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Comment by Dr. Krishna Kumari Challa on August 26, 2021 at 11:40am

Protecting gardens and crops from insects using the 'smell of fear'

For home gardeners and farmers, herbivorous insects present a major threat to their hard work and crop yields. The predator insects that feed on these bugs emit odors that pests can sense, which changes the pests' behavior and even their physiology to avoid being eaten. With bugs becoming more resistant to traditional pesticides, researchers now report they have developed a way to bottle the "smell of fear" produced by predators to repel and disrupt destructive insects naturally without the need for harsh substances.

Smell of fear: Harnessing predatory insect odor cues as a pest management tool for herbivorous insects, ACS Fall 2021.

Comment by Dr. Krishna Kumari Challa on August 26, 2021 at 11:36am

YouTube says it removed 1mn 'dangerous' videos on COVID-19

YouTube said Wednesday it has removed more than one million videos with "dangerous coronavirus misinformation" since the start of the COVID-19 pandemic.

YouTube said in a blog post it relies on "expert consensus from health organizations," including the US Centers for Disease Control and the World Health Organization, but noted that, in some cases, "misinformation is less clear-cut" as new facts emerge.

YouTube said it was working to accelerate the process for removing videos with misinformation while simultaneously delivering those from authoritative sources.

IANS

Comment by Dr. Krishna Kumari Challa on August 26, 2021 at 11:27am

In a first, scientists capture a 'quantum tug' between neighboring water molecules

Water is the most abundant yet least understood liquid in nature. It exhibits many strange behaviors that scientists still struggle to explain. While most liquids get denser as they get colder, water is most dense at 39 degrees Fahrenheit, just above its freezing point. This is why ice floats to the top of a drinking glass and lakes freeze from the surface down, allowing marine life to survive cold winters. Water also has an unusually high surface tension, allowing insects to walk on its surface, and a large capacity to store heat, keeping ocean temperatures stable.

Now, a team of researchers   has made the first direct observation of how hydrogen atoms in water molecules tug and push neighboring water molecules when they are excited with laser light. Their results, published in Nature today, reveal effects that could underpin key aspects of the microscopic origin of water's strange properties and could lead to a better understanding of how water helps proteins function in living organisms.

Each water molecule contains one oxygen atom and two hydrogen atoms, and a web of hydrogen bonds between positively charged hydrogen atoms in one molecule and negatively charged oxygen atoms in neighboring molecules holds them all together. This intricate network is the driving force behind many of water's inexplicable properties, but until recently, researchers were unable to directly observe how a water molecule interacts with its neighbors.

The low mass of the hydrogen atoms accentuates their quantum wave-like behavior. This study is the first to directly demonstrate that the response of the hydrogen bond network to an impulse of energy depends critically on the quantum mechanical nature of how the hydrogen atoms are spaced out, which has long been suggested to be responsible for the unique attributes of water and its hydrogen bond network.

Direct observation of ultrafast hydrogen bond strengthening in liquid water, Nature (2021). DOI: 10.1038/s41586-021-03793-9 , www.nature.com/articles/s41586-021-03793-9

https://phys.org/news/2021-08-scientists-capture-quantum-neighborin...

Comment by Dr. Krishna Kumari Challa on August 26, 2021 at 11:20am

A Badge That Measures Exposures to Dangerous Chemicals

Comment by Dr. Krishna Kumari Challa on August 26, 2021 at 10:47am

Comment by Dr. Krishna Kumari Challa on August 26, 2021 at 10:45am

Comment by Dr. Krishna Kumari Challa on August 26, 2021 at 10:04am

Why the changing colour of our streetlights could be a danger for insect populations

Life on Earth has evolved alongside predictable cycles of day and night. But this pattern has become increasingly blurred. Between 2012 and 2016, satellite measurements revealed that the global area polluted by artificial light grew by 2% each year, intruding ever deeper into biodiversity hotspots like tropical forests.

