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Comment by Dr. Krishna Kumari Challa on February 7, 2023 at 9:23am

Scientists detect molten rock layer hidden under Earth's tectonic plates

Scientists have discovered a new layer of partly molten rock under the Earth's crust that might help settle a long-standing debate about how tectonic plates move.

Researchers had previously identified patches of melt at a similar depth. But a new study  revealed for the first time the layer's global extent and its part in plate tectonics.

The molten layer is located about 100 miles from the surface and is part of the asthenosphere, which sits under the Earth's tectonic plates in the upper mantle. The asthenosphere is important for plate tectonics because it forms a relatively soft boundary that lets tectonic plates move through the mantle.

The reasons why it is soft, however, are not well understood. Scientists previously thought that molten rocks might be a factor. But this study shows that melt, in fact, does not appear to notably influence the flow of mantle rocks.

The convection of heat and rock in the mantle are the prevailing influence on the motion of the plates. Although the Earth's interior is largely solid, over long periods of time, rocks can shift and flow like honey.

Showing that the melt layer has no influence on plate tectonics means one less tricky variable for computer models of the Earth.

Junlin Hua, Asthenospheric low-velocity zone consistent with globally prevalent partial melting, Nature Geoscience (2023). DOI: 10.1038/s41561-022-01116-9. www.nature.com/articles/s41561-022-01116-9

Comment by Dr. Krishna Kumari Challa on February 6, 2023 at 11:55am

In the new study, teh researchers delved further into this activation failure, which occurs in the lymph nodes, which filter fluids that drain from nearby tissues. The lymph nodes are where “killer T cells” encounter dendritic cells, which present antigens (tumor proteins) and help to activate the T cells.

To explore why some killer T cells fail to be properly activated, researchers studied mice that had tumors implanted either in the lungs or in the flank. All of the tumors were genetically identical.

The researchers found that T cells in lymph nodes that drain from the lung tumors did encounter dendritic cells and recognize the tumor antigens displayed by those cells. However, these T cells failed to become fully activated, as a result of inhibition by another population of T cells called regulatory T cells.

These regulatory T cells became strongly activated in lymph nodes that drain from the lungs, but not in lymph nodes near tumors located in the flank, the researchers found. Regulatory T cells are normally responsible for making sure that the immune system doesn’t attack the body’s own cells. However, the researchers found that these T cells also interfere with dendritic cells’ ability to activate killer T cells that target lung tumors.

The researchers also discovered how these regulatory T cells suppress dendritic cells: by removing stimulatory proteins from the surface of dendritic cells, which prevents them from being able to turn on killer-T-cell activity.

Further studies revealed that the activation of regulatory T cells is driven by high levels of interferon gamma in the lymph nodes that drain from the lungs. This signaling molecule is produced in response to the presence of commensal bacterial — bacteria that normally live in the lungs without causing infection.

The researchers have not yet identified the types of bacteria that induce this response or the cells that produce the interferon gamma, but they showed that when they treated mice with an antibody that blocks interferon gamma, they could restore killer T cells’ activity.

Interferon gamma has a variety of effects on immune signaling, and blocking it can dampen the overall immune response against a tumor, so using it to stimulate killer T cells would not be a good strategy to use in patients.

Researchers are now exploring other ways to help stimulate the killer T cell response, such as inhibiting the regulatory T cells that suppress the killer-T-cell response or blocking the signals from the commensal bacteria, once the researchers identify them.

Maria Zagorulya, Leon Yim, et al. Tissue-specific abundance of interferon-gamma drives regulatory T cells to restrain DC1-mediated priming of cytotoxic T cells against lung cancer. Immunity. DOI: 10.1016/j.immuni.2023.01.010

Part 2

Comment by Dr. Krishna Kumari Challa on February 6, 2023 at 11:52am

Why lung cancer doesn't respond well to immunotherapy

Immunotherapy — drug treatment that stimulates the immune system to attack tumors — works well against some types of cancer, but it has shown mixed success against lung cancer.

A new study helps to shed light on why the immune system mounts such a lackluster response to lung cancer, even after treatment with immunotherapy drugs. In a study of mice, the researchers found that bacteria naturally found in the lungs help to create an environment that suppresses T-cell activation in the lymph nodes near the lungs.

The researchers did not find that kind of immune-suppressive environment in lymph nodes near tumours growing near the skin of mice. They hope that their findings could help lead to the development of new ways to rev up the immune response to lung tumours.

There is a functional difference between the T-cell responses that are mounted in the different lymph nodes. Researchers are hoping to identify a way to counteract that suppressive response, so that they can reactivate the lung-tumor-targeting T cells.
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For many years, scientists have known that cancer cells can send out immunosuppressive signals, which leads to a phenomenon known as T-cell exhaustion. The goal of cancer immunotherapy is to rejuvenate those T cells so they can begin attacking tumors again.

