Smell loss is linked to more than 100 diseases in new study

Researchers reveal a powerful link between olfactory loss and inflammation in a staggering 139 medical conditions. 

This research  emphasizes a little-known but potentially life-altering connection: the role our sense of smell plays in maintaining our physical and mental health.

Olfactory dysfunction, often dismissed as a minor inconvenience, may actually be an early sign of various neurological and bodily diseases, as indicated by this research.

The data are particularly interesting because scientists had previously found that olfactory enrichment can improve the memory of older adults by 226%. Scientists  now know that pleasant scents can decrease inflammation, potentially pointing to the mechanism by which such scents can improve brain health.

This finding, they think, could hold key implications for mitigating symptoms and possibly even reducing the onset of certain diseases through therapeutic olfactory stimulation.

Part 1

The study delves into the methodical tracking of 139 medical conditions associated with both olfactory loss and heightened inflammation, uncovering insights into a shared pathway linking these factors. Olfactory loss, which often precedes conditions such as Alzheimer's and Parkinson's diseases, may serve as an early indicator of disease onset, allowing for more proactive therapeutic approaches.
It was difficult to track down the studies for so many medical conditions, say the scientists, reflecting on the complexity of linking olfactory loss to such a wide array of disorders. The challenge, they emphasize, underscores the importance of these findings in framing olfactory health as integral to overall well-being.
By showing how olfactory enrichment can mitigate inflammation, this research has laid a foundation for future studies aiming to explore the therapeutic use of scent to address a broader range of medical conditions.
The researchers are now working on a device to deliver olfactory therapy, which could hold promise as a novel, non-invasive way to improve health outcomes.

Michael Leon et al, Inflammation and olfactory loss are associated with at least 139 medical conditions, Frontiers in Molecular Neuroscience (2024). DOI: 10.3389/fnmol.2024.1455418

Part 2

Researchers identify key metabolites impacting lifespan in flies and humans

Discoveries that impact lifespan and healthspan in fruit flies are usually tested in mice before being considered potentially relevant in humans, a process that is expensive and time-intensive. A pioneering approach taken by researchers leapfrogs over that standard methodology.

Utilizing cutting-edge machine learning and systems biology, researchers have analyzed and correlated huge data sets from flies and humans to identify key metabolites that impact lifespan in both species. Results published in Nature Communications suggest that one of the metabolites, threonine, may hold promise as a potential therapeutic for aging interventions.

Threonine has been shown to protect against diabetes in mice. The essential amino acid plays an important role in collagen and elastin production and is also involved in blood clotting, fat metabolism and immune function.

In flies, threonine extended lifespan in a strain-and-sex-specific manner. Individuals with higher levels of threonine-related metabolites had longer, healthier lives.

Scientists are not saying that threonine is going to work in all conditions. This  research shows it works in subsets of both flies and people. However, this is not a magic bullet. 

The results also include findings that were not so positive for both species. Orotate, which is relatively understudied and has been linked with fat metabolism, was negatively associated with aging. In flies, orotate counteracted the positive impact of dietary restriction across every strain of the animals. In humans, orotate was linked to a shorter lifespan.

Tyler A. U. Hilsabeck et al, Systems biology approaches identify metabolic signatures of dietary lifespan and healthspan across species, Nature Communications (2024). DOI: 10.1038/s41467-024-52909-y

What is transcranial ultrasound stimulation (TUS)?

Constraining the body of a hydra can cause it to grow two heads

Hydra are small, invertebrate, predatory animals that live in water. They're tubular, radially symmetric and up to 10 mm long, with a head (mostly a mouth), a single, adhesive foot, and tentacles.

In a study published in the journal PRX Life, researchers investigated how technical forces and feedbacks on a Hydra might affect its body plan.

They choose Hydra because they are notable for being able to regenerate, as most of their body cells are stem cells, which can continually divide and then differentiate into any of the body's cell types. In fact, Hydra are so good at it that do not appear to age and may be immortal, constantly regenerating whatever cells they need, even from an initial small piece of tissue.

All animals share a common body plan because all come from a common ancestor, including bilateral symmetry, segmented bodies and a digestive system. Over billions of years, evolution has modified their shapes to create the enormous variety of body morphologies observed in the animal kingdom. But this biological pattern formation is still not well understood.

Morphogenesis is the biological process that causes a cell, tissue, or organism to develop its shape. It involves the differentiation of cells, tissues, and organs, leading to the creation of order in the developing organism.

Morphogenesis is a fundamental aspect of developmental biology, alongside tissue growth control and cellular differentiation. But what if an organism is constrained in some way due to external forces?

In this study, a team of researchers confined Hydra into a narrow cylindrical channel. The channel constrained the morphology of the animal—the form and structure of an organism, and particular features of its structure.

Part 1

In the group's earlier work, they focused on the role of multi-cellular arrays of actomyosin fibers in guiding and stabilizing the body axis of the Hydra as they regenerated. (Actomyosin is a complex formed by two interacting proteins, actin and myosin. It plays crucial roles in muscle contraction and cell movement, with the myosin motor protein pulling the actin filaments into place.)

Hydra have parallel actomyosin fibers that contract, and previous work by the same group found that the body axis of Hydra regenerated when tissue segments were aligned with the inherited body axis of the parent.

They decided to investigate how the orientation field of the actomyosin fibers, which contained locally disordered regions called topological defects, is relevant to the body plan of Hydra morphogenesis, which was still unknown.

They developed a methodology to confine regenerating Hydra in an anisotropic manner—on an axis other than the Hydra's parallel fibers. This required a method of confinement that did not damage the organism's tissue or regenerating capacity over the course of several days. They also needed high resolution live imaging over the entire time of regeneration.

The confinement was in a glass capillary tube, equipped with small cylindrical channels on its inner surface, 120 to 300 microns wide, made of a stiff gel between the spherical tissue samples and the glass wall.

When the Hydra tissue was introduced into the resulting channel, while a softer gel was pushed into the channel cavities on the edges to create a width available to the Hydra, care was taken not to tear the tissue during the soft gel insertion.

This reduced the movement of the tissue along the cylinder axis, with about 20 to 50 cells along the circumference of the cavity (a typical cell size is 20 microns), while allowing the spherical tissue to unfold and regenerate into an elongated, ellipsoidal shape.

After some time, the regenerating tissue fills the channel available to it, then forms a mouth and tentacles as the body column becomes narrower than the channel, and the animal separates from the channel walls.

In this way, an angle develops between the constrained body axis and the inherited body axis. The relative angle between the inherited body axis and the channel axis depends on the orientation in which the Hydra tissue spheroid enters the channel, with its inherited axis parallel or perpendicular to the channel's axis.
Part 2

The constraint imposed on the tissue geometry by the channel walls affects the patterns of mechanical stress experienced by the Hydra tissue, from both the hydrostatic pressure gradient across the tube and the frequent muscle contractions that take place.

The group found there was a strong preference of the body axes and the actomyosin fiber to come into alignment with the "easy-axis" of the channel, with one head and one foot along the channel axis. But different body plans developed if the initial tissue was perpendicular to the channel axis.

They wrote, "samples that are initially oriented with their primary fiber alignment perpendicular to the channel direction often regenerate into multiaxial morphologies."

But if the animals that were confined in length, perpendicular to the channel axis, they consisted mostly of animals with, amazingly, two heads, and often more than one foot. These multiple morphological features are not arranged along a single axis, but rather at junctions between axes with particular topological defects in the fiber organization.

Yonit Maroudas-Sacks et al, Confinement Modulates Axial Patterning in Regenerating Hydra, PRX Life (2024). DOI: 10.1103/PRXLife.2.043007

Part 3

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Animal alcohol consumption more common than thought

Anecdotes abound of wildlife behaving "drunk" after eating fermented fruits, but despite this, nonhuman consumption of ethanol has been assumed to be rare and accidental. Ecologists challenge this assumption in a review published October 30 in Trends in Ecology & Evolution. They argue that since ethanol is naturally present in nearly every ecosystem, it is likely consumed on a regular basis by most fruit- and nectar-eating animals.

It is much more abundant in the natural world than we previously thought, and most animals that eat sugary fruits are going to be exposed to some level of ethanol.

Ethanol first became abundant around 100 million years ago, when flowering plants began producing sugary nectar and fruits that yeast could ferment. Now, it's present naturally in nearly every ecosystem, though concentrations are higher, and production occurs year-round in lower-latitude and humid tropical environments compared to temperate regions.

