Tree rings reveal that it has not been this warm in the past 1,200 years

A new 1,200 year-long time series based on tree rings shows that the current warming is unprecedented during this period. This is reported by researchers  in the scientific journal Nature.

The Middle Ages and the centuries that followed were not only turbulent socially, but also climatically. Not only was there a "Little Ice Age," but also its opposite: the "Medieval climate anomaly," during which it may have been unusually warm. The latter can clearly be seen in reconstructed temperatures from annual tree rings. In fact, reconstructed Medieval temperatures are often portrayed as higher than today's temperatures.

The previous reconstructions based on tree ring density, in contrast, indicated significantly higher temperatures for the Medieval climate anomaly and lower temperatures for the current warming. "This is critical because such reconstructions are considered when evaluating the accuracy of climate models. If the previous reconstructions were used as a benchmark, this would significantly downplay the human influence on current  climate warming and reduce confidence in model projections.

This has long been a puzzle because there is no known physical explanation for such exceptional Medieval warmth. Climate models are therefore unable to simulate it and instead show only moderately warm temperatures for the Medieval climate anomaly.

Previous reconstructions are based on the width or density of the annual tree rings. Both are very much dependent on temperature, but sometimes other factors play a role in how wide or dense a tree ring gets.

For their study researchers now  used a new method optimized at WSL to directly measure the cell wall thickness of the wood cells in the annual tree rings. Each individual cell in each tree ring records climatic information under which it was formed. By analyzing hundreds, sometimes thousands of cells per ring, extraordinary pure climate information can be obtained.

For their new time series, the researchers measured the cell walls of 50 million cells. These come from 188 living and dead Swedish and Finnish Scots pines (Pinus sylvestris), whose annual rings together cover a period of 1,170 years. Based on these measurements, the researchers then reconstructed the summer temperatures in this region and compared them both with model simulations of the regional climate and with previous reconstructions based on the density of the annual rings.

Researchers have created a new reconstruction based on a particularly precise method to extract temperature information from trees. In contrast to previous work, the new results lead to the same conclusion as the climate models: the Medieval climate anomaly was cooler than previously thought, at least in Scandinavia, where the wood studied originated. Today's warming is thus likely outside the range of natural fluctuations in temperatures over the past 1,200 years, the researchers conclude.

Jesper Björklund et al, Fennoscandian tree-ring anatomy shows a warmer modern than medieval climate, Nature (2023). DOI: 10.1038/s41586-023-06176-4

The Bioconcrete Revolution

Concrete is the most important building material on Earth – and it’s also responsible for a MASSIVE chunk of global carbon emissions. Join George as he discovers how a surprising discovery in 1973 could dramatically change how we make concrete forever.

Exploring what happens in the brain under the influence of psychedelics, while meditating and during hypnosis

Changes in a person's "normal" mental state after taking drugs, while meditating, during hypnosis or due to specific medical conditions have been a topic of study for several years now. Some of these mental changes, which are known as altered states of consciousness, have been found by some to have potentially beneficial effects, reducing stress and fostering greater well-being.

Researchers have recently been exploring the potential of psychedelic drugs, such as psilocybin and lysergic acid diethylamide (LSD) for treating depression and other mental disorders. In a recent paper published in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, they compared the brains of people who had taken psychedelics to those of others who were meditating or were hypnotized. 

Anecdotally, people often report similarities in experiences induced by hypnosis, meditation, or psychedelics. However, our neurobiological understanding of these states is only just evolving.

While many studies looked at individual altered states of consciousness and how they manifest in the brain, comparisons between these states remain scarce. This study tried to bridge that gap. 

Rather than conducting a single experiment that collectively involved psychedelics, meditation and hypnosis, the researchers analyzed datasets conducted during four distinct experimental trials. The first two trials examined the effects of two different psychedelic drugs on the brain, namely psilocybin and LSD, while the last two focused on hypnosis and meditation.

For the psychedelic studies, they included healthy participants who subsequently received psilocybin, LSD, or a placebo, whereas the meditation and hypnosis studies were conducted with participants who were experts in the respective field to make sure they can reach the state in an MR environment.

During the team's four experimental trials, all participants were asked to simply lay inside an MRI scanner without completing any task or engaging in any activity. The MRI scanner recorded their brain activity both while they were in a normal state of consciousness and under the altered state of consciousness relevant to that trial (i.e., after taking psychedelics, while meditating or while under hypnosis).

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Researchers analyzed the participants' brain activity throughout the whole brain and investigated whether different brain areas work together in a distinct way compared to the baseline scan.

Their findings showed that even though psilocybin, LSD, meditation and hypnosis induce overlapping subjective effects, the underlying brain changes are distinct.

The findings gathered by this team of researchers suggest that while some might report having similar experiences or feelings under these different states of consciousness, what is happening in their brain is actually very different. While psilocybin and LSD appeared to produce similar brain activity, the changes they induced were markedly different from those observed during meditation or hypnosis. This suggests that psychedelics, meditation and hypnosis have distinct underlying mechanisms of action and overall different effects on the brain.

Overall, these results suggest that these three distinct states may have synergistic therapeutic effects and may not therapeutically substitute each other. In the future, they could pave the way for further investigations of their unique strengths and benefits, potentially informing the development of new promising therapeutic strategies for psychiatric disorders.

Flora F. Moujaes et al, Comparing neural correlates of consciousness: from psychedelics to hypnosis and meditation, Biological Psychiatry: Cognitive Neuroscience and Neuroimaging (2023). DOI: 10.1016/j.bpsc.2023.07.003

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Consuming added sugars may increase risk of kidney stones

Between 7% and 15% of people in North America, between 5% and 9% of people in Europe, and between 1% and 5% of people in Asia suffer from kidney stones. Common symptoms are severe pain, nausea, vomiting, fever, chills, and bloody urine. But kidney stones don't just reduce the quality of life; in the long run, they may lead to infections, swollen kidneys (hydronephrosis), renal insufficiency, and end-stage renal disease. Known risk factors for developing kidney stones include being an adult male, obesity, chronic diarrhea, dehydration, and having inflammatory bowel disease, diabetes, or gout.

Now, a study in Frontiers in Nutrition has shown for the first time that an elevated consumption of added sugars should probably be added to the list of 

risk factors for kidney stones. Added sugars occur in many processed foods, but are especially abundant in sugar-sweetened sodas, fruit drinks, candy, ice cream, cakes, and cookies. It suggests that limiting added sugar intake may help to prevent the formation of kidney stones.

Researchers analyzed epidemiological data on 28,303 adult women and men, collected between 2007 to 2018 within the US National Health and Nutrition Examination Survey (NHANES). Participants self-reported if they had a history of kidney stones. Each participant's daily intake of added sugars was estimated from their recall of their most recent consumption of food and drinks, given twice: once in a face-to-face interview, and once in a telephone interview between three and 10 days later. For example, participants were asked if they had eaten syrups, honey, dextrose, fructose, or pure sugar during the past 24 hours.

Each participants also received a healthy eating index score (HEI-2015), which summarized their diet in terms of the adequacy of beneficial diet components such as fruits, vegetables, and whole grains, and moderation of potentially harmful foods, for example refined grains, sodium, and saturated fats.

The researchers adjusted the odds of developing kidney stones per year during the trial for a range of explanatory factors. These included gender, age, race or ethnicity, relative income, BMI, HEI-2015 score, smoking status, and whether the participants had a history of diabetes.

The researchers showed that after adjusting for these factors, the percentage of energy intake from added sugars was positively and consistently correlated with kidney stones. For example, participants whose intake of added sugars was among the 25% highest in the population had 39% greater odds of developing kidney stones over the course of the study.

Similarly, participants who derived more than 25% of their total energy from added sugars had a 88% greater odds than those who derived less than 5% of their total energy from added sugars.

The results also indicated that participants from "other" ethnicities—for example Native American or Asian people—had higher odds of developing kidney stones when exposed to greater-than-average amounts of added sugars than Mexican American, other Hispanic, non-Hispanic white, and non-Hispanic Black people. People with a greater poverty-income ratio (PIR; i.e., the ratio between their income and the federal poverty level) had greater odds of developing kidney stones when exposed to more added sugars than people at or slightly above poverty level.

