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Comment by Dr. Krishna Kumari Challa on March 29, 2022 at 12:22pm

Study shows advances in street lighting are reducing the efficacy of coastal species' camouflage

Species that rely on darkness to forage and feed are losing the gift of camouflage thanks to advances in the lighting used to illuminate the world's cities and coastlines, a study has shown.

It is one of the first to examine the potential for artificial light at night (ALAN) to affect the camouflage mechanisms of coastal species.

The worldwide proliferation of energy efficient broad spectrum lighting has the potential to disrupt an array of visually guided ecological processes.

New research has demonstrated that these new lighting technologies can significantly improve a predator's ability to discriminate prey species against a natural background.

The magnitude of this effect varies depending on an organism's color, meaning certain color variations may be at greater risk.

For this study, scientists used a well-established model to determine the conspicuousness of three distinct color morphs of Littorinid snail found commonly along the world's coastlines.

They compared how the species appeared to three common coastal predators when illuminated by different forms of lighting. This included 20th century narrow spectrum Low Pressure Sodium (LPS) lighting, three types of modern broad spectrum lighting—High Pressure Sodium (HPS); Light Emitting Diodes (LEDs); and Metal Halide (MH) – and the natural light provided by the sun and moon.

Under LPS lighting, all snails were effectively camouflaged. However, when illuminated by LEDs, MH, the sun or the moon, yellow snails were significantly more visible compared to brown and olive ones in the majority of cases.

This study clearly indicates that new lighting technologies will increase the conspicuousness of prey species by reducing the efficacy of their camouflage. Our findings revealed that species of Littorinid snails found commonly on our coastlines will remain camouflaged when illuminated by older style lighting. However, when illuminated by modern broad spectrum lighting, they are clearly visible to predators and at far greater long-term risk as a result.

Oak McMahon et al, Broad spectrum artificial light at night increases the conspicuousness of camouflaged prey, Journal of Applied Ecology (2022). DOI: 10.1111/1365-2664.14146

https://phys.org/news/2022-03-advances-street-efficacy-coastal-spec...

Comment by Dr. Krishna Kumari Challa on March 29, 2022 at 8:55am

New Kind of Ultraviolet Light Safely Kills Airborne Pathogens Indoors

A type of ultraviolet light called Far-UVC could dramatically change how we combat the transmission of airborne pathogens in indoor environments, scientists report in a new study.

Researchers say the technology represents a new 'hands off' way of curbing the spread of COVID-19, compared to existing control measures that involve significant changes in people's behavior – such as abiding by lockdowns, physical distancing, mask-wearing, or getting vaccinated.

In contrast to the challenges of these effective but often unpopular measures, installing Far-UVC lighting in indoor environments could be about as easy as changing a light bulb, scientists say – and the effectiveness of the device's antimicrobial radiation is no less impressive.

"Far-UVC rapidly reduces the amount of active microbes in the indoor air to almost zero, making indoor air essentially as safe as outdoor air.

While the germicidal properties of ultraviolet C light (UVC) have been known for decades, the radiation's ability to cause sunburn, skin cancer, and harm people's eyes have led to strict controls on its usage, with UVC mostly limited to sterilizing medical equipment.

However, in more recent times, research into shorter-wavelength Far-UVC emitters (aka Krypton Chloride or KrCl excimer lamps) suggests that this subset of the UVC spectrum doesn't pose safety risks to mouse or human skin cells, while retaining the ability to kill airborne pathogens.

According to the team, the Far-UVC lamps reduced up to 98.4 percent of the pathogen load in a matter of minutes, and maintained an ambient level of 92 percent reduction . Using this technology in locations where people gather together indoors could prevent the next potential pandemic.

https://www.nature.com/articles/s41598-022-08462-z

https://www.sciencealert.com/new-kind-of-ultraviolet-light-safely-k...

Comment by Dr. Krishna Kumari Challa on March 26, 2022 at 11:23am

"The patient's clinical process was quite interesting," the authors of the new report wrote. "The lesions only appeared after immersion in water, disappeared about 30 minutes after drying, and no lesions occurred with the absence of water contact."

These short-lived symptoms are a telltale sign of ASA known as "hand in the bucket sign."

https://jamanetwork.com/journals/jamadermatology/article-abstract/2...

https://www.livescience.com/excessive-wrinkling-young-man-case-report

Part 2

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Comment by Dr. Krishna Kumari Challa on March 26, 2022 at 11:22am

Young Man Has 'Excessive' Skin Wrinkling From Water in Incredibly Rare Medical Case

A man in his 20s developed "excessive wrinkling"; bright, white bumps; and patches of thick skin on his hands whenever he immersed them in water. Doctors initially thought the condition might be a symptom of chronic eczema, but they later determined that the wrinkling was caused by a rare skin disease, according to a new report of his case.  

