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Comment by Dr. Krishna Kumari Challa on February 13, 2024 at 8:31am

Researchers predict the young universe had two phases. During the first phase, high-speed outflows from black holes accelerated star formation, and then, in a second phase, the outflows slowed down. A few hundred million years after the big bang, gas clouds collapsed because of supermassive black hole magnetic storms, and new stars were born at a rate far exceeding that observed billions of years later in normal galaxies. The creation of stars slowed down because these powerful outflows transitioned into a state of energy conservation reducing the gas available to form stars in galaxies.

The future has more secrets to reveal!

Joseph Silk et al, Which Came First: Supermassive Black Holes or Galaxies? Insights from JWST, The Astrophysical Journal Letters (2024). DOI: 10.3847/2041-8213/ad1bf0

Part 2

Comment by Dr. Krishna Kumari Challa on February 13, 2024 at 8:30am

New light on Black holes

Black holes not only existed at the dawn of time, they birthed new stars and supercharged galaxy formation, a new analysis of James Webb Space Telescope data suggests.

The insights upend theories of how black holes shape the cosmos, challenging classical understanding that they formed after the first stars and galaxies emerged. Instead, black holes might have dramatically accelerated the birth of new stars during the first 50 million years of the universe, a fleeting period within its 13.8 billion-year history.

We know these monster black holes exist at the center of galaxies near our Milky Way, but the big surprise now is that they were present at the beginning of the universe as well and were almost like building blocks or seeds for early galaxies.

They really boosted everything, like gigantic amplifiers of star formation, which is a whole turnaround of what we thought possible before—so much so that this could completely shake up our understanding of how galaxies form.

Conventional wisdom holds that black holes formed after the collapse of supermassive stars and that galaxies formed after the first stars lit up the dark early universe. But the analysis by researchers suggests that black holes and galaxies coexisted and influenced each other's fate during the first 100 million years.

Researchers now think  that black hole outflows crushed gas clouds, turning them into stars and greatly accelerating the rate of star formation. Otherwise, it's very hard to understand where these bright galaxies came from because they're typically smaller in the early universe. Why on earth should they be making stars so rapidly?

Black holes are regions in space where gravity is so strong that nothing can escape their pull, not even light. Because of this force, they generate powerful magnetic fields that make violent storms, ejecting turbulent plasma and ultimately acting like enormous particle accelerators.

We can't quite see these violent winds or jets far, far away, but we know they must be present because we see many black holes early on in the universe. These enormous winds coming from the black holes crush nearby gas clouds and turn them into stars. That's the missing link that explains why these first galaxies are so much brighter than we expected.

Part 1

The work is newly published in the Astrophysical Journal Letters.

Comment by Dr. Krishna Kumari Challa on February 13, 2024 at 7:08am

Global deforestation leads to more mercury pollution, finds study

About 10% of human-made mercury emissions into the atmosphere each year are the result of global deforestation, according to a new MIT study.

The world's vegetation, from the Amazon rainforest to the savannahs of sub-Saharan Africa, acts as a sink that removes the toxic pollutant from the air. However, if the current rate of deforestation remains unchanged or accelerates, the researchers estimate that net mercury emissions will keep increasing.

The researchers' model shows that the Amazon rainforest plays a particularly important role as a mercury sink, contributing about 30% of the global land sink. Curbing Amazon deforestation could thus have a substantial impact on reducing mercury pollution.

The team also estimates that global reforestation efforts could increase annual mercury uptake by about 5%. While this is significant, the researchers emphasize that reforestation alone should not be a substitute for worldwide pollution control efforts.

Aryeh Feinberg et al, Deforestation as an Anthropogenic Driver of Mercury Pollution, Environmental Science & Technology (2024). DOI: 10.1021/acs.est.3c07851

Comment by Dr. Krishna Kumari Challa on February 13, 2024 at 6:59am

Nearly half of the world's migratory species are in decline, UN report says

Nearly half of the world's migratory species are in decline, according to a new United Nations report released recently. 

Many songbirds, sea turtles, whales, sharks and other migratory animals move to different environments with changing seasons and are imperiled by habitat loss, illegal hunting and fishing, pollution and climate change.

