When electrons slowly vanish during cooling: Researchers observe an effect unique to the quantum world

Many substances change their properties when they are cooled below a certain critical temperature. Such a phase transition occurs, for example, when water freezes. However, in certain metals there are phase transitions that do not exist in the macrocosm. They arise because of the special laws of quantum mechanics that apply in the realm of nature's smallest building blocks.

It is thought that the concept of electrons as carriers of quantized electric charge no longer applies near these exotic phase transitions. Researchers have now found a way to prove this directly. Their findings allow new insights into the exotic world of quantum physics. The publication has now been released in the journal Nature Physics.

If you cool water below zero degrees Celsius, it solidifies into ice. In the process, it abruptly changes its properties. As ice, for example, it has a much lower density than in a liquid state—which is why icebergs float. In physics, this is referred to as a phase transition. But there are also phase transitions in which characteristic features of a substance change gradually. If, for example, an iron magnet is heated up to 760 degrees Celsius, it loses its attraction to other pieces of metal—it is then no longer ferromagnetic, but paramagnetic. However, this does not happen abruptly, but continuously: The iron atoms behave like tiny magnets.At low temperatures, they are oriented parallel to each other. When heated, they fluctuate more and more around this rest position until they are completely randomly aligned, and the material loses its magnetism completely. So while the metal is being heated, it can be both somewhat ferromagnetic and somewhat paramagnetic.

The phase transition thus takes place gradually, so to speak, until finally all the iron is paramagnetic. Along the way, the transition slows down more and more. This behavior is characteristic of all continuous phase transitions. Physicists call it 'critical slowing down'. The reason is that with continuous transitions, the two phases get energetically closer and closer together.

Part 1

Such a "slowing down" is typical for phase transitions based on the excitation of bosons. Bosons are particles that "generate" interactions (on which, for example, magnetism is based). Matter, on the other hand, is not made up of bosons but of fermions. Electrons, for example, belong to the fermions.

Phase transitions are based on the fact that particles (or also the phenomena triggered by them) disappear. This means that the magnetism in iron becomes smaller and smaller as fewer atoms are aligned in parallel. Fermions, however, cannot be destroyed due to fundamental laws of nature and therefore cannot disappear. "That's why normally they are never involved in phase transitions."

Electrons can be bound in atoms; they then have a fixed place which they cannot leave. Some electrons in metals, on the other hand, are freely mobile—which is why these metals can also conduct electricity. In certain exotic quantum materials, both varieties of electrons can form a superposition state. This produces what are known as quasiparticles.

They are, in a sense, immobile and mobile at the same time—a feature that is only possible in the quantum world. These quasiparticles—unlike "normal" electrons—can be destroyed during a phase transition. This means that the properties of a continuous phase transition can also be observed there, in particular, critical slowing down. So far, this effect could be observed only indirectly in experiments.

Researchers have now developed a new method, which allows direct identification of the collapse of quasiparticles at a phase transition, in particular the associated critical slowing down.

The result contributes to a better understanding of phase transitions in the quantum world. On the long term, the findings might also be useful for applications in quantum information technology.

Critical slowing down near a magnetic quantum phase transition with fermionic breakdown, Nature Physics (2023). DOI: 10.1038/s41567-023-02156-7. www.nature.com/articles/s41567-023-02156-7

Part 2

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Scientists want to understand how the worms survived in extreme conditions for extraordinarily long periods of time.

The discovery, published  recently in the peer-reviewed journal PLOS Genetics, offers new insight into how the worms, also known as nematodes, can survive in extreme conditions for extraordinarily long periods of time, in this case tens of thousands of years.

In 2018, Anastasia Shatilovich, a scientist from the Institute of Physicochemical and Biological Problems in Soil Science RAS in Russia, thawed two female worms from a fossilized burrow dug by gophers in the Arctic.

The worms, which were buried approximately 130 feet in the permafrost, were revived simply by putting them in water, according to a news release from the Max Planck Institute of Molecular Cell Biology and Genetics in Germany.

