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Comment by Dr. Krishna Kumari Challa on July 28, 2021 at 10:35am

Physicists Have Figured Out How We Could Make Antimatter Out of Light

A new study by scientists has demonstrated how researchers may be able to create an accelerating jet of antimatter from light.

A team of physicists has shown that high-intensity lasers can be used to generate colliding gamma photons – the most energetic wavelengths of light – to produce electron-positron pairs. This, they say, could help us understand the environments around some of the Universe's most extreme objects: neutron stars.

The process of creating a matter-antimatter pair of particles – an electron and a positron – from photons is called the Breit-Wheeler process, and it's extremely difficult to achieve experimentally.

The probability of it taking place when two photons collide is very small. You need very high-energy photons, or gamma rays, and a lot of them, in order to maximize the chances of observation.

We don't yet have the capability to build a gamma-ray laser, so the photon-photon Breit-Wheeler process currently remains experimentally unachieved. But a team of physicists led by Yutong He of the University of California, San Diego (UC San Diego) has proposed a new workaround that, according to their simulations, could actually work.

It consists of a plastic block, carved with a pattern of criss-crossing channels on the micrometer scale. Two powerful lasers, one on either side of the block, fire strong pulses at this target.

"When the laser pulses penetrate the sample, each of them accelerates a cloud of extremely fast electrons. 

These two electron clouds then race toward each other with full force, interacting with the laser propagating in the opposite direction."

The resulting collision is so energetic that it produces a cloud of gamma photons. These gamma photons should collide with each other to produce electron-positron pairs,  in accordance with Einstein's theory of general relativity.

Even more excitingly, this process should generate powerful magnetic fields that collimate the positrons (rather than the electrons) into strongly accelerated, jet-shaped beams. In a distance of just 50 micrometers, the researchers found, the acceleration should increase the energy of the particles to one gigaelectronvolt.

Using a complex computer simulation, the researchers tested their model, and found that it should work, even when using less powerful lasers than previous proposals.

Not only would the collimation and acceleration of the positron beam improve the detection rate of the particles, but it bears a strong similarity to the powerful collimated particle jets beamed out by strongly magnetic, rapidly rotating neutron stars known as pulsars.

Scientists believe that processes that take place close to these stars could result in clouds of gamma radiation, similar to their proposed experiment.

https://www.nature.com/articles/s42005-021-00636-x

https://www.sciencealert.com/physicists-have-figured-out-how-we-cou...

Comment by Dr. Krishna Kumari Challa on July 28, 2021 at 9:50am

Fingertip-powered wearable

Comment by Dr. Krishna Kumari Challa on July 28, 2021 at 9:47am

'Good cholesterol' may protect liver

 The body's so-called good cholesterol may be even better than we realize. New research from Washington University School of Medicine in St. Louis suggests that one type of high-density lipoprotein (HDL) has a previously unknown role in protecting the liver from injury. This HDL protects the liver by blocking inflammatory signals produced by common gut bacteria. The study was published July 23 in the journal Science. HDL is mostly known for mopping up cholesterol in the body and delivering it to the liver for disposal. But in the new study, the researchers identified a special type of HDL called HDL3 that, when produced by the intestine, blocks gut bacterial signals that cause liver inflammation. If not blocked, these bacterial signals travel from the intestine to the liver, where they activate immune cells that trigger an inflammatory state, which leads to liver damage. Even though HDL has been considered good cholesterol,’ drugs that increase overall HDL levels have fallen out of favor in recent years because of clinical trials that showed no benefit in cardiovascular disease.  study suggests that raising levels of this specific type of HDL, and specifically raising it in the intestine, may hold promise for protecting against liver disease, which, like heart disease, also is a major chronic health problem.

Any sort of intestinal damage can impact how a group of microbes called Gram-negative bacteria can affect the body. Such microbes produce an inflammatory molecule called lipopolysaccharide that can travel to the liver via the portal vein. The portal vein is the major vessel that supplies blood to the liver, and it carries most nutrients to the liver after food is absorbed in the intestine. Substances from gut microbes may travel along with nutrients from food to activate immune cells that trigger inflammation. In this way, elements of the gut microbiome may drive liver disease, including fatty liver disease and liver fibrosis, in which the liver develops scar tissue.

https://researchnews.cc/news/8017/-Good-cholesterol--may-protect-li...

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Comment by Dr. Krishna Kumari Challa on July 28, 2021 at 9:39am

When our defences turn on us

When the body becomes the target of its own defensive arsenal, medicine must step in. This Nature Outlook explores why autoimmune disease is around three times more common in women than in men, the genetic variants that increase the risk of autoimmunity and how the microbes in our gut might sometimes be to blame. It also reveals how the possible links between long COVID and the immune system might finally prove that viruses can spark autoimmune disease.

Nature | Full collection

Comment by Dr. Krishna Kumari Challa on July 27, 2021 at 1:04pm

The Universe has an average colour – and it’s called cosmic latte

In a 2002 study, astronomers found that the light coming from galaxies (and the stars within them) – alongside all the visible clouds of gas and dust in the Universe – when averaged, would produce an ivory colour very close to white. They named this colour ‘cosmic latte’.