Most of the time, naturally fermented fruits only reach 1–2% alcohol by volume (ABV), but concentrations as high as 10.2% ABV have been found in over-ripe palm fruit in Panama.

Animals already harbored genes that could degrade ethanol before yeasts began producing it, but there is evidence that evolution fine-tuned this ability for mammals and birds that consume fruit and nectar. In particular, primates and tree-shrews have adapted to efficiently metabolize ethanol.

From an ecological perspective, it is not advantageous to be inebriated as you're climbing around in the trees or surrounded by predators at night—that's a recipe for not having your genes passed on.

It's the opposite of humans who want to get intoxicated but don't really want the calories—from the non-human perspective, the animals want the calories but not the inebriation.

Part 1

It's unclear whether animals intentionally consume ethanol for ethanol's sake, and more research is needed to understand its impact on animal physiology and evolution. However, the researchers say that ethanol consumption could carry several benefits for wild animals.
First and foremost, it's a source of calories, and the odorous compounds produced during fermentation could guide animals to food sources, though the researchers say it's unlikely that animals can detect ethanol itself.

Ethanol could also have medicinal benefits: fruit flies intentionally lay their eggs in substances containing ethanol, which protects their eggs from parasites, and fruit fly larvae increase their ethanol intake when they become parasitized by wasps.

On the cognitive side, ideas have been put forward that ethanol can trigger the endorphin and dopamine system, which leads to feelings of relaxation that could have benefits in terms of sociality.

 The evolutionary ecology of ethanol, Trends in Ecology & Evolution (2024). DOI: 10.1016/j.tree.2024.09.005

Part 2

Comb jellies can reverse age

A new article published in Proceedings of the National Academy of Sciences reveals the unprecedented ability for reverse development in a ctenophore, also called comb jelly. The findings suggest that life cycle plasticity in animals might be more common than previously thought.

Animal life cycles typically follow a familiar pattern of decline in countless variations: they are born, grow, reproduce and die, giving way to the next generation. Only a few species are able to deviate from this general principle, the best-known example being the "immortal jellyfish" Turritopsis dohrnii, which can revert from an adult medusa back to a polyp. This elusive group of animals with flexible life cycles now includes the ctenophore Mnemiopsis leidyi.

The work challenges our understanding of early animal development and body plans, opening new avenues for the study of life cycle plasticity and rejuvenation. The fact that we have found a new species that uses this peculiar 'time-travel machine' raises fascinating questions about how spread this capacity is across the animal tree of life.

Joan J. Soto-Angel et al, Reverse development in the ctenophore Mnemiopsis leidyi, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2411499121

Researchers show nanoplastics can reduce the effectiveness of antibiotics

In a recent study, an international research team has investigated how nanoplastic particles deposited in the body affect the effectiveness of antibiotics.

The study showed that the plastic particles not only impair the effect of the drugs, but could also promote the development of antibiotic-resistant bacteria. These results were recently published in the journal Scientific Reports.

The focus was on the broad-spectrum antibiotic tetracycline, which is used to treat many bacterial infections, such as those of the respiratory tract, skin or intestines.

When it came to plastics, the choice fell on polyethylene (PE), polypropylene (PP) and polystyrene (PS), which are ubiquitous components of packaging materials, as well as nylon 6,6 (N66), which is contained in many textiles such as clothing, carpets, sofa covers and curtains. Nanoplastics are smaller than 0.001millimeters and are considered particularly harmful to humans and the environment due to their small size.

Using complex computer models, the team was able to prove that the nanoplastic particles can bind tetracycline and thus impair the effectiveness of the antibiotic. The binding was particularly strong with nylon.

The micro- and nanoplastic load is around five times higher there than outdoors. Nylon is one of the reasons for this: it is released from textiles and enters the body via respiration, for example.

As the study results show, the binding of tetracycline to nanoplastic particles can reduce the biological activity of the antibiotic. At the same time, binding to nanoplastics could lead to the antibiotic being transported to unintended sites in the body, causing it to lose its targeted effect and possibly cause other undesirable effects.

This increase in concentration could lead to the development of antibiotic-resistant bacteria. Plastics such as nylon 6,6, but also polystyrene, which bind more strongly to tetracycline, could therefore increase the risk of resistance.

The study shows that exposure to nanoplastics is not only a direct health risk, but can also indirectly influence the treatment of diseases. If nanoplastics reduce the effectiveness of antibiotics, the dosage poses a massive problem.

Leonard Dick et al, The adsorption of drugs on nanoplastics has severe biological impact, Scientific Reports (2024). DOI: 10.1038/s41598-024-75785-4

Some wildfire suppressants contain heavy metals and could contaminate the environment

In fire-prone areas, water isn't the only thing used to quell blazes. Wildland firefighters also apply chemical or synthetic suppressants. Researchers reporting in Environmental Science & Technology Letters explored whether these suppressants could be a source of elevated metal levels sometimes found in waterways after wildfires are extinguished.

Several products they investigated contained high levels of at least one metal, including chromium and cadmium, and could contribute to post-fire increases in the environment.

Wildfires are associated with the release of toxic heavy metals to the environment, but until now, it was assumed that these metals came from natural sources like soil. We now know that fire retardants may contribute to these metal releases.

Wildfire suppressant products, which are intended to inhibit fire activity before and after water evaporates, include fire retardants, water enhancers and foams. As wildfires have become more frequent and severe, larger volumes of water along with chemical and synthetic suppressants—sprayed from the ground and dropped from planes—have been required to extinguish them. Although manufacturers identify most of the active ingredients in suppressants, some components are proprietary. In addition, previous researchers have observed increased concentrations of potentially toxic metals in soil and streams after wildfires.

These results show that fire suppression activities could contribute to elevated metal levels in the environment but that more work is needed to determine potential risks to human and environmental health.

Marella H. Schammel et al, Metals in Wildfire Suppressants, Environmental Science & Technology Letters (2024). DOI: 10.1021/acs.estlett.4c00727

Electric fans fail to lower core body temperature of seniors during heat waves, study finds

A team of physiologists at the University of Ottawa's Human and Environmental Physiology Research Unit reports that use of an electric fan during periods of high temperatures by older people does not lower core body temperatures. In their study, published in JAMA, the group conducted experiments with elderly volunteers using fans in high-temperature conditions.

As several heat waves have struck parts of North America, high numbers of older people have died of heat stroke. This was notable due to the location of many of the deaths—the Pacific Northwest, where extremely high temperatures are rare. Because of the rarity of such high temperatures, many people in the region do not have air conditioners. Prior research has shown that older people are at higher risk of dying of heat stroke due to their lessened ability to reduce their body temperature. One notable problem is less efficient sweating.

During heat waves, officials in the affected regions suggested that older people without access to air conditioning use electric fans to stay cool. In this new effort, the research team tested the approach to see if the advice was valid.

The researchers recruited 18 people ranging in age from 65 to 72, who sat in a climate-controlled temperature chamber with an electric fan. The temperature and the fan settings were both controlled by the research team. All the volunteers were monitored during the experiments to ensure they did not become overheated.

The researchers kept the temperature inside the chamber at a steady 36°C, with a humidity level of 45%. The fans had three spin settings: off, slow and fast. All three settings were tested with the volunteers.

The researchers found that neither the slow nor the fast setting had any measurable impact on core body temperature—it was the same as if the fan was off. They also found that the slow setting did little to make the volunteers feel cooler, but the fast setting did, which, they suggest, was dangerous. Because they felt somewhat cool, the volunteers did not realize that their core body temperatures might be rising to dangerous levels.

 Fergus K. O'Connor et al, Effect of Electric Fans on Body Core Temperature in Older Adults Exposed to Extreme Indoor Heat, JAMA (2024). DOI: 10.1001/jama.2024.19457

Once again, tuberculosis becomes world's top infectious disease killer

In the highest tally ever recorded for tuberculosis cases, the World Health Organization report that over 8 million people worldwide were diagnosed with the lung disease last year.

Of that number, 1.25 million people died of TB, the new report found, meaning that it is once again the leading cause of deaths from infectious disease after COVID-19 displaced it briefly during the pandemic.

The fact that TB still kills and sickens so many people is an outrage, when we have the tools to prevent it, detect it and treat it," WHO Director-General Dr. Tedros Adhanom Ghebreyesus said in an agency news release. "WHO urges all countries to make good on the concrete commitments they have made to expand the use of those tools, and to end TB."

