the formation of structures in the universe and the conditions for life to develop in the cosmos.

Dark energy makes the universe expand faster, balancing gravity's pull and creating a universe where both expansion and structure formation are possible.

However, for life to develop, there would need to be regions where matter can clump together to form stars and planets, and it would need to remain stable for billions of years to allow life to evolve.
Crucially, the research suggests that the astrophysics of star formation and the evolution of the large-scale structure of the universe combine in a subtle way to determine the optimal value of the dark energy density needed for the generation of intelligent life.
Part 2

Comment by Dr. Krishna Kumari Challa on November 14, 2024 at 8:55am

A formula for life? New model calculates chances of intelligent beings in our universe and beyond

The chances of intelligent life emerging in our universe—and in any hypothetical ones beyond it—can be estimated by a new theoretical model which has echoes of the famous Drake Equation.

This was the formula that American astronomer Dr. Frank Drake came up with in the 1960s to calculate the number of detectable extraterrestrial civilizations in our Milky Way galaxy.

More than 60 years on, astrophysicists led by Durham University have produced a different model which instead focuses on the conditions created by the acceleration of the universe's expansion and the amount of stars formed.

It is thought this expansion is being driven by a mysterious force called dark energy that makes up more than two thirds of the universe.

Since stars are a precondition for the emergence of life as we know it, the model could therefore be used to estimate the probability of generating intelligent life in our universe, and in a multiverse scenario of different hypothetical universes.

The new research does not attempt to calculate the absolute number of observers (i.e. intelligent life) in the universe but instead considers the relative probability of a randomly chosen observer inhabiting a universe with particular properties. The study has been published in Monthly Notices of the Royal Astronomical Society.

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