Called Panagrolaimus kolymaensis, after the Kolyma River in Russia, where they were found, the worms were sent to Germany for further study. The creatures, which have a life span measured in days, died after reproducing several generations in the lab, researchers said.

Using radiocarbon dating, researchers determined the specimens were frozen between 45,839 and 47,769 years ago, during the late Pleistocene.

The roughly millimeter-long worms were able to resist extreme low temperatures by entering a dormant state called cryptobiosis, a process researchers at the institute have been trying to understand.

No nematodes had been known to achieve such a dormant state for thousands of years at a time, Teymuras Kurzchalia, a professor emeritus at the institute who was involved in the study, said recently.

The major take-home message or summary of this discovery is that it is, in principle, possible to stop life for more or less an indefinite time and then restart it.

Researchers identified key genes in the nematode that allow it to achieve the cryptobiotic state. The same genes were found in a contemporary nematode called Caenorhabditis elegans, which can also achieve cryptobiosis.

This led researchers to understand that they cannot survive without a specific sugar called trehalose. Without this sugar, they just die.

The Siberian permafrost has long offered the scientific community a window into the organisms of the distant past. Ancient viruses, mummified bodies and a suite of microscopic creatures have been resurrected from the ice over the years.

Mysterious Creatures Feed Microbes to Their Babies in New Scientific First

Caecilian mothers grow a fatty skin layer for their babies to tear off and eat. It offers not only nourishment for their offspring but also microbes, providing a starter kit for their young's own microbiome, new research has discovered.

Caecilians are weird, mysterious creatures. They look sort of like huge worms or small snakes, but they're really limbless amphibians, lesser-known relatives of frogs and salamanders. They lead secretive lives, generally hidden from view in soil or stream beds.

What little we do know about caecilians invites more curiosity. They can be surprisingly doting parents, especially by amphibian standards. In some species, mothers provide the skin meals for their young, who have uniquely adapted baby teeth to help them eat it.

Many animals are known to pass microbes to the next generation through parental care in some way, but this is the first direct evidence of it happening in any amphibian. And of all the amphibian species it could be, the study's authors found this happening in caecilians.

 Even after the period of skin feeding (or maternal dermatophagy) ends, a mother and her babies often stay together, the researchers note, coiling up together as a family.

The study found that bacteria from the environment were the least important source for microbiomes of young caecilians. But all juveniles shared at least some of their skin and gut microbiomes with their mothers, which they obtained via both skin feeding and coiling.

https://animalmicrobiome.biomedcentral.com/articles/10.1186/s42523-...

Early-life lead exposure linked to higher risk of criminal behaviour in adulthood

An evaluation of 17 previously published studies suggests that exposure to lead in the womb or in childhood is associated with an increased risk of engaging in criminal behavior in adulthood. 

Lead exposure can cause a variety of health challenges, such as cardiac issues,kidney damage, immune system dysfunction, reproductive problems, and impaired neurodevelopmental function in children. Research has also uncovered statistical associations between lead exposure and criminal behaviour, both at the level of the entire population and at the level of individual people. However, the findings of individual-level studies have been inconsistent.

To help clarify the existing evidence, researchers conducted a systematic review of studies that address links between individual lead exposure and crime or other antisocial behaviors. Their analysis included 17 studies, which employed a variety of methods for measuring lead exposure—using blood, bones, or teeth—and addressed the effects of exposure at different ages, including in the womb or early childhood, later childhood, and adolescence or adulthood.

The review highlighted a wide range of findings among the studies. For instance, in some cases, no statistical links were found between early childhood lead exposure and later delinquent behavior. One study showed a link between exposure and antisocial behavior, but not arrests. Still, several studies found links between early childhood exposure to lead and later arrests, including drug-related arrests. The authors also used a tool called ROBINS-E to evaluate each study for statistical bias, finding some studies to be more statistically robust than others.

Overall, in light of the known biological effects of lead, this review suggests that an individual exposed to lead in the womb or in early childhood may have a higher risk of engaging in criminal behaviour as an adult.