Some countries are hit harder by the disease than others. It continues to mostly affect people in Southeast Asia, Africa and the Western Pacific. India, Indonesia, China, the Philippines and Pakistan account for more than half of the world's cases, the WHO noted.

According to the report, 55% of people who developed TB were men, while 33% were women and 12% were children and young adolescents. Many new TB cases were driven by five major risk factors: undernutrition, HIV infection, alcohol use disorders, smoking [especially among men] and diabetes.

Tackling these issues, along with other social determinants such as poverty, requires a coordinated approach, the WHO added.

https://www.who.int/news/item/29-10-2024-tuberculosis-resurges-as-t...

Bats have acoustic cognitive maps

Echolocating bats have been found to possess an acoustic cognitive map of their home range, enabling them to navigate over kilometer-scale distances using echolocation alone.

This finding, published in Science, was demonstrated by researchers.

Would you be able to instantly recognize your location and find your way home from any random point within a three-kilometer radius, in complete darkness, with only a flashlight to guide you?

Echolocating bats face a similar challenge, with a local and directed beam of sound—their echolocation—to guide their way. Bats have long been known for their use of echolocation to avoid obstacles and orient themselves.

The researchers have now shown that bats can identify their location even after being displaced and use echolocation to perform map-based navigation over long distances.

Remarkably in experiments, even with echolocation alone, 95% of the displaced bats  returned to their roosts within minutes, demonstrating that bats can conduct kilometer-scale navigation using only this highly directional, and relatively local, mode of sensing. However, it was also shown that, when available, bats improve their navigation using vision.

The model created revealed that bats tend to fly near environmental features with higher "echoic entropy"—areas that provide richer acoustic information.

Bats can use this acoustic information to distinguish between environmental features such as a tree and a road, and thus use them as acoustic landmarks.

After being displaced, these  bats first identify their new location and then fly home, using environmental features with distinctive acoustic cues as landmarks. This behaviour suggests they possess an acoustic mental map of their home range.

Aya Goldshtein, Acoustic cognitive map-based navigation in echolocating bats, Science (2024). DOI: 10.1126/science.adn6269. www.science.org/doi/10.1126/science.adn6269

Part 2

It's time to rewrite the textbooks: 

Chemists just broke a 100-year-old rule

I love this!

Chemists have found a big problem with a fundamental rule of organic chemistry that has been around for 100 years—it's just not true. And they say, It's time to rewrite the textbooks.

Organic molecules, those made primarily of carbon, are characterized by having specific shapes and arrangements of atoms. Molecules known as olefins have double bonds, or alkenes, between two carbon atoms. The atoms, and those attached to them, ordinarily lie in the same 3D plane. Molecules that deviate from this geometry are uncommon.

The rule in question, known as Bredt's rule in textbooks, was reported in 1924. It states that molecules cannot have a carbon-carbon double bond at the ring junction of a bridged bicyclic molecule, also known as the "bridgehead" position. The double bond on these structures would have distorted, twisted geometrical shapes that deviate from the rigid geometry of alkenes taught in textbooks.

Olefins are useful in pharmaceutical research, but Bredt's rule has constrained the kind of synthetic molecules scientists can imagine making with them and prevented possible applications of their use in drug discovery.

A paper published by scientists in the journal Science has invalidated that idea. They show how to make several kinds of molecules that violate Bredt's rule, called anti-Bredt olefins, or ABOs, allowing chemists to find practical ways to make and use them in reactions.

People aren't exploring anti-Bredt olefins because they think they can't (very bad for science).

"We shouldn't have rules like this—or if we have them, they should only exist with the constant reminder that they're guidelines, not rules. It destroys creativity when we have rules that supposedly can't be overcome", say the scientists.

What this study shows is that contrary to one hundred years of conventional wisdom, chemists can make and use anti-Bredt olefins to make value-added products.

There's a big push in the pharmaceutical industry to develop chemical reactions that give three-dimensional structures like these because they can be used to discover new medicines.

Luca McDermott et al, A solution to the anti-Bredt olefin synthesis problem, Science (2024). DOI: 10.1126/science.adq3519. www.science.org/doi/10.1126/science.adq3519

Scientists engineer 'glowing' gel to improve eye surgery

Cataracts—a condition that causes clouding of the eye's lens and deteriorating vision—will affect nearly everyone who lives long enough. Now  scientists have pioneered a new color-changing hydrogel that could reduce complications from cataract surgery, one of the world's most commonly performed procedures.

During cataract surgery, doctors remove the cloudy lens and replace it with an artificial one. The procedure requires injecting a clear hydrogel to keep the eye inflated and protect the cornea. However, incomplete removal of this gel can lead to increased eye pressure, pain, and even long-term vision loss.

Researchers have created a clear gel that turns fluorescent green under blue light, allowing surgeons to verify complete removal following surgery. This innovation could enhance both the safety and efficiency of cataract surgery and other eye procedures, according to the researchers.

Now, when surgeons finish up a case, they can rest assured that all the gel has been removed versus beforehand when they just had to do their best and hope they'd gotten it all.

Their results were featured on the cover of the Journal of Cataract & Refractive Surgery.

 Erick E. Rocher et al, Fluorescein-conjugated hyaluronic acid enables visualization of retained ophthalmic viscosurgical device in anterior chamber, Journal of Cataract & Refractive Surgery (2024). DOI: 10.1097/j.jcrs.0000000000001503

Low sugar intake in utero and in early childhood found to significantly reduce risk of midlife chronic disease

A low-sugar diet in utero and in the first two years of life can meaningfully reduce the risk of chronic diseases in adulthood, a new study has found, providing compelling new evidence of the lifelong health effects of early-life sugar consumption.

Published in Science, the study finds that children who experienced sugar restrictions during their first 1,000 days after conception had up to 35% lower risk of developing type 2 diabetes and as much as 20% less risk of hypertension as adults. Low sugar intake by the mother prior to birth was enough to lower risks, but continued sugar restriction after birth increased the benefits.

 Tadeja Gracner et al, Exposure to sugar rationing in the first 1000 days of life protected against chronic disease, Science (2024). DOI: 10.1126/science.adn5421

Causal relationship seen between GERD and hypertension

There is a positive causal relationship between gastroesophageal reflux disease (GERD) and hypertension, according to a study published online Sept. 23 in Frontiers in Cardiovascular Medicine.

Researchers  investigated the causal  between GERD and hypertension using a two-sample Mendelian randomization analysis.

The researchers reported that a total of 16 single nucleotide polymorphisms strongly associated with GERD were screened out, and the inverse variance weighting suggested a causal relationship between GERD and hypertension (odds ratio, 1.057). A similar relationship was seen using a weighted median (odds ratio, 1.051). No heterogeneity or horizontal pleiotropy was seen, suggesting a robustness of the outcome.

"Although the specific mechanism was not elucidated, this study provides another perspective on the risk factors for the development of hypertension," the authors write. "Timely diagnosis and treatment of GERD can significantly improve and reduce the development of associated hypertension and deserves further research and application."

Weige Li et al, Study of the causal relationship between gastroesophageal reflux disease and hypertension through two-sample Mendelian randomization analysis, Frontiers in Cardiovascular Medicine (2024). DOI: 10.3389/fcvm.2024.1326348

Obesity combined with polycystic ovary syndrome in mothers poses risk to children

Women with polycystic ovary syndrome (PCOS) and obesity are at a higher risk of giving birth to smaller babies in terms of birth weight, length, and head circumference, according to a recent study conducted.

 

One in eight women is affected by the hormone disorder PCOS. PCOS is commonly characterized by elevated levels of male sex hormones, infrequent or irregular menstrual periods, and the formation of small cysts on the ovaries.

In the study, 390 children born to women with PCOS were compared to around 70,000 children from the Norwegian Mother, Father and Child Cohort Study (MoBa).

The researchers found that on average, the babies born to mothers with PCOS weighed less, were shorter, and had a smaller head circumference  at birth. This was particularly the case when the mothers were obese, meaning they had a BMI over 30.

The findings are published in the journal JAMA Network Open.

PCOS is a disease that follows women throughout their lives and can trigger different metabolic diseases and problems such as diabetes, high blood pressure, and obesity. Women with PCOS are generally more likely to develop overweight and obesity.

