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Comment by Dr. Krishna Kumari Challa on June 18, 2024 at 9:34am

A 2016 study led by Steckler shows that these zones are now building stress, and could produce earthquakes comparable to the one 2,500 years ago. The last one of this size occurred in 1762, producing a deadly tsunami that traveled up the river to Dhaka. Another may have occurred around 1140 CE.

The 2016 study estimates that a modern recurrence of such a quake could affect 140 million people. Large earthquakes impact large areas and can have long-lasting economic, social and political effects.
The Ganges is not the only river facing such hazards. Others cradled in tectonically-active deltas include China's Yellow River; Myanmar's Irrawaddy; the Klamath, San Joaquin and Santa Clara rivers, which flow off the U.S. West Coast; and the Jordan, spanning the borders of Syria, Jordan, the Palestinian West Bank and Israel.
Cascading hazards of a major Bengal basin earthquake and abrupt avulsion of the Ganges River, Nature Communications (2024). DOI: 10.1038/s41467-024-47786-4
Part 3
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Comment by Dr. Krishna Kumari Challa on June 18, 2024 at 9:33am

In satellite imagery, the authors of the new study spotted what they say was probably the former main channel of the river, some 100 kilometers south of the Bangladeshi capital of Dhaka. This is a low-lying area about 1.5 kilometers wide that can be found intermittently for some 100 kilometers more or less parallel to the current river course. Filled with mud, it frequently floods, and is used mainly for rice cultivation.

Chamberlain and other researchers were exploring this area in 2018 when they came across a freshly dug excavation for a pond that had not yet been filled with water.

On one flank, they spotted distinct vertical dikes of light-colored sand cutting up through horizontal layers of mud. This is a well-known feature created by earthquakes: In such watery areas, sustained shaking can pressurize buried layers of sand and inject them upward through overlying mud. The result: literal sand volcanoes, which can erupt at the surface. Called seismites, here, they were 30 or 40 centimeters wide, cutting up through 3 or 4 meters of mud.

Further investigation showed the seismites were oriented in a systematic pattern, suggesting they were all created at the same time. Chemical analyses of sand grains and particles of mud showed that the eruptions and the abandonment and infilling of the channel both took place about 2,500 years ago.

Furthermore, there was a similar site some 85 kilometers downstream in the old channel that had filled in with mud at the same time. The authors' conclusion: This was a big, sudden avulsion triggered by an earthquake, estimated to be magnitude 7 or 8.
The quake could have had one of two possible sources, they say. One is a subduction zone to the south and east, where a huge plate of oceanic crust is shoving itself under Bangladesh, Myanmar and northeastern India. Or it could have come from giant splay faults at the foot of the Himalayas to the north, which are slowly rising because the Indian subcontinent is slowly colliding with the rest of Asia.
Part 2

Comment by Dr. Krishna Kumari Challa on June 18, 2024 at 9:32am

An earthquake changed the course of the Ganges: Could it happen again?

A major earthquake 2,500 years ago caused one of the largest rivers on Earth to abruptly change course, according to a new study. The previously undocumented quake rerouted the main channel of the Ganges River in what is now densely populated Bangladesh, which remains vulnerable to big quakes. The study was published in the journal Nature Communications.

Scientists have documented many river-course changes, called avulsions, including some in response to earthquakes.

It was not previously confirmed that earthquakes could drive avulsion in deltas, especially for an immense river like the Ganges.

The Ganges rises in the Himalayas and flows for some 1,600 miles, eventually combining with other major rivers including the Brahmaputra and the Meghna to form a labyrinth of waterways that empty into a wide stretch of the Bay of Bengal spanning Bangladesh and India. Together, they form the world's second-largest river system as measured by discharge. (The Amazon is first.)

Like other rivers that run through major deltas, the Ganges periodically undergoes minor or major course changes without any help from earthquakes. Sediments washed from upstream settle and build up in the channel, until eventually the river bed grows subtly higher than the surrounding flood plain.

At some point, the water breaks through and begins constructing a new path for itself. But this does not generally happen all at once—it may take successive floods over years or decades. An earthquake-related avulsion, on the other hand, can occur more or less instantaneously.

Part 1

Comment by Dr. Krishna Kumari Challa on June 18, 2024 at 9:08am

A new look at why old age is linked to severe, even fatal COVID

A longstanding question has nagged the COVID battle for more than four years: Why does the infection cause severe disease in older people?

Ever since the beginning of the pandemic in 2020, it has been abundantly clear that older adults are at substantial risk of severe, even fatal COVID. Yet, the underlying mechanisms for their susceptibility were not always clear despite studies that took co-morbidities into account, like diabetes, heart and lung disorders, and other chronic vagaries of age that can worsen a bout with an infectious disease.