Policy action to prevent lead exposure is of utmost importance as our research shows an excess risk for criminal behavior in adulthood exists when an individual is exposed to lead in utero or during childhood. Preventing lead exposure is crucial to safeguard public health and promote a safer society for all.

Talayero MJ, The association between lead exposure and crime: A systematic review, PLOS Global Public Health (2023). DOI: 10.1371/journal.pgph.0002177

Chatbots sometimes make things up. Is AI's hallucination problem fixable?

Spend enough time with ChatGPT and other artificial intelligence chatbots and it doesn't take long for them to spout falsehoods. 

Described as hallucination, confabulation or just plain making things up, it's now a problem for every business, organization and high school student trying to get a generative AI system to compose documents and get work done. Some are using it on tasks with the potential for high-stakes consequences, from psychotherapy to researching and writing legal briefs.

According to experts there isn't any model today that doesn't suffer from some hallucination! They're really just sort of designed to predict the next word, and so there will be some rate at which the model does that inaccurately. 

So experts are now trying to make them truthful. But they aren't very sure. Because the problem is inherent in the mismatch between the technology and the proposed use cases.

But still what is wrong with trying to improve the software/hardware? let us cross our fingers and hope for the best.

Source: AP 

Is AI only software? 

AI is about the principles of making machines learn and make intelligent decisions. AI has many subfields under it: Machine Learning, Reinforcement Learning, Computer Vision (very tightly coupled with Machine Learning), Deep Learning, NLP, data representation and semantics, learning theory, Robotics (which is the hardware side of things) which includes things like planning, motion and manipulation...etc.

So its not only about software. AI can be in the form of abstract theory, learning from data to make predictions and intelligent decisions (software) or in robotics (hardware).

You shouldn't declaw tigers or other big cats

Declawing house cats to keep them from scratching people and furniture is controversial – and even banned in some countries  – but the practice is not limited to house cats. In a new study, researchers looked at the effects of declawing on larger cat species and found that declawing disproportionately impacts their muscular capabilities as compared to their smaller brethren.

Declawing is still done on large cats like lions and tigers, often in an effort to allow cubs to more safely be handled in photo opportunities or for entertainment purposes.

What people might not realize is that declawing a cat is not like trimming our fingernails; rather, it is removing part or all of the last bone of each digit. Like us, each cat finger has three bones, and declawing is literally cutting that third bone off at the joint.

The researchers looked at the muscular anatomy of over a dozen exotic cats – from smaller species including bobcats, servals and ocelots, to lions and tigers – to determine the effect of declawing on their forelimb musculature.

They measured muscle density and mass, and also examined muscle fibers from both clawed and declawed exotic cats. They found that for the larger species declawing resulted in 73% lighter musculature in the forearm’s digital flexors. These muscles are involved in unsheathing the claws. They also found that overall, forelimb strength decreased by 46% to 66%, depending on the size of the animal, and that other muscles in the forelimb did not compensate for these reductions.

With big cats, there’s more force being put through the paws. So if you alter them, it is likely that the effects will be more extreme.

This is because paw size and body mass don’t scale up at a 1:1 ratio. Paw area increases at a slower rate than does body mass (which is proportional to volume), so larger cats have smaller feet relative to their body size, and their paws must withstand more pressure.

Additionally, big cats are more reliant on their forelimbs – they bear most of the weight, and these bigger cats use their forelimbs to grapple because they hunt much larger prey. So biomechanically speaking, declawing has a more anatomically devastating effect in larger species.

