Animal-to-human diseases could kill 12 times as much by 2050: Study

Certain diseases transmitted from animals to humans could kill 12 times as many people in 2050 than they did in 2020, researchers have claimed.

Epidemics caused by zoonotic diseases—also known as spillovers—could be more frequent in the future due to climate change and deforestation, experts warned.

The team's analysis looked at historic trends for four particular viral pathogens.

These were filoviruses, which include Ebola virus and Marburg virus, SARS Coronavirus 1, Nipah virus, and Machupo virus, which causes Bolivian hemorrhagic fever.

The study did not include COVID-19, which caused the global pandemic in 2020 and is likely to have originated in bats.

It looked at more than 3,150 outbreaks between 1963 and 2019, identifying 75 spillover events in 24 countries.

The database covered epidemics reported by the World Health Organization, outbreaks occurring since 1963 that killed 50 or more people, and historically significant events including the flu pandemics of 1918 and 1957.

The events caused 17,232 deaths, with 15,771 caused by filoviruses and occurring mostly in Africa.

Researchers said epidemics have been increasing by almost 5% every year between 1963 and 2019, with deaths up by 9%.

"If these annual rates of increase continue, we would expect the analyzed pathogens to cause four times the number of spillover events and 12 times the number of deaths in 2050 than in 2020," they added.

Researchers also suggested the figures are likely to be an underestimate due to the strict inclusion criteria for the pathogens in the analysis and the exclusion of COVID-19. They said the evaluation of evidence suggests recent epidemics sparked by zoonotic spillovers "are not an aberration or random cluster" but follow "a multi-decade trend in which spillover-driven epidemics have become both larger and more frequent." The team added that "urgent action is needed to address a large and growing risk to global health" based on historical trends.

Amanda Jean Meadows et al, Historical trends demonstrate a pattern of increasingly frequent and severe spillover events of high-consequence zoonotic viruses, BMJ Global Health (2023). DOI: 10.1136/bmjgh-2023-012026

No appetite for vegetarian diet to help the planet, finds study

Social media users believe reducing and eliminating meat intake is ineffective in addressing climate change and reported low willingness to engage in either action, according to a new study.

This is despite recent global reports revealing the strong links between the animal agricultural industry and greenhouse gas emissions, as well as the idea that what people put on their plate is an important piece in confronting the climate crisis. The study, published in Sustainability, asked more than 700 Facebook account users, between the ages of 18 to 84, about their beliefs on climate change, the impact of meat consumption on the environment and meat intake.

Although past research has shown that animal agriculture contributes significantly to greenhouse gas emissions, the participants believed reducing and eliminating meat intake to be some of the least effective actions against climate change.

This study highlighted an increased awareness that meat-eating has environmental impacts, yet its impact was rated significantly less than other pro-environmental behaviors, such as using public transport, recycling, and renewable energy.

The findings of this study can help shed light on the disconnect between research and public knowledge and subsequently, how to bridge this gap. Sci-com? Yes!

 Ashley Rattenbury et al, Perceptions of the Benefits and Barriers to Vegetarian Diets and the Environmental Impact of Meat-Eating, Sustainability (2023). DOI: 10.3390/su152115522

Dose response: The basics

An implantable wireless cardiac pacemaker

Cardiac pacemakers are battery-dependent, where the pacing leads are prone to introduce valve damage and infection. In addition, complete pacemaker retrieval is necessary for battery replacement. Despite the presence of a wireless bioelectronics device to pace the epicardium, surgeons still need to implant the device via thoracotomy, an invasive surgical procedure in health care that necessitates wound healing.

A research team of scientists in bioengineering, microbiology, and cardiology devised a biocompatible wireless microelectronics device to form a microtubular pacemaker for intravascular implantation and pacing. 

The pacemaker provided effective pacing to restore cardiac contraction from a non-beating heart in a porcine animal model. The microtubular pacemaker paves the way for the minimally-invasive implantation of leadless and battery-free microelectronics for health care and cardiac pace restoration.

Shaolei Wang et al, A self-assembled implantable microtubular pacemaker for wireless cardiac electrotherapy, Science Advances (2023). DOI: 10.1126/sciadv.adj0540

The story of a teenage boy who swallowed 21 disc magnets

Doctors at Guthrie Healthcare System, in Sayre, Pennsylvania, have documented a case of a teenage boy who swallowed 21 disc magnets. In their paper published in BMJ Case Reports, the medical team describes how they found the magnets, removed them, and cared for the boy afterward.

Prior research and anecdotal evidence by doctors and other medical personnel has shown that swallowing magnets can be harmful. Their magnetic field and caustic properties can lead to damage in the digestive tract.

In this new study, the researchers report that a teenage boy was transferred to their facility from another hospital with metal objects of some kind in his stomach. When asked, the boy told the medical staff at both hospitals that he did not know how the objects could have wound up in this stomach. X-rays and a CT scan showed the presence of multiple metallic items. An initial procedure involved removing three small discs that had become embedded in the stomach wall using forceps and a surgical net. After removal, the doctors determined that the metal objects were small disc magnets. Three more of the magnets had become embedded in the walls of the large intestine—notably, there were also signs that the wound caused by the discs had led to decay of intestinal tissue. Further investigation showed that there were another 15 magnets embedded in various parts of both the large and small intestine, most of which required surgery for removal.