In women of normal weight who have PCOS, researchers only find that their children have a lower birth weight compared to women who do not have PCOS. Instead, the group of children born to mothers with obesity stands out the most. These babies weigh less, are shorter and have a smaller head circumference. Obesity places an additional burden on mothers who have PCOS as well as their children.

Part 1

What is unusual is that women who are generally overweight and gain a lot of weight during pregnancy usually have an increased risk of giving birth to large babies. This also applies to women who develop gestational diabetes.

On average, women with PCOS have higher BMIs, gain more weight during pregnancy, and 25 percent develop gestational diabetes. However, the outcome is the opposite: these women give birth to babies who are smaller than average. We still don't know why, but we see that the placenta is affected in these women.
Even though the placenta in these women is smaller in size, it seems to deliver more nutrients relative to the baby's body weight compared to a normal placenta. It is a placenta in overdrive.
The placenta delivers nutrients to the baby through the umbilical cord. In women with PCOS, we see that the placenta is generally smaller in size. At the same time, it must provide everything the baby needs, so it has to work very hard to meet these demands. Sometimes, however, the placenta can't keep up, which can lead to placental insufficiency and, in rare cases, fetal death.
There are no definitive answers tot eh question "why"?
Previously, researchers thought the cause was linked to the high levels of male sex hormones, but they have not been able to fully connect the two. Researchers also know that women with PCOS have a slightly different immune profile during pregnancy.
The researchers have also followed up on some of the children when they were 7 years old. They saw that the children born to mothers with PCOS generally had more central obesity, meaning they were larger around the waist.

Other studies have shown that children born to mothers with PCOS are at higher risk of developing overweight and obesity at a young age. Research has also shown that low birth weight is linked to the development of type 2 diabetes and cardiovascular disease later in life.
We see differences in children as early as seven or eight years old, where children born to mothers with PCOS have a larger waist circumference and higher BMI.

Maren Sophie Aaserud Talmo et al, Growth Restriction in the Offspring of Mothers With Polycystic Ovary Syndrome, JAMA Network Open (2024). DOI: 10.1001/jamanetworkopen.2024.30543

**

Part 2

The link between hepatitis and kidney damage

The hepatitis E virus affects the liver. But infected liver cells secrete a viral protein that reacts with antibodies in the blood and may form complexes that can damage the filter structure of the kidneys, as researchers have shown for the first time.

The hepatitis E virus infects some 70 million people every year. This infection is the most common form of acute hepatitis and a major global health problem.

In the majority of cases, the infection is asymptomatic or mild. However, sometimes it not only involves serious damage to the liver, but also to the kidneys.

The infected liver cells produce an excess of a viral protein that can bind with other viral proteins to form a viral envelope. Because the virus's genetic material replicates to a far lesser extent, the vast majority of the envelopes remain empty when they are secreted by the liver cells. This is how they enter the bloodstream, where they are detected by the immune system, which then forms antibodies that stick to the viral proteins.

These viral envelope-antibody complexes are then deposited in the filter structures of the kidneys, known as the glomeruli. If the complexes accumulate more quickly than they are removed, they can damage the glomeruli, triggering what is known as glomerulonephritis—a pattern of damage that in the worst case can lead to kidney failure.

The researchers discovered this mechanism when they were examining the cause of death of a patient who had received a new kidney years earlier. From the patient's medical record, it was clear that his chronic hepatitis E had not been diagnosed straight away. This is not uncommon as the disease still receives too little attention in some parts of the world.

This  discovery will help to raise awareness of hepatitis E and its link to kidney damage. 

 Anne-Laure Leblond et al, HEV ORF2 protein-antibody complex deposits are associated with glomerulonephritis in hepatitis E with reduced immune status, Nature Communications (2024). DOI: 10.1038/s41467-024-53072-0

Scientists successfully reverse liver fibrosis in mice

Cirrhosis, hepatitis infection and other causes can trigger liver fibrosis—a potentially lethal stiffening of tissue that, once begun, is irreversible. For many patients, a liver transplant is their only hope. However, new research may offer patients a glimmer of hope. Scientists who worked on this say they've successfully reversed liver fibrosis in mice.

Reporting in the journal Nature Communications, the team say they've discovered a genetic pathway that, if blocked, might bring fibrosis to a halt.

The three genes involved in this fibrotic process are called FOXM1, MAT2A and MAT2B.

The new  findings suggest that blocking any of these gene-produced proteins might be useful in treating this condition.

FOXM1, is present in liver cells called hepatocytes and can trigger liver cancer, inflammation and fibrosis if it becomes overactive. The two other genes, MAT2A and MAT2B, are active within a second kind of liver cell called stellate cells, which also play a role in fibrosis. All three genes code for different proteins necessary for the fibrotic process, the scientists explained.

Scientists discovered that these proteins 'talk' with each other inside liver cells. They even influence nearby cells through extracellular vesicles—fat molecules filled with genetic fragments, proteins and other biological materials that act as messengers between cells. Working together, that is how these proteins stimulate each other, driving liver inflammation and fibrosis

What if production of even one of the proteins produced by the genetic trio was interrupted?

To find out, the research group first induced liver inflammation and fibrosis in lab mice.

They then treated those mice with a substance known as FDI-6 that blocks the protein produced by the FOXM1 gene.

The result was impressive: Not only did this therapy put a halt to further fibrosis, it seemed to reverse some of the stiff fibrotic scarring of the mouse liver tissue that had already taken place.

This is selfishness at its peak!

Government interventions can reduce deadly air pollution in South Asia, study finds

Air pollution, driven in large part by practices like crop burning, contributes to 2 million deaths a year in South Asia and persists as a public health emergency. But a new study co-led by Brown University researcher Gemma Dipoppa found that government incentives may be able to curb the illegal practice of crop burning, according to a study published in the journal Nature.

In South Asia, farmers often burn leftover material from harvesting crops to clear their fields for the next planting season. The method is efficient and cost-effective but has devastating effects on air quality and health and contributes to 40% to 60% of the total air pollution in the region during the winter harvest season.

This is a very clear health emergency, and researchers wondered, 'Why isn't the government able to address this challenge, which is visible and extremely damaging for people?'

They  decided to study the aspect of government intervention and in particular the administration of the state that is in charge of reducing air pollution from a big-picture point of view.

Through their analysis of a decade of wind, fire and health data from satellites and surveys, Dipoppa and Gulzar found that government officials in India and Pakistan were more likely to reduce crop residue burning when its negative effects were felt in their own jurisdictions rather than outside of them: crop-burning fires increased by 15% when wind was most likely to direct pollution to neighboring jurisdictions and decreased by 14.5% when it polluted their own, the study found.

The researchers found that government-led actions against burning, such as fines for those violating the law, deterred future polluters and reduced fires by an additional 13%, a finding that contradicted a common perception that the widespread problem is impossible to control.

"Government officials are already acting on this issue, but they are doing it only in times and places where it is incentive-compatible for them, including when the pollution affects their own jurisdictions and not neighboring areas, the researchers conclude.

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This is important because it tells us that government leaders do have the power to reduce crop burning. If they had more resources, they would probably be capable of reducing pollution to a larger extent."

The problem of air pollution from crop burning is especially prevalent at the border between India and Pakistan, where there is a lack of coordination between jurisdictions, the researchers added.

As part of the study, the researchers also examined the effects of crop-burning pollution on infant and child mortality and estimated that that 1.5 to 2.7 deaths per 1,000 children could be prevented if action were taken to reduce crop fires.

The researchers hope that this paper can contribute to the public debate on how to address this widespread problem and how to solve this selfishness problem.

Government leaders can explore punishment, incentives, information campaigns and many other initiatives that will encourage farmers to find alternative solutions to burning if they leave their "I, me , myself" thoughts .

Gemma Dipoppa et al, Bureaucrat incentives reduce crop burning and child mortality in South Asia, Nature (2024). DOI: 10.1038/s41586-024-08046-z

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Drone with its own 'nervous system' trialed by scientists

Scientists are testing a drone fitted with its own "nervous system" which they claim can keep it operating in the sky for longer. The system, made of optical fibers, reduces the frequency it needs to land for inspection.

Cargo-carrying drones are required to make regular pitstops for manual safety checks, which limits its use and can increase operating costs.

The optical fiber system developed by researchers makes drones more efficient by continuously monitoring its structural health just like nerves in the body.