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The mechanisms of the relation between consuming more added sugars and a greater risk of developing kidney stones is not yet known. Because this was an uncontrolled observational trial, it can't yet be ruled out that unknown confounding factors might drive this association.

Further studies are needed to explore the association between added sugar and various diseases or pathological conditions in detail. For example, what types of kidney stones are most associated with added sugar intake? How much should we reduce our consumption of added sugars to lower the risk of kidney stone formation? Nevertheless, these  findings already offer valuable insights for decision-makers.

 Association between added sugars and kidney stones in US adults: data from National Health and Nutrition Examination Survey 2007-2018, Frontiers in Nutrition (2023). DOI: 10.3389/fnut.2023.1226082 , www.frontiersin.org/articles/1 … ut.2023.1226082/full

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Scientists discover how parasites of viruses drive superbug evolution

In a study published in Cell, scientists  have discovered a new way by which bacteria transmit their genes, enabling them to evolve much faster than previously understood.

The ability to share genetic material is the major driver of microbial evolution because it can transform a benign bacterium into a deadly pathogen in an instant. Phages, the viruses of bacteria, can act as conduits that allow genes to transfer from one bacterium to another by a process known as genetic transduction.

Currently, there are three known mechanisms of transduction: generalized, specialized, and lateral. Lateral transduction was also discovered by the same groups of researchers in 2018, and it is at least one thousand times more efficient than the next most powerful mechanism, generalized transduction.

The new process is termed lateral cotransduction, and the architects behind this new frequency and speed in bacterial evolution are the Staphylococcus aureus pathogenicity islands (SaPIs), which are selfish DNA elements that exploit and parasitise phages and are commonly found integrated into the chromosomes of S. aureus isolates.

S. aureus is a type of bacteria that can cause Staph infections in humans and animals. While it primarily manifests as skin infections, it can become life-threatening if it spreads to the bloodstream and infects organs, bones, or joints.

This newly-discovered process, lateral cotransduction, rivals lateral transduction in terms of efficiency but surpasses the latter in versatility and complexity. While lateral transduction is only known to occur when dormant phages within  bacterial genomesbecome reactivated and initiate reproduction in the lytic cycle, lateral cotransduction can occur during the reactivation process and the infection of new bacterial cells.

Additionally, unlike phages that sacrifice their genes to transmit bacterial host DNA, SaPIs can transfer themselves completely intact with bacterial DNA through lateral cotransduction. This remarkable capability enables them to perpetually repeat the process, making them significantly more potent and efficient in transmitting bacterial genes.

Through the study, scientists  have demonstrated that bacteria can evolve much faster than we understood.

This process likely occurs in various other bacterial species as well. This groundbreaking finding marks a paradigm shift in our understanding of bacterial evolution and will immensely influence the ways we combat antibiotic resistance.

They [phages] could be used to destroy bacteria in the short term but end up spreading harmful genes to other cells in the long term, which could prove to be disastrous. With this new way of understanding the evolutionary mechanisms of disease-causing organisms, it is important for therapeutic phages to be carefully vetted before they are used for therapy.

Melissa Su Juan Chee et al, Dual pathogenicity island transfer by piggybacking lateral transduction, Cell (2023). DOI: 10.1016/j.cell.2023.07.001

Insulin-like hormones critical for brain plasticity, research suggests

Research has identified a mechanism through which insulin-like growth factors facilitate brain plasticity.

The insulin superfamily of hormones, including insulin, insulin-like growth factor 1 (IGF1), and insulin-like growth factor 2 (IGF2), play a crucial role not only in regulating blood sugar, metabolism, and growth, but also in healthy brain development and function, including learning and memory.

These hormones can enter the brain through the bloodstream from the liver or can be synthesized directly in neurons and glial cells within the brain. They bind to receptors, including the IGF1-receptor, activating signals that modulate neuron growth and activity. Disruption of this signaling pathway is involved in cognitive decline and diseases such as Alzheimer's.

In the present work one group of neurons in the hippocampus, CA1 neurons, produced IGF1; another group, CA3 neurons, produced IGF2. When either CA1 or CA3 neurons were activated in a way that mimicked synaptic plasticity, IGF wasreleased. Importantly, when the scientists disrupted the ability of the neurons to produce IGF, the activation of the IGF1-Receptor during plasticity and synaptic growth and strengthening was blocked.

This work reveals a local, autocrine mechanism in neurons that is critical forbrain plasticity. When a synapse undergoes plasticity, IGF is released locally to activate the IGF1-Receptor on the same neuron. Disrupting this mechanism impairs the plasticity, highlighting its critical role in maintaining cognitive health.

This discovery of this new mechanism sheds light on how memories are encoded in the brain and highlights the importance of further study on the insulin superfamily of hormones in the brain. 

 Xun Tu et al, Local autocrine plasticity signaling in single dendritic spines by insulin-like growth factors, Science Advances (2023). DOI: 10.1126/sciadv.adg0666

Multiwavelength Astronomy: The Big Picture

For the first time researchers restore feeling and lasting movement in man living with quadriplegia

In a first-of-its-kind clinical trial, bioelectronic medicine researchers, engineers and surgeons  have successfully implanted microchips into the brain of a man living with paralysis, and have developed artificial intelligence (AI) algorithms to re-link his brain to his body and spinal cord.

This double neural bypass forms an electronic bridge that allows information to flow once again between the man's paralyzed body and brain to restore movement and sensations in his hand with lasting gains in his arm and wrist outside of the laboratory. The research team unveiled the trial participant's groundbreaking progress four months after a 15-hour open-brain surgery that took place on March 9 at North Shore University Hospital (NSUH).

This is the first time the brain, body and spinal cord have been linked together electronically in a paralyzed human to restore lasting movement and sensation.

When the study participant thinks about moving his arm or hand, researchers 'supercharge' his spinal cord and stimulate his brain and muscles to help rebuild connections, provide sensory feedback, and promote recovery. This type of thought-driven therapy is a game-changer. Their goal is to use this technology one day to give people living with paralysis the ability to live fuller, more independent lives.

Paralyzed from the chest down, Keith Thomas, 45, of Massapequa, NY, is the first human to use the technology. During the height of the pandemic, on July 18, 2020, a diving accident caused Mr. Thomas to suffer injury at the C4 and C5 level of the vertebrae in his spine, leaving him unable to move and feel from the chest down..

Now science has changed his fate!

Source: The Feinstein Institutes for Medical Research at Northwell Health

Ancient lake microbes caused global warming during ice age

Global warming is not just a modern issue, but has occurred numerous times over Earth's history, with one such event happening 304 million years ago during the Late Paleozoic Ice Age (which spanned from 340 to 290 million years ago). Studies have discovered evidence of increased sea surface temperature, continental ice decline and oceanic environments flooding the land at the time.

Scientists researched the effect of a large injection of methane from alkaline lakes (pH 9 to 12) into the atmosphere, in work published in Geology.

Large quantities of atmospheric methane causes global warming as it is a potent greenhouse gas trapping heat 28 times more effectively than carbon dioxide over 100 years. Methane-producing microorganisms are responsible for 74% of global methane emissions, therefore defining the environmental conditions that encourage them to not only survive but thrive is important for understanding climate change.

