Comment

Comment by Dr. Krishna Kumari Challa 4 hours ago

Physicists overcome two key operating hurdles in fusion reactions

A team of physicists has devised a way to overcome two key hurdles standing in the way of using fusion as a general power source.

In their paper published in the journal Nature, the group describes how they devised a way to raise the density of the plasma in their reactor while also keeping it stable.

Scientists at various sites around the world have been working for several years to figure out how to use fusion reactions to create electricity for general use—thereby freeing the world from using coal and gas fired power plants that spew greenhouse gases into the atmosphere. But it has been a long and difficult road.

It was just in the past couple of years that researchers were able to show that a fusion reaction could be made to sustain itself, and that more power could be produced than was input into such a system.

The next two hurdles to overcome are increasing the density of the plasma in the reactor and then containing it for extended periods of time—long enough for it to be useful for producing electricity. In this new study, the research team has devised a way to do both in a tokamak chamber.

To contain the plasma as its density was increased, the team used additional magnets and bursts of deuterium where needed. They also allowed for higher densities at the core than near the edges, helping to ensure the plasma could not escape. They held it in that state for 2.2 seconds, long enough to prove that it could be done.

They also found that during that short time span, the average density in the reactor was 20% over the Greenwald limit—a theoretical barrier that had been predicted to mark the point at which adding pressure would escape the magnetic field holding the plasma in place.

They also found that the stability of the plasma was H_98y2 above 1, which means that the experiment was successful.

The research team acknowledges that their experiment was done in a very small reactor—one with a diameter of just 1.6 meters. For such an achievement to be considered fully successful, it will have to be done in a much larger reactor, such as the one currently under construction in France, which will have a diameter of 6.2 meters.

S. Ding et al, A high-density and high-confinement tokamak plasma regime for fusion energy, Nature (2024). DOI: 10.1038/s41586-024-07313-3

Comment by Dr. Krishna Kumari Challa 4 hours ago

Researchers  find brown fat's 'off-switch'

Brown fat, also known as brown adipose tissue (BAT), is a type of fat in our bodies that's different from the white fat around our belly and thighs that we are more familiar with. Brown fat has a special job—it helps to burn calories from the foods that we eat into heat, which can be helpful, especially when we're exposed to cold temperatures like during winter swimming or cryotherapy.

For a long time, scientists thought that only small animals like mice and newborns had brown fat. But new research shows that a certain number of adults maintain their brown fat throughout life. Because brown fat is so good at burning calories, scientists are trying to find ways to activate it safely using drugs that boost its heat-producing abilities.

A new study  has found that brown fat has a previously unknown built-in mechanism that switches it off shortly after being activated. This limits its effectiveness as treatment against obesity. The team has now discovered a protein responsible for this switching-off process. It is called "AC3-AT."

Hande Topel et al, Cold-induced expression of a truncated Adenylyl Cyclase 3 acts as rheostat to brown fat function, Nature Metabolism (2024). DOI: 10.1038/s42255-024-01033-8

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Comment by Dr. Krishna Kumari Challa 4 hours ago

Using existing data from various sources, including measurements of fluid movements related to oil and gas extraction and water injections for geothermal energy, the team found that the current fluid movement rates induced by human activities are higher compared to how fluids moved before human intervention.

As human activities like carbon capture and sequestration and lithium extraction ramp up, the researchers also predicted how these activities might be recorded in the geological record, which is the history of Earth as recorded in the rocks that make up its crust.

Human activities have the potential to alter not just the deep subsurface fluids but also the microbes that live down there.
As fluids move around, microbial environments may be altered by changes in water chemistry or by bringing new microbial communities from Earth's surface to the underground.

For example, with hydraulic fracturing, a technique that is used to break underground rocks with pressurized liquids for extracting oil and gas, a deep rock formation that previously didn't have any detectable number of microbes might have a sudden bloom of microbial activity.

There remain a lot of unknowns about Earth's deep subsurface and how it is impacted by human activities, and it's important to continue working on those questions, say the scientists.

Grant Ferguson et al, Acceleration of Deep Subsurface Fluid Fluxes in the Anthropocene, Earth's Future (2024). DOI: 10.1029/2024EF004496

Part 2

Comment by Dr. Krishna Kumari Challa 4 hours ago

Human activities have an intense impact on Earth's deep subsurface fluid flow

The impact of human activities—such as greenhouse gas emissions and deforestation—on Earth's surface have been well-studied. Now, hydrology researchers  have investigated how humans impact Earth's deep subsurface, a zone that lies hundreds of meters to several kilometers beneath the planet's surface.

They looked at how the rates of fluid production with oil and gas compare to natural background circulation of water and showed how humans have made a big impact on the circulation of fluids in the subsurface.

In the future, these human-induced fluid fluxes are projected to increase with strategies that are proposed as solutions for climate change, according the study. Such strategies include: geologic carbon sequestration, which is capturing and storing atmospheric carbon dioxide in underground porous rocks; geothermal energy production, which involves circulating water through hot rocks for generating electricity; and lithium extraction from underground mineral-rich brine for powering electric vehicles.