The disease, known as aquagenic syringeal acrokeratoderma (ASA), mostly occurs in young women, according to the report, which was published Wednesday (March 23) in the journal JAMA Dermatology.

It's also fairly common in people with cystic fibrosis, a genetic disorder that affects hormone-producing glands in the body and causes mucus-producing organs to produce abnormally thick, sticky mucus, according to the Genetic and Rare Diseases Information Center (GARD). 

People with cystic fibrosis carry two defective copies of the cystic fibrosis transmembrane conductance regulator (CFTR) gene, but even people who have just one copy of this gene and who don't have cystic fibrosis are prone to the condition, which hints that ASA may be partially caused by a genetic mutation.

That said, the exact cause of ASA is unknown, but theories suggest that the condition may have something to do with abnormal sweat glands, according to GARD.

In the case of the young man with wrinkly hands, he reported to the dermatology department at The First Hospital of China Medical University in Shenyang after having experienced this condition for three years. The skin of his hands would become thick, swollen, wrinkly and scaly after being in water, and these changes would be accompanied by an itchy, burning sensation.

Although the ASA symptoms initially affected only his hands, the man noted that, in the past year and a half or so, the condition had also spread to his wrists and elbows.

"He attributed these changes to the need for washing hands frequently in the period of the COVID-19 epidemic," doctors wrote in the report. Upon closer examination, the doctors determined that the sweat glands and pores on the man's hands would become unusually large and dilated after exposure to water.

Part 1

Comment by Dr. Krishna Kumari Challa on March 26, 2022 at 11:04am

How the gut communicates with the brain

New research has discovered how the enteric nervous system -- or 'second brain' -- can communicate with both the brain and spinal cord, which up until now had remained a major mystery. The study found specialized cells within the gut wall release serotonin when stimulated by food, which then acts on the nerves to communicate with the brain. The authors say as there is a direct connection between serotonin levels in our body and depression and how we feel, understanding how the gut communicates with the brain is of major importance.

Kelsi Nicole Dodds, Lee Travis, Melinda A. Kyloh, Lauren A Jones, Damien John Keating, Nick J Spencer. The gut-brain axis: spatial relationship between spinal afferent nerves and 5-HT-containing enterochromaffin cells in mucosa of mouse colon. American Journal of Physiology-Gastrointestinal and Liver Physiology, 2022; DOI: 10.1152/ajpgi.00019.2022

https://www.sciencedaily.com/releases/2022/03/220323130316.htm

Comment by Dr. Krishna Kumari Challa on March 26, 2022 at 9:39am

TB antibiotic activity impacted by cell pH

Researchers have shown that an antibiotic used to treat tuberculosis (TB) is affected by pH levels in the environment the bacteria has infected.

On infection with TB, the bacteria enter into a type of immune cell, called macrophages. One of the defense mechanisms these cells use is creating an acidic environment to kill the infecting agent.

In their study, published in mBio on World TB Day (24 March), the researchers developed a fluorescence-based imaging technique to study the effects of this acidic environment on both the bacteria and antibiotics. Using this approach, they were able to monitor, in real-time, the effects of changes in pH levels.

By experimentally changing pH levels in infected cells, they found that TB is able to maintain and regulate its own pH independently of the pH of the macrophage, providing a defense against the immune system.

The researchers then tested whether four front-line TB antibiotic treatments are affected by different acidity levels. They found that one antibiotic often used as part of the TB treatment regime, pyrazinamide, is only effective within an acidic environment.

Pierre Santucci et al, Visualizing Pyrazinamide Action by Live Single-Cell Imaging of Phagosome Acidification and Mycobacterium tuberculosis pH Homeostasis, mBio (2022). DOI: 10.1128/mbio.00117-22

https://phys.org/news/2022-03-tb-antibiotic-impacted-cell-ph.html?u...

Comment by Dr. Krishna Kumari Challa on March 26, 2022 at 9:22am

Scientists find microplastics in blood for first time

Scientists have discovered microplastics in human blood for the first time, warning that the ubiquitous particles could also be making their way into organs.

The tiny pieces of mostly invisible plastic have already been found almost everywhere else on Earth, from the deepest oceans to the highest mountains as well as in the air, soil and food chain.

A Dutch study published in the Environment International journal on Thursday examined blood samples from 22 anonymous, healthy volunteers and found microplastics in nearly 80 percent of them.

