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Comment by Dr. Krishna Kumari Challa on February 6, 2021 at 12:42pm

Study: 'Hidden' genes could be key in development of new antibiotics

A study from the Center for Phage Technology, part of Texas A&M's College of Agriculture and Life Sciences and Texas A&M AgriLife Research, shows how the "hidden" genes in bacteriophages—types of viruses that infect and destroy bacteria—may be key to the development of a new class of antibiotics for human health.

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Research establishes a new method to predict individual risk of cogn...

The early prognosis of high-risk older adults for amnestic mild cognitive impairment (aMCI), using noninvasive and sensitive neuromarkers, is key for early prevention of Alzheimer's disease. A recent study, published in the Journal of Alzheimer's Disease, by researchers at the University of Kentucky establishes what they believe is a new way to predict the risk years before a clinical diagnosis. Their work shows that direct measures of brain signatures during mental activity are more sensitive and accurate predictors of memory decline than current standard behavioral testing.

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Removing microRNAs from triple-negative breast cancer cells can rev...

A new study led by the University of Westminster shows that removing small genetic parts of our genomes called microRNAs from triple negative breast cancer cells can reverse its spread.

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Phys.Org Vibrating nanodroplets may invade a tumor Phys.Org Researchers of the University of Twente now demonstrate a new phenomenon triggering droplet vaporization: It happens at the exact acoustic resonance frequency and causes fast and efficient lowering of the pressure inside the droplet, until below the ...

Comment by Dr. Krishna Kumari Challa on February 6, 2021 at 12:22pm

Genes for face shape identified

Genes that determine the shape of a person's facial profile have been discovered by a UCL-led research team.

The researchers identified 32 gene regions that influenced facial features such as nose, lip, jaw, and brow shape, nine of which were entirely new discoveries while the others validated genes with prior limited evidence.

The analysis of data from more than 6,000 volunteers across Latin America was published today in Science Advances.

"A GWAS in Latin Americans identifies novel face shape loci, implicating VPS13B and a Denisovan introgressed region in facial variation" Science Advances (2021). DOI: 10.1126/sciadv.abc6160

Comment by Dr. Krishna Kumari Challa on February 6, 2021 at 12:19pm

CRISPR editing of mitochondria: Promising new biotech?

Although the CRISPR/Cas9 system has seen widespread application in editing the nuclear genome, using it to edit the mitochondrial genome has been problematic. The main hurdles have been a lack of suitable editing sites in the small mtDNA, and the traditional difficulty of importing the guide RNA into the mitochondrial matrix where nucleoids can be accessed.

Two recently published papers suggest that significant progress is being made on both fronts. The first paper, published in the journal SCIENCE CHINA Life Sciences, used CRISPR techniques to induce insertion/deletion (InDel) events at several mtDNA microhomologous regions. These InDel events were triggered specifically by double-strand break (DSB) lesions. The authors found that InDel mutagenesis was significantly improved by sgRNA multiplexing and a DSB repair inhibitor called iniparib, suggesting a rewiring DSB repair mechanisms to manipulate mtDNA. In the second paper, published in the journal Trends in Molecular Medicine, the researchers give a global overview of recent advances in different forms of nuclear and mitochondrial genome editing.

Bang Wang et al. CRISPR/Cas9-mediated mutagenesis at microhomologous regions of human mitochondrial genome, Science China Life Sciences (2021). DOI: 10.1007/s11427-020-1819-8

Jiameng Dan et al. Expanding the Toolbox and Targets for Gene Editing, Trends in Molecular Medicine (2021). DOI: 10.1016/j.molmed.2020.12.005

https://phys.org/news/2021-02-crispr-mitochondria-biotech.html?utm_...

Comment by Dr. Krishna Kumari Challa on February 5, 2021 at 10:31am

Science can be magic!

https://twitter.com/PhysicsVldeo/status/1357298542692376577?s=20

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https://twitter.com/WElRDPHYSICS/status/1357294888488849409?s=20

Comment by Dr. Krishna Kumari Challa on February 5, 2021 at 10:02am

COVID-19 antibodies last for 6 months following infection, study finds

Coronavirus antibodies last for at least six months after infection for the majority of people who have had the virus, according to a new study.

Antibodies are produced by the body’s immune system to fight off an invading bacteria or virus. After an infection they can linger on to fend off future infections, though it’s clear not whether this is the case in COVID-19 infections.

According to the study, 99 per cent of participants who tested positive retained coronavirus antibodies for three months after being infected, while 88 per cent did so for the full six months of the study.

