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Comment by Dr. Krishna Kumari Challa on February 26, 2021 at 10:51am

Forests' long-term capacity to store carbon is dropping in regions with extreme annual fires

Researchers have analyzed decades' worth of data on the impact of repeated fires on ecosystems across the world. Their results, published today in the journal Nature Ecology and Evolution, show that repeated fires are driving long-term changes to tree communities and reducing their population sizes.

Savannah ecosystems, and regions with extreme wet or dry seasons were found to be the most sensitive to changes in fire frequency. Trees in regions with moderate climate are more resistant. Repeated fires also cause less damage to tree species with protective traits like thicker bark.

These effects only emerge over the course of several decades: the effect of a single fire is very different from repeated burning over time. The study found that after 50 years, regions with the most extreme annual fires had 72% lower wood area—a surrogate for biomass—with 63% fewer individual trees than in regions that never burned. Such changes to the tree community can reduce the forest's long-term ability to store carbon, but may buffer the effect of future fires.

Pellegrini, A.F.A. et al: 'Decadal changes in fire frequencies shift tree communities and functional traits.' Nature Ecology & Evolution, February 2021. DOI: 10.1038/s41559-021-01401-7

• More intense and frequent fires are reducing the size of tree communities in many regions of the world.
• Slower-growing tree species are better at surviving fires, but these may capture less atmospheric carbon and reduce nutrient availability in the soil.
• Not all regions are suitable for planting trees to tackle climate change; schemes must consider local wildfire frequency, vegetation cover and climate, and how these might change over time.

https://phys.org/news/2021-02-forests-long-term-capacity-carbon-reg...

Comment by Dr. Krishna Kumari Challa on February 26, 2021 at 10:35am

How obesity affects skin infections

The list of diseases and conditions complicated by obesity is a long one; it includes heart disease, cancer, diabetes and impaired wound healing, as well as skin infections. It is not always clear, however, in what way this complication is caused. New research published last month in Science Translational Medicine, has uncovered the mechanisms that link obesity and skin infections, and identified a treatment option that will soon be tested in a Phase 2 clinical trial.

The work is focused on discovering links between disease and the epithelial microbiome—that is, the normal bacteria that live on our skin—and how the skin's defense system can be optimized to treat or prevent disease. In this study, the goal was to identify how obesity contributes to higher rates of atopic dermatitis.

During the studies it was found that when mice 're fed a high fat diet and became obese as result, skin adipocytes (or fat cells) become enlarged and lost the ability to fight against bacterial invasion during a skin infection. The findings revealed that an increased number of mature adipocytes (fat cells) increases TGFβ signaling, which in turn decreases the number dermal adipocyte progenitors that produce an antimicrobial peptide called cathelicidin. This absence leaves the epidermis vulnerable to infection from common culprits like Staphylococcus aureus. In lean subjects (both mice and human in this study), the skin microbiome was successful in preventing Staph infections, as the number of mature fat cells was insufficient to disrupt the normal dermal fat functions that keep such infections at bay.

 Ling-juan Zhang et al. Diet-induced obesity promotes infection by impairment of the innate antimicrobial defense function of dermal adipocyte progenitors, Science Translational Medicine (2021). DOI: 10.1126/scitranslmed.abb5280

https://medicalxpress.com/news/2021-02-obesity-infection-link-treat...

Comment by Dr. Krishna Kumari Challa on February 26, 2021 at 8:40am

Could comedy offer a way to communicate science more effectively?

Conference to explore adapting science communication to new challenges

https://www.irishtimes.com/news/science/could-comedy-offer-a-way-to...

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How wildfires may have larger effects on cloud formation than previ...

As the frequency and size of wildfires continues to increase worldwide, new research from Carnegie Mellon University scientists shows how the chemical aging of the particles emitted by these fires can lead to more extensive cloud formation and intense storm development in the atmosphere. The research was published online today in the journal Science Advances.