This is a kind of nervous system for drones. 

It sends back real-time information using light—rather than electricity—which avoids problems that electronic systems have with interference from radio frequencies.

This system not only reduces the burden on ground crews but also ensures that drones can operate more safely and efficiently.

The system uses a unique technique called optical speckle which projects specific images dependent on what the optical fiber nervous system feels. These can be interpreted using AI to assess the health of the drone.

This speckle system keeps track of the stresses and strains on the drone, helping ground crews spot issues early without needing to land the drone as often for inspections.

The real reason behind gout

 

Gout is often associated with drinking too much or not eating healthily enough, but new research suggests genetics play more of a factor in developing the arthritic condition than previously thought. The research, carried out by an international team of scientists, looked at genetic data collected from 2.6 million people across 13 different cohorts of DNA data. That number included 120,295 people with "prevalent gout".

By comparing the genetic codes of the people with gout against the people without, the team found 377 specific DNA regions where there were variations specific to having the condition – 149 of which hadn't been previously linked to gout.

While lifestyle and environmental factors are certainly still in play, the findings suggest genetics play a major role in determining whether or not someone gets gout – and the researchers think there may be more undiscovered genetic links still to be found, too.

Gout takes hold when there are high levels of uric acid in the blood, which then form sharp crystal needles in the joints. When the body's immune system starts to attack those crystals, it leads to significant pain and discomfort.

Genetics is important in every stage of that process, the researchers suggest. Particularly, it affects the likelihood of the body's immune system attacking the crystals, and in the way uric acid is transported around the body.

Gout can come and go, but there are treatments available – and the authors behind the new study think misconceptions can put people off getting those treatments. That's a real problem with cases of the condition rising and rising.

https://www.nature.com/articles/s41588-024-01921-5

Exactly What Happens When an Atom Splits in Two?

The word atom comes from Latin for indivisible. But don't let the name fool you.

A simulation by US theoretical physicists has provided the first fully microscopic characterization of the moment an atom snips in two, revealing fresh insights into an energetic event that came to define a new age in science and technology.

theoretical physicists from Los Alamos National Laboratory and the University of Washington (UW) break the fission process down into four steps.

In the first 10^-14 seconds (give or take), the introduction of a slow-moving neutron forces the nucleus to bulge and rearrange itself in what's described as a saddle point, making the atom look a little like a tiny peanut shell.

This is quickly followed by a far more rapid shift, referred to as saddle-to-scission, where the fragments of the fission process are established. This lasts around 5×10^-21 seconds.

Step three is even faster again, transforming in a relative blink of 10^-22 seconds. In what's called the scission, or neck rupture, the nucleus officially breaks apart.

In the final step, which takes a lazy 10^-18 seconds to unfold, the fission fragments pull themselves into shape and accelerate away, releasing neutrons and gamma rays and potentially generating other decay processes after a brief delay.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.132.242501

Scientists Found Structural, Brain-Wide Changes During Menstruation

The constant ebb and flow of hormones that guide the menstrual cycle don't just affect reproductive anatomy. They also reshape the brain, and a study has given us insight into how this happens.

 A team of researchers tracked 30 women who menstruate over their cycles, documenting in detail the structural changes that take place in the brain as hormonal profiles fluctuate.

The results, published in a peer-reviewed study in July this year, suggest that structural changes in the brain during menstruation may not be limited to those regions associated with the menstrual cycle.

"These results are the first to report simultaneous brain-wide changes in human white matter microstructure and cortical thickness coinciding with menstrual cycle-driven hormone rhythms," the researchers wrote.

Strong brain-hormone interaction effects may not be limited to classically known hypothalamic-pituitary-gonadal-axis (HPG-axis) receptor-dense regions."
People who menstruate will experience some 450 or so periods during the course of their lifetimes, so it would be nice to know the different effects they can have on the body, really.

However, although it is something that happens to half the world's population for half their lives, research has been somewhat lacking. Who knows why. Total mystery.
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Most of the research on the hormonal effect on the brain has been focused on brain communication during cognitive tasks, not the actual structures themselves.
Cyclic fluctuations in HPG-axis hormones exert powerful behavioral, structural, and functional effects through actions on the mammalian central nervous system.
The microstructure of white matter – the fatty network of neuronal fibers that transfer information between regions of gray matter – has been found to change with hormonal shifts, including puberty, oral contraception use, gender-affirming hormone therapy, and post-menopausal estrogen therapy.
To address the menstruation gap in our understanding, the team took MRI scans of their subjects during three menstrual phases: menses, ovulation, and mid-luteal. At the time of each of these scans, the researchers also measured the participants' hormone levels.

The results showed that, as hormones fluctuate, gray and white matter volumes change too, as does the volume of cerebrospinal fluid.

In particular, just before ovulation, when the hormones 17β-estradiol and luteinizing hormone rise, the brains of the participants showed white matter changes suggesting faster information transfer.

Follicle-stimulating hormone, which rises before ovulation, and helps stimulate the ovary follicles, was associated with thicker gray matter.
Progesterone, which rises after ovulation, was associated with increased tissue and decreased cerebrospinal fluid volume.

What this means for the person driving the brain is unknown, but the research lays the groundwork for future studies, and perhaps understanding the causes of unusual but severe period-related mental health problems.
Although we do not currently report functional consequences or correlates of structural brain changes, our findings may have implications for hormone-driven alterations in behavior and cognition," the researchers wrote.
Investigation of brain-hormone relationships across networks is necessary to understand human nervous system functioning on a daily basis, during hormone transition periods, and across the human lifespan.

https://onlinelibrary.wiley.com/doi/10.1002/hbm.26785

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Insulin resistance caused by sympathetic nervous system over-activation, a paradigm-shifting study finds

Researchers  have found that overnutrition leads to insulin resistance and metabolic disorders through increased activity of the sympathetic nervous system (SNS). The study shows that reducing SNS activity can prevent insulin resistance induced by a high-fat diet, suggesting a new understanding of how obesity causes insulin resistance.

Obesity causes type 2 diabetes and metabolic diseases primarily by inducing insulin resistance. Impaired cellular insulin signaling is the most understood mechanism, but it does not always accompany impaired insulin action, indicating other factors must be involved.

The role of the SNS in obesity is complex and somewhat controversial. Previous studies have reported both increased and decreased SNS activity in obese people.

Overnutrition has been known to rapidly increase plasma norepinephrine (NE) levels, indicating overactivation of the SNS. Methods that directly measure SNS activity, such as nerve recordings and NE turnover, often report increased SNS activity in obesity.

In contrast, studies focusing on adrenergic signaling pathways sometimes report reduced catecholamine responses, interpreted as decreased SNS activity.

This discrepancy may be explained by the development of catecholamine resistance due to chronic sympathetic overactivation, leading to diminished physiological responses despite elevated NE levels.

In a study titled "Overnutrition causes insulin resistance and metabolic disorder through increased sympathetic nervous system activity," published in Cell Metabolism, the researchers investigated the conflicting reports on SNS activity in obesity.

 Kenichi Sakamoto et al, Overnutrition causes insulin resistance and metabolic disorder through increased sympathetic nervous system activity, Cell Metabolism (2024). DOI: 10.1016/j.cmet.2024.09.012

Rainwater samples reveals it's literally raining 'forever chemicals'

PFAS are in rainwater. And it is the latest evidence the synthetic "forever chemicals"—that have raised health concerns for people and wildlife—hitch a ride on the water cycle, using the complex system to circulate over greater distances.

For more than a year, FIU researchers collected and analyzed 42 rainwater samples across three different sites in Miami-Dade County. A total of 21 perfluoroalkyl and polyfluoroalkyl substances, or PFAS, were detected, including PFOS and PFOA (since phased out of production over cancer concerns), as well as the newer varieties used in manufacturing today.

While profiles of several PFAS matched back to local sources, others did not. According to the study, published in Atmospheric Pollution Research, this suggests Earth's atmosphere acts as a pathway to transport these chemicals far and wide—contributing to the worldwide pollution problem.

PFAS are practically everywhere. Now scientists are able to show the role air masses play in potentially bringing these pollutants to other places where they can impact surface water and groundwater.

Widely used in consumer products—non-stick cookware, clothing, cosmetics, food packaging, detergents and firefighting foams, to name a few—PFAS were purposefully created to be almost indestructible. They don't break down easily or simply go away.