One type of drug commonly used for immunotherapy involves checkpoint inhibitors, which remove the brakes on exhausted T cells and help reactivate them. This approach has worked well with cancers such as melanoma, but not as well with lung cancer.

Recent research work has offered one possible explanation for this: Researchers found that some T cells stop working even before they reach a tumor, because of a failure to become activated early in their development. In a 2021 paper, they identified populations of dysfunctional T cells that can be distinguished from normal T cells by a pattern of gene expression that prevents them from attacking cancer cells when they enter a tumor.

“Despite the fact that these T cells are proliferating, and they’re infiltrating the tumor, they were never licensed to kill”.
Part 1

Comment by Dr. Krishna Kumari Challa on February 6, 2023 at 11:43am

Genes decide the willow warbler's migration routes

Since antiquity, humans have been fascinated by birds’ intercontinental migratory journeys. A new study shows that two areas in their genome decide whether a willow warbler flies across the Iberian Peninsula to western Africa, or across the Balkans to eastern and southern Africa.

Researchers have long known that the behaviour that causes songbirds to migrate in a specific direction towards a remote winter location is something they are born with. The recent study aims to further understanding of the genetics behind this behaviour. With the help of modern technology, and 20 years of research into the genetics of songbirds and their migration routes, the researchers managed to identify which parts of the genome that determine the songbirds’ routes.

“The songbirds’ direction of travel is determined by two areas in the genome. Genes from the southern subspecies take the bird towards the southwest, across the Iberian peninsula to their wintering grounds in western Africa. Genes belonging to the northern subspecies instead lead the willow warblers towards the southeast, over the Balkans, to locations in eastern and southern Africa, according to the study.

Researchers have previously assumed that interbreeding between subspecies that move in different directions would result in offspring that migrate in a direction in between these two. For willow warblers, this would mean a route straight over the Mediterranean and the Sahara, with probable higher mortality than if they flew west or east of that route. Instead, researchers discovered that crosses between northern and southern willow warblers usually migrate like one or other of the subspecies. The price of interbreeding, then, is lower than researchers previously thought. 

Researchers are surprised that such complex behaviour as variations in migratory patterns can to such a large extent be explained by just two genetic areas.

Knowledge of the willow warbler’s behaviour also helps us to understand how different species’ spectacular migratory patterns have developed through evolution. Climate change means that many species are being forced to alter their routes when the habitats they are adapted to change. The more we know about the genetics of migration, the better understanding we will gain of the birds’ capacity to adapt their migration patterns in response to climate change.

Kristaps Sokolovskis et al, Migration direction in a songbird explained by two loci, Nature Communications (2023). DOI: 10.1038/s41467-023-35788-7

Comment by Dr. Krishna Kumari Challa on February 6, 2023 at 9:26am

Will revitalizing old blood slow aging?

Young blood has a rejuvenating effect when infused into older bodies, according to recent research: Aging hearts beat stronger, muscles become stronger, and thinking becomes sharper.

Many scientists are looking for the elements of young blood that can be captured or replicated and put into a pill. But what if the best way to get the benefits of young blood is to simply rejuvenate the system that makes blood?

An aging blood system, because it's a vector for a lot of proteins, cytokines, and cells, has a lot of bad consequences for the organism. A 70-year-old with a 40-year-old blood system could have a longer healthspan, if not a longer lifespan. Rejuvenating an older person's blood may now be within reach, based on recent findings according to a paper published in Nature Cell Biology.

According to new research ,  an anti-inflammatory drug, already approved for use in rheumatoid arthritis, can turn back time in mice and reverse some of the effects of age on the hematopoietic system. These results indicate that such strategies hold promise for maintaining healthier blood production in the elderly.

The researchers only identified the drug after a comprehensive investigation of the stem cells that create all blood cells and the niches where they reside in the center of the bones.

All blood cells in the body are created by a small number of stem cells that reside in bone marrow. Over time, these hematopoietic stem cells start to change: They produce fewer red blood cells (leading to anemia) and fewer immune cells (which raises the risk of infection and impedes vaccination efforts), and they have trouble maintaining the integrity of their genomes (which can lead to blood cancers).

The researchers first tried to rejuvenate old hematopoietic stem cells, in mice, with exercise or calorie-restricting diet, both generally thought to slow the aging process. Neither worked. Transplanting old stem cells into young bone marrow also failed. Even young blood had no effect on rejuvenating old blood stem cells.