The Junggar Basin in northwest China was investigated by assessing methane levels derived from microbial activity. The researchers took core samples from the lake bed and undertook chemical analyses of the rock to determine the type of carbon present based upon its source from aquatic green algae, cyanobacteria (photosynthesising microorganisms) and halophilic archaea (an extreme microorganisms that lives in high salt environments). When the lake contains more dissolved inorganic carbon (a form that doesn't have carbon and hydrogen bonds) the algae, cyanobacteria and archaea preferentially take up the lighter form (carbon-12) meaning the heavier carbon-13 remains in the lake water and is deposited, leading to distinct differences in the measurements taken from the rock. The researchers found one particular type, alkalophilic methanogenic archaea, took a competitive advantage in the low sulfate anoxic environmental conditions of the lake, preserving the heaviest carbon-13 values in the rock. This species thrived by obtaining the energy required for growth by producing large quantities of methane in the lake water, which was then released into the atmosphere. Methane emissions from microbial activity alone are suggested to have been up to 2.1 gigatons. Carbon dioxide derived from volcanic activity and hydrothermal processes transported to the lake was converted into bicarbonate and carbonate (forms of dissolved inorganic carbon), which increased the alkalinity of the lake and is noted to enhance the creation of methane as it promotes microbial activity. Dissolved inorganic carbon provides an almost limitless supply of carbon to the algae, cyanobacteria and archaea for their metabolic processes.

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Therefore, linking this increased and consistent supply of methane to the Late Paleozoic Ice Age, which had a peak in atmospheric methane 304 million years ago, may suggest that the combined contribution from numerous alkaline lakes globally could have had a significant impact on global greenhouse gas levels. The researchers suggest that, taking the lakes in northwest China alone, methane emissions could have reached 109 gigatonnes, which is equivalent to the greenhouse forcing power of up to 7521 gigatonnes of carbon dioxide.

Clearly this highlights the potency of methane in affecting our climate, and specifically the importance of identifying alkaline lakes globally to monitor their current emissions and find solutions to help combat their activity. This can include reducing the pH of the lakes so that they become more acidic, adding certain types of clay or even dredging the lake bottom, but all of these solutions naturally introduce a host of their own effects on the environment. As such, there may not yet be a clear solution to reducing methane emissions from lakes and abating their global warming potential.

Liuwen Xia et al, Effects on global warming by microbial methanogenesis in alkaline lakes during the Late Paleozoic Ice Age (LPIA), Geology (2023). DOI: 10.1130/G51286.1

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Scientists observe first evidence of 'quantum superchemistry' in the laboratory

A research team  has announced the first evidence for "quantum superchemistry"—a phenomenon where particles in the same quantum state undergo collective accelerated reactions. The effect had been predicted, but never observed in the laboratory till now.

The findings, published July 24 in Nature Physics, open the door to a new field. Scientists are intensely interested in what are known as "quantum-enhanced" chemical reactions, which could have applications in quantum chemistry, quantum computing, and other technologies, as well as in better understanding the laws of the universe.

Near absolute zero, particles can link up so that they are all in the same quantum state—where they can display unusual abilities and behaviors. It had been theorized that a group of atoms and molecules in the same quantum state would behave differently during chemical reactions, but the difficulty in orchestrating the experiment meant it had never been observed.

In the experiments, the scientists cooled down cesium atoms and coaxed them into the same quantum state. Next, they watched as the atoms reacted to form molecules. In ordinary chemistry, the individual atoms would collide, and there's a probability for each collision to form a molecule. However, quantum mechanics predicts that atoms in a quantum state perform actions collectively instead. You are no longer treating a chemical reaction as a collision between independent particles, but as a collective process. All of them are reacting together, as a whole.

One consequence is that the reaction happens faster than it would under ordinary conditions. In fact, the more atoms in the system, the faster the reaction happens.

Another consequence is that the final molecules share the same molecular state.

the same molecules in different states can have different physical and chemical properties —but there are times when you want to create a batch of molecules in a specific state. In traditional chemistry, you're rolling the dice. But with this technique, you can steer the molecules into an identical state.

Researchers  saw evidence that the reaction was taking place as a three-body interaction more often than as a two-body interaction. That is, three atoms would collide; two would form a molecule, and the third remained single. But the third played some role in the reaction.

 Zhendong Zhang et al, Many-body chemical reactions in a quantum degenerate gas, Nature Physics (2023). DOI: 10.1038/s41567-023-02139-8

Mosquito-dwelling microbe stops malaria
Malaria-carrying mosquitoes are less likely to pass on the parasite that causes the disease if they are infected with a naturally occurring bacterium. The microbe secretes a chemical that hobbles the malaria parasite’s development in the insects’ guts. So far, researchers trying to prevent the spread of the disease have had to rely on genetically modified bacteria — a major obstacle to regulatory and public acceptance, says malaria researcher Carolina Barillas-Mury. In experiments, one-third of mice bitten by bacterium-carrying mosquitoes became infected, compared with 100% of those bitten by regular malaria mosquitoes. And the mosquitoes don’t seem to develop resistance against the bacterium as they do to insecticides. The approach “has great potential to be implemented”.

 https://www.science.org/doi/10.1126/science.adf8141

Brain's 'appetite control center' found to be different in people who are overweight or living with obesity

Scientists have shown that the hypothalamus, a key region of the brain involved in controlling appetite, is different in the brains of people who are overweight and people with obesity when compared to people who are a healthy weight.

The researchers say their findings add further evidence to the relevance of brain structure to weight and food consumption.

A large number of factors influence how much we eat and the types of food we eat, including our genetics, hormone regulation, and the environment in which we live. What happens in our brains to tell us that we are hungry or full is not entirely clear, though studies have shown that the hypothalamus, a small region of the brain about the size of an almond, plays an important role.

Researchers  used an algorithm developed using machine learning to analyze MRI brain scans taken from 1,351 young adults across a range of BMI scores, looking for differences in the hypothalamus when comparing individuals who are underweight, healthy weight, overweight and living with obesity.

In a study published in Neuroimage: Clinical, the scientists found that the overall volume of the hypothalamus was significantly larger in the overweight and obese groups of young adults. In fact, they found a significant relationship between volume of the hypothalamus and body-mass index(BMI).

These volume differences were most apparent in those sub-regions of the hypothalamus that control appetite through the release of hormones to balance hunger and fullness.

While the precise significance of the finding is unclear—including whether the structural changes are a cause or a consequence of the changes in body weight—one possibility is that the change relates to inflammation. Previous animal studies have shown that a high fat diet can cause inflammation of the hypothalamus, which in turn prompts insulin resistance and obesity.

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In mice, just three days of a fat-rich diet is enough to cause this inflammation. Other studies have shown that this inflammation can raise the threshold at which animals are full—in other words, they have to eat more food than usual to feel full.

Inflammation may explain why the hypothalamus is larger in these individuals, the team say. One suggestion is that the body reacts to inflammation by increasing the size of the brain's specialist immune cells, known as glia.

The team say more research is needed to confirm whether increased volume in the hypothalamus is a result of being overweight or whether people with larger hypothalami are predisposed to eat more in the first place. It is also possible that these two factors interact with each other causing a feedback loop.

Stephanie S.G. Brown Conceptualisation et al, Hypothalamic volume is associated with body mass index, NeuroImage: Clinical (2023). DOI: 10.1016/j.nicl.2023.103478

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Asteroid Mining & Orbital Settlements

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Microwaving 'Safe' Plastics Can Release Billions of Particles, Scientists Warn

Billions of nanometer-wide particles can be released from plastic containers into the food they're holding when they're microwaved, a new study reveals. A team from the University of Nebraska-Lincoln in the US ran experiments using baby food containers made from polypropylene and polyethylene, which are both approved as safe to use by the regulators at the US Food and Drug Administration (FDA).

After three minutes of being heated in a 1,000-watt microwave, a variety of liquids put inside the containers were analyzed for microplastics (at least 1/1,000th of a millimeter in diameter) and nanoplastics (even smaller).

Particle numbers varied, but the researchers estimated that 4.22 million microplastic and 2.11 billion nanoplastic particles from only one square centimeter of plastic could be released during those three minutes of microwave heating.

Microwaving water or dairy products inside polypropylene or polyethylene products is likely to deliver the highest relative concentrations of plastic, the researchers revealed. Particles were also released when food and drinks were refrigerated and stored at room temperature, but significantly fewer in number.

What's not clear right now is what these microscopic plastic particles are doing to us. Studies have shown they can potentially be harmful to the intestine and key biological processes, but it's an area scientists aren't sure about.

It's probably safe to say that the less plastic we're ingesting the better, though. Embryonic kidney cells cultured by the researchers and exposed to plastic particles at levels of concentrations released by the containers over several days revealed a potential for concern.

