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Comment by Dr. Krishna Kumari Challa on April 4, 2023 at 11:47am

From yeast to mice, from mice to man: Senescent cells get noisier with age

Getting old seems completely avoidable in youth but becomes less and less so as we age. Many of the obstacles of advanced aging are well understood, including declining eyesight, hearing loss, back, neck and arthritic joint pains, shortness of breath, diabetes, Alzheimer's disease, dementia, cancer and stroke, just to name a few. What is less understood are the cellular-level molecular mechanisms responsible for our overall decline.

So researchers pursued an investigation into the chromatin-mediated loss of transcriptional fidelity during human cellular senescence. Their findings are described in an article titled "Spurious intragenic transcription is a feature of mammalian cellular senescence and tissue aging," published in the journal Nature Aging. 

Senescence is the step cells take when they determine it is best not to replicate, inhibiting the proliferation of abnormal cells by altering chromosomal configurations. Essentially as we age, our dividing cells accumulate mutations, little changes from one generation of cells to the next. Enough of these and the cell is at risk of being unsustainable or becoming a tumor cell. In this sense, senescence plays an essential role in limiting tumor progression.

Senescence is also a response to damage, allowing for the suppression of damaged or poorly repaired cells or damage of the telomeres. Accelerated accumulation of senescent cells with age is associated with various forms of disease—osteoarthritis, lung disease, Alzheimer's, dementia and cancer, to name a few.

Scientists found that during aging and senescence, cryptic transcription (proteins not normally produced) are suddenly created inside cells and that this is related to changes in the chromatin landscape. The study proposes that cryptic transcription is spurious and not created for a specific purpose. The noisy cryptic transcriptome then competes indirectly with coherent transcriptional networks by expending cells' energy on their production. Researchers saw no evidence of cryptic transcription being sensed as damage by the cell, nor do they think it is causative of senescence but simply a result of changes brought on by senescence.

The study, along with an experiment in mouse livers, builds on previous observations of cryptic transcription and indicates that this senescence  mechanism is conserved from yeast to mice and humans. The study also finds, similar to previous reports, that cryptic transcription tissue location is sex-dependent, as males and females will manifest spurious proteins in different cell types.

Payel Sen, Spurious intragenic transcription is a feature of mammalian cellular senescence and tissue aging, Nature Aging (2023). DOI: 10.1038/s43587-023-00384-3. www.nature.com/articles/s43587-023-00384-3

Isima, N., Gil, J. Spurious transcription may be a hallmark of aging. Nature Aging (2023). DOI: 10.1038/s43587-023-00398-x. www.nature.com/articles/s43587-023-00398-x

Comment by Dr. Krishna Kumari Challa on April 3, 2023 at 9:47am

Obesity treatment could offer dramatic weight loss without surgery ...

Imagine getting the benefits of gastric bypass surgery without going under the knife—a new class of compounds could do just that. In lab animals, these potential treatments reduce weight dramatically and lower blood glucose. The injectable compounds also avoid the side effects of nausea and vomiting that are common with current weight-loss and diabetes drugs. Now, scientists report that the new treatment not only reduces eating but also boosts calorie burn.

ACS Spring 2023: Peptide triagonists of the GLP-1-, neuropeptide Y1- and neuropeptide Y2- receptors for glycemic control and weight loss, www.acs.org/meetings/acs-meetings/spring-2023.html

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Time-restricted eating vs. daily calorie restriction in reducing no...

Adults with obesity and nonalcoholic fatty liver disease did not see additional reductions in intrahepatic triglyceride while on a time-restricted eating regimen compared to subjects on a daily calorie-restriction diet. This is according to a recent study published in the journal JAMA Network Open and led by researchers at Southern Medical University in Guangzhou, China and colleagues in the US at Tulane University School of Public Health and Tropical Medicine in New Orleans.

Xueyun Wei et al, Effects of Time-Restricted Eating on Nonalcoholic Fatty Liver Disease, JAMA Network Open (2023). DOI: 10.1001/jamanetworkopen.2023.3513

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Study finds harmful PFAS don't actually prevent furniture stains

The health and environmental harms of per- and polyfluoroalkyl substances (PFAS) are well-known, but a new study calls into question their touted stain-fighting benefits. The study, published today in the AATCC Journal of Research, tested the performance of PFAS finishings on furniture fabrics and found that they had limited to no effectiveness, particularly under real-world conditions.

Comment by Dr. Krishna Kumari Challa on April 2, 2023 at 1:43pm

Photosynthetic Sea Slugs 

Comment by Dr. Krishna Kumari Challa on April 2, 2023 at 1:42pm

Crystallised intelligence (the ability to accumulate knowledge, facts and skills) 

Fluid intelligence (the ability to reason and think flexibly)

Comment by Dr. Krishna Kumari Challa on April 1, 2023 at 12:35pm

Neck cracking

It is thought that one of the most common causes of neck ‘cracking’ is gas bubbles in the synovial fluid escaping a tight space. This synovial fluid

is a lubricant between the joints, formed by a combination of carbon dioxide, nitrogen and oxygen.

If you deliberately roll your neck, it is thought that you can sometimes release these bubbles, resulting in a series of popping sounds that may sound like cracking. The release of the gas build-up explains why muscles or joints often feel looser and more comfortable after they’ve been ‘popped’ or ‘cracked’.