The ‘beigeness’ of the Universe is because there are slightly more regions that produce red, yellow and green light than those that produce blue. Averaged over the entire sky, however, this beige colour is diluted and appears almost, but not entirely, black.

https://www.sciencefocus.com/space/universe-average-colour-cosmic-l...

Comment by Dr. Krishna Kumari Challa on July 27, 2021 at 12:51pm

Acoustic Manipulation off a Reflective Surface

https://www.sciencealert.com/scientists-have-developed-a-new-way-to...

Comment by Dr. Krishna Kumari Challa on July 27, 2021 at 12:39pm

A Lagoon in Argentina Turned Bright Pink, But This Time The Reason Is Unnatural

A lagoon in Argentina's southern Patagonia region has turned bright pink in a striking, but frightful phenomenon experts and activists blame on pollution by a chemical used to preserve prawns for export.

The color is caused by sodium sulfite, an anti-bacterial product used in fish factories, whose waste is blamed for contaminating the Chubut river that feeds the Corfo lagoon and other water sources in the region, according to activists.

Residents have long complained of foul smells and other environmental issues around the river and lagoon.

Environmental engineer and virologist Federico Restrepo told AFP the coloration was due to sodium sulfite in fish waste, which by law, should be treated before being dumped.

https://www.sciencealert.com/prawn-chemical-turns-argentina-lake-br...

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Comment by Dr. Krishna Kumari Challa on July 27, 2021 at 11:52am

Innovative Gene Therapy ‘Reprograms’ Cells to Reverse Neurological Deficiencies

Comment by Dr. Krishna Kumari Challa on July 27, 2021 at 11:45am

COVID-19 immunity varies among genders and age groups

As experts continue to learn more about immune responses to COVID-19 and the effectiveness of vaccines, researchers.

 indicates that the level of antibodies changes according to age groups, gender, symptoms, and time elapsed since vaccination. The findings are the latest from the researchers in a series of studies aimed at providing reliable measures on the effectiveness of COVID-19 vaccination. The new study examined the level of antibodies in over 26,000 blood samples taken from COVID-19 convalescents, as well as vaccinated and unvaccinated individuals. In vaccinated individuals, the researchers found differences between women and men in the concentration of antibodies in the blood relative to both age and gender.

In women, the level of antibodies begins to rise from the age of 51, and is higher than the levels found in men of similar age. This phenomenon may be related change in levels of the estrogen hormone, observed around this age, which affects the immune system. In men, a rise in antibody levels is seen at an earlier age, starting around 35, and may be related to changes in levels of testosterone and the effect on the immune system.

In young adults, a high concentration of antibodies generally signals a strong healthy functioning immune response, while in older demographics it typically indicates overreaction of the immune system associated with severe illness. In general, young adults were found to have a higher level of antibodies sustained for a longer period of time compared to older vaccinated persons. The findings further validate existing evidence that, depending on age, higher antibody count isn't necessarily equivalent to higher rates of recovery.

Furthermore, the study found that the immune response of vaccinated individuals (after two doses) is much stronger than that of people who have recovered from COVID-19. The findings show that vaccinated individuals have four times the level of antibodies compared to convalescents.

https://www.medrxiv.org/content/10.1101/2021.07.07.21259499v1

https://english.tau.ac.il/news/covid_immunity_varies

Comment by Dr. Krishna Kumari Challa on July 27, 2021 at 11:20am

Plastic accumulation in food may be underestimated

A new study has found plastic accumulation in foods may be underestimated. There is also concern these microplastics will carry potentially harmful bacteria such as E. coli, which are commonly found in coastal waters, up the food chain.

Researchers  tested a theory that microplastics covered in a biofilm coating (much like natural algae) were more likely to be ingested by oysters than microplastics that were completely clean. Although the experiment was carried out on oysters under laboratory conditions, scientists believe similar results could be found in other edible marine species that also filter seawater for food.

Up until now, studies to test the impacts of microplastics on marine life have typically used clean, virgin microplastics. However, this is not representative of what happens to microplastics in the marine environment. Bacteria readily colonize microplastics that enter the ocean. In this study, published in Science of the Total Environment, scientists compared the uptake rates of clean microplastics versus microplastics with an E.coli biofilm coating. The results were worrying—oysters contained 10 times more microplastics when exposed to the biofilm coated beads. It is hypothesized that these coated MPs appeared to be more like food to the oysters, explaining their preferential ingestion over clean microplastics.

The scientists say the implications for the food chain are concerning. The ingestion of microplastics is not only bad for the oysters, but it affects human health too. The plastic does not break down in the marine animal and is consumed when we eat it.

The findings in this research give us further insight into the potential harm microplastics are having on the food chain. It demonstrates how we could be vastly underestimating the effect that microplastics currently have. It is clear that further study is urgently needed.

Monica Fabra et al, The plastic Trojan horse: Biofilms increase microplastic uptake in marine filter feeders impacting microbial transfer and organism health, Science of The Total Environment (2021). DOI: 10.1016/j.scitotenv.2021.149217

https://phys.org/news/2021-07-plastic-accumulation-food-underestima...

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