To date, scientists have blamed a dysregulated immune system, an age-related affinity toward excessive blood clotting, and an overall decline in the key soldiers of the adaptive immune system, T and B cells, to explain increased risks for severe COVID in the aging population. And while all of those factors may play a role, an inevitable question looms large: Why?

A new multicenter clinical study, reported in Science Translational Medicine, has provided comprehensive answers and peels away some of the mystery surrounding poor outcomes for older people. 

Results from the new tests bore novel data and a new level of understanding.

Older age correlated with increased SARS-CoV-2 viral abundance upon hospital admission, delayed viral clearance, and increased type I interferon gene expression in both the blood and upper airway.

Researchers also observed age-dependent up-regulation of innate immune signaling pathways and down-regulation of adaptive immune signaling pathways.

The innate immune system's monocyte production escalated while naïve T and B cells of the adaptive immune system were low.

Unlike younger patients, older ones also displayed more active innate immune pathways and a persistent rise in pro-inflammatory genes and cytokines, suggesting that advancing age may disrupt the body's ability to turn off the inflammatory response. Additionally, biomarkers of disease severity, such as interleukin-6, were the most extreme in the oldest patients. Together, these data provide insight into why age is a major risk factor for severe COVID, the research team concluded.

The study finds that aging is associated with impaired viral clearance, dysregulated immune signaling, and persistent and potentially pathologic activation of pro-inflammatory genes and proteins.

These differences raise the possibility that older adults with severe COVID-19 may respond differently, and perhaps more favorably, to immunomodulatory therapies directed at certain inflammatory cytokines.

 Hoang Van Phan et al, Host-microbe multiomic profiling reveals age-dependent immune dysregulation associated with COVID-19 immunopathology, Science Translational Medicine (2024). DOI: 10.1126/scitranslmed.adj5154

Comment by Dr. Krishna Kumari Challa on June 17, 2024 at 6:47am

Comment by Dr. Krishna Kumari Challa on June 16, 2024 at 10:47am

Drinking Alcohol on Planes May Pose a  Danger

The next time you're on a long-haul flight, you might want to think twice about taking a drink and a nap: it's a combination that could be putting your heart under extra pressure, according to a new study. A team from the Institute of Aerospace Medicine at the German Aerospace Center split 40 volunteers between two sleep lab chambers: one at a normal ground level pressure, and one with artificially engineered pressure designed to mimic an airplane cruising at 2,438 meters (or around 8,000 feet).

We know that at these higher altitudes, with oxygen at a premium, blood oxygen levels (SpO2) begin to drop – technically known as hypobaric hypoxia. What this new research shows is that together with alcohol and a snooze, it's a potentially dangerous mix.
This study is the first to investigate the combined impact of hypobaric hypoxia and alcohol during sleep. on-board consumption of alcohol is an underestimated health risk that could be easily avoided.
There were four groups in total: those sleeping at normal pressure with or without having had a drink, and those sleeping at cabin pressure with or without having had a drink.

The alcohol given to participants was the equivalent of two cans of beer or two glasses of wine. During the experiments, participants were limited to sleeping four hours in a night, presumably to mimic the experience of disrupted sleep during flights.
At normal pressure, the average individual who consumed alcohol had a blood oxygen level of 94.97 percent and a heart rate of 76.97 beats-per-minute (bpm). Those who did not have alcohol at normal pressure had a blood oxygen level of 95.88 percent and 63.74 bpm. At the reduced pressure, the equivalent stats were 85.32 percent SpO2 and 87.73 bpm for drinkers, and 88.07 percent SpO2 and 72.90 bpm for non-drinkers.

Together, the findings suggests that at airplane cabin conditions, blood oxygen was lower and heart rate higher than in the control group, and those impacts were even greater among those who consumed alcohol.

That's a significant difference both for being high up in the air and for drinking – the healthy clinical norm for SpO2 is 90 percent. These factors also reduced time spent in deep and REM sleep, which are both important for sleep quality.

A low SpO2 and a high heart rate puts extra strain on the cardiovascular system, and the worry is that our long-haul flight habits are unnecessarily increasing the risk of heart problems – especially for those with existing conditions.

The study had a very small sample size, and participants were all young and healthy individuals. The shift in stats for the elderly and more vulnerable might be even more pronounced, which is something that future research can look into.
https://thorax.bmj.com/content/early/2024/05/03/thorax-2023-220998

Comment by Dr. Krishna Kumari Challa on June 15, 2024 at 7:16am

A fully edible robot could soon end up on our plate, say scientists

A fully edible robot could soon end up on our plate if we overcome some technical hurdles, say  scientists involved in RoboFood—a project which aims to connect robots to food.