The team found 77 percent of the kidney cells exposed to the highest levels of plastic were killed off. While this isn't to say our own kidneys would necessarily be exposed directly to such concentrations, it gives us some idea of the potential toxicity of these microplastics and nanoplastics – particular in developing bodies.

https://pubs.acs.org/doi/10.1021/acs.est.3c01942

World's largest study shows the more you walk, the lower your risk of death, even if you walk fewer than 5,000 steps

The number of steps you should walk every day to start seeing benefits to your health is lower than previously thought, according to the largest analysis to investigate this.

The study, published in the European Journal of Preventive Cardiology recently, found that walking at least 3967 steps a day started to reduce the risk of dying from any cause, and 2337 steps a day reduced the risk of dying from diseases of the heart and blood vessels (cardiovascular disease). However, the new analysis of 226,889 people from 17 different studies around the world has shown that the more you walk, the greater the health benefits. The risk of dying from any cause or from cardiovascular disease decreases significantly with every 500 to 1000 extra steps you walk. An increase of 1000 steps a day was associated with a 15% reduction in the risk of dying from any cause, and an increase of 500 steps a day was associated with a 7% reduction in dying from cardiovascular disease.

They found that even if people walked as many as 20,000 steps a day, the health benefits continued to increase. They have not found an upper limit yet.

This study confirms that the more you walk, the better. They found that this applied to both men and women, irrespective of age, and irrespective of whether you live in a temperate, sub-tropical or sub-polar region of the world, or a region with a mixture of climates. In addition, this analysis indicates that as little as 4,000 steps a day are needed to significantly reduce deaths from any cause, and even fewer to reduce deaths from cardiovascular disease.

There is strong evidence that a sedentary lifestyle may contribute to an increase in cardiovascular disease and a shorter life. Studies have shown that insufficient physical activity affects more than a quarter of the world's population.

According to World Health Organization data, insufficient physical activity is the fourth most frequent cause of death in the world, with 3.2 million deaths a year related to physical inactivity.

Maciej Banach et al, The Association Between Daily Step Count and All-Cause and Cardiovascular Mortality: A Meta-Analysis, European Journal of Preventive Cardiology (2023). DOI: 10.1093/eurjpc/zwad229

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Scientists look beyond climate change and El Nino for other factors that heat up Earth

Scientists are trying to find out if global warming and El Niño have an accomplice in fueling this summer's record-shattering heat.

The European climate agency Copernicus reported that July was one-third of a degree Celsius (six-tenths of a degree Fahrenheit) hotter than the old record. That's a bump in heat that is so recent and so big, especially in the oceans and even more so in the North Atlantic, that scientists are split on whether something else could be at work.

Scientists agree that by far the biggest cause of the recent extreme warming is climate change from the burning of coal, oil and natural gas that has triggered a long upward trend in temperatures. A natural El Niño, a temporary warming of parts of the Pacific that changes weather worldwide, adds a smaller boost. But some researchers say another factor must be present.

One surprising source of added warmth could be cleaner air resulting from new shipping rules. Another possible cause is 165 million tons (150 million metric tons) of water spewed into the atmosphere by a volcano. Both ideas are under investigation.

Shipping is "probably the prime suspect". Maritime shipping has for decades used dirty fuel that gives off particles that reflect sunlight in a process that actually cools the climate and masks some of global warming.

In 2020, international shipping rules took effect that cut as much as 80% of those cooling particles, which was a "kind of shock to the system". The sulfur pollution used to interact with low clouds, making them brighter and more reflective, but that's not happening as much now.

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In those spots, and to a lesser extent globally, new studies show a possible warming from the loss of sulfur pollution. And the trend is in places where it really can't be explained as easily by El Niño. There was a cooling effect that was persistent year after year, and suddenly it was removed.

In January 2022, the Hunga Tonga-Hunga Ha'apai undersea volcano in the South Pacific blew, sending more than 165 million tons of water, which is a heat-trapping greenhouse gas as vapour. The volcano also blasted 550,000 tons (500,000 metric tons) of sulfur dioxide into the upper atmosphere. A couple of studies use computer models to show a warming effect from all that water vapour.

However, the studies that showed warming from Hunga Tonga didn't incorporate sulfur cooling, which is hard to do.

Scientists 're still just trying to figuring it out.

Lesser suspects in the search include a dearth of African dust, which cools like sulfur pollution, as well as changes in the jet stream and a slowdown in ocean currents.

Some nonscientists have looked at recent solar storms and increased sunspot activity in the sun's 11-year cycle and speculated that Earth's nearest star may be a culprit. However, for decades, scientists have tracked sunspots and solar storms, and they don't match warming temperatures.

Solar storms were stronger 20 and 30 years ago, but there is more warming now.

 Still, other scientists said there's no need to look so hard. They say human-caused climate change, with an extra boost from El Niño, is enough to explain recent temperatures. The fact that the world is coming out of a three-year La Niña, which suppressed global temperatures a bit, and going into a strong El Niño, which adds to them, makes the effect bigger.

Climate change and El Niño can explain it all. That doesn't mean other factors didn't play a role. But we should definitely expect to see this again without the other factors being present.

Source: The Associate Press

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Anti-bacterial virus treated antibiotic resistant infections with 86.6% success rate

A new international study conducted by the Israeli Phage Therapy Center (IPTC)  using phage PASA16 on compassionate basis to treat tough Pseudomonas aeruginosa infections, has shown promising results with an 86.6% success rate.

This research involving 16 patients with persistent infections represents the largest of its kind and brings encouraging findings. The study's success demonstrates the potential effectiveness of PASA16 phage therapy in tackling challenging Pseudomonas aeruginosa infections, paving the way for future clinical trials and encouraging further exploration of phage therapy as an alternative and auxiliary approach against antibiotic-resistant infections.

This study sheds light on the potential role of phages in combination with antibiotics in combating the hard-to-treat pathogen P. aeruginosa infections that were unresponsive to conventional treatments.

 Ran Nir-Paz, Refractory Pseudomonas aeruginosa infections treated with Phage PASA16: a compassionate use case series, Med (2023). DOI: 10.1016/j.medj.2023.07.002. www.cell.com/med/fulltext/S2666-6340(23)00225-8

Physicists demonstrate how sound can be transmitted through vacuum

Did you think that sound waves can't travel through vacuum?

Physicists have demonstrated that in certain situations, sound can be transmitted strongly across a vacuum region!

In a recent article published in Communications Physics they show that in some cases, a sound wave can jump or "tunnel" fully across a vacuum gap between two solids if the materials in question are piezoelectric. In such materials, vibrations (sound waves) produce an electrical response as well, and since an electric field can exist in vacuum, it can transmit the sound waves.

The requirement is that the size of the gap is smaller than the wavelength of the sound wave. This effect works not only in audio range of frequencies (Hz–kHz), but also in ultrasound (MHz) and hypersound (GHz) frequencies, as long as the vacuum gap is made smaller as the frequencies increase.

In most cases the effect is small, but researchers also found situations where the full energy of the wave jumps across the vacuum with 100% efficiency, without any reflections. As such, the phenomenon could find applications in microelectromechanical components (MEMS, smartphone technology) and in the control of heat.

Zhuoran Geng et al, Complete tunneling of acoustic waves between piezoelectric crystals, Communications Physics (2023). DOI: 10.1038/s42005-023-01293-y

Researchers engineer bacteria that can detect tumor DNA

Pushing into a new chapter of technologically advanced biological sensors, scientists have engineered bacteria that can detect the presence of tumor DNA in a live organism.

Their innovation, which detected cancer in the colons of mice, could pave the way to new biosensors capable of identifying various infections, cancers and other diseases.

The advancement is described in the journal Science. Bacteria previously have been designed to carry out various diagnostic and therapeutic functions, but lacked the ability to identify specific DNA sequences and mutations outside of cells. The new "Cellular Assay for Targeted CRISPR-discriminated Horizontal gene transfer," or "CATCH," was designed to do just that.