In this context, there is an important change taking place in the world: the replacement of older, less energy-efficient sodium street-lighting with white LEDs.

LEDs used in streetlights typically emit white light, while sodium lamps have a characteristic yellow glow – as seen in the picture below. This change in the colour of artificial light is predicted to have major consequences for wildlife. That’s because white LEDs emit light across the entire visible spectrum. The more wavelengths emitted, the greater the diversity of species and biological processes that are likely to be disrupted.

Insects are known to be more sensitive to shorter, bluer wavelengths of light, which are largely absent from sodium lighting. Biological processes that are controlled by daylight and internal circadian rhythms, such as reproduction, are more likely to be disrupted or prevented by white LEDS.

A study results published in Science Advances recently were striking. Lighting reduced the numbers of caterpillars by between one half and one third. Lit areas almost universally had lower numbers than their darker counterparts. Sites with white LEDs also had a steeper reduction in numbers compared to sites with sodium lamps.

We suspect the reason there were fewer caterpillars in lit areas was because the lighting prevented females from laying eggs, a behaviour that has evolved in darkness. In addition, adult moths can be drawn up to streetlights, where they’re easy pickings for bats. Our recent review article revealed many other plausible mechanisms through which lighting could cause population declines throughout the moths’ life cycles.

https://advances.sciencemag.org/content/7/35/eabi8322

https://theconversation.com/why-the-changing-colour-of-our-streetli...

Comment by Dr. Krishna Kumari Challa on August 25, 2021 at 1:52pm

In the last 50 years, we've seen increasing levels of new pathogens spreading through humans. SARS-CoV-2 is the most obvious example, but even in the last few decades we've had swine flu, bird flu, Ebola, and many, many more.

"Together with recent estimates of increasing rates of disease emergence from animal reservoirs associated with environmental change," the team writes, "this finding suggests a high probability of observing pandemics similar to COVID-19 (probability of experiencing it in one's lifetime currently about 38 percent), which may double in coming decades.

So, even while we are recovering from a current outbreak, it's important that we don't assume we won't see another life-changing pandemic soon enough.

In fact, if we play our cards right, our response and resources for COVID-19 can prepare us for the next pandemic.

https://www.pnas.org/content/118/35/e2105482118

part 2

Comment by Dr. Krishna Kumari Challa on August 25, 2021 at 1:51pm

The Probability of Another COVID-Level Pandemic Emerging is higher than you think

a new statistical study has discovered that large pandemics are much more common than you might expect. In fact, the team found that a pandemic with a similar level of impact to COVID-19 has around a 2 percent probability of occurring each year.

When you add that up across an entire lifetime, this means we each have a 38 percent chance of experiencing a big one at least once, and the odds look set to get worse with time.

The most important takeaway is that large pandemics like COVID-19 and the Spanish flu are relatively likely.

The team looked at the historical record of epidemics from the year 1600 until now. They found 476 documented epidemics, around half of which had a known number of casualties. About 145 caused less than 10,000 deaths, while 114 others we know existed, but not the number of deaths.

Importantly, infectious diseases that are currently active were excluded from the analysis – so that means no COVID-19, HIV, or malaria.

The team used detailed modelling with a generalized Pareto distribution to analyze the data, finding that the yearly number of epidemics is immensely variable, and an extreme epidemic like the Spanish flu of 1918-1920 had a probability of occurring somewhere between 0.3 and 1.9 percent each year over the last 400 years.

"The slow decay of probability with epidemic intensity implies that extreme epidemics are relatively likely, a property previously undetected due to short observational records and stationary analysis methods

part 1

Comment by Dr. Krishna Kumari Challa on August 25, 2021 at 1:09pm

Can DNA be washed away?

In forensic casework, DNA of suspects could be found frequently on clothes of drowned bodies after hours, sometimes days of exposure to water. ... All in all, the results demonstrate that DNA could still be recovered from clothes exposed to water for more than 1 week.3

https://pubmed.ncbi.nlm.nih.gov/28963636/

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