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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...

Comment by Dr. Krishna Kumari Challa on February 5, 2021 at 8:44am

Spicy perfection isn't to prevent infection: study

Do spices used in dishes  help stop infection?

We have an answer to this Q now.

The quick takeaway is: probably not.

Researchers from Australia feasted on a true smorgasbord of data, examining more the 33,000 recipes from 70 cuisines containing 93 different spices to find the answer  and this is their conclusion: 

The theory  that spicy foods helped people survive in hot climates where the risk of infection from food can have a big cost in terms of health and survival doesn't hold up. 

Spicier food is found in hotter countries, but our analysis provides no clear reason to believe that this is primarily a cultural adaptation to reducing infection risk from food.

The study instead shows that while use of spice is related to the risk of foodborne illness, it's also associated with a wide range of health outcomes. In fact, spice use is even related to causes of death that have nothing to do with infection risk, such as fatal car accidents.

So there is a significant relationship between life expectancy and spicy food. But this doesn't mean that spicy food shortens your life span or makes you crash your car. Instead, there are many socioeconomic indicators that all scale together, and many of them also scale with spice use.

because the spiciness of cuisines scales with many socio-economic factors, like gross domestic product per capita and life expectancy, it is difficult to tease apart the key causes. However, the researchers could rule out some possible explanations of why some areas use more spices in their cooking.

Spicier foods are not explained by variation in climate, human population density or cultural diversity.

And patterns of spice use don't seem to be driven by biodiversity, nor by the number of different crops grown, nor even by the number of spices growing naturally in the area.

Whatever the key drivers for the use of spice, one thing is certain—our palettes and plates are a lot better for it!

 There is little evidence that spicy food in hot countries is an adaptation to reducing infection risk, Nature Human Behaviour (2021). DOI: 10.1038/s41562-020-01039-8 , www.nature.com/articles/s41562-020-01039-8

https://phys.org/news/2021-02-spicy-isnt-infection.html?utm_source=...

Comment by Dr. Krishna Kumari Challa on February 5, 2021 at 8:23am

Deforestation is stressing mammals out

Lots of us are feeling pretty anxious about the destruction of the natural world. It turns out, humans aren't the only ones stressing out—by analyzing hormones that accumulate in fur, researchers found that rodents and marsupials living in smaller patches of South America's Atlantic Forest are under more stress than ones living in more intact forests.

Small mammals, primarily rodents and little marsupials, tend to be more stressed out, or show more evidence that they have higher levels of stress hormones, in smaller forest patches than in larger forest patches."

The destruction of an animal's habitat can drastically change its life. There's less food and territory to go around, and the animal might find itself in more frequent contact with predators or in increased competition with other animals for resources. These circumstances can add up to long-term stress.

Stress isn't a bad thing in and of itself—in small doses, stress can be life-saving. A stress response is normally trying to bring your body back into balance. If something perturbs you and it can cause you to be injured or die, the stress response mobilizes energy to deal with that situation and bring things back into a normal state. It allows you to survive.

But then these animals are placed into these small fragments of habitat where they're experiencing elevated stress over prolonged periods, and that can lead to disease and dysregulation of various physiological mechanisms in the body.

The study not only sheds light on how animals respond to deforestation, but it could also lead to a better understanding of the circumstances in which animals can pass diseases to humans. If you have lots of stressed out mammals, they can harbour viruses and other diseases, and there are more and more people living near these deforested patches that could potentially be in contact with these animals. By destroying natural habitats, we're potentially creating hotspots for zoonotic disease outbreaks.

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The tropics hold the highest diversity of organisms on the planet. Therefore, this has potential to impact the largest variety of living organisms on the planet, as more and more deforestation is happening. We're gonna see individuals and populations that tend to show higher levels of stress

1. Sarah A. Boyle, Noé U. de la Sancha, Pastor Pérez, David Kabelik. Small mammal glucocorticoid concentrations vary with forest fragment size, trap type, and mammal taxa in the Interior Atlantic Forest. Scientific Reports, 2021; 11 (1) DOI: 10.1038/s41598-021-81073-2

https://www.sciencedaily.com/releases/2021/02/210204101640.htm#:~:t....

https://phys.org/news/2021-02-deforestation-stressing-mammals.html?...