Engineered bacteria detect tumor DNA

The new research is based on previous ideas related to horizontal gene transfer, a technique used by organisms to move genetic material between one another in a manner distinct from traditional parent-to-offspring genetic inheritance. While horizontal gene transfer is widely known from bacteria to bacteria, the researchers achieved their goal of applying this concept from mammalian tumors and human cells into bacteria.

The researchers are now adapting their bacteria biosensor strategy with new circuits and different types of bacteria for detecting and treating human cancers and infections.

 Robert M. Cooper et al, Engineered bacteria detect tumor DNA, Science (2023). DOI: 10.1126/science.adf3974. www.science.org/doi/10.1126/science.adf3974

Repairing the heart with silicon nanowires and stem cell cardiomyocytes

A research group  has developed a strategy to improve heart repair using human pluripotent stem cell–derived cardiomyocytes combined with biodegradable and biocompatible electroconductive silicon nanowires.

In the paper, "Nanowired human cardiac organoid transplantation enables highly efficient and effective recovery of infarcted hearts," published in Science Advances, the authors detail how cells self-assemble to form organoids that mimic fundamental cardiac tissue–level functions and contain vascular networks that reduce the risk of apoptosis during oxygen deprivation.

Nanowired cardiac organoids, tiny living and contracting orbs of heart tissue with microscopic wires embedded, were fabricated from human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) and cultured along with electroconductive silicon nanowires (e-SiNWs) so that the wires were integrated into the tissues. The engineered spheres were then injected into damaged and dying tissues of rat hearts.

While the use of cardiac organoids for tissue repair is not new, there have been limitations of low cell retention at the repair site, leading to moderate functional improvements and scalability issues.

The addition of nanowires increased the conductivity of the tissues, allowing them to synchronize better, facilitating better communication among cells and integration with the existing heart tissue.

Nanowired organoids achieved double the functional recovery in the rats, with a lower number of engrafted cells (~0.5 × 10⁶ hPSC-CMs per rat) compared to previous studies without nanowires in the hPSC-CMs (~10 × 10⁶ hPSC-CMs per rat).

Integrating e-SiNWs did not exacerbate inflamatory responses in healthy or damage repair settings, as expected from the biocompatible nature of silicon.

Nanowired cardiac organoids also exhibited significantly less apoptosis than wireless cardiac spheroids.

Yu Tan et al, Nanowired human cardiac organoid transplantation enables highly efficient and effective recovery of infarcted hearts, Science Advances (2023). DOI: 10.1126/sciadv.adf2898

Advice to freeze out risk of thermal attacks

A team of computer security experts have developed a set of recommendations to help defend against "thermal attacks" which can steal personal information.

Thermal attacks use heat-sensitive cameras to read the traces of fingerprints left on surfaces like smartphone screens, computer keyboards and PIN pads.

Hackers can use the relative intensity of heat traces across recently-touched surfaces to reconstruct users' passwords.

Last year experts demonstrated how easily thermal images could be used to crack passwords.

They developed ThermoSecure, a system which used AI to scan heat-trace images and correctly guess passwords in seconds, alerting many to the threat of thermal attacks.

Their research,  presented as a paper at the USENIX Security Symposium conference in Anaheim, California, on Friday 11 August, also includes advice to manufacturers on how their devices could be made more secure. 

The team identified 15 different approaches described in previous papers on computer security which could reduce the risk of thermal attacks.

Those included ways to reduce the transfer of heat from users' hands, by wearing gloves or rubber thimbles, or changing the temperature of hands by touching something cold before typing.

Approaches suggested in the literature also included pressing hands against surfaces or breathing on them to obscure their fingerprint heat once they had finished typing.

Other suggestions for increased security focused on hardware and software. A heating element behind surfaces could erase traces of finger heat, or surfaces could be made from materials which dissipate heat more rapidly.

Security on public surfaces could be increased by introducing a physical shield which covers keys until heat has dissipated. Alternatively, eye-tracking inputs or biometric security could reduce the risk of successful thermal attacks.

The paper concludes with recommendations for users on how they can defend themselves against thermal attacks in public, and for device manufacturers on how safety measures could be built into future generations of hardware and software.

 In the Quest to Protect Users from Side-Channel Attacks—A User-Centred Design Space to Mitigate Thermal Attacks on Public Payment Terminals. www.usenix.org/conference/usen … 3/presentation/marky

Chemicals from maize roots influence wheat yield

Maize roots secrete certain chemicals that affect the quality of soil. In some fields, this effect increases yields of wheat planted subsequent to maize in the same soil by more than 4%. This was proven by researchers . While the findings from several field experiments show that these effects are highly variable, in the long term they may yet help to make the cultivation of grains more sustainable, without the need for additional fertilizers or pesticides.

Plants produce an abundance of special chemicals. Some of these are released into the soil and influence its quality. This, in turn, affects the next plant to grow in the soil. So far, little research has taken place on the extent to which the excreted chemicals can be used in agriculture to increase productivity.

Recently, however, researchers from the Institute of Plant Sciences (IPS) at the University of Bern have conducted field experiments in this area. With their findings published in the scientific journal eLife, the researchers demonstrate that specialized metabolitesfrom the roots of the maize plant can bring about an increase in the yields of subsequently planted wheat under agriculturally realistic conditions.

On the basis of earlier studies conducted by researchers at the Institute of Plant Sciences (IPS) at the University of Bern, it was known that so-called benzoxazinoids—natural chemicals which maize plants release through their roots—change the composition of microorganisms in the soil on the roots and therefore influence the growth of the subsequent plants that grow in the soil. The present study investigated whether plant-soil feedbacks of this kind also occur under realistic agricultural conditions.

During a two-year field experiment, two lines of maize were initially grown, only one of which released benzoxazinoids into the soil. Three varieties of winter wheat were then grown on the differently conditioned soils.

On this basis, it was possible to demonstrate that the excretion of benzoxazinoids improves germination and increases tillering, growth and crop yield.

In addition to the increased crop, lower levels of infestation by some pests were also observed. A yield increase of 4% may not sound spectacular, but it is still significant considering how challenging it has become to enhance wheat yields without additional inputs.

Valentin Gfeller et al, Plant secondary metabolite-dependent plant-soil feedbacks can improve crop yield in the field, eLife (2023). DOI: 10.7554/eLife.84988

Muon magnetism dashes physics dreams
The most precise measurement of an elementary particle’s magnetism suggests that the ‘standard model’ of physics could be right after all. A discrepancy between predicted and measured values of the magnetic moment of the muon — a heavier cousin of the electron — was seen as a possible signal of undiscovered subatomic particles. Physicists at the Muon g – 2 experiment at Fermilab have now doubled the precision of the previous best measurement, to an estimated error of just 201 parts per billion. And an alternative theoretical prediction is in agreement with this result, suggesting there might not be any discrepancy to explain.

https://muon-g-2.fnal.gov/result2023.pdf?utm_source=Nature+Briefing...

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Soil is home to more than half of all life About 59% of all species on Earth live in soil, estimate researchers who reviewed global biodiversity data. This would make the ground the planet’s single most biodiverse habitat. The figure doubles an earlier estimate and could be even higher because so little is known about soil, the researchers suggest. It is home to 99% of Enchytraeidae worms, 90% of fungi, 86% of plants and more than 50% of bacteria — but only 3% of mammals live in it.

https://www.pnas.org/doi/10.1073/pnas.2304663120

Researchers discover antifungal molecule

Fungal infections are killing thousands of people each year, some with a morbidity rate of nearly 80%. The rise in fungal infections is due, in part, to the successful treatment of other diseases. As people live longer and successfully undergo treatments like chemotherapy and organ transplants, they often live with weakened immune systems. When drugs that treat arthritis and other ailments that also weaken immune systems are added to the mix, a perfect storm is created for potentially deadly fungal infections.