Responsible management of the subsurface is central to any hope for a green transition, sustainable future and keeping warming below a few degrees.

With oil and natural gas production, there is always some amount of water, typically saline, that comes from the deep subsurface. The underground water is often millions of years old and acquires its salinity either from evaporation of ancient seawater or from reaction with rocks and minerals. For more efficient oil recovery, more water from near-surface sources is added to the salt water to make up for the amount of oil removed and to maintain reservoir pressures. The blended saline water then gets reinjected into the subsurface. This becomes a cycle of producing fluid and reinjecting it to the deep subsurface.

The same process happens in lithium extraction, geothermal energy production and geologic carbon sequestration, the operations of which involve leftover saline water from the underground that is reinjected.

Researchers showed that the fluid injection rates or recharge rates from those oil and gas activities is greater than what naturally occurs .

Part 1

Comment by Dr. Krishna Kumari Challa 4 hours ago

Research shows 'profound' link between dietary choices and brain health

A recent study published in Nature Mental Health shows that a healthy, balanced diet is linked to superior brain health, cognitive function and mental well-being. The study, involving researchers at the University of Warwick, sheds light on how our food preferences not only influence physical health but also significantly impact brain health.

The dietary choices of a large sample of 181,990 participants from the UK Biobank were analyzed against and a range of physical evaluations, including cognitive function, blood metabolic biomarkers, brain imaging, and genetics—unveiling new insights into the relationship between nutrition and overall well-being.

The food preferences of each participant were collected via an online questionnaire, which the team categorized into 10 groups (such as alcohol, fruits and meats). A type of AI called machine learning helped the researchers analyze the large dataset.

A balanced diet was associated with better mental health, superior cognitive functions and even higher amounts of gray matter in the brain—linked to intelligence—compared with those with a less varied diet.

The study also highlighted the need for gradual dietary modifications, particularly for individuals accustomed to highly palatable but nutritionally deficient foods. By slowly reducing sugar and fat intake over time, individuals may find themselves naturally gravitating towards healthier food choices.

Genetic factors may also contribute to the association between diet and brain health, the scientists think, showing how a combination of genetic predispositions and lifestyle choices shape well-being.

 Ruohan Zhang et al, Associations of dietary patterns with brain health from behavioral, neuroimaging, biochemical and genetic analyses, Nature Mental Health (2024). DOI: 10.1038/s44220-024-00226-0

Comment by Dr. Krishna Kumari Challa 5 hours ago

Study suggests that stevia is the most brain-compatible sugar substitute

Given the known risks of consuming high amounts of sugar, today many people are looking for alternative sweeteners that produce a similar taste without prompting significant weight gain and causing other health issues. While research suggests that the brain can tell the difference between different sweet substances, the neural processes underlying this ability to tell sweeteners apart remain poorly understood.

Researchers recently carried out a study aimed at better understanding what happens in the brain of mice when they are fed different types of sweeteners. Their findings, published in Neuroscience Research, suggest that the response of neurons to sucrose and stevia is similar, suggesting that stevia could be an equally pleasant but healthier sugar substitute.

Stevia is a sweet sugar substitute that is about 50 to 300 times sweeter than sugar. It is extracted from the leaves of Stevia rebaudiana, a plant native to areas of Paraguay and Brazil in the southern Amazon rainforest.The active compounds in stevia are steviol glycosides (mainly stevioside and rebaudioside). Stevia is heat-stable, pH-stable, and not fermentable. Humans cannot metabolize the glycosides in stevia, and therefore it has zero calories. Its taste has a slower onset and longer duration than that of sugar, and at high concentrations some of its extracts may have an aftertaste described as licorice-like or bitter. Stevia is used in sugar- and calorie-reduced food and beverage products as an alternative for variants with sugar.

Interestingly, the team's recordings revealed that compared to other sugar substitutes considered as part of this study, stevia induced activity in the PVT that more closely resembled that elicited by sugar intake. This suggests that stevia is the most "brain compatible" among most widely used sugar alternatives, most closely mirroring the perceived taste of sugar.

Shaolei Jiang et al, Neuronal activity in the anterior paraventricular nucleus of thalamus positively correlated with sweetener consumption in mice, Neuroscience Research (2024). DOI: 10.1016/j.neures.2024.02.002

Comment by Dr. Krishna Kumari Challa yesterday

The harm artificial sweeteners can cause

Artificial sweeteners are chemical compounds are up to 600 times sweeter than sugar with very few (if any) calories, and are cheap and easy for manufacturers to use.

Traditional artificial sweeteners, such as aspartame, sucralose and acesulfame potassium (acesulfame K) have been found in a wide range of foods and drinks for many years as a way to increase the sweet taste without adding significant calories or costs. However, in the last few years, there has been controversy in the field. Several studies have suggested potential health harms associated with consuming these sweeteners, ranging from gastrointestinal disease to dementia. Although none of these harms have been proved, it has paved the way for new sweeteners to be developed to try to avoid any possible health issues. These next-generation sweeteners are up to 13,000 times sweeter than sugar, have no calories and no aftertaste (a common complaint with traditional sweeteners). An example of this new type of sweetener is neotame. Neotame was developed as an alternative to aspartame with the aim of being a more stable and sweet version of the traditional sweetener. It is very stable at high temperatures, which means it is a good additive to use in baked goods. It is also used in soft drinks and chewing gum.