Robots and food have long been distant worlds: Robots are inorganic, bulky, and non-disposable; food is organic, soft, and biodegradable. Yet, research that develops edible robots has progressed recently and promises positive impacts: Robotic food could reduce electronic waste, help deliver nutrition and medicines to people and animals in need, monitor health, and even pave the way to novel gastronomical experiences.

But how far are we from having a fully edible robot for lunch or dessert? And what are the challenges? Scientists from the RoboFood project, based at EPFL, address these and other questions in a perspective article in the journal Nature Reviews Materials.

In the perspective article, RoboFood authors analyze which edible ingredients can be used to make edible robot parts and whole robots, and discuss the challenges of making them.

Dario Floreano et al, Towards edible robots and robotic food, Nature Reviews Materials (2024). DOI: 10.1038/s41578-024-00688-9

Comment by Dr. Krishna Kumari Challa on June 15, 2024 at 7:07am

What if you just put a robot in the driver's seat instead of automating the car?

A team of roboticists  has taken a new approach to autonomous driving—instead of automating the entire car, simply put a robot in the driver's seat. The group built a robot capable of driving a car and tested it on a real-world track. They also published a paper describing their efforts on the arXiv preprint server.

Virtually all efforts to build a self-driving car have focused on making the car itself autonomous—humans sit in the passenger seat or in the back. These efforts involve adding a host of sensors in addition to processing power. They have also been met with mixed results.

In this new effort, the research team wondered if it might not be easier and cheaper simply to build a robot that can be taught how to drive a car and put it in the driver's seat of a normal vehicle. To find out if that might be possible, they built such a robot and tested it on a track at the University of Tokyo's Kashiwa Campus.

The robot is named Musashi and it was designed to operate in much the same way as a human car driver. To that end, the researchers created what they describe as a "musculoskeletal humanoid"—a robot with two arms and two legs, with feet and hands, a torso, neck and head.

They also gave it movable eyes, each equipped with a high-resolution camera. The jointed arms have hands with five digits, and the feet have "grippiness" to ensure precise control of the gas pedal and brake. The robot has a computer, of course, with software for training and to serve as the brains of the robot when driving. After building their robot, the research team put it in a small electric car and then sent it off for some test driving. In addition to simply driving around, the robot was tested on its ability to recognize and respond to objects in its path, including humans.

The team reports that initial testing was "encouraging", though they acknowledge that Musashi is a long way from being ready to drive on a public road.

Kento Kawaharazuka et al, Toward Autonomous Driving by Musculoskeletal Humanoids: A Study of Developed Hardware and Learning-Based Software, arXiv (2024). DOI: 10.48550/arxiv.2406.05573

Comment by Dr. Krishna Kumari Challa on June 15, 2024 at 6:54am

Across four experiments requiring participants to make trade-offs between reward, uncertainty and effort, patients with acute limbic encephalitis demonstrated blunted sensitivity to reward and effort whenever uncertainty was considered, despite demonstrating intact uncertainty sensitivity.

By contrast, the valuation of these two attributes (reward and effort) was intact on uncertainty-free tasks. Reduced sensitivity to changes in reward under uncertainty correlated with the severity of hippocampal damage.

They found that patients diagnosed with ALE were sensitive to uncertainty, yet they were less sensitive to information related to changes in reward values and effort. Their study gathered evidence suggesting that the hippocampus has a context-sensitive role in value-based decision-making, which is specifically relevant under conditions of uncertainty and influences how they evaluate the rewards and efforts linked with different options.

The researchers' new observations are a further step towards better understanding the hippocampus and its contribution to decision making in instances where outcomes are uncertain.

Bahaaeddin Attaallah et al, The role of the human hippocampus in decision-making under uncertainty, Nature Human Behaviour (2024). DOI: 10.1038/s41562-024-01855-2.

Part 2

Comment by Dr. Krishna Kumari Challa on June 15, 2024 at 6:52am

How the human hippocampus contributes to value-based decision-making under uncertainty

Value-based decision-making is the process through which humans choose between options associated with different costs or efforts, as well as rewards. These choices include, for instance, selecting different products at the grocery stores or making substantial lifestyle changes to accomplish a specific goal.

Past studies on animals have found that the hippocampus, a key brain region associated with learning and memory, could play a role in the processing and evaluation of rewards, which is thought to also occur during value-based decision-making. In addition, research on humans has linked the hippocampus to memory, associative learning and imagination, which could also be connected to value-based decision-making.

Researchers  have recently been investigating the role of this brain region in the valuation and selection of different options. In one study involving individuals with cognitive impairments, they found that the hippocampus could support the active gathering of information that precedes value-based decisions in situations where outcomes are uncertain.

Their latest paper, published in Nature Human Behaviour, built on these findings to further explore how the hippocampus contributes to human decision-making under uncertainty. In this new work, they specifically examined how individuals with a neurological condition affecting the hippocampus decided between different options associated with varying rewards.

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