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Comment by Dr. Krishna Kumari Challa on February 27, 2021 at 8:37am

https://www.youtube.com/watch?v=mwr-wF_IMeU

https://www.youtube.com/watch?v=9nzkF0hmy04

https://www.youtube.com/watch?v=I1Bdp2tMFsY

Comment by Dr. Krishna Kumari Challa on February 27, 2021 at 8:31am

Scientists use Doppler to peer inside cells

Doppler radar improves lives by peeking inside air masses to predict the weather. A Purdue University team is using similar technology to look inside living cells, introducing a method to detect pathogens and treat infections in ways that scientists never have before.

In a new study, the team used Doppler to sneak a peek inside cells and track their metabolic activity in real time, without having to wait for cultures to grow. Using this ability, the researchers can test microbes found in food, water, and other environments to see if they are pathogens, or help them identify the right medicine to treat antibiotic-resistant bacteria.

Researchers worked with immortalized cell lines—cells that will live forever unless you kill them. They exposed the cells to different known pathogens, in this case salmonella and E. coli. They then used the Doppler effect to spy out how the cells reacted. These living cells are called "sentinels," and observing their reactions is called a biodynamic assay.

This strategy is broadly applicable when scientists have isolated an unknown microbe and want to know if it is pathogenic—harmful to living tissues—or not. Such cells may show up in food supply, water sources or even in recently melted glaciers.

Another benefit is the ability to quickly and directly diagnose which bacteria respond to which antibiotics.

 Honggu Choi et al, Doppler imaging detects bacterial infection of living tissue, Communications Biology (2021). DOI: 10.1038/s42003-020-01550-8

https://phys.org/news/2021-02-scientists-doppler-peer-cells.html?ut...

Comment by Dr. Krishna Kumari Challa on February 27, 2021 at 7:25am

Were it not for humans, woolly mammoths would have lived for 4,000 more years, simulation shows

An international team of researchers has used computer simulations to show that it was likely a combination of climate change and human hunting that led to the extinction of the woolly mammoth. They have written a paper describing their findings, available on the bioRxiv preprint server—in it, they suggest that were it not for human hunters, the mammoths would have lasted another 4,000 years.

the researchers created a simulation showing wooly mammoth populations from approximately 21,000 years ago, to 4,000 years ago—the time when the last of the mammoths died out. To recreate conditions the mammoths faced, the researchers added climate data as well as known human hunting data. They ran their simulation over 90,000 times with slight changes to the factors that might have led to their demise. The simulations showed that the most likely scenario involved climate change pushing the mammoths into smaller environments and hunters finishing them off. Interestingly, the researchers also found that if they removed human hunters from the simulations, the majority of the mammoths held on for another 4,000 years.

 Damien A. Fordham et al. Humans hastened the range collapse and extinction of woolly mammoth, bioRxiv (2021). DOI: 10.1101/2021.02.17.431706

https://phys.org/news/2021-02-humans-woolly-mammoths-years-simulati...

Comment by Dr. Krishna Kumari Challa on February 26, 2021 at 12:06pm

Microscopic Wrinkles in Leaves Ward Off Bugs

Crops have advanced a formidable vary of methods to beat back hungry, leaf-chomping bugs. Properly-known defenses embrace foul-tasting toxins, sticky resins and sharp thorns, and now scientists have recognized one more instance: microscopic wrinkles that make leaves more durable to stroll on.

Wrinkles kind in lots of leaves’ cuticles—coatings that restrict water evaporation, mediate gasoline alternate, and shield the plant from pathogens. The brand new analysis, revealed in Royal Society Open Science, finds that together with the cuticle’s inherently slippery floor, its tiny wrinkles additionally assist discourage bugs. The wrinkles most certainly grow to be extra pronounced because the leaf matures and its cuticle builds up, ultimately increasing and buckling.

https://royalsocietypublishing.org/doi/10.1098/rsos.201319

Comment by Dr. Krishna Kumari Challa on February 26, 2021 at 11:51am

Dancing Roots

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...

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