Half of the blood samples showed traces of PET plastic, widely used to make drink bottles, while more than a third had polystyrene, used for disposable food containers and many other products.

This is the first time scientists have actually been able to detect and quantify such microplastics in human blood.

This is proof that we have plastics in our body—and we shouldn't. It impacts our health.

The study said the microplastics could have entered the body by many routes: via air, water or food, but also in products such as particular toothpastes, lip glosses and tattoo ink.

Heather A. Leslie et al, Discovery and quantification of plastic particle pollution in human blood, Environment International (2022). DOI: 10.1016/j.envint.2022.107199

https://phys.org/news/2022-03-scientists-microplastics-blood.html?u...

Comment by Dr. Krishna Kumari Challa on March 26, 2022 at 9:18am

Comment by Dr. Krishna Kumari Challa on March 26, 2022 at 9:15am

New technique transplants mitochondria from one living cell to another

In a technological breakthrough, researchers  have announced the development of a new technique that can transplant mitochondria—the tiny powerhouses of the cell—from one living cell to another with unparalleled efficiency.

Just as the human body can be divided into different organs—such as the heart, lungs, kidneys, intestine or liver—our cells also consist of several complementary and interdependent systems. These are referred to as organelles, meaning small organs. And much as we are sometimes able to add several decades to the life of a patient with kidney disease by transplanting a healthy kidney, we may one day also be able to rejuvenate individual cells by transplanting cell components.

New findings  suggest that it has now reached the point of technical feasibility. In their research, recently published in the journal PLOS Biology, the researchers successfully used a "nanosyringe" they had previously developed to transplant mitochondria from one living cell to another.

Using cylindrical nanosyringes that were specially developed for this study, the researchers pierced the cell membrane and sucked up the spherical mitochondria. They then pierced the membrane of a different cell and pumped the mitochondria back out of the nanosyringe into the recipient cell.

The position of the nanosyringe is controlled by laser light from a converted atomic force microscope. A pressure regulator adjusts the flow, allowing scientists to transfer incredibly small volumes of fluid in the femtolitre range (millionths of a millionth of a milliliter) during organelle transplants. "Both the donor and acceptor cells survive this minimally invasive procedure.

The transplanted mitochondria also have a high survival rate—more than 80 percent. In most cells, the injected mitochondria begin to fuse with the filamentous network of the new cell 20 minutes after transplantation. The host cell accepts them. This holds true in most cases, though in a few cells they fall victim to the host cell's quality control system and are degraded.

 It is conceivable that it could be used to rejuvenate stem cells, which exhibit a decline in metabolic activity as they age. 

Christoph G. Gäbelein et al, Mitochondria transplantation between living cells, PLOS Biology (2022). DOI: 10.1371/journal.pbio.3001576

https://phys.org/news/2022-03-technique-transplants-mitochondria-ce...

Comment by Dr. Krishna Kumari Challa on March 26, 2022 at 8:42am

New study reveals why HIV remains in human tissue even after antiretroviral therapy

Thanks to antiretroviral therapy, HIV infection is no longer the life sentence it once was. But despite the effectiveness of drugs to manage and treat the virus, it can never be fully eliminated from the human body, lingering in some cells deep in different human tissues where it goes unnoticed by the immune system.

Now, new research  reveals a possible answer to the mystery of why infected people can't get rid of HIV altogether. 

The study found that in HIV patients, killer T cells—a type of white blood cells responsible for identifying and destroying cells infected with viruses—have very little to none of a protein called CD73.

Because CD73 is responsible for migration and cell movement into the tissue, the lack of the protein compromises the ability of killer T cells to find and eliminate HIV-infected cells. This mechanism explains one potential reason for why HIV stays in human tissues forever.

Following extensive studies, researchers discovered that chronic inflammation results in increased levels of a type of RNA found in cells and in blood, called microRNAs. These are very small types of RNA that can bind to messenger RNAs to block them from making CD73 protein. It was  found that this was causing the CD73 gene to be suppressed.

The team's discovery also helps explain why people with HIV have a lower risk of developing multiple sclerosis,

This provides us the opportunity to come up with potential new treatments that would help killer T cells migrate better to gain access to the infected cells in different tissues.

Shima Shahbaz et al, Elevated ATP via enhanced miRNA-30b, 30c, and 30e downregulates the expression of CD73 in CD8+ T cells of HIV-infected individuals, PLOS Pathogens (2022). DOI: 10.1371/journal.ppat.1010378

https://medicalxpress.com/news/2022-03-reveals-hiv-human-tissue-ant...

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