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Comment by Dr. Krishna Kumari Challa on September 21, 2021 at 5:39am

Science of Concrete & the Surfside Condo Collapse

Comment by Dr. Krishna Kumari Challa on September 21, 2021 at 5:35am

Yeast and bacteria together biosynthesize plant hormones for weed control

Plants regulate their growth and development using hormones, including a group called strigolactones that prevent excessive budding and branching. For the first time, scientists  have synthesized strigolactones from microbes.

Strigolactones also help plant roots form symbiotic relationships with microorganisms that allow the plant to absorb nutrients from the soil. These two factors have led to agricultural interest in using strigolactones to control the growth of weeds and root parasites, as well as improving nutrient uptake.

These root-extruding compounds don't come without risks. They also stimulate germination of witchweeds and broomrapes, which can cause entire crops of grain to fail, making thorough research essential prior to commercial development. Scientists are still learning about the physiological roles played by this diverse group of hormones in plants. Until recently, manufacturing pure strigolactones for scientific study has been difficult and too costly for agricultural use.

The new  work provides a unique platform to investigate strigolactone biosynthesis and evolution, and it lays the foundation for developing strigolactone microbial bioproduction processes as alternative sourcing.

Researchers directed a group that inserted plant genes associated with strigolactone production into ordinary baker's yeast and nonpathogenic Escherichia coli bacteria that together produced a range of strigolactones.

Sheng Wu et al, Establishment of strigolactone-producing bacterium-yeast consortium, Science Advances (2021). DOI: 10.1126/sciadv.abh4048

https://phys.org/news/2021-09-yeast-bacteria-biosynthesize-hormones...

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Comment by Dr. Krishna Kumari Challa on September 21, 2021 at 5:27am

Nano-scale discovery could help to cool down overheating in electronics

A team of physicists  solved the mystery behind a perplexing phenomenon in the nano realm: why some ultra-small heat sources cool down faster if you pack them closer together. The findings  could one day help the tech industry design faster electronic devices that overheat less.

Often, heat is a challenging consideration in designing electronics. You build a device then discover that it's heating up faster than desired.

In 2015, physicists  were experimenting with bars of metal that were many times thinner than the width of a human hair on a silicon base. When they heated those bars up with a laser, something strange occurred.

They behaved very counterintuitively. These nano-scale heat sources do not usually dissipate heat efficiently. But if you pack them close together, they cool down much more quickly.

Now, the researchers know why it happens.

In the new study, they used computer-based simulations to track the passage of heat from their nano-sized bars. They discovered that when they placed the heat sources close together, the vibrations of energy they produced began to bounce off each other, scattering heat away and cooling the bars down.

The group's results highlight a major challenge in designing the next generation of tiny devices, such as microprocessors or quantum computer chips: When you shrink down to very small scales, heat does not always behave the way you think it should.

 Directional thermal channeling: A phenomenon triggered by tight packing of heat sources, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2109056118

https://phys.org/news/2021-09-nano-scale-discovery-cool-overheating...

Comment by Dr. Krishna Kumari Challa on September 21, 2021 at 5:16am

Engineers create light-emitting plants that can be charged repeatedly

Using specialized nanoparticles embedded in plant leaves, MIT engineers have created a light-emitting plant that can be charged by an LED. After 10 seconds of charging, plants glow brightly for several minutes, and they can be recharged repeatedly.

These plants can produce light that is 10 times brighter than the first generation of glowing plants that the research group reported in 2017.

Creating ambient light with the renewable chemical energy of living plants is a bold idea. It represents a fundamental shift in how we think about living plants and electrical energy for lighting.

The particles can also boost the light production of any other type of light-emitting plant, including those the researchers originally developed. Those plants use nanoparticles containing the enzyme luciferase, which is found in fireflies, to produce light. The ability to mix and match functional nanoparticles inserted into a living plant to produce new functional properties is an example of the emerging field of "plant nanobionics."