About 44% of migratory species worldwide are declining in population, the report found. More than a fifth of the nearly 1,200 species monitored by the U.N. are threatened with extinction. These are species that move around the globe. They move to feed and breed and also need stopover sites along the way.

Habitat loss or other threats at any point in their journey can lead to dwindling populations. 

Migration is essential for some species. If you cut the migration, you're going to kill the species.

The report relied on existing data, including information from the International Union for Conservation of Nature's Red List, which tracks whether a species is endangered.

Participants of the U.N. meeting plan to evaluate proposals for conservation measures and also whether to formally list several new species of concern.

One country alone cannot save any of these species. In 2022, governments pledged to protect 30% of the planet's land and water resources for conservation at the U.N. Biodiversity Conference.

But these results don't reflect that!

Source: AP and other news agencies.

Comment by Dr. Krishna Kumari Challa on February 12, 2024 at 10:29am

New research finds that young planets are flattened structures rather than spherical

Astrophysicists  have found that planets have flattened shapes like smarties just after they form rather than being spherical as previously thought.

The research, accepted for publication in Astronomy & Astrophysics Letters, shows that protoplanets, which are very young planets recently formed around stars, are flattened structures called oblate spheroids. The paper can currently be accessed on the arXiv preprint server.

The researchers used computer simulations to model the formation of planets according to the theory of disk-instability, which suggests that protoplanets form in short timescales from the breaking up of large rotating disks of dense gas orbiting around young stars.

Taking this approach, the team determined planet properties, compared them with observations and examined the formation mechanism of gas giant planets. They focused on investigating the shapes of young planets and on how these planets may grow to become large gas giant planets, even larger than Jupiter. They also examined the properties of planets forming in a variety of physical conditions, such as ambient temperature and gas density.

Observational confirmation of the flattened shape of young planets may answer the critical question about how planets form, pointing towards the currently less-favored disk-instability model rather than the standard planet formation theory of core accretion.

The researchers also discovered that new planets grow as material falls onto them, predominately from their poles rather than their equators.

These findings have important implications for observations of young planets as they suggest that the way planets appear through a telescope depends on the viewing angle. Such observations of young planets are important in order to understand the planet formation mechanism.

The researchers are following up this discovery with improved computational models to examine how the shape of these planets is affected by the environment in which they form, and to determine their chemical composition to compare with future observations from the James Webb Space Telescope (JWST). Observations of young planets have become possible in the last few years with observing facilities such as the Atacama Large Millimeter Array (ALMA) and the Very Large Telescope (VLT).

 Adam Fenton et al, The 3D structure of disc-instability protoplanets, arXiv (2024). DOI: 10.48550/arxiv.2402.01432

Comment by Dr. Krishna Kumari Challa on February 12, 2024 at 10:20am

Gender-based heat map images show where men tend to look and where women tend to look on a path at night. Women focused significantly more on potential safety hazards—the periphery of the images—while men looked directly at focal points or their intended destination. Credit: Violence and Gender (2023). DOI: 10.1089/vio.2023.0027

Part 2

Comment by Dr. Krishna Kumari Challa on February 12, 2024 at 10:19am

Study visually captures a hard truth: Walking home at night is not the same for women

An eye-catching new study shows just how different the experience of walking home at night is for women versus men.

The study provides clear visual evidence of the constant environmental scanning women conduct as they walk in the dark, a safety consideration the study shows is unique to their experience.

Researchers showed pictures of campus areas at four Utah universities—Utah Valley University, Westminster, Brigham Young University and University of Utah—to participants and asked them to click on areas in the photos that caught their attention. Women focused significantly more on potential safety hazards—the periphery of the images—while men looked directly at focal points or their intended destination.

The resulting heat maps represent perhaps what people are thinking or feeling or doing as they are moving through these spaces.

While men tended to focus on the path or a fixed object (like a light, the walking path or a garbage can), the women's visual pattern represented a scanning of the perimeter (bushes, dark areas next to a path).

The researchers say the findings provide some insight into what it is like to walk home as a woman, which could be multiplied through years or a lifetime of experiences.