They then took a closer look at the stem cells' environment, the bone marrow. Blood stem cells live in a niche; they thought what happens in this specialized local environment could be a big part of the problem. 

With new techniques developed  that enable detailed investigation of the bone marrow milieu, the researchers found that the aging niche is deteriorating and overwhelmed with inflammation, leading to dysfunction in the blood stem cells. One inflammatory signal released from the damaged bone marrow niche, IL-1B, was critical in driving these aging features, and blocking it with the drug anakinra remarkably returned the blood stem cells to a younger, healthier state. Even more youthful effects on both the niche and the blood system occurred when IL-1B was prevented from exerting its inflammatory effects throughout the animal's life.

The researchers are now trying to learn if the same processes are active in humans and if rejuvenating the stem cell niche earlier in life, in middle age, would be a more effective strategy. Meanwhile, "treating elderly patients with anti-inflammatory drugs blocking IL-1B function should help with maintaining healthier blood production".

Carl A. Mitchell et al, Stromal niche inflammation mediated by IL-1 signalling is a targetable driver of haematopoietic ageing, Nature Cell Biology (2023). DOI: 10.1038/s41556-022-01053-0

Comment by Dr. Krishna Kumari Challa on February 4, 2023 at 12:54pm

Bird flu detected in mammals but risk to humans low: experts

Experts have warned that the recent detection of bird flu in mammals including foxes, otters, minks, seals and even grizzly bears is concerning but emphasized that the virus would have to significantly mutate to spread between humans.

It is rare that bird flu jumps over into mammals—and rarer still that humans catch the potentially deadly virus.

However two recent larger scale infections have raised concerns that bird flu has the potential to spread between mammals.

One was an outbreak of H5N1 with the PB2 mutation at a Spanish farm in October that led to the culling of more than 50,000 minks.

Transmission between the minks has not been confirmed, with further research ongoing.

The mass death of some 2,500 endangered seals found along Russia's Caspian Sea coast last month has also raised concern.

But it was always concerning when a flu virus enters mammals "because they're often the mixing point of influenza viruses, or they create an environment where mutations can occur and then can become adapted in humans".

If H5N1 did mutate into a strain that could circulate among humans, the current seasonal flu vaccine could be fairly easily updated to include it.

Over the last two decades, there have been 868 confirmed H5N1 cases in humans with 457 deaths, according to the World Health Organization. There were four confirmed cases and one death last year.

Last month, Ecuador reported South America's first case of the A(H5) bird flu virus in a human—a nine-year-old girl who was in contact with backyard poultry.

The experts called for continued surveillance of avian influenza in wild birds, poultry and mammals, in order for humans to limit their exposure.

source: AFP

Comment by Dr. Krishna Kumari Challa on February 4, 2023 at 12:48pm

Rocket industry could undo decades of work to save the ozone layer

The ozone layer is on track to heal within four decades, according to a recent UN report, but this progress could be undone by an upsurge in rocket launches expected during the same period.

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Rates of hatching failure in birds almost twice as high as previous...

Hatching failure rates in birds are almost twice as high as experts previously estimated, according to the largest ever study of its kind by researchers 

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How long does COVID immunity last?

How quickly does immunity from vaccination, infection with SARS-CoV-2, or a combination of the two, wane? Studies from Portugal, Israel, Sweden and Qatar have offered clues, but the real answer is: it’s complicated. ‘Hybrid’ immunity gained from vaccination and infection provides some protection against reinfection for around eight months, longer than immunity acquired from a booster alone. But the emergence of new variants makes it hard to determine the role of immune evasion. One study suggests that immunity against reinfection could last up to three years — if the virus does not mutate. The data make it difficult to predict when new surges of infections might occur — or when to schedule booster shots.

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Using muon detectors to remotely create a 3D image of the inside of...

A team of physicists affiliated with several institutions in France has developed a way to use muon detectors to create 3D images of difficult-to-access objects, such as a reactor inside a nuclear plant. The research is published in the journal Science Advances.

Comment by Dr. Krishna Kumari Challa on February 4, 2023 at 12:47pm

Coffee can pollute too!

Caffeine is an emerging global pollutant. It enters our waterways through the wastewater system, and impacts water quality and marine life. And while coffee grounds are often used as a soil amendment, caffeine is a killer for emerging seedlings.

But there are things consumers can do to reduce the pollution; some are listed  below. And scientists are looking at innovative strategies for removing the contamination.

Five ways to clean up your caffeine habit

1. Stop drinking caffeinated beverages

Since at least 90% of adults drink coffee, tea or energy drinks regularly, I imagine some of you are laughing (or crying) right now. So consider reducing your consumption, and move on to No. 2.