Their  first generation of light-emitting plants contained nanoparticles that carry luciferase and luciferin, which work together to give fireflies their glow. Using these particles, the researchers generated watercress plants that could emit dim light, about one-thousandth the amount needed to read by, for a few hours.

In the new study, Strano and his colleagues wanted to create components that could extend the duration of the light and make it brighter. They came up with the idea of using a capacitor, which is a part of an electrical circuit that can store electricity and release it when needed. In the case of glowing plants, a light capacitor can be used to store light in the form of photons, then gradually release it over time.

To create their "light capacitor," the researchers decided to use a type of material known as a phosphor. These materials can absorb either visible or ultraviolet light and then slowly release it as a phosphorescent glow. The researchers used a compound called strontium aluminate, which can be formed into nanoparticles, as their phosphor. Before embedding them in plants, the researchers coated the particles in silica, which protects the plant from damage.

The particles, which are several hundred nanometers in diameter, can be infused into the plants through the stomata—small pores located on the surfaces of leaves. The particles accumulate in a spongy layer called the mesophyll, where they form a thin film. A major conclusion of the new study is that the mesophyll of a living plant can be made to display these photonic particles without hurting the plant or sacrificing lighting properties, the researchers say.

This film can absorb photons either from sunlight or an LED. The researchers showed that after 10 seconds of blue LED exposure, their plants could emit light for about an hour. The light was brightest for the first five minutes and then gradually diminished. The plants can be continually recharged for at least two weeks.

Pavlo Gordiichuk et al, Augmenting the living plant mesophyll into a photonic capacitor, Science Advances (2021). DOI: 10.1126/sciadv.abe9733

https://phys.org/news/2021-09-light-emitting-repeatedly.html?utm_so...

Comment by Dr. Krishna Kumari Challa on September 20, 2021 at 12:48pm

The Future of Wearable Tech

Comment by Dr. Krishna Kumari Challa on September 19, 2021 at 12:24pm

Will Indian researchers lose free access to scientific papers?

It’ll depend on the outcome of an ongoing case against SciHub and LibGen websites in the Delhi High Court.

On December 21, 2020, academic publishers Elsevier Ltd, Wily Pvt Ltd, and the American Chemical Society sued websites SciHub and Library Genesis, also known as LibGen, for copyright infringement in the Delhi High Court, demanding that ISP providers permanently block them in India.

These websites are a primary source for researchers in India, making available for free thousands of otherwise paywalled research papers. Because, as SciHub notes, “Research should be free to read.” Having intellectual property restrictions in research throttle access to and flow of knowledge while science can only progress when it’s widely read and debated.

Elsevier owns over 2,600 journals, including the Lancet, and all of them are paywalled with subscription rates going up to thousands of dollars, making the latest knowledge hard to access for researchers.

part 1

https://www.newslaundry.com/2021/09/18/will-indian-researchers-lose...

Comment by Dr. Krishna Kumari Challa on September 19, 2021 at 12:13pm

Antibodies from original strain COVID-19 infection don't bind to variants, study finds

People infected with the original strain of the virus that causes COVID-19 early in the pandemic produced a consistent antibody response, making two main groups of antibodies to bind to the spike protein on the virus’s outer surface. However, those antibodies don’t bind well to newer variants, a new study found.

Researchers found that many antibody sequences converged into two main groups, indicating a consistent human immune response to the virus. The researchers studied the convergent antibodies’ ability to bind to several variants and found that they no longer bound to some. The finding has implications for the ability of new variants to reinfect people who contracted earlier versions of the virus, as well as for the continuing efficacy of vaccines and the design of possible vaccine boosters.

Even though this antibody response is very common with the original strain, it doesn’t really interact with variants. That, of course, raises the concern of the virus evolving to escape the body’s main antibody response. Some antibodies should still be effective – the body makes antibodies to many parts of the virus, not only the spike protein – but the particular groups of antibodies that we saw in this study will not be as effective.