Researchers say this indicates antibodies produced following natural infection may provide a degree of protection for most people against getting infected again for at least six months.

https://www.ukbiobank.ac.uk/media/x0nd5sul/ukb_serologystudy_report...

https://www.sciencefocus.com/news/covid-19-antibodies-last-for-6-mo...

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Comment by Dr. Krishna Kumari Challa on February 5, 2021 at 9:56am

How a tiny spider uses silk to lift prey 50 times its own weight

Spinning the right lines can accomplish feats of strength when muscle isn’t enough

A family of spiders can catch prey many times their own weight by hitching silk lines to their quarry and hoisting the meaty prize up into the air.

Tangle web spiders, in the Theridiidae family, are masters of using silk to amplify muscle power.

See how a tiny spider hoists massive prey into its web 

https://www.sciencenews.org/article/tiny-spider-uses-silk-lift-prey...

Comment by Dr. Krishna Kumari Challa on February 5, 2021 at 9:50am

Scientists Discover an Immense, Unknown Hydrocarbon Cycle Hiding in The Oceans

In the awful wake of an oil spill, it's typically the smallest of organisms who do most of the cleaning up. Surprisingly, scientists know very little about the tools these tiny clean-up crews have at their disposal.

In  a new study, researchers have uncovered a whole new cycle of natural hydrocarbon emissions and recycling facilitated by a diverse range of tiny organisms – which could help us better understand how some microbes have the power to clean up the mess an oil spill leaves in the ocean.

Just two types of marine cyanobacteria are adding up to 500 times more hydrocarbons to the ocean per year than the sum of all other types of petroleum inputs to the ocean, including natural oil seeps, oil spills, fuel dumping and run-off from land.

But unlike more familiar human contributions of hydrocarbons into our ocean, this isn't a one-way, local dump.

These hydrocarbons, primarily in the form of pentadecane (nC15), are spread across 40 percent of Earth's surface, and other microbes feast on them. They're constantly being cycled in such a way that Love and colleagues estimate only around 2 million metric tonnes are present in the water at any one time.

Every two days you produce and consume all the pentadecane in the ocean. So it probably shouldn't be a huge surprise that traces of our own emissions drowned out our ability to see the immense hydrocarbon cycle that naturally occurs in our oceans.

The researchers were able to confirm the pentadecane in their seawater samples were of biological origin, by using a gas chromatograph. 

Analysing their data, they found concentrations of pentadecane increased with greater abundance of cyanobacteria cells, and the hydrocarbon's geographic and vertical distribution were consistent with these microbe's ecology.

Cyanobacteria Prochlorococcus and Synechococcus are responsible for around a quarter of the global ocean's conversion of sunlight energy into organic matter (primary production) and previous laboratory cultivation revealed they produce pentadecane in the process.

Valentine explains the cyanobacteria likely use pentadecane as a stronger component for highly curved cellular membranes, like those found in chloroplasts (the organelle that photosynthesise). 

https://www.nature.com/articles/s41564-020-00859-8

https://www.sciencealert.com/we-ve-overlooked-an-immense-hydrocarbo...

Comment by Dr. Krishna Kumari Challa on February 5, 2021 at 9:09am

Tiny 'micro' earthquakes turn groundwater acidic

Tiny earthquakes, too small to be felt on the Earth's surface, create chemical changes which turn groundwater acidic, according to newly-published research at the University of Strathclyde.

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Distant 'baby' black holes seem to be misbehaving—and experts are p...

Radio images of the sky have revealed hundreds of "baby" and supermassive black holes in distant galaxies, with the galaxies' light bouncing around in unexpected ways.

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New window system cuts sound levels by 26 decibels, achieves four t...

Home owners, especially those in noisy districts, can look forward to greater living comfort with a new invention by researchers from the National University of Singapore (NUS) School of Design and Environment (SDE) that reduces outdoor noise and improves indoor ventilation.

Comment by Dr. Krishna Kumari Challa on February 5, 2021 at 9:08am

Fluid dynamics of COVID-19 airborne infection suggests urgent data ...

Part 1

Infection by COVID-19 is largely caused by airborne transmission, a phenomenon that has rapidly attracted a great deal of attention from the scientific community. The SARS-CoV-2 virus hosted in different tracts of the respiratory system is emitted as we breathe, speak or sing or through more violent expulsions like coughing or sneezing. In these common actions, people emit thousands or even millions of small droplets of saliva acting as a vector for the virus. Given that the disease travels on respiratory droplets, social distancing is of paramount importance to limit the spread. Indeed, droplets are heavier than air, and sooner or later, they fall to the ground, which will tame their infectious potential.