To make matters worse, only a handful of antifungal treatments are available, and even those are becoming less effective as fungi become more resistant. However,  researchers have recently published findings in the Journal of Natural Products indicating that a novel breakthrough treatment may have been discovered.
The molecule they're excited about is called persephacin. This antifungal discovery appears to work on a broad spectrum of infectious fungi, and it is reasonably non-toxic to human cells, which is a huge deal because many current treatments are toxic to the human body.

Fungi are found throughout the botanical world, and plants and fungi often work together. Some of these fungi kill competitors or deter insects from eating the plan. So researchers  hypothesized that if these plant-dwelling fungi, known as endophytes, could help the plants fight off infections by killing the invading fungi, then these molecules might also be able to protect humans and animals from fungal pathogens. As it turns out, they were right.

The researchers  developed a novel way to procure leaf samples using a laser device called the Fast Laser-Enabled Endophyte Trapper, or FLEET. This method helps generate samples in a sterile environment and drastically increases the number of samples that can be acquired.

Using traditional methods, they could process roughly four to six samples per minute. But the FLEET system is capable of aseptically generating between 500-600 tissue specimens in 10 minutes. This allowed them to rapidly screen more samples and enhanced the opportunity for potential drug discoveries. This is one of them. Antifungal resistance keeps evolving, and this could provide a new alternative. That's why this molecule is so exciting.

Lin Du et al, Persephacin Is a Broad-Spectrum Antifungal Aureobasidin Metabolite That Overcomes Intrinsic Resistance in Aspergillus fumigatus, Journal of Natural Products (2023). DOI: 10.1021/acs.jnatprod.3c00382

Stealth swimmers: the fish that hide behind others to hunt

The Heliophysics Big Year

Carbon dioxide - not water - triggers explosive volcanoes

Geoscientists have long thought that water  along with shallow magma stored in Earth's crust drives volcanoes to erupt. Now, thanks to newly developed research tools , scientists have learned that gaseous carbon dioxide can trigger explosive eruptions. A new model suggests that basaltic volcanoes, typically located on the interior of tectonic plates, are fed by a deep magma within the mantle, stored about 20 to 30 kilometers below Earth's surface. The research, which offers a clearer picture of our planet's deep internal dynamics and composition, with implications for improving volcanic-hazards planning, was published Aug. 7 in the Proceedings of the National Academy of Sciences. 

Skeletal elements preserve differing evolutionary forces

Human skeletal morphology is highly diverse and varies among individuals and populations around the globe. This diversity is the result of a complex interplay of various evolutionary forces over a long period of time. Evolutionary biologists divide these forces into two distinct processes. A neutral process refers to mutations producing new diversity which, however, offers no direct advantages or disadvantages to the affected individuals. This new diversity then increases or decreases randomly via what is known as genetic drift within a population.

This is contrasted with non-neutral processes, for example, when mutations do affect the fitness of an individual. As a result, the affected individuals have a greater or lesser ability to adapt to environmental factors.

To draw detailed conclusions about underlying genetic kinship only skeletal elements that evolved through neutral processes should be used.

Therefore , researchers should focus on the teeth and skull, whose structures are considered to have evolved primarily through neutral processes. Contrary to earlier assumptions, not all features in the teeth and skull reliably reflect the underlying genetic code; some are much more suitable than others.  Small morphological features on the teeth, such as groove patterns in the crowns, the number and size of cusps, the shape of the roots, and the presence or absence of wisdom teeth, proved to be particularly suitable. 

Researchers obtain the best results, almost identical to a conventional genetic relationship analysis, when they include all features of the skull and teeth. This is also expected, as more skeletal features provide a richer knowledge of underlying genetic information.

Genetic analyses are often constrained by poor DNA preservation. This is commonly the case with very old bones or those that have been exposed to a warm climate. Damaging bones for DNA analyses is also often out of the question in the case of fragile material or rare finds, or due to ethical reasons. In such cases, the non-destructive examination of skulls and teeth is a valuable alternative for tracing past population history and hominin phylogeny in archaeological contexts, for example, or for inferring ancestry profiles in forensic cases. This , therefore, has implications for the scientific community and society at large.

Nanoscale 'tattoos' for individual cells could provide early warnings for health problems

Engineers have developed nanoscale tattoos dots and wires that adhere to live cells in a breakthrough that puts researchers one step closer to tracking the health of individual cells. The new technology allows for the first time the placement of optical elements or electronics on live cells with tattoo-like arrays that stick on cells while flexing and conforming to the cells' wet and fluid outer structure. 

They 're talking about putting something like an electronic tattoo on a living object tens of times smaller than the head of a pin. It's the first step towards attaching sensors and electronics on live cells. The structures were able to stick to soft cells for 16 hours even as the cells moved.

The researchers built the tattoos in the form of arrays with gold, a material known for its ability to prevent signal loss or distortion in electronic wiring. They attached the arrays to cells that make and sustain tissue in the human body, called fibroblasts. The arrays were then treated with molecular glues and transferred onto the cells using an alginate hydrogel film, a gel-like laminate that can be dissolved after the gold adheres to the cell. The molecular glue on the array bonds to a film secreted by the cells called the extracellular matrix.

This work has shown we can attach complex nanopatterns to living cells, while ensuring that the cell doesn't die. It's a very important result that the cells can live and move with the tattoos because there's often a significant incompatibility between living cells and the methods engineers use to fabricate electronics.

The researcher's ability to attach the dots and wires in an array form is also crucial. To use this technology to track bioinformation, researchers must be able to arrange sensors and wiring into specific patterns not unlike how they are arranged in electronic chips.

This is an array with specific spacing, not a haphazard bunch of dots. 

Kam Sang Kwok et al, Toward Single Cell Tattoos: Biotransfer Printing of Lithographic Gold Nanopatterns on Live Cells, Nano Letters (2023). DOI: 10.1021/acs.nanolett.3c01960

Cancers Protect Themselves Against Their Own Mutations

Tumors overexpress certain genes to survive a growing pile of harmful mutations, a trait that scientists could exploit to target with drugs.

Most cancerous tumors accumulate thousands of potentially protein-damaging mutations over time, yet they mysteriously continue to thrive. Now, a new computational study helps explain how that is possible: Tumors with a large number of mutations upregulate genes that minimize misfolded proteins to protect them from their own mutations.

To reveal that coping mechanism, researchers explored the gene expression of nearly 10,300 human tumors across 33 cancer types catalogued in the Cancer Genome Atlas database.3 They found consistent upregulation of chaperone proteins and the proteasome, which respectively prevent and degrade misfolded proteins. Next, the researchers validated their findings using cell line data from the Cancer Cell Line Encyclopedia. The cell lines showed similar expression patterns, and when the scientists calculated the effect of knocking down the upregulated genes, higher mutational loads correlated with reduced cell viability. These results suggest that the gene upregulation protects tumors.

This discovery signals a general vulnerability in many tumors that could be exploited, for example by using chaperone and proteasome inhibitors. Scientists developed such drugs decades ago, but this new information might help target them to the tumors that will be most vulnerable.

https://elifesciences.org/reviewed-preprints/87301

A Realistic Way to Make Space Habitats From Asteroids

We can build space habitats from asteroids by spinning them fast enough. That's what Professor Adam Frank suggests in a recent paper he co-wrote. In this interview, we discussed the idea, how realistic it is and what technology will be needed to achieve it, what applications it can have and when we can expect something like that.