2. Reuse and recycle

Some businesses, artists and engineers are finding creative ways to reuse and recycle grounds. For example, companies in the United Kingdom are collecting coffee pulp and spent grounds to use in textiles, ink, aromatics, and biofuels. Coffee shops and manufacturers could partner with such companies to reuse their coffee waste.

3. Don't dump spent grounds or leftover drink down the sink

Compost or dispose of grounds in the trash rather than send caffeine down the drain and into the wastewater system.

4. Reduce plastic pollution, too

The plastic and disposable cups that often go with caffeine habits is a different but related type of pollution we can reduce. Remember to bring your own cup to the café, or use one of the many low-waste techniques of brewing at home.

5. Support government funding to update sewage facilities

"Investing in outdated treatment plants is how we can actually solve it," Subuyuj said. "In the U.S., outdated water treatment plants, especially in bigger cities, is the main source of caffeine entering waterways. That would also reduce other contaminants to the environment, like heavy metals and microplastics."

Comment by Dr. Krishna Kumari Challa on February 4, 2023 at 12:43pm

Genetic analysis can reduce adverse drug reactions by 30%

Patients can experience 30% fewer serious adverse reactions if their drugs are tailored to their genes, reports a study published in The Lancet. A European collaboration research suggests that a genetic analysis prior to drug therapy could significantly reduce suffering and health care costs.

A significant proportion of patients experience adverse reactions to their medication. Since we each carry a unique set of genes, we react differently to the same drugs. For example, some people break them down faster, meaning that they require a higher dose to obtain the desired effect.

To overcome this problem, researchers have developed the principle for a "DNA pass" that has been clinically validated in the recently published study.

It's basically a credit card-sized card with a magnetic strip containing all the important genetic data on a particular patient. When a patient's card is scanned, doctors and pharmacists can work out the optimal dose of a drug for that particular individual.

The study included almost 7,000 patients from seven European countries between March 2017 and June 2020 all of whom were genotyped with respect to variations in twelve specific genes of significance to drug metabolism, transport and side-effects. All participants then received their drugs either conventionally or with a genotype-based modification.

Twelve weeks after their drug regimen began, the patients were contacted by a specialist nurse about any adverse reactions, such as diarrhea, pain or loss of taste. The study concluded that such adverse reactions to drugs can be greatly reduced by analyzing the genes that code for enzymes that metabolize them.

The patients who'd received genotype-driven treatment had, on average, 30% fewer adverse reactions than the controls in the study.

Jesse J Swen et al, A 12-gene pharmacogenetic panel to prevent adverse drug reactions: an open-label, multicentre, controlled, cluster-randomised crossover implementation study, The Lancet (2023). DOI: 10.1016/S0140-6736(22)01841-4

Comment by Dr. Krishna Kumari Challa on February 4, 2023 at 12:21pm

Here is another reason to stop wars and voilence : Life in a violent country can be years shorter and much less predictable, even for those not involved in conflict

How long people live is less predictable and life expectancy for young people can be as much as 14 years shorter in violent countries compared to peaceful countries, according to a new study today from an international team. It reveals a direct link between the uncertainty of living in a violent setting, even for those not directly involved in the violence, and a "double burden" of shorter and less predictable lives.

According to the research, violent deaths are responsible for a high proportion of the differences in lifetime uncertainty between violent and peaceful countries. But, the study says, "The impact of violence on mortality goes beyond cutting lives short. When lives are routinely lost to violence, those left behind face uncertainty as to who will be next."

What the researchers found most striking is that lifetime uncertainty has a greater association with violence than life expectancy. Lifetime uncertainty, therefore, should not be overlooked when analyzing changes in mortality patterns.

Using mortality data from 162 countries, and the Internal Peace Index between 2008–2017, the study shows the most violent countries are also those with the highest lifetime uncertainty. It also says, in the most violent societies, lifetime uncertainty is even experienced by those not directly involved in violence. The report states, "Poverty-insecurity-violence cycles magnify pre-existing structural patterns of disadvantage for women and fundamental imbalances in gender relations at young ages."

Whilst men are the major direct victims of violence, women are more likely to experience non-fatal consequences in violent contexts. These indirect effects of violence should not be ignored as they fuel gender inequalities, and can trigger other forms of vulnerability and causes of death.

According to the report, lower life expectancy is usually associated with greater lifetime uncertainty. In addition, living in a violent society creates vulnerability and uncertainty—and that, in turn, can lead to more violent behavior.

Therefore, countries with high levels of violence experience lower levels of life expectancy than more peaceful ones.

José Aburto, A global assessment of the impact of violence on lifetime uncertainty, Science Advances (2023). DOI: 10.1126/sciadv.add9038. www.science.org/doi/10.1126/sciadv.add9038

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