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Our joints contain synovial fluid, a sac of liquid which acts as a lubricant, protecting bones from grinding against each other. When someone cracks their knuckles, they increase the space in the joint, causing bubbles of gas (think oxygen, nitrogen and carbon dioxide) to form in the fluid. It’s the popping of these bubbles that make the cracking noise.

While it may sound worrying, there isn’t actually much evidence to suggest this is dangerous – or increases the risk of getting arthritis. The most important risk factors for developing arthritis are family history, age, gender, joint injury, and lifestyle elements such as smoking and obesity.

It is true that people with arthritis sometimes find their joints crack, but this is because their cartilage has already been damaged. Cracking isn’t usually the most common symptom of arthritis, either.

Although there are isolated reports of self-injury caused from cracking knuckles, such as sprained ligaments, these are very rare. You’re much more likely to harm yourself by cracking joints in your spine and neck, which are surrounded by important blood vessels.

Comment by Dr. Krishna Kumari Challa on April 1, 2023 at 11:54am

Gigapixel 3D Microscope Captures Life in Unprecedented Detail

A new kind of microscope that stitches together videos from dozens of smaller cameras can provide researchers with 3D views of their experiments. Whether recording 3D movies of the behavior of dozens of freely swimming zebrafish or the grooming activity of fruit flies at near cellular-level detail across a very wide field of view, the device is opening new possibilities to researchers the world over. Learn more at https://www.pratt.duke.edu/about/news...

Comment by Dr. Krishna Kumari Challa on April 1, 2023 at 11:48am

Scientists have found microplastic pollution in krill and salps from the Southern Ocean. A new study led by researchers at British Antarctic Survey shares important evidence that these animals, as well as other zooplankton, ingest plastic in their natural environment. Krill and salps are vital food sources to much of the Southern Ocean’s wildlife as well as helping to trap carbon from the atmosphere in the deep ocean. The impact of the microplastics in this environment is not fully understood and could interfere with their ability to trap carbon as well as getting transferred up the food chain to animals such as whales and penguins. The team found plastics in most krill and salp samples with the most common type being nylon, a fibre with wider ranging applications from clothing to car tires. ➡ Read this news story on the British Antarctic Survey website: https://www.bas.ac.uk/media-post/micr...

Part 2

Comment by Dr. Krishna Kumari Challa on April 1, 2023 at 11:48am

Microplastic found in Antarctic krill and salps

A new study by researchers discovered microplastics in krill (Euphausia superba), a small shrimp-like crustacean, and salps (Salpa thompsoni), a gelatinous marine invertebrate. The results were published in the journal Royal Society Open Science.

While Antarctic krill have been observed ingesting microplastics in laboratory settings, the team's findings provide important evidence that these animals, as well as other zooplankton, ingest plastic in their natural environment.

Microplastics are present in the Southern Ocean from the sea surface to seabed. Due to the small size of these particles (<5 mm), Antarctic zooplankton are likely to mistake the plastics for their natural food source. The team focused on two of the most abundant species of Southern Ocean zooplankton: Antarctic krill, and salps. These two species are critical to the diet of much of the Southern Ocean's marine wildlife. Krill is the main food source for whales, penguins, and seals while salps are eaten by some fish and larger marine birds.

Krill and salp samples were collected onboard the research ship RRS James Clark Ross on two research missions off the Northern tip of the Antarctic Peninsula in 2016 and near the island of South Georgia in 2018. Microplastics were extracted from both species with plastic microfibers most common. One of the largest sources of these fibers is shedding from clothing during washing and drying. Around 60% of the krill and salps contained nylon, a microplastic with significant commercial applications in clothing, fishing gear, ropes, and reinforcing car tires.

The findings underline how sensitive the Antarctic marine ecosystem is to plastic pollution. Due to the short food chains in the Antarctic, transfer of these microplastics from the krill to larger predators such as whales, penguins, and seals is highly likely. Plastic in krill and salps could also negatively impact the Southern Ocean as one of the planets largest carbon sinks.

Comment by Dr. Krishna Kumari Challa on April 1, 2023 at 11:15am

Ban On Tattoo Ink: Breaking Down the Chemistry

Comment by Dr. Krishna Kumari Challa on April 1, 2023 at 10:12am

Scientists observe flattest explosion ever seen in space

An explosion the size of our solar system has baffled scientists, as part of its shape—similar to that of an extremely flat disk—challenges everything we know about explosions in space.

The explosion observed was a bright Fast Blue Optical Transient (FBOT)—an extremely rare class of explosion which is much less common than other explosions, such as supernovas. The first bright FBOT was discovered in 2018 and given the nickname "the cow."

Explosions of stars in the universe are almost always spherical in shape, as the stars themselves are spherical. However, this explosion, which occurred 180 million light years away, is the most aspherical ever seen in space, with a shape like a disk emerging a few days after it was discovered. This section of the explosion may have come from material shed by the star just before it exploded.

It's still unclear how bright FBOT explosions occur, but it's hoped that this observation, published in Monthly Notices of the Royal Astronomical Society, will bring us closer to understanding them.

Justyn R Maund et al, A flash of polarized optical light points to an aspherical 'cow', Monthly Notices of the Royal Astronomical Society (2023). DOI: 10.1093/mnras/stad539

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