Lara L. Martens et al, The Effects of Onychectomy (Declawing) on Antebrachial Myology across the Full Body Size Range of Exotic Species of Felidae, Animals (2023). DOI: 10.3390/ani13152462

Conjunctivitis is the swelling or inflammation of the conjunctiva, the thin, transparent layer of tissue that lines the inner surface of the eyelid and covers the white part of the eye. Causes may or may not be infectious. Allergic Conjunctivitis  ( seasonal allergies) Infectious Conjunctivitis  ( Bacterial, Viral ) Chemical Conjunctivitis ( air pollution, chlorine in water ) Ippudu ee season lo sadharanam ga vachedi viral or bacterial conjunctivitis. There are Eye drops or ointments  for Bacterial con. There are  Antibiotics too. But no drops or ointments can treat viral conjunctivitis. Antibiotics will not cure a viral infection. The virus has to run its course, which may take up to two or three weeks.  In case you have to deal with infectious people,  frequent hand washing and keeping hands away from eyes can make a difference. Don't use Common towels, soaps .Be Careful. If you feel  pain and irritation  please visit a doctor . Self medication is not good.

Novel molecules fight viruses by bursting their bubble-like membranes

Antiviral therapies are notoriously difficult to develop, as viruses can quickly mutate to become resistant to drugs. Viruses have different proteins on their surfaces that are often the targets of therapeutics like monoclonal antibodies and vaccines. But targeting these proteins has limitations, as viruses can quickly evolve, changing the properties of the proteins and making treatments less effective. These limitations were on display when new SARS-CoV-2 variants emerged that evaded both the drugs and the vaccines developed against the original virus.

But what if a new generation of antivirals ignores the fast-mutating proteins on the surface of viruses and instead disrupts their protective layers?

Scientists found an Achilles heel of many viruses: their bubble-like membranes. Exploiting this vulnerability and disrupting the membrane is a promising mechanism of action for developing new antivirals.

In a new study published Aug. 2 in the journal ACS Infectious Diseases, the researchers show how a group of novel molecules inspired by our own immune system inactivates several viruses, including Zika and chikungunya. Their approach may not only lead to drugs that can be used against many viruses, but could also help overcome antiviral resistance.

Drawing inspiration from our immune system is the new mantra. Our innate immune system combats pathogens by producing antimicrobial peptides, the body's first line of defense against bacteria, fungi, and viruses. Most viruses that cause disease are encapsulated in membranes made of lipids, and antimicrobial peptides work by disrupting or even bursting these membranes. While antimicrobial peptides can be synthesized in the lab, they are rarely used to treat infectious diseases in humans because they break down easily and can be toxic to healthy cells. Instead, scientists have developed synthetic materials called peptoids, which have similar chemical backbones to peptides but are better able to break through virus membranes and are less likely to degrade. 

Part 1

The membranes surrounding viruses are made of different molecules than the virus itself, as lipids are acquired from the host to form membranes. One such lipid, phosphatidylserine, is present in the membrane on the outside of viruses, but is sequestered towards the interior of human cells under normal conditions.

Because phosphatidylserine is found on the exterior of viruses, it can be a specific target for peptoids to recognize viruses, but not recognize—and therefore spare—our own cells. Moreover, because viruses acquire lipids from the host rather than encoding from their own genomes, they have better potential to avoid antiviral resistance.

The researchers tested seven peptoids against the four viruses. They found that the peptoids inactivated all three enveloped viruses—Zika, Rift Valley fever, and chikungunya—by disrupting the virus membrane, but did not disrupt coxsackievirus B3, the only virus without a membrane.

Moreover, chikungunya virus containing higher levels of phosphatidylserine in its membrane was more susceptible to the peptoids. In contrast, a membrane formed exclusively with a different lipid named phosphatidylcholine was not disrupted by the peptoids, suggesting that phosphatidylserine is crucial in order for peptoids to reduce viral activity.

The researchers are continuing pre-clinical studies to evaluate the potential of these molecules in fighting viruses and to understand if they can overcome the development of resistance. Their peptoid-focused approach may hold promise for treating a wide range of viruses with membranes that can be difficult to treat, including Ebola, SARS-CoV-2, and herpes.