Once in the environment, they accumulate over time. People can ingest or inhale them, and exposure has been linked to liver and kidney damage, fertility issues, cancer and other diseases. The EPA warned even low levels of exposure can be dangerous, setting strict near-zero limits for some PFAS in drinking water.

It's still not very clear, though, how exactly these long-lived chemicals journey through the environment.

Scientists  have been trying to piece this picture together. They've detected PFAS in drinking water and surface water.

And, subsequently, also found PFAS in animals that live in those areas, including oysters and economically important recreational fish and lobsters. Rain was the natural next place they found it!

PFAS can infiltrate the atmosphere by either evaporation or getting absorbed into microscopic particles and dust. Wind and shifting air currents shuttle them along. Eventually, it rains. As each drop falls to earth, it brings along some of the pollutants. The cycle begins and ends and begins again.

This played out in the team's data.

Maria Guerra de Navarro et al, It's raining PFAS in South Florida: Occurrence of per- and polyfluoroalkyl substances (PFAS) in wet atmospheric deposition from Miami-Dade, South Florida, Atmospheric Pollution Research (2024). DOI: 10.1016/j.apr.2024.102302

How many trees does it take to cool a city? Researchers develop tool to set urban tree canopy goals

Cities around the globe are increasingly experiencing dangerous heat as urban concrete and asphalt amplify rising temperatures. Tree-planting programs are a popular, nature-based way to cool cities, but these initiatives have been largely based on guesswork and extrapolation. A study published recently in Proceedings of the National Academy of Sciences offers a new tool for urban planners and decision makers to set more specific and science-based city-wide greening goals.

Trees are good at cooling because they pump a lot of water from the ground into the air, and when that water evaporates at the leaf surface, it absorbs a vast amount of heat. That's just the physics of evaporation. The shade provided by trees also helps with cooling.

To date, most studies measuring the cooling effects of urban trees focus on the hyperlocal level, such as on a particular street or neighborhood. When the urban tree canopy expands by 1%, for example, nearby temperatures may decrease by 0.04 to 0.57 degrees Celsius.

But how much tree canopy do we actually need for the whole city?

Researchers set out to determine how trees' cooling efficiency—the temperature reduction associated with a 1% increase urban tree canopy—changes across larger areas.

The team analyzed satellite imagery and temperature data from four cities with very different climates: Beijing and Shenzhen in China, and Baltimore and Sacramento in the US. Baltimore and Beijing are temperate, Shenzhen is subtropical, and Sacramento is in a Mediterranean climate zone.

First, they divided each city into pixels approximately the size of a city block. For each pixel, they measured the land surface temperature and how much of the ground was covered by trees. Then they ran the same analyses across larger and larger sections of each city, spanning the neighborhood level, city level, and beyond. Finally, they calculated how the mathematical relationship between greenery and temperature—the cooling efficiency—changed at different scales.

Overall, the team discovered that the cooling efficiency of urban trees increased at larger scales. But it did so at a slower rate at larger unit sizes. In Beijing, for example, a 1% increase in canopy at the block level decreases temperature by about 0.06 degrees, whereas a 1% increase in canopy at the city level could decrease temperature by about 0.18 degrees.
The additional benefit at larger scales seems to come from being able to include large groups of trees, which have a larger cooling capacity.

With greater clarity about the relationships between area, tree canopy cover, and cooling effects, the paper makes it possible to predict cooling effects at the whole-city scale, offering a valuable tool for managers to set urban tree canopy goals to reduce extreme heat.

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They found that cooling efficiency follows a power law across scales—from as small as 120 by 120 meters to as large as regions covering the entire city. The relationship holds across all four of the studied cities, which are in very different climates. This suggests that it could be used to predict the amount of additional tree cover needed to achieve specific heat mitigation and climate adaptation goals in cities worldwide.
While the paper provides essential information for decision-making at the municipal level, the researchers caution that urban planners may also need to work at smaller scales to ensure that urban trees—and their potential benefits—are distributed equitably across the city, and with community buy-in.

Jia Wang et al, A scaling law for predicting urban trees canopy cooling efficiency, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2401210121

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Deep sea rocks suggest oxygen can be made without photosynthesis, deepening the mystery of life

Oxygen, the molecule that supports intelligent life as we know it, is largely made by plants. Whether underwater or on land, they do this by photosynthesizing carbon dioxide. However, a recent study demonstrates that oxygen may be produced without the need for life at depths where light cannot reach.

The authors of a recent publication in Nature Geoscience were collecting samples from deep ocean sediments to determine the rate of oxygen consumption at the seafloor through things like organisms or sediments that can react with oxygen. But in several of their experiments, they actually found oxygen was increasing as opposed to decreasing as they would have expected. This left them questioning how this oxygen was being produced.

They found that this "dark" oxygen production at the seafloor seems to only happen in the presence of mineral concentrates called polymetallic nodules and deposits of metals called metalliferous sediments. The authors think the nodules have the right mixture of metals and are densely packed enough for an electrical current to pass through for electrolysis, creating enough energy to separate the hydrogen (H) and oxygen (O) from water (H₂O).

The authors also suggested that the amount of oxygen created may fluctuate depending on the number and mixture of nodules on the ocean floor.

https://www.nature.com/articles/s41561-024-01480-8

Why do flowers wilt? 

Wilting flowers might not signal poor flower or plant health, but rather the effects of a sophisticated resource management strategy in plants, millions of years in the making.

A study in the journal Plant Biology by researchers from Macquarie University and international collaborators has shown for the first time that plants reuse resources from wilting flowers to support future reproduction.

It turns out the plants were playing a longer game than we anticipated, not using their reclaimed resources immediately, but saving them for the next flowering season.

Plants have evolved diverse strategies for managing their flowers after they've served their primary reproductive function, with wilting just one of several possible approaches.

Not all plants follow the flower wilt pattern; flowers will still bloom on some plants long after they can be fertilized and after they stop producing nectar.

Flowers make the whole plant more attractive to pollinators even when they are just there as part of the overall display.

Some plants will even drop their blooms well before they wilt. For example, jacaranda flowers that seem perfectly good will just drop to the ground; frangipani trees will also shed intact flowers rather than have them wilt.

The study tested resource reuse in different ways.

Results showed plants with wilting flowers were more likely to reflower the next season than those where wilting was prevented. The study also considered other factors that might influence seed production, such as flowering stem height, number of flowers per stem, and flower position. Taller flowering stems, for example, produced more seeds and heavier seeds, as did stems with more flowers. But flowers positioned lower down on the plant tended to have fewer seeds, and seeds that weighed less.

 G. H. Pyke et al, Why do flowers wilt?, Plant Biology (2024). DOI: 10.1111/plb.13720

Spraying rice with zinc oxide nanoparticles protects yields during heat waves

A small team of horticulturists has found that spraying rice plants with a zinc oxide nanoparticle solution helps them better handle the stress of a heat wave. In their study, published in Proceedings of the National Academy of Sciences, the group conducted experiments involving spraying rice plants in a heated greenhouse.

Prior research has shown that heat waves can reduce rice yields or kill plants altogether, depending on the severity of the heat wave. Because of that, plant scientists have been looking for ways to help plants survive the likely increase in number and severity of heat waves expected due to global warming. The research team found that zinc oxide nanoparticles may be one such tool.

Prior research has also shown that zinc oxide is a natural part of plant metabolism—rice farmers have used it as a form of fertilizer for many years.

More recently, researchers have found that applying zinc nanoparticles is a much more efficient approach—it allows the particles to pass through the pores in leaves.

The team wondered if zinc oxide might also help rice plants maintain their yields during heat waves. To find out, the researchers planted rice in a climate-controlled greenhouse. Once the plants were grown, the team raised the temperature to 37°C for six consecutive days. During the induced heat wave, they sprayed some of the plants with a zinc oxide nanoparticle solution, while the other plants were only watered. Upon harvesting the rice, the research team found that those plants that had been sprayed with zinc oxide nanoparticles had yields that were 22.1% greater than the plants that had been sprayed with water alone.

In taking a closer look at the rice grains, the research team also found that they contained more nutrients, as well. In conducting another similar experiment, the researchers found that spraying rice plants with zinc oxide nanoparticles also led to increased yields compared to those not sprayed even when there was no heat wave.