An artificial sweetener called neotame can cause significant harm to the gut, scientists found.It does this harm in two ways. One, by breaking down the layer of cells that line the intestine. And, two, by causing previously healthy gut bacteria to become diseased, resulting in them invading the gut wall.

The study, published in the journal Frontiers in Nutrition, is the first to show this double-hit negative effect of neotame on the gut, resulting in damage similar to that seen in inflammatory bowel disease and sepsis.

https://www.frontiersin.org/articles/10.3389/fnut.2024.1366409/full

Comment by Dr. Krishna Kumari Challa yesterday

In the study, the researchers asked more than 80 people to sit down and grab the handle of a robotic arm, which, in turn, operated the cursor on a computer screen. The subjects reached forward, moving the cursor toward a target. If they succeeded, they received a reward—not a big one, but still enough to make their brains happy.

Sometimes, the targets exploded, and they would get point rewards. It would also make a 'bing bing' sound.

That's when a contrast between the two groups of people began to emerge.

Both the 18 to 35-year-olds and 66 to 87-year-olds arrived at their targets sooner when they knew they would hear that bing bing—roughly 4% to 5% sooner over trials without the reward. But they also achieved that goal in different ways.

The younger adults, by and large, moved their arms faster toward the reward. The older adults, in contrast, mainly improved their reaction times, beginning their reaches about 17 milliseconds sooner on average.

When the team added an 8-pound weight to the robotic arm for the younger subjects, those differences vanished.

The brain seems to be able to detect very small changes in how much energy the body is using and adjusts our movements accordingly. Even when moving with just a few extra pounds, reacting quicker became the energetically cheaper option to get to the reward, so the young adults imitated the older adults and did just that.

The research seems to paint a clear picture. Both the younger and older adults didn't seem to have trouble perceiving rewards, even small ones. But their brains slowed down their movements under tiring circumstances.

The experiment can't completely rule out the brain's reward centers as a culprit behind why we slow down when we age. But if scientists can tease out where and how these changes emerge from the body, they may be able to develop treatments to reduce the toll of aging and disease.

Putting it all together, these results suggest that the effort costs of reaching seem to be determining what's slowing the movement of older adults. 

Erik M. Summerside et al, Slowing of Movements in Healthy Aging as a Rational Economic Response to an Elevated Effort Landscape, The Journal of Neuroscience (2024). DOI: 10.1523/JNEUROSCI.1596-23.2024

Part 2

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Comment by Dr. Krishna Kumari Challa yesterday

Why do we move slower the older we get? New study delivers answers

It's one of the inescapable realities of aging: The older we get, the slower we tend to move.

A new study led by University of Colorado Boulder engineers helps explain why.

The research is one of the first studies to experimentally tease apart the competing reasons why people over age 65 might not be as quick on their feet as they used to be. The group reported that older adults may move slower, at least in part, because it costs them more energy than younger people—perhaps not too shocking for anyone who's woken up tired the morning after an active day.

Why we move the way we do, from eye movements to reaching, walking, and talking, is a window into aging and Parkinson's. Scientists are trying to understand the neural basis of that.

For the study, the group asked subjects aged 18 to 35 and 66 to 87 to complete a deceptively simple task: to reach for a target on a screen, a bit like playing a video game on a Nintendo Wii. By analyzing patterns of these reaches, the researchers discovered that older adults seemed to modify their motions under certain circumstances to conserve their limited supplies of energy.

All of us, whether young or old, are inherently driven to get the most reward out of our environment while minimizing the amount of effort to do so.

researchers have long known that older adults tend to be slower because their movements are less stable and accurate. But other factors could also play a role in this fundamental part of growing up.

According to one hypothesis, the muscles in older adults may work less efficiently, meaning that they burn more calories while completing the same tasks as younger adults—like running a marathon or getting up to grab a soda from the refrigerator.

Alternatively, aging might also alter the reward circuitry in the human brain. As people age, their bodies produce less dopamine, a brain chemical responsible for giving you a sense of satisfaction after a job well done. If you don't feel that reward as strongly, the thinking goes, you may be less likely to move to get it. People with Parkinson's disease experience an even sharper decline in dopamine production.

Part 1

Comment by Dr. Krishna Kumari Challa on Saturday

Given that zoonotic prion disease is absolutely possible, and that transmission to humans has been predicted for some time, the situation, the doctors say, warrants caution and attention.

Although causation remains unproven, this cluster emphasizes the need for further investigation into the potential risks of consuming CWD-infected deer and its implications for public health," they write.

"Clusters of sporadic CJD cases may occur in regions with CWD-confirmed deer populations, hinting at potential cross-species prion transmission. Surveillance and further research are essential to better understand this possible association."

https://www.neurology.org/doi/10.1212/WNL.0000000000204407

Part 2

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