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Titan's atmosphere recreated in an Earth laboratory

Beyond Earth, the general scientific consensus is that the best place to search for evidence of extraterrestrial life is Mars. However, it is by no means the only place. Aside from the many extrasolar planets that have been designated as "potentially-habitable," there are plenty of other candidates right here in our solar system. These include the many icy satellites that are thought to have interior oceans that could harbor life.

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How plant stem cells renew themselves—a cytokinin story

The mechanism by which the plant hormone cytokinin controls cell division has been discovered—a breakthrough that significantly improves our understanding of how plants grow.

Comment by Dr. Krishna Kumari Challa on February 25, 2021 at 10:23am

A Vaccination against the Pandemic of Misinformation

False beliefs, similar to those seen in Alzheimer’s patients, may result from a lack of science literacy

Low educational attainment is a risk factor for Alzheimer’s disease and other forms of dementia, suggesting that high educational attainment is associated with fostering neuroanatomical conditions that protect our brain from the pathophysiologic changes of Alzheimer’s disease. This remarkable scientific finding supports the idea that high quality education and science literacy physiologically and functionally strengthen the brain, protecting us from the threat of false beliefs during times of uncertainty and crisis.

https://www.scientificamerican.com/article/a-vaccination-against-th...

Comment by Dr. Krishna Kumari Challa on February 25, 2021 at 9:37am

Superstructures formed by 'walking' molecules could help create neu...

Superstructures formed by 'walking' molecules could help create neurons for regenerative medicine

If surgeons could transplant healthy neurons into patients living with neurodegenerative diseases or brain and spinal cord injuries?! And imagine if they could grow these neurons in the laboratory from a patients own cells using a synthetic, highly bioactive material that is suitable for 3D printing. By discovering a new printable biomaterial that can mimic properties of brain tissue, Northwestern University researchers are now closer to developing a platform capable of treating these conditions using regenerative medicine. A key ingredient to the discovery is the ability to control the self-assembly processes of molecules within the material, enabling the researchers to modify the structure and functions of the systems from the nanoscale to the scale of visible features.

 A research group  has demonstrated that these superstructures can enhance neuron growth, an important finding that could have implications for cell transplantation strategies for neurodegenerative diseases such as Parkinson’s and Alzheimer’s disease, as well as spinal cord injury.

This is the first example where researchers have been able to take the phenomenon of molecular reshuffling we reported in 2018 and harness it for an application in regenerative medicine.

https://onlinelibrary.wiley.com/doi/10.1002/advs.202004042

https://onlinelibrary.wiley.com/doi/full/10.1002/advs.202004042

Comment by Dr. Krishna Kumari Challa on February 25, 2021 at 8:52am

World's first video of a space-time crystal

A research  team has succeeded in creating a micrometer-sized space-time crystal consisting of magnons at room temperature. With the help of the scanning transmission X-ray microscope Maxymus at Bessy II at Helmholtz Zentrum Berlin, they were able to film the recurring periodic magnetization structure in a crystal.

Comment by Dr. Krishna Kumari Challa on February 25, 2021 at 8:40am

New study suggests supermassive black holes could form from dark matter

A new theoretical study has proposed a novel mechanism for the creation of supermassive black holes from dark matter. The international team find that rather than the conventional formation scenarios involving 'normal' matter, supermassive black holes could instead form directly from dark matter in high density regions in the centers of galaxies. The result has key implications for cosmology in the early Universe, and is published in Monthly Notices of the Royal Astronomical Society.

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Exactly how supermassive black holes initially formed is one of the biggest problems in the study of galaxy evolution today. Supermassive black holes have been observed as early as 800 million years after the Big Bang, and how they could grow so quickly remains unexplained.

Standard formation models involve normal baryonic matter—the atoms and elements that that make up stars, planets, and all visible objects—collapsing under gravity to form black holes, which then grow over time. However the new work investigates the potential existence of stable galactic cores made of dark matter, and surrounded by a diluted dark matter halo, finding that the centers of these structures could become so concentrated that they could also collapse into supermassive black holes once a critical threshold is reached.