A Drug For Regrowing Teeth Could Be Available Within The Next Decade

Teeth don't grow back once we become adults: any wear and tear is permanent – as those of us with fillings will know – which is why it's important to keep them as clean and healthy as we can. However, this is something scientists are now looking to change. It's been announced that clinical trials for a potential tooth regrowth treatment are set to begin in July 2024, building on decades of research in the field. If those trials are successful, therapeutic drugs could be available by 2030. A team from the Medical Research Institute at Kitano Hospital in Japan is in charge of the trial, which is targeting people with anodontia, a rare genetic condition that prevents baby teeth and adult teeth from growing in the normal way. The treatment would initially target young children with the condition, but further down the line, the researchers think it could also be used more broadly – with people who have more common dental problems, such as gum disease, for example. Here's how it works: having found a link between a specific gene called USAG-1 and limits on tooth growth in mice, the researchers then moved on to tests that tried to block the expression of USAG-1.An antibody was discovered that could safely block some of the activity of USAG-1 in mice and ferrets without leading to any serious side effects, leading to induced tooth growth. The next step is to see if the same chemical reactions can be controlled in humans. We're talking about potential rather than reality at the moment, but it might be possible to use the new drug to prompt the growth of a third generation of teeth in the mouth, after baby teeth and full-sized adult teeth. As the researchers point out in a recent scientific review, the benefit of the approach is that teeth growth is being triggered in a natural way, through a process known as bone morphogenetic protein (BMP) signaling. Our bodies are naturally doing the work, without any complicated engineering of stem cells required. The team also suggests that advancements in scanning technology (such as mass spectrometry, for example) will make it easier to spot biomarkers indicating the people who will benefit most from the treatment. Anti-USAG-1 antibody treatment in mice is effective for tooth regeneration and can be a breakthrough in treating tooth anomalies in humans," write the researchers.

https://www.nature.com/articles/s41598-021-93256-y

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Videos of snakes eating themselves

Changing flies into degradable plastics?

Imagine using insects as a source of chemicals to make plastics that can biodegrade later—with the help of that very same type of bug. That concept is closer to reality than you might expect. Researchers describe their progress to date, including isolation and purification of insect-derived chemicals and their conversion into functional bioplastics, at the fall meeting of the American Chemical Society (ACS).

Researchers have been developing methods for several years to transform natural products—such as glucose obtained from  sugar cane or trees—into degradable, digestible polymers that don't persist in the environment. But those natural products are harvested from resources that are also used for food, fuel, construction and transportation.

So some researchers began searching for alternative sources that wouldn't have these competing applications.

And they thought of using waste products left over from farming black soldier flies. The larvae of these flies contain many proteins and other nutritious compounds, so the immature insects are increasingly being raised for animal feed and to consume wastes. However, the adults have a short life span after their breeding days are over and are then discarded. How about using them instead of useless plastics?

When  researchers examined the dead flies, they determined that chitin is a major component. This nontoxic, biodegradable, sugar-based polymer strengthens the shell, or exoskeleton, of insects and crustaceans. Manufacturers already extract chitin from shrimp and crab shells for various applications, and researchers now  have been applying similar techniques using ethanol rinses, acidic demineralization, basic deproteinization and bleach decolorization to extract and purify it from the insect carcasses.

Fly-sourced chitin powder is probably purer, since it lacks the yellowish colour and clumpy texture of the traditional product. Researchers also note that obtaining chitin from flies could avoid possible concerns over some seafood allergies. Some other researchers isolate chitin or proteins from fly larvae, but this is the first time the use chitin from discarded adult flies, which—unlike the larvae—aren't used for feed.

Harvesting of building blocks from insect feedstocks for transformation into carbohydrate-derived superabsorbent hydrogels, ACS Fall 2023. www.acs.org/meetings/acs-meetings/fall-2023.html

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Scientists theorize a hidden phase transition between liquid and a solid

Anything made out of plastic or glass is known as an amorphous material. Unlike many materials that freeze into crystalline solids, the atoms and molecules in amorphous materials never stack together to form crystals when cooled. In fact, although we commonly think of plastic and glass as "solids," they instead remain in a state that is more accurately described as a supercooled liquid that flows extremely slowly.

And although these "glassy dynamic" materials are ubiquitous in our daily lives, how they become rigid at the microscopic scale has long eluded scientists.

Now, researchers  have discovered molecular behavior in supercooled liquids that represents a hidden phase transition between a liquid and a solid.

Their improved understanding applies to ordinary materials like plastics and glass, and could help scientists develop new amorphous materials for use in medical devices, drug delivery, and additive manufacturing.

Specifically, using theory, computer simulations,  and previous experiments, the scientists explained why the molecules in these materials, when cooled, remain disordered like a liquid until taking a sharp turn toward a solid-like state at a certain temperature called the onset temperature—effectively becoming so viscous that they barely move. This onset of rigidity—a previously unknown phase transition—is what separates supercooled from normal liquids.

Any supercooled liquid continuously jumps between multiple configurations of molecules, resulting in localized particle movements known as excitations. In their proposed theory, the researchers treated the excitations in a 2D supercooled liquid as though they were defects in a crystalline solid.

As the supercooled liquid's temperature increased to the onset temperature, they propose that every instance of a bound pair of defects broke apart into an unbounded pair. At precisely this temperature, the unbinding of defects is what made the system lose its rigidity and begin to behave like a normal liquid. "The onset temperature for glassy dynamics is like a melting temperature that 'melts' a supercooled liquid into a liquid. This should be relevant for all supercooled liquids or glassy systems.

The theory and simulations captured other key properties of glassy dynamics, including the observation that, over short periods of time, a few particles moved while the rest of the liquid remained frozen.

Dimitrios Fraggedakis et al, Inherent-state melting and the onset of glassy dynamics in two-dimensional supercooled liquids, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2209144120

Source of hidden consciousness in 'comatose' brain injury patients found

 Researchers have identified brain injuries that may underlie hidden consciousness, a puzzling phenomenon in which brain-injured patients are unable to respond to simple commands, making them appear unconscious despite having some level of awareness.

This study suggests that patients with hidden consciousness can hear and comprehend verbal commands, but they cannot carry out those commands because of injuries in brain circuits that relay instructions from the brain to the muscles.

The findings could help physicians more quickly identify brain-injured patients who might have hidden consciousness and better predict which patients are likely to recover with rehabilitation.

Hidden consciousness, also known as cognitive motor dissociation (CMD), occurs in about 15% to 25% of patients with brain injuries stemming from head trauma, brain hemorrhage, or cardiac arrest.

In previous research, researchers found that subtle brainwaves detectable with EEG are the strongest predictor of hidden consciousness and eventual recovery for unresponsive brain-injured patients. But the precise pathways in the brain that become disrupted in this condition were unknown.

Part 1

In the new study, the researchers used EEG to examine 107 brain injury patients. The technique can determine when patients are trying, though unable, to respond to a command such as "keep opening and closing your right hand."

The analysis detected CMD in 21 of the patients. 
The researchers then analyzed structural MRI scans from all of the patients.

Using a technique they developed called bi-clustering analysis, they were able to identify patterns of brain injury that are shared among patients with CMD and contrast to those without CMD.

The researchers found that all of the CMD patients had intact brain structures related to arousal and command comprehension, supporting the notion that these patients were hearing and understanding the commands but were unable to carry them out.  They saw that all of the CMD patients had deficits in brain regions responsible for integrating comprehended motor commands with motor output, preventing CMD patients from acting on verbal commands.

The findings may allow researchers to better understand which brain injury patients have CMD, which will be useful for clinical trials that support recovery of consciousness.

Eva Franzova, Qi Shen, Kevin Doyle, Justine M Chen, Jennifer Egbebike, Athina Vrosgou, Jerina C Carmona, Lauren Grobois, Gregory A Heinonen, Angela Velazquez, Ian Jerome Gonzales, Satoshi Egawa, Sachin Agarwal, David Roh, Soojin Park, E Sander Connolly, Jan Claassen. Injury patterns associated with cognitive motor dissociation. Brain, 2023; DOI: 10.1093/brain/awad197

Part 2

Annular Eclipse

Mysterious Form of Vision Loss May Brew Inside The Gut!

In some glaucoma patients, vision loss mysteriously progresses despite treatment, and new research from China points to immune cells that migrate from the digestive tract to the eyes. These "gut-retina axis" cells bind a specific protein and gain access to the eye's light-sensitive tissue, where they damage retinal ganglion cells (RGCs). Glaucoma, classified as a group of neurodegenerative diseases, is an umbrella term for eye diseases caused by loss of RGCs, whose axons form the optic nerve which transmits visual information to the brain. Your optic nerve is sending this to your brain's visual cortex to process right now, if you're reading with your eyes. A leading cause of blindness, glaucoma is currently incurable; treatment aims to halt disease progression. These new findings emphasize the importance of the gut-retina axis in glaucoma pathogenesis and for the development of therapeutic strategies. Pressure inside the eyeball, called elevated intraocular pressure (EIOP), is the main risk factor for glaucoma. Lowering EIOP is a primary goal of treatment, but it isn't always successful in stopping progression of the disease.