Comment by Dr. Krishna Kumari Challa on February 5, 2021 at 7:45am

One in every 5 adults had Covid by mid-Dec, says ICMR survey

More than one-fifth of the country’s adult population had at some point been infected by Covid-19 by mid-December, the third serological survey conducted by the Indian Council of Medical Research shows.

More than one-fifth of the country’s adult population had at some point been infected by Covid-19 by mid-December, the third serological survey conducted by the Indian Council of Medical Research shows.

The separate data released on seroprevalence among those aged 10-18 was found to be 25.3%. The data released reflect the prevalence of antibodies, read as evidence that the person has had Covid-19.

Among healthcare workers, seroprevalence was 25.7%, with 26.6% among doctors and nurses.

The government emphasised that a large proportion of the population is still vulnerable and there is no scope to lower the guard as herd immunity could not be assumed and added that following Covid-appropriate behaviour is needed.

https://health.economictimes.indiatimes.com/news/industry/one-in-ev...

Comment by Dr. Krishna Kumari Challa on February 5, 2021 at 7:01am

Drugging the undruggable, improbable new targets for lung cancer therapy

The growth of solid tumors is frequently driven by mutations in key proto-oncogenes. For non-small-cell lung cancers (NSCLC), somatic mutations in the KRAS (Kirsten RAt Sarcoma virus) gene turn it into an oncogene that renders tumors resistant to common chemotherapies like erlotinib (Tarceva) or gefitinib (Iressa). 

Previously, KRAS was considered to be "undruggable" because the surface of the tiny protein had no deep pockets for drug interaction with potential small molecule inhibitors. Since many NSCLCs rely on a constitutively activated mutant KRAS, researchers have continued to explore KRAS and its downstream signaling pathways as possible targets. That research has finally begun to pay off. Complementary approaches to NSCLC lung cancer that collectively embrace immune self-defenses within the context of the larger KRAS ecosystem have now come fully into view.

Together, they flesh out a therapeutic microcosm of tumor biology that can be copied and modified to serve as a blueprint for treating many cancer types, each sustained by their own unique oncogenic drivers. In an article in Cell Reports Medicine researchers outline four ways to combat KRAS-dependent NSCLC: immune checkpoint inhibitors, KRAS neoantigen targeting, direct KRAS inhibitors and KRAS signaling inhibitors.

 Ravi Salgia et al. The improbable targeted therapy: KRAS as an emerging target in non-small cell lung cancer (NSCLC), Cell Reports Medicine (2021). DOI: 10.1016/j.xcrm.2020.100186

https://medicalxpress.com/news/2021-02-drugging-undruggable-improba...

Comment by Dr. Krishna Kumari Challa on February 4, 2021 at 11:35am

New software allows scientists to 'walk inside' fossil and mummy samples

New software will allow scientists to see data in 3-D and create life-like models of objects like fossils and mummies, making it possible to "zoom in" on smaller details without damaging the original.

The revolutionary software involved, called Drishti, is simple, but powerful.

Applications of the latest version, Drishti Paint, have been explained in a new paper published in Royal Society Open Science.

You can even 'walk around' inside the object to see what's there. 

After researchers scan the sample, they then have a set of 3-D data which can be digitally dissected effectively using this new tool. This is the first known tool that can perform this kind of 3-D segmentation directly on a volume of data.

According to the team, the software could prove especially useful when it comes to scientific communication and education.

It has already been used to create an identical model from a mummy sample, so the mummy can be studied closely without damaging the original sample.

It had been used to scan data of a fish fossil as a case study, but this new  procedure can be used in biological, medical and industrial research.

Drishti was first developed by NCI in 2004 and has been under continuous development since then

Importantly, the software is free and available online for anyone to use.

Yuzhi Hu et al. Three-dimensional segmentation of computed tomography data using Drishti Paint : new tools and developments, Royal Society Open Science (2020). DOI: 10.1098/rsos.201033

https://phys.org/news/2021-02-software-scientists-fossil-mummy-samp...

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