Shuqing Guo et al, Zinc oxide nanoparticles cooperate with the phyllosphere to promote grain yield and nutritional quality of rice under heatwave stress, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2414822121

Study disproves idea that weather-dependent renewable energy systems are more prone to blackouts

Wind turbines and photovoltaics (PVs) are becoming increasingly widespread worldwide, which could contribute to reducing air pollution caused by fossil fuel emissions. To produce energy, however, these renewable energy solutions rely on specific weather conditions (e.g., the presence of wind and sufficient hours of sunlight).

As the use of these technologies grows, some energy system operators have expressed concerns about the weather-dependency of these systems, suggesting that an overreliance on these technologies could increase the risk of blackouts. In some instances, renewable energy systems were even blamed for blackouts experienced during adverse weather events.

Researchers at the University of Tennessee recently carried out a study exploring the vulnerability of renewable energy systems to adverse weather and the extent to which these systems could be responsible for severe blackouts. Their findings, published in Nature Energy, suggest that solar panels and wind turbines are less likely to cause severe blackouts than traditional power systems.

In this study, researchers find that although WD-RESs are non-dispatchable and weather sensitive, blackout intensities and extreme weather vulnerability are mitigated in high-penetration WD-RES grids.

Overall, the results of this recent study suggest that weather-dependent renewable energy systems, particularly solar panels and wind turbines, are not as prone to causing severe bulk power system blackouts during extreme weather as some people have assumed them to be. In fact, blackouts that occurred in regions with a high penetration of WD-RES power grids were often less severe than those occurring in places that only relied on the traditional power grid.

Jin Zhao et al, Impacts of renewable energy resources on the weather vulnerability of power systems, Nature Energy (2024). DOI: 10.1038/s41560-024-01652-1

Prodrug: Researchers discover localized pain relief using known chemical reaction

A team of international researchers have taken a well-known chemical reaction as the basis of a new generation of targeted pain relief medication.

The team has created a targeted prodrug (a compound which metabolizes inside the body into a pharmacologically active drug), and found it to be capable of relieving chronic pain during preclinical trials.

The mechanism of action for the targeted prodrug involves activation of the active drug by a chemical reaction with reactive oxygen species such as hydrogen peroxide, which are present in much higher amounts at sites of pain than the rest of the body.

This means that the prodrug is distributed around the body as an inactive chemical until it reaches a site of pain where it is then converted into the active drug.

The prodrug was tested in both chemical and preclinical models and found to provide localized relief of sciatic nerve injuries, as well as other models of chronic pain featuring oxidative stress like osteoarthritis, chemotherapy-induced peripheral neuropathy and diabetic neuropathy.

Testing found multi-day oral administration of the compound six months after the injury reversed hypersensitivity to touch and cold stimuli; while further tests demonstrated the effects of the drug were dose dependent, with maintained pain relief upon repeated dosing. This showed us that the compound did not induce a tolerance, which is a major limiting factor to powerful painkillers like morphine.

Chronic pain remains a large unmet medical need and nonaddictive treatments like this would revolutionize the field, which is currently dominated by addictive opioids.

The project will now undergo more pre-clinical trials to determine effectiveness and safety.

Thomas D. Avery et al, Site-specific drug release of monomethyl fumarate to treat oxidative stress disorders, Nature Biotechnology (2024). DOI: 10.1038/s41587-024-02460-4

Biologists reveal the genetic 'switch' behind parrot color diversity

Parrots are synonymous with colour for people across the world. In a study published in the journal Science, scientists  have uncovered for the first time a "switch" in the DNA of parrots that controls their wide gamut of colours.

Parrots are unique birds in many ways, including how they produce their vibrant colour diversity.

Although other birds also produce yellow and red feathers, parrots evolved unique pigments, called psittacofulvins. Parrots combine these with other pigments to create vibrant yellows, reds, and greens, making these animals among nature's most colourful.

To understand this unique colouration the scientists started by demonstrating that, across all major parrot lineages, yellow and red in feathers correspond to two specific pigments that do not occur in other birds.

The scientists focused on a species with naturally occurring red or yellow forms, a phenomenon that is extremely rare in nature.

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The scientists found that only one protein controlled the color difference in the lories, a type of aldehyde dehydrogenase (or ALDH), essential "tools" for detoxification in complex organisms—for example, they contribute to elimination of alcohol in the liver of humans.
Parrot feathers found a way to 'borrow' this protein, using it to transform red to yellow psittacofulvins." According to the scientists, "This functions like a dial, in which higher activity of the protein translates to less intense red colour."
To understand the general role of this protein in controlling the plumage color in other parrot species, scientists studied another parrot, the rosy-faced lovebirds, a species that displays both green (i.e., yellow psittacofulvin-containing) and red plumage patches.

The rosy-faced lovebird is a familiar parrot that provides an excellent system to study the genes determining the color difference between red and yellow psittacofulvin-containing plumage patches.
They found that the same aldehyde dehydrogenase gene in the lovebirds is expressed at high levels in yellow psittacofulvin-containing feathers, but not in red feathers. When this gene expresses at a high level, the psittacofulvins turn from red to yellow.
To demonstrate this simple dial mechanism, scientists turned to an even more familiar parrot, the budgerigar and, in a world-first, explored how individual cells turn different genes on or off throughout feather growth, pinpointing a small number of cells that use this detox protein for controlling pigment conversion.

The final validation came when the scientists genetically engineered yeasts with the parrot color gene, Incredibly, their modified yeast produced parrot colours, demonstrating that this gene is sufficient to explain how parrots control the amount of yellow and red in their feathers.
This study showcases how cutting-edge developments in biotechnology are increasingly used to unravel nature's mysteries.
Scientists now understand how these stunning colours can evolve in wild animals through a simple dial-like "molecular switch" that "borrows" a detoxifying protein to serve a new function.

These findings help scientists paint a new colorful picture of evolution as a process in which complexity can be achieved through simple innovations.

 Roberto Arbore et al, A molecular mechanism for bright color variation in parrots, Science (2024). DOI: 10.1126/science.adp7710

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Deaf male mosquitoes don't mate, researchers discover

Romance is a complex affair in humans. There's personality, appearance, seduction, all manner of physical and social cues. Mosquitoes are much more blunt. Mating occurs for a few seconds in midair. And all it takes to woo a male is the sound of a female's wingbeats. Imagine researchers' surprise when a single change completely killed the mosquitoes' libidos.

Now a study  reveals that this is really all there is to it. Researchers created deaf mosquitoes and found that the males had absolutely no interest in mating. You could leave them together with the females for days, and they will not mate.

The dramatic change was simple to produce. The absence of a single gene, trpVa, produced this profound effect on mosquito mating behaviour.

The results, published in the Proceedings of the National Academy of Sciences could have major implications for how we manage disease transmission by better controlling the populations of mosquito vectors, such as Aedes aegypti, that infect hundreds of millions of people every year with viruses that cause diseases.

Courtship for Aedes aegypti usually progresses like this: Females flap their wings at around 500 Hz. When males hear this, they take off, buzzing at about 800 Hz. The males also rapidly modulate this frequency when the ladies are around. Then there's a quick midair rendezvous, and the paramours go their separate ways. Males are always scouting out new potential partners, but a female that's successfully mated generally won't do so again.

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Researchers suspected that hearing played a role in this behaviour, so they investigated the insect's auditory neurons. These lie at the base of the antennae in a structure called the Johnston's organ.

The antennae are magnificent multi-sensory apparatuses, chock-full of olfactory, mechanosensory and even thermal infrared sensilla, scientists recently discovered. In the current study, the team focused on a particular sensory channel called TRPVa—and the corresponding gene, trpVa—which is the mosquito analog of a channel required for hearing in fruit flies.
The team used CRISPR-Cas9 to knock out the gene that codes for TRPVa in Aedes aegypti mosquitoes. The resulting animals showed no reaction to sound. In fact, they found that sound elicited no electrical activity from neurons in the Johnston's organ. The insects were truly deaf.

And when the reearchers placed deaf males in chambers with females … nothing happened. If they can't hear the female wingbeat, they're not interested. Their hearing counterparts, on the other hand, wasted no time in getting busy: mating many times in the course of a few minutes.
Hearing is not only necessary for males to mate, it seems to be sufficient to rouse their desires. When the authors played the sound of female wingbeats to normal males, the males typically responded with abdominal thrusts. They were primed and ready for action. Deaf males barely twitched.
Females, however, were a different story. Deaf females still had some desire to mate left in them. The impact on the female is minimal, but the impact on the male is absolute.
In most organisms, mating behaviour is dependent on a combination of several sensory cues. In mosquitoes it depends on only one! A mosquito's physiology reveals just how important hearing is to these insects.