The reach of a droplet depends on its size. We all know from direct experience that when we speak, cough or sneeze, we often discharge large droplets: We can clearly see them and even feel them on our skin. But besides the visible droplets, we also scatter a myriad of invisible tiny droplets. This substantial variation in droplet size, from micron to millimeter, causes a great deal of uncertainty in determining the actual reach of the viral load expelled by an infected individual.

 One meter is not a sound safety distance. To be clear, it is important to keep as far apart as possible, but we should not feel safe when standing one meter apart.

 The life of a respiratory droplet is dictated by the exact same physical processes that produce clouds. As cloud droplets are carried by the wind, they often encounter moist air and grow by condensation to become rain; we know all about the equations that describe both transport and condensation in clouds because they have been studied for centuries. Respiratory droplets undergo the same two physical processes, except respiratory droplets are carried by the air emitted in the cough and encounter dry air outside the mouth; thus, instead of growing, they shrink from their original size to their final size by evaporation.

Does droplet size matter? The answer is yes, and the reason is quite intuitive: Large droplets fall quickly, whereas small droplets fall slowly. As a consequence, smaller droplets linger in air for longer and may travel several meters before they finally reach ground. On the other hand, larger droplets travel less far in air, as they promptly reach ground. To follow the erratic path and shrinkage of the many diverse droplets from emission to landing, we used the equations from cloud physics for the two key processes of droplet transport and evaporation. Importantly, we could predict the fate of a droplet given its initial size when it first exited the mouth.

 We do not really know the typical size of the emitted droplets in a cough; some studies claim that the vast majority (97%) of saliva droplets are smaller than one micron in radius; other authors report evidence that only 45% of droplets are sub-micron in size. Others yet find no evidence of sub-micron droplets. Discrepancies may be partly explained by the use of different techniques, but it is also possible that there is an intrinsic variability, with different people and conditions causing droplets to shift in size. 

Comment by Dr. Krishna Kumari Challa on February 5, 2021 at 9:08am

Part 2

The scientific community is only now starting to study the fascinating physical processes that produce respiratory droplets. We just do not much about it yet. Having no reason to discard any of these data, we set out to compare the consequent scenarios.

a major effort is needed to gain an understanding or at least a robust characterization of droplet size distribution in human expulsions. In the absence of more conclusive data, and despite the importance of social distancing, we are unable to predict what the safe distance is.

disease transmission may also depend on the relative humidity (RH) of the environment. In dry conditions (RH lower than about 45%), droplets dry out and shrink to their crystallized salt core, similar to what happens as sea water dries out leaving solid salt on our skin. This process leaves the virions trapped onto the solid salt nucleus within a fraction of a second. In contrast, in moist conditions (RH larger than 45%), droplets never evaporate entirely and remain liquid at all times. The evaporation process is highly nontrivial, as humidity fluctuates widely due to turbulence as shown in the video for a typical cough (color coded according to the value of RH).

Are dry nuclei or liquid droplets more infective? This second issue is still debated, and no consensus has been reached. Imagine that SARS-Cov-2 absolutely needs water to survive. In dry days, disease transmission would be hindered and we would be much safer than in moist conditions. The question for social distancing would then be how far liquid droplets travel before complete evaporation, and we could interrogate the model described above to find the answer. We could also imagine the opposite scenario, where virions better thrive on solid nuclei and suffer in droplets, for example, due to the large concentration of salt or saliva. In this case, we would want to pay particular attention during dry days, and potentially keep indoors environments more moist.

Conclusion 2

• Humidity in the environment dictates the final state of the exhaled saliva droplets which either remain in a liquid state or reduce to their dry residual depending on the ambient relative humidity.
• A major effort is needed to define the infectious potential of the SARS-CoV-2 virus when transported on dry nuclei versus liquid droplets.

M. E. Rosti et al. Fluid dynamics of COVID-19 airborne infection suggests urgent data for a scientific design of social distancing, Scientific Reports (2020). DOI: 10.1038/s41598-020-80078-7

Duguid, J. P. The size and the duration of air-carriage of respiratory droplets and droplet-nuclei. Epidemiol. Infect. 44, 471–479 (1946).

Yang, S., Lee, G. W., Chen, C.-M., Wu, C.-C. & Yu, K.-P. The size and concentration of droplets generated by coughing in human subjects. J. Aerosol Med. 20, 484–494 (2007).

https://sciencex.com/news/2021-02-fluid-dynamics-covid-airborne-inf...

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