Previous studies hinted that immune system T cells may play a role in glaucoma damage, but the underlying mechanism has been unclear. T cells and other circulating immune cells are normally denied permission to enter the retina.

These very scientists were part of a 2021 study that found a subset of CD4+ T cells express a gut-homing receptor, integrin β7, which somehow gained entry to the retina with a little help from a protein called mucosal addressin cell adhesion molecule 1 (MAdCAM-1). 

In their new study, tehy confirmed a link between CD4+ T cells that express integrin β7, MAdCAM-1, and glaucoma disease severity in patients.

Part 1

The first step was to test blood samples from 519 glaucoma patients and 189 healthy controls. A significantly higher percentage of β7-expressing CD4+ T cells was found in glaucoma patients compared to healthy controls, and glaucoma patients with more of these cells in their blood had more severe eye damage.

Using an EIOP-induced mouse model of glaucoma, researchers next showed that to gain access to the retina, β7+ CD4+ T cells in these early stage glaucoma mice must make a detour through the gut.

The team found the β7+ CD4+ T cells of EIOP-induced mice were reprogrammed in the gut, so they could use integrin β7 as a kind of license, returning to the blood circulation functionally equipped to travel to the retina.

While normal T cells are unable to bind to MAdCAM-1 in the retina, the gut-licensed cells were able to do so, allowing them access to the eye tissue, which "eventually led to neuroinflammation".

The ability to induce MAdCAM-1 expression on retinal [vessels] might be one of the mechanisms whereby gut-licensed β7+ CD4+ T cells cross the blood-retina barrier and invade the retina, To investigate the link between these suspect cells and proteins and glaucoma damage, the team administered antibodies to mice that blocked the β7+ CD4+ T cells' interaction with MAdCAM-1. Inhibiting the communication with MAdCAM-1 significantly reduced the damage caused by glaucoma.

https://www.science.org/doi/10.1126/scitranslmed.adg1656

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Part 2

Blood factor can turn back time in the aging brain

Platelets are behind the cognitive benefits of young blood, exercise and the longevity hormone klotho. In a remarkable convergence, scientists have discovered that the same blood factor is responsible for the cognitive enhancement that results from young blood transfusion, the longevity hormone klotho, and exercise.

In a trio of papers appearing in Nature, Nature Aging and Nature Communications, three research teams identify platelet factor 4 (PF4) as a common messenger of each of these interventions.

As its name suggests, PF4 is made by platelets, a type of blood cell that alerts the immune system when there is a wound and helps to form clots. It turns out that PF4 is also a cognitive enhancer. Under its influence, old mice recover the sharpness of middle age and young mice get smarter.

Young blood, klotho, and exercise can somehow tell your brain, 'Hey, improve your function'. With PF4, we're starting to understand the vocabulary behind this rejuvenation.

Part 1

Parabiosis: an experiment in which two animals are linked together by their blood circulation. When a young, sprightly animal is connected to an aging animal, the aging animal becomes more youthful–its muscles more resilient, its brain more capable of learning.

In 2014, researchers found that plasma, consisting of blood minus red blood cells, mimicked parabiosis: young blood plasma, injected into old animals, was restorative. When they compared young plasma to old plasma, they found it contained much more PF4. Just injecting PF4 into old animals was about as restorative as young plasma. It calmed down the aged immune system in the body and the brain. Old animals treated with PF4 performed better on a variety of memory and learning tasks.

PF4 actually causes the immune system to look younger, it's decreasing all of these active pro-aging immune factors, leading to a brain with less inflammation, more plasticity and eventually more cognition.

A decade ago, other researchers showed that klotho enhances cognition in young and old animals and also makes the brain more resistant to age-related degeneration. 

But the researchers knew its effects had to be indirect because klotho molecules, injected into the body, never reached the brain. They found that one connection was PF4, released by platelets after an injection of klotho. PF4 had a dramatic effect on the hippocampus, the brain region responsible for making memories, where it enhanced the formation of new neural connections at the molecular level.

Exercise can keep the mind sharp for decades. Researchers also found that platelets released PF4 into the bloodstream following exercise. So exercise  also improved cognition in old animals. 

But for a lot of people with health conditions, mobility issues or of advanced age, exercise isn't possible, so pharmacological intervention is an important area of research. We can now target platelets to promote neurogenesis, enhance cognition and counteract age-related cognitive decline.

Adam B. Schroer et al, Platelet factors attenuate inflammation and rescue cognition in ageing, Nature (2023). DOI: 10.1038/s41586-023-06436-3. www.nature.com/articles/s41586-023-06436-3

Park, C. et al. Platelet factors are induced by longevity factor klotho and enhance cognition in young and aging mice, Nature Aging (2023). DOI: 10.1038/s43587-023-00468-0. www.nature.com/articles/s43587-023-00468-0

Odette Leiter et al, Platelet-derived exerkine CXCL4/platelet factor 4 rejuvenates hippocampal neurogenesis and restores cognitive function in aged mice, Nature Communications (2023). DOI: 10.1038/s41467-023-39873-9

Part 2

Sugars affect brain 'plasticity,' helping with learning, memory, recovery

Can you recognize someone you haven't seen in years, but forget what you had for breakfast yesterday? Our brains constantly rearrange their circuitry to remember familiar faces or learn new skills, but the molecular basis of this process isn't well understood. Recently scientists reported that sulfate groups on complex sugar molecules called glycosaminoglycans (GAGs) affect "plasticity" in the brains of mice. Determining how GAGs function could help us understand how memory and learning work in humans, and provide ways to repair neural connectivity after injuries.

The researchers will present their results today at the fall meeting of the American Chemical Society (ACS).

The sugars that sweeten fruits, candies or cakes are actually just a few simple varieties of the many types of sugars that exist. When strung together, they can make a wide array of complex sugars. GAGs are formed by then attaching other chemical structures, including sulfate groups.

If we study the chemistry of GAGs in the brain, we can learn about brain plasticity and hopefully, in the future, use this information to restore or enhance neural connections involved in memory. These sugars regulate numerous proteins, and their structures change during development and with disease.

In the brain, the most common GAG form is chondroitin sulfate, which is found throughout the extra cellular matrix surrounding the brain's many cells. Chondroitin sulfate can also form structures known as "perineuronal nets," which wrap around individual neurons and stabilize the synaptic connections between them.

One way a GAG's function can be changed is through sulfation motifs, or patterns of sulfate groups tacked onto the sugar chains.

Source: Harnessing chemistry to understand the roles of glycans in neuroplasticity, ACS Fall 2023.

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Cleaning water with 'smart rust' and magnets
Pouring flecks of rust into water usually makes it dirtier. But researchers have developed special iron oxide nanoparticles they call "smart rust" that actually makes it cleaner. Smart rust can attract many substances, including oil, nano- and microplastics, as well as the herbicide glyphosate, depending on the particles' coating. And because the nanoparticles are magnetic, they can easily be removed from water with a magnet along with the pollutants. Now, the team is reporting that they've tweaked the particles to trap estrogen hormones that are potentially harmful to aquatic life.
Using magnetic rust nanoparticles to clean water

These ‘living’ rocks can give birth to baby stones

The staggering science behind trovants, the rocks that can grow, move – and reproduce.

Trovants are bulbous, otherworldly stones that grow over time, thus appearing to be alive. Parent rocks can even push out baby trovants, which then grow independently.

The sandstone structures are found mainly in Romania, with the most famous cluster in and around a village named Costeşti. There, a Trovants Museum Natural Reserve celebrates and protects them.

The stones’ smooth curves give the appearance of modern, man-made sculptures. They feature heavily in local folklore, with people at one time believing them to be giant dinosaur eggs, plant fossils or alien creations. The word trovant was coined by a naturalist and means cemented sand.