 Yijin Wang et al, Deafness due to loss of a TRPV channel eliminates mating behavior in Aedes aegypti males, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2404324121

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Cracking the code of DNA circles in cancer: Scientists uncover potential therapy

A trio of research papers from Stanford Medicine researchers and their international collaborators transforms scientists' understanding of how small DNA circles—until recently dismissed as inconsequential—are major drivers of many types of human cancers.

The papers, published simultaneously in Nature on Nov. 6, detail the prevalence and prognostic impact of the circles, called ecDNA for extrachromosomal DNA, in nearly 15,000 human cancers; highlight a novel mode of inheritance that overthrows a fundamental law of genetics; and describe an anti-cancer therapy targeting the circles that is already in clinical trials.

The team, jointly known as eDyNAmiC, are a group of international experts led by professor of pathology Paul Mischel, MD. In 2022, Mischel and the eDyNAmiC team were awarded a grant to learn more about the circles.

Cancer Grand Challenges, a research initiative co-founded by Cancer Research UK and the National Cancer Institute in the United States, supports a global community of interdisciplinary, world-class research teams to take on cancer's toughest challenges.

We're in the midst of a completely new understanding of a common and aggressive mechanism that drives cancer, say these scientists. 

Each paper alone is noteworthy, and taken together they represent a major inflection point in how we view cancer initiation and evolution.

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Those featured circles, ecDNAs, are small and often contain a few genes on their circular DNA. Frequently, these genes are cancer-associated genes called oncogenes. When a cancer cell contains multiple oncogene-encoding ecDNAs, they can supercharge the cell's growth and allow it to evade internal checkpoints meant to regulate cell division.

The ecDNAs also sometimes encode genes for proteins that can tamp down the immune system's response to a developing cancer—further advantaging tumor growth.
Until recently, it was thought that only about 2% of tumors contained meaningful amounts of ecDNA. But in 2017, research showed that the small circles were widespread and likely to play a critical role in human cancers.

In 2023, researchers further showed that their presence jumpstarts a cancerous transformation in precancerous cells.

In the first of the three papers researchers built on 2017 finding by analyzing the prevalence of ecDNA in nearly 15,000 cancer patients and 39 tumor types.

They found that 17.1% of tumors contained ecDNA, that ecDNA was more prevalent after targeted therapy or cytotoxic treatments like chemotherapy, and that the presence of ecDNA was associated with metastasis and poorer overall survival.

The researchers also showed that the circles can contain not just cancer-driving oncogenes and genes that modulate the immune response, but also that others can contain only DNA sequences called enhancers that drive the expression of genes on other circles by linking two or more ecDNAs together.
The ecDNAs with enhancer elements don't confer any benefit to the cell on their own; they have to work with other ecDNAs to spur cancer cell growth. If looked at through a conventional lens, the presence of ecDNAs that solely encode enhancers wouldn't seem to be a problem. But the teamwork and physical connection between different types of circles is actually very important in cancer development."
Through these studies researchers learned critical lessons about which cancer patients are affected and what genes or DNA sequences are found in ecDNAs. They identified the genetic backgrounds and mutational signatures that give them clues as to how cancers originate and thrive.

Howard Chang, Coordinated inheritance of extrachromosomal DNAs in cancer cells, Nature (2024). DOI: 10.1038/s41586-024-07861-8. www.nature.com/articles/s41586-024-07861-8

Paul Mischel, Enhancing transcription–replication conflict targets ecDNA-positive cancers, Nature (2024). DOI: 10.1038/s41586-024-07802-5. www.nature.com/articles/s41586-024-07802-5

Charles Swanton, Origins and impact of extrachromosomal DNA, Nature (2024). DOI: 10.1038/s41586-024-08107-3. www.nature.com/articles/s41586-024-08107-3

Part2

Researchers show astrocytes in the brain play a role in memory retrieval

A study published in Nature by researchers  changes the way we understand memory. Until now, memories have been explained by the activity of brain cells called neurons that respond to learning events and control memory recall.

The present work  expanded this theory by showing that non-neuronal cell types in the brain called astrocytes—star-shaped cells—also store memories and work in concert with groups of neurons called engrams to regulate storage and retrieval of memories.

The researchers show that during learning events, such as fear conditioning, a subset of astrocytes in the brain expresses the c-Fos gene. Astrocytes expressing c-Fos subsequently regulate circuit function in that brain region.

The c-Fos-expressing astrocytes are physically close with engram neurons.

Furthermore, the researchers found that engram neurons and the physically associated astrocyte ensemble are also functionally connected. Activating the astrocyte ensemble specifically stimulates synaptic activity or communication in the corresponding neuron engram. This astrocyte-neuron communication flows both ways; astrocytes and neurons depend on each other.

The team also found that astrocytes activated by learning events have elevated levels of the NFIA protein, and preventing NFIA production in these astrocytes suppresses memory recall. Importantly, this suppression is memory specific.

These findings speak to the nature of the role of astrocytes in memory.

Benjamin Deneen, Learning-associated astrocyte ensembles regulate memory recall, Nature (2024). DOI: 10.1038/s41586-024-08170-w. www.nature.com/articles/s41586-024-08170-w

Climate change is contributing to drought in the American West even without rainfall deficits, scientists find

Higher temperatures caused by anthropogenic climate change made an ordinary drought into an exceptional drought that parched the American West from 2020–2022. A study by UCLA and National Oceanic and Atmospheric Administration climate scientists has found that evaporation accounted for 61% of the drought's severity, while reduced precipitation only accounted for 39%. The research found that evaporative demand has played a bigger role than reduced precipitation in droughts since 2000, which suggests droughts will become more severe as the climate warms.

Research has already shown that warmer temperatures contribute to drought, but this is the first study that actually shows that moisture loss due to demand is greater than the moisture loss due to lack of rainfall," say the authors of a study published in Science Advances.

For generations, drought has been associated with drier-than-normal weather. This study further confirms we've entered a new paradigm where rising temperatures are leading to intense droughts, with precipitation as a secondary factor.

A warmer atmosphere holds more water vapour before the air mass becomes saturated, allowing water to condense and precipitation to form. In order to rain, water molecules in the atmosphere need to come together. Heat keeps water molecules moving and bouncing off each other, preventing them from condensing. This creates a cycle in which the warmer the planet gets, the more water will evaporate into the atmosphere—but the smaller fraction will return as rain. Therefore, droughts will last longer, cover wider areas and be even drier with every little bit that the planet warms.

 Yizhou Zhuang et al, Anthropogenic warming has ushered in an era of temperature-dominated droughts in the western United States, Science Advances (2024). DOI: 10.1126/sciadv.adn9389

Waste Heat to Electricity

Pathogens that cling to microplastics may survive wastewater treatment

Wastewater treatment fails to kill several human pathogens when they hide out on microplastics in the water, reports a study published November 6, 2024 in the open-access journal PLOS ONE.

Wastewater treatment plants are designed to remove contaminants from wastewater, but microplastics persist and can become colonized by a sticky microbial biofilm. Previous research has suggested that these microbial communities, called plastispheres, include potential pathogens, and thus might pose a risk to human health and the environment when treated wastewater and sludge are released.

In the new study, researchers identified food-borne pathogens in plastispheres living on three types of plastic in wastewater. They cultured the microorganisms and used genetic techniques to understand the diversity and members of the plastisphere communities.

The team found evidence of pathogenic bacteria and viruses, including Listeria monocytogenes, Escherichia coli, norovirus and adenovirus. They also successfully grew Klebsiella pneumoniae and Acinetobacter spp. from raw and treated wastewater, indicating that the plastisphere biofilms likely protect the pathogens from wastewater treatment.

These findings highlight the potential of plastispheres to harbor and spread pathogens, which poses a challenge to safely reusing wastewater. Without efficient wastewater treatment and plastic waste management, wastewater could act as a vehicle for transferring plastic-associated pathogens into the food chain.

The researchers emphasize that continued research and innovation are essential to remove microplastics—and their pathogens—from wastewater.

 Wastewater-associated plastispheres: A hidden habitat for microbial pathogens?, PLOS ONE (2024). DOI: 10.1371/journal.pone.0312157