According to the model this could have happened much more quickly than other proposed formation mechanisms, and would have allowed supermassive black holes in the early Universe to form before the galaxies they inhabit, contrary to current understanding.

Carlos R. Argüelles, the researcher at Universidad Nacional de La Plata and ICRANet who led the investigation comments: "This new formation scenario may offer a natural explanation for how supermassive black holes formed in the early Universe, without requiring prior star formation or needing to invoke seed black holes with unrealistic accretion rates."

Another intriguing consequence of the new model is that the critical mass for collapse into a black hole might not be reached for smaller dark matter halos, for example those surrounding some dwarf galaxies. The authors suggest that this then might leave smaller dwarf galaxies with a central dark matter nucleus rather than the expected black hole. Such a dark matter core could still mimic the gravitational signatures of a conventional central black hole, whilst the dark matter outer halo could also explain the observed galaxy rotation curves.

Carlos R Argüelles et al, On the formation and stability of fermionic dark matter haloes in a cosmological framework, Monthly Notices of the Royal Astronomical Society (2020). DOI: 10.1093/mnras/staa3986

https://phys.org/news/2021-02-supermassive-black-holes-dark.html?ut...

Comment by Dr. Krishna Kumari Challa on February 25, 2021 at 8:34am

Asteroid dust found in crater closes case of dinosaur extinction

Researchers think they have closed the case of what killed the dinosaurs, definitively linking their extinction with an asteroid that slammed into Earth 66 million years ago by finding a key piece of evidence: asteroid dust inside the impact crater.

Death by asteroid rather than by a series of volcanic eruptions or some other global calamity has been the leading hypothesis since the 1980s, when scientists found asteroid dust in the geologic layer that marks the extinction of the dinosaurs. This discovery painted an apocalyptic picture of dust from the vaporized asteroid and rocks from impact circling the planet, blocking out the sun and bringing about mass death through a dark, sustained global winter—all before drifting back to Earth to form the layer enriched in asteroid material that's visible today.

Researchers collected nearly 3,000 feet of rock core from the crater buried under the seafloor. Research from this mission has helped fill in gaps about the impact, the aftermath and the recovery of life.

The telltale sign of asteroid dust is the element iridium—which is rare in the Earth's crust, but present at elevated levels in certain types of asteroids. An iridium spike in the geologic layer found all over the world is how the asteroid hypothesis was born. In the new study, researchers found a similar spike in a section of rock pulled from the crater. In the crater, the sediment layer deposited in the days to years after the strike is so thick that scientists were able to precisely date the dust to a mere two decades after impact.

"Globally distributed iridium layer preserved within the Chicxulub impact structure" Science Advances (2021). advances.sciencemag.org/lookup … .1126/sciadv.abe3647

https://phys.org/news/2021-02-asteroid-crater-case-dinosaur-extinct...

Comment by Dr. Krishna Kumari Challa on February 24, 2021 at 1:13pm

How to improve your life using science

https://www.sciencefocus.com/science/improve-your-life-with-science...

Comment by Dr. Krishna Kumari Challa on February 24, 2021 at 1:10pm

Physicists Just Reached a New Speed Limit For Moving Quantum Information

This latest research answers a fundamental question – how fast can a quantum process be? It's a useful piece of information to know if you want to build a quantum computer or a quantum network, as it tells you some of the limitations inherent in the system.

https://journals.aps.org/prx/abstract/10.1103/PhysRevX.11.011035

https://www.sciencealert.com/a-new-quantum-speed-limit-discovery-sh...

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Scientists begin building highly accurate digital twin of our planet

A digital twin of our planet is to simulate the Earth system in future. It is intended to support policy-makers in taking appropriate measures to better prepare for extreme events. A new strategy paper by European scientists and ETH Zurich computer scientists shows how this can be achieved.

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