 Peptidomimetic Oligomers Targeting Membrane Phosphatidylserine Exhibit Broad Antiviral Activity, ACS Infectious Diseases (2023). DOI: 10.1021/acsinfecdis.3c00063 , pubs.acs.org/doi/abs/10.1021/acsinfecdis.3c00063

Part 2

Zap these cells for insulin
Genetically engineered human cells that produce insulin when stimulated by a small electric current could one day be used to develop insulin implants for people with type 1 diabetes. Reactive oxygen species — unstable oxygen-containing radicals that are produced when a current is applied — are involved in a chain that switches on a gene needed to make insulin. Researchers implanted the cells into mice with high blood sugar and used acupuncture needles to apply a current — which triggered the cells to release insulin.

https://www.nature.com/articles/s42255-023-00850-7.epdf?sharing_tok...

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Chatbots are coming to science search Scopus, Dimensions and Web of Science are introducing conversational search using large language models (LLMs). Scopus AI is intended to be a light, playful tool to help researchers quickly get summaries of topics that they’re unfamiliar with. The bot uses a version of GPT-3.5 to return a fluent summary paragraph, together with references and further questions to explore. The Dimensions chatbot first uses a search engine to retrieve relevant articles and then an Open AI GPT model to generate a summary paragraph around the top-ranked abstracts. Both tools will probably be released widely by the end of this year or the beginning of the next. It’s unclear when Web of Science’s LLM-powered search will become available.

https://www.nature.com/articles/d41586-023-02470-3?utm_source=Natur...

Genetic predisposition to atrial fibrillation accelerated by air pollution, research suggests

Research has connected the effects of air pollutants on the risk of atrial fibrillation (AF). In a paper, "Air pollution, genetic susceptibility, and the risk of atrial fibrillation: A large prospective cohort study," published in PNAS, researchers find long-term exposure to air pollutants increases the risk of AF, particularly among individuals with high genetic susceptibility.

Air pollutants have long been associated with cardiovascular diseases. Recent studies have linked short-term exposure to these pollutants with acute exacerbations of AF. Studies on twins suggest that genetic susceptibility plays a big part in the risk of AF, but these risk factors explain only about half of AF cases.

The current study focuses on the cumulative damage caused by long-term exposure to these pollutants, revealing an association between increased concentrations of particulate matter with aerodynamic diameters smaller than 2.5 μm (PM_2.5), particulate matter with diameters of 10 μm (PM₁₀), nitrogen dioxide (NO₂), and nitrogen oxide and the underlying genetic risk of AF.

Despite the visible haze that can come with smoke, dust or vehicle emissions, particle pollution is comprised of tiny non-visible elements under 10 μm, and these can travel deep into the lungs. For reference, the average width of human hair is around 70 μm.

The particles can be hundreds of different chemicals depending on their source. Direct emissions from agricultural, automotive, industrial, fire or construction sites will reflect what is coming from those sources. In the atmosphere, more environmentally complex sources like those emitted from power plants, heavy industries and automobile emissions can undergo reactions to produce chemicals like sulfur dioxide and nitrogen oxides.

When combining genetic susceptibility with high air pollutant levels, participants exposed to high air pollutants with high genetic risk had approximately 149–182% higher risk of AF than individuals with low genetic risk factors.

The study also found a significant additive risk interaction between PM₁₀ and NO₂ and genetic risk, with approximately 16.4–35.1% of cases attributable to the joint effects of these pollutants and genetic predisposition.

The combined effects of  air pollutants and genetic risk showed a dose-response manner, such that exposure to high air pollutant levels and having high genetic risk resulted in high AF chances.

Yudiyang Ma et al, Air pollution, genetic susceptibility, and the risk of atrial fibrillation: A large prospective cohort study, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2302708120

A new discovery in a cause of inner-ear bone loss

Chronic inflammation of the middle ear can cause several problems and complications that can affect a person's hearing and balance. One such problem is the formation of a cholesteatoma, which is an abnormal collection of cells in the ear that can cause bone erosion if left untreated. In turn, this can cause symptoms such as hearing loss, dizziness, facial paralysis, and even a brain infection.

In a study published recently in Nature Communications, researchers have revealed the cause of cholesteatomas, which may help in developing new therapies for patients who are suffering from this disease.