The researchers said the data suggests that because environment is perceived and experienced differently by women and men, decision-makers in building campus and community environments should consider the varied experiences, perceptions and safety of both. Why can't we live in a world where women don't have to think about these things? , they ask!

Yes, why?!

Robert A. Chaney et al, Gender-Based Heat Map Images of Campus Walking Settings: A Reflection of Lived Experience, Violence and Gender (2023). DOI: 10.1089/vio.2023.0027

Part 1

Comment by Dr. Krishna Kumari Challa on February 10, 2024 at 9:12am

Industrial pollutants found in Mediterranean corals for the first time

Pollutants from burning fossil fuels have been found embedded in corals, for the first time, offering scientists a potential new tool to track the history of pollution, finds a new study by researchers.

The study, published in the journal Science of the Total Environment, identified carbon particles emitted by burning fossil fuels embedded in the corals of Illa Grossa Bay, off the Columbretes Islands in the Mediterranean Sea. Finding this type of pollution—known as fly-ash or spheroidal carbonaceous particles (SCPs)—contaminating natural deposits is seen as an indicator of the presence of human influence on the environment, and an historical marker of the beginning of the proposed Anthropocene epoch.

Corals are a commonly used natural archive for paleoclimate studies because of their measurable growth rates. Akin to tree rings, their long life and slow and regular growth can provide scientists with annual, monthly or even weekly, environmental data going back years.

Up to now, they've largely been used to gauge past climatic conditions like water teperatures and chemistries, but this is the first time that pollutant particles—other than microplastics—have been recovered from corals.

The discovery of these pollutants embedded in coral skeletons extend over decades and paint a clear picture of how extensive human influence is on the environment. It's the first time we've been able to see this kind of contaminant in corals, and its appearance in these deposits parallels the historic rate of fossil fuel combustion in the region.

Corals, which are small invertebrates that tend to dwell in expansive colonies, ingest the SCP pollutants from the surrounding waters, incorporating them as they grow their calcium carbonate skeletons.

As it becomes clearer that humans have altered the natural environment to an unprecedented level, these pollutants act as indelible markers, indicating the start of the Anthropocene epoch. This is valuable to researchers trying to better understand the history of human impact on the natural world and serves as a powerful reminder of how extensive human influence is over the environment.

L.R. Roberts et al, First recorded presence of anthropogenic fly-ash particles in coral skeletons, Science of The Total Environment (2024). DOI: 10.1016/j.scitotenv.2024.170665

Comment by Dr. Krishna Kumari Challa on February 9, 2024 at 11:51am

Ocean Color Countdown

The color of our oceans, lakes and rivers can tell us a lot about what's going on just beneath the surface. With the new hyperspectral capabilities of the Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission, we'll know more about the health of aquatic ecosystems and those impacts on human health and climate studies. Scientists explore just five different ocean colours around the globe and find out what those colours tell us.

Comment by Dr. Krishna Kumari Challa on February 9, 2024 at 11:36am

Common Plastic Chemicals Linked to 10% of Premature Births, Major Study Finds

One in 10 premature births in the United States have been linked to pregnant women being exposed to chemicals in extremely common plastic products, a large study sowed recently. The chemicals, called phthalates, are used to soften plastic and can be found in thousands of consumer items including plastic containers and wrapping, beauty care products and toys. Phthalates have been known for decades to be "hormone disruptors" which affect a person's endocrine system and have been previously linked to obesity, heart disease, some cancers and fertility problems. Because they affect hormones, these chemicals "can precipitate early labour and early birth. By analysing the level of phthalates in the urine of more than 5,000 pregnant women in the United States, the researchers were able to examine how exposure to the chemicals could have affected how early the babies were born. The 10 percent of mothers with the highest levels of phthalates had a 50-percent increased risk of giving birth before week 37 compared to the lowest 10 percent, according to the study in The Lancet Planetary Health. Extrapolating their findings across the US, the researchers said that nearly 56,600 preterm births could have been linked to phthalate exposure in 2018 alone, roughly 10 percent of the country's premature births that year. Babies born prematurely or at a lower weight tend to have more health problems later in life. Researchers say that more than three quarters of exposure to phthalates was due to plastic.

https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(23)00270-X/fulltext

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