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Comment by Dr. Krishna Kumari Challa on February 26, 2021 at 11:14am

 How reliable are existing studies on microplastics in table salt?

Just as environmentally conscious scientists predicted, our excessive use of plastics is coming back to bite us. Microplastics (MPs), plastic particles smaller than a few millimeters, can now be found everywhere, but more so in seawater. As expected, MPs are harmful to both environment and health, although their exact effects are unclear.

To get a better grasp of the extent of the MP problem, it is necessary to quantify how much we are exposed to them. Table salt has been shown to contain MPs, making it an ideal study target to gauge human exposure to MPs. Although many studies have measured the concentration of MPs in different edible salts, each research group used vastly different methodologies of quantification, causing much variability between the results, and calling into question their validity.

To address this problem, in a study published in the Journal of Hazardous Materials, scientists from Incheon National University, Korea, conducted a systematic review of all published papers on MPs in table salt and analyzed the differences between their methodologies and results in detail.

They found that the concentration of MPs in edible salt according to the literature varied quite a bit, and that measurement and sample-preparation procedures of each study were causing these differences. However, the largest differences were caused by the methods used to identify MPs, the minimum cut-off size and the criteria for the selection of particles. 

When not corrected by different measured minimum MP cutoff sizes, MP content differed from 10 to 600 times among different MP identification methods, with greatest values originating from visual observation and followed by spectroscopy methods

Scientists also found a notable correlation between logarithmic mean abundances of MPs and minimum cut-off size used, regardless of the identification method.

Hee-Jee Lee et al, Variation and Uncertainty of Microplastics in Commercial Table Salts: Critical Review and Validation, Journal of Hazardous Materials (2020). DOI: 10.1016/j.jhazmat.2020.123743

https://phys.org/news/2021-02-salt-reliable-microplastics-table.htm...

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Comment by Dr. Krishna Kumari Challa on February 26, 2021 at 11:07am

Scientists achieve breakthrough in culturing corals and sea anemones cells

Researchers have perfected the recipe for keeping sea anemone and coral cells alive in a petri dish for up to 12 days. The new study has important applications to study everything from evolutionary biology to human health.

Cnidarians are emerging model organisms for cell and molecular biology research. Yet, successfully keeping their cells in a laboratory setting has proved challenging due to contamination from the many microorganisms that live within these marine organisms or because the whole tissue survive in a culture environment.

Researchers used two emerging model organisms in developmental and evolutionary biology—the starlet sea anemone (Nematostella vectensis) and cauliflower coral (Pocillopora damicornis)—to find more successful way to grow these cell cultures in a laboratory setting. They tested 175 cell cultures from the two organisms and found that their cells can survive for on average 12 days if they receive an antibiotic treatment before being cultured.

James D. Nowotny et al, Novel methods to establish whole-body primary cell cultures for the cnidarians Nematostella vectensis and Pocillopora damicornis, Scientific Reports (2021). DOI: 10.1038/s41598-021-83549-7

https://phys.org/news/2021-02-scientists-breakthrough-culturing-cor...

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Comment by Dr. Krishna Kumari Challa on February 26, 2021 at 10:57am

Nanobodies could help CRISPR turn genes on and off

The genetic tool CRISPR has been likened to molecular scissors for its ability to snip out and replace genetic code within DNA. But CRISPR has a capability that could make it useful beyond genetic repairs. CRISPR can precisely locate specific genes.

Scientists now attached CRISPR to nanobodies to help it perform specific actions when it reached the right spot on DNA. They used this combo technique to transform CRISPR from a gene-editing scissors into a nanoscale control agent that can toggle specific genes on and off, like a light switch, to start or stop the flow of some health-related protein inside a cell.

This  could enable researchers to explore new therapeutic applications in the field of epigenetics—which is the study of how genes behave inside cells.

Mike V. Van et al, Nanobody-mediated control of gene expression and epigenetic memory, Nature Communications (2021). DOI: 10.1038/s41467-020-20757-1

https://phys.org/news/2021-02-nanobodies-crispr-genes.html?utm_sour...

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...

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