Cholesteatomas are made up of cysts or bumps in the ear that consist of skin, collagen fibers, skin cells, fibroblasts, keratin, and dead tissue. There are many theories on how these cholesteatomas can cause bone erosion, including the activation of cells responsible for the breakdown of the minerals and matrix of the bone, the presence of inflammatory markers and enzymes, and the accumulation and pressure from dead cells and tissues in the ear. However, the exact mechanism for the creation of cholesteatomas remains unknown.

A cholesteatoma can still return or happen again even after its surgical removal, so it is important to know what is actually causing it.

To investigate this, researchers looked at human cholesteatoma tissues that were surgically removed from patients. A process called single-cell RNA sequencing analysis was employed to identify cells responsible for triggering bone erosion; these were called osteoclastogenic fibroblasts. This study demonstrated how these fibroblasts expressed an abundant amount of activin A, a molecule that regulates different physiologic functions of the body. The presence of activin A is said to cause bone erosion through a process in which specialized cells initiate bone resorption through a process wherein the minerals and matrix of the bones are broken down and absorbed by the body. 

The researchers were successful in showing the relationship between activin A and bone erosion in cholesteatoma.

Currently in clinical settings, the only effective treatment for cholesteatomas is complete surgical removal. However, the discovery of how a cholesteatoma can cause bone erosion in this study offers new hope for developing novel medical treatments as first-line management for cholesteatomas.

Single-cell transcriptomics of human cholesteatoma identifies an activin A-producing osteoclastogenic fibroblast subset inducing bone destruction, Nature Communications (2023). DOI: 10.1038/s41467-023-40094-3

Study reveals unexpected importance of the thymus in adults

The thymus gland—which produces immune T cells before birth and during childhood— is often regarded as nonfunctional in adults, and it's sometimes removed during cardiac surgery for easier access to the heart and major blood vessels.

New research  by investigators and  published in the New England Journal of Medicine has uncovered evidence that the thymus is in fact critical for adult health generally and for preventing cancer and perhaps autoimmune disease.

To determine whether the thymus provides health benefits to adults, the team evaluated the risk of death, cancer, and autoimmune disease among 1,146 adults who had their thymus removed during surgery and among 1,146 demographically matched patients who underwent similar cardiothoracic surgery without thymectomy. The scientists also measured T cell production and blood levels of immune-related molecules in a subgroup of patients.

Five years after surgery, 8.1% of patients who had a thymectomy died compared with 2.8% of those who did not have their thymus removed, equating to a 2.9-times higher risk of death. Also during that time, 7.4% of patients in the thymectomy group developed cancer compared with 3.7% of patients in the control group, for a 2.0-times higher risk.

The thymus is absolutely required for health. If it isn't there, people's risk of dying and risk of cancer is at least double. This indicates that the consequences of thymus removal should be carefully considered when contemplating thymectomy.

In an additional analysis involving all patients in the thymectomy group with more than five years of follow-up, the overall mortality rate was higher in the thymectomy group than in the general U.S. population (9.0% vs. 5.2%), as was mortality due to cancer (2.3% vs. 1.5%).

Kameron A. Kooshesh et al, Health Consequences of Thymus Removal in Adults, New England Journal of Medicine (2023). DOI: 10.1056/NEJMoa2302892

Study shows people experience emotions with computer-generated art

Computers and artificial intelligence (AI) are becoming increasingly important in the art world. AI-generated artworks fetch millions at auction, and artists routinely use algorithms to create aesthetic content.

Now, a team of researchers  has conducted experiments showing that, contrary to popular intuition, people perceive emotions and intentions when viewing art, even when they know the work was generated by a computer. The study was published in the journal Computer in Human Behavior.

Jason Allen’s A.I.-generated work, “Théâtre D’opéra Spatial,” ( Source: nytimes)

Researchers investigated whether people respond emotionally to, or perceive intentionality in, art that they believe was generated by a computer.