The researchers said they would like to conduct similar studies characterizing antibody responses to delta and other variants, to see whether they also produce a convergent response and how it differs from the original strain. 

It is expected that the antibody response to those variants would be quite different. 

https://www.nature.com/articles/s41467-021-24123-7'

https://news.illinois.edu/view/6367/1126344363

https://researchnews.cc/news/8965/Antibodies-from-original-strain-C...

Comment by Dr. Krishna Kumari Challa on September 18, 2021 at 10:46am

Do the northern lights make sounds that you can hear?

https://theconversation.com/do-the-northern-lights-make-sounds-that...

Comment by Dr. Krishna Kumari Challa on September 18, 2021 at 10:38am

Mass extinction: A warning that this can happen now too

The end-Permian mass extinction event of roughly 252 million years ago—the worst such event in earth's history—has been linked to vast volcanic emissions of greenhouse gases, a major temperature increase, and the loss of almost every species in the oceans and on land.

Now, it seems that even the lakes and rivers were no safe havens. A recent study published by an international team of researchers  has identified a new cause of extinction during extreme warming events: toxic microbial blooms.

In a healthy ecosystem, microscopic algae and cyanobacteria provide oxygen to aquatic animals as a waste product of their photosynthesis. But when their numbers get out of control, these microbes deplete free oxygen, and even release toxins into the water. By studying the fossil, sediment, and chemical records of rocks near Sydney, Australia, the researchers discovered that several pulses of bloom events had occurred soon after the first volcanic rumblings of the end-Permian mass extinction. Once the bottom-feeder animals, or "detritivores," were killed off, there was no one left to keep the microbes in check. The fresh water systems then seethed with algae and bacteria, delaying the recovery of animals for perhaps millions of years.

We're seeing more and more toxic algae blooms in lakes and in shallow marine environments that's related to increases in temperature and changes in plant communities which are leading to increases in nutrient contributions to freshwater environments. So, a lot of parallels to today. The volcanism was a source of CO₂ in the past but we know that the rate of CO₂ input that was seen back then was similar to the rate of CO₂ increases we're seeing today because of anthropogenic effects.

We can get a sense of how much climate has changed in the past, what the extremes are, how fast it can change, what the causes of climate change are and that gives us a nice backdrop for understanding what's happening today. The end-Permian is one of the best places to look for parallels with what's happening now.

The other big parallel is that the increase in temperature at the end of the Permian coincided with massive increases in forest fires. One of the things that that destroyed whole ecosystems was fire, and we're seeing that right now in several  places .

We should be concerned like hell!

Chris Mays et al, Lethal microbial blooms delayed freshwater ecosystem recovery following the end-Permian extinction, Nature Communications (2021). DOI: 10.1038/s41467-021-25711-3

https://phys.org/news/2021-09-animals-died-toxic-soup-earth.html?ut...

Comment by Dr. Krishna Kumari Challa on September 18, 2021 at 10:28am

How to make dormant seeds to germinate

Seeds that would otherwise lie dormant will spring to life with the aid of a new chemical discovered by researchers. 

Plants have the ability to perceive drought. When they do, they emit a hormone that helps them hold on to water. This same hormone, ABA, sends a message to seeds that it isn't a good time to germinate, leading to lower crop yields and less food in places where it's hot—an increasingly long list as a result of climate change.

"If you block ABA, you mess with the chemical pathway that plants use to prevent seed germination. A new chemical, Antabactin, does exactly this. If we apply it,  dormant seeds will sprout.

Demonstrations of Antabactin's effectiveness are described in a new paper published in the Proceedings of the National Academy of Sciences.

Aditya S. Vaidya et al, Click-to-lead design of a picomolar ABA receptor antagonist with potent activity in vivo, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2108281118

https://phys.org/news/2021-09-chemical-discovery-reluctant-seeds.ht...

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