The researchers presented participants with abstract black-and-white artworks, explaining that the artworks were either randomly generated by a computer or intentionally created by a person to evoke emotion.

Before viewing each artwork, participants were told whether it was supposedly created by a computer or a person; this information was true in half of the cases. The participants were then asked to rate the artworks based on several dimensions. In addition, they were asked to indicate the emotions they personally experienced while viewing the artworks, the emotions they believed the artworks were intended to evoke in viewers, and the emotions, if any, they believed the artists themselves felt while creating the artworks.

The results showed that participants almost always experienced some emotion and perceived some level of intentionality.

The study thereby provides new empirical evidence that people can form emotional attachments to computer-generated art. So contrary to common assumptions, people seem to perceive emotions and intentions even when they know that something was created by a computer. However, they reported stronger emotions and rated the artwork more positively if it had actually been created by a person—even when they got the wrong information that the art was computer-generated.

Thus, the results also show that a subtle but significant difference in emotional impact remains between human and artificial art. This could point to specific characteristics in man-made art that are perceived by viewers.

Overall, the results raise new questions for human-computer interaction and the growing role of AI as a creative entity in art, design, and entertainment.

 Theresa Rahel Demmer et al, Does an emotional connection to art really require a human artist? Emotion and intentionality responses to AI- versus human-created art and impact on aesthetic experience., Computers in Human Behavior (2023). DOI: 10.1016/j.chb.2023.107875

Geostationary satellite reveals widespread midday depression in dryland photosynthesis during 2020 heat wave

We are facing unprecedented heat waves . These conditions have resulted in severe consequences for both human and nature systems, including dire water shortages, rampant wildfires, substantial agricultural losses, and increased human mortality.

The places where these heat waves occur, ecosystems face exacerbated water stress due to more frequent and protracted droughts and heat waves, which can profoundly impair ecosystem photosynthesis and carbon uptake, in turn affecting the global carbon cycle.

Investigating vegetation photosynthesis at various time scales provides valuable insights into vegetation growth, carbon uptake, and environmental interactions. Traditional polar-orbiting satellite observations have aided in monitoring gross primary production (GPP) at longer scales (e.g., monthly, annual), but they are limited in capturing diurnal variations. Fortunately, in recent years, emerging new-generation geostationary satellites with sub-daily sampling capability, provide unique opportunities to study diurnal variations of vegetation photosynthesis and their responses to environmental conditions over the course of day at large spatial scales.

In a recent study, scientists estimated hourly GPP across the Conterminous U.S. based on observations from Geostationary Operational Environmental Satellite-R (GOES-R), and then investigated how the diurnal cycle of photosynthesis responded to the severe late-summer heat wave of 2020. The work is published in the journal Science Advances.

The study provides an exploration of heat wave impacts on the diurnal dynamics of photosynthesis at a continental scale, revealing a widespread midday and afternoon depression of photosynthesis in dryland ecosystems during the heat wave. In the study the researchers examine the environmental regulation of diurnal photosynthesis dynamics across diverse ecosystems, and illustrate how current radiation-based methods for upscaling polar-orbiting satellite snapshots to daily means may under- or overestimate daily GPP.

They found a widespread midday and afternoon depression in ecosystem photosynthesis during the heat wave .

The diurnal metrics exhibit divergent responses to the heat wave across vegetation types and along aridity gradients. Overall, shrubland and grassland are more sensitive to the heat wave than the other vegetation types.

The impact of the heat wave on the diurnal cycle of photosynthesis is predominantly observed in arid and semiarid regions with an aridity index (AI) below 0.6. They found that the largest GPP loss occurred at noon or during the afternoon for the majority of western regions, later than the GPP peak hour during the heat wave year, further substantiating the asymmetric influence of heat waves on diurnal photosynthesis fluctuations.

 Xing Li et al, New-generation geostationary satellite reveals widespread midday depression in dryland photosynthesis during 2020 western U.S. heatwave, Science Advances (2023). DOI: 10.1126/sciadv.adi0775

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.