The surgeon noted that some of the magnets had begun to create holes in the intestinal walls. The case study team notes that the dangers of ingesting magnets are well known. Instead of passing harmlessly through the digestive tract, they become embedded in the walls of organs, causing tissue decay.

They also note that that the boy in their case study was lucky in the sense that pain caused by the magnets had brought him to the hospital before any of the magnets had time to burrow all the way through organ walls. Leakage of material from the stomach or intestines into other parts of the body can be deadly due to infection.

Simona Maksimyan et al, Clinical course and management of an unknown multiple-magnet ingestion in a teenage male, BMJ Case Reports (2023). DOI: 10.1136/bcr-2023-256418

How global warming shakes the Earth: Seismic data show ocean waves gaining strength as the planet warms

As oceans waves rise and fall, they apply forces to the sea floor below and generate seismic waves. These seismic waves are so powerful and widespread that they show up as a steady thrum on seismographs, the same instruments used to monitor and study earthquakes.

That wave signal has been getting more intense in recent decades, reflecting increasingly stormy seas and higher ocean swell. In a new study in the journal Nature Communications, researchers tracked that increase around the world over the past four decades. These global data, along with other ocean, satellite and regional seismic studies, show a decadeslong increase in wave energy that coincides with increasing storminess attributed to rising global temperatures.

 Richard C. Aster et al, Increasing ocean wave energy observed in Earth's seismic wavefield since the late 20th century, Nature Communications (2023). DOI: 10.1038/s41467-023-42673-w

The cell's 'read–write' mechanism: Researchers uncover how instructions for gene expression are relayed

The "read–write" mechanism by which cells replicate and use chemical instructions for expressing genes has been uncovered by  researchers. The quality and quantity of gene expression correlates not only with instructions by transcription factors but also with chemical modifications to the various histone proteins, which provide a scaffold for DNA in the chromosomes.

Scientists have long argued whether these modifications to histones are the epigenetic cause for activating gene expression. And, if that is the case, how they activate gene expression and are maintained during the process of mitosis, in which a cell divides into two daughter cells.

Researchers now have developed an experimental technology that allowed them to generate histones with acetylations at defined sites. They then monitored how p300/CBP interacts with and acetylates a nucleosome containing these selectively acetylated human histones.

The researchers found that p300/CBP recognizes and binds to specific acetylation marks on the H3–H4 complex. The enzyme then replicates acetylation marks to unacetylated sites of H3–H4, while also transcribing them from H3–H4 to H2B–H2A within the same nucleosome. Since this newly acetylated H2B–H2A complex is more likely to be stripped from the nucleosome, a model emerges in which it finally instructs which genes to be transcribed by the cellular transcription machinery. These results provide an unprecedented glimpse into how p300/CBP inherits acetylation marks to newly divided cells and utilizes those marks epigenetically for gene expression.

Masaki Kikuchi et al, Epigenetic mechanisms to propagate histone acetylation by p300/CBP, Nature Communications (2023). DOI: 10.1038/s41467-023-39735-4

Contraceptive Pills Have a strange Effect on The Fear-Promoting Area of The Brain

Scientists have found a possible link between using oral contraceptives and changes in parts of the brain that process fear. The findings may help explain fear-related mechanisms that disproportionately affect women. Hormonal changes during a menstrual cycle are currently understood to affect the fear circuitry in the brain. So researchers looked into the effects of combined oral contraceptive (COC) use to learn more about the relationship between sex hormones our bodies make naturally and synthetic versions of those hormones. This effect appeared to be reversible. A comparison with those who stopped using contraceptives or those who had never used contraceptives indicated this physiological change didn't seem to be lasting. To be clear, these are just associations, and there are no known negative effects linked to the change in size of certain brain regions. But the authors think it could be worth exploring further. This part of the prefrontal cortex is thought to sustain emotion regulation, such as decreasing fear signals in the context of a safe situation. The result may represent a mechanism by which combined OCs could impair emotion regulation in women. Researchers found levels of both natural and synthetic sex hormones were linked to changes in the size and thickness of the vmPFC compared to the same anatomy in men. However, only women who were currently using oral contraceptives had a thinner vmPFC than that in men. The researchers also found the structure in a fear-promoting brain region – the dorsal anterior cingulate cortex (dACC) – varied between men and women. This was noticeable regardless of COC use, emphasizing one way naturally-produced sex hormones can influence brain structure. Given the results that men have smaller dACC volume than women and thicker vmPFC than COC users, these findings may represent structural vulnerabilities to psychopathologies that predominantly affect women.

https://www.frontiersin.org/articles/10.3389/fendo.2023.1228504/full

Researchers identify brain network that is uniquely activated through injection vs. oral drug use

Understanding the brain mechanisms that underlie addiction is crucial for informing prevention interventions, developing new therapies for substance use disorders, and addressing the overdose crisis.

Results from a new clinical trial suggest that a group of brain regions known as the "salience network" is activated after a drug is taken intravenously, but not when that same drug is taken orally.

When drugs enter the brain quickly, such as through injection or smoking, they are more addictive than when they enter the brain more slowly, such as when they are taken orally. However, the brain circuits underlying these differences are not well understood. This study offers new information that helps explain what may be causing this difference.

People who smoke or inject drugs—two methods that deliver drugs to the brain quickly—often report doing so to get faster relief from withdrawal or to experience euphoria more quickly. However, drug smoking and injection are associated with developing a substance use disorder more quickly than taking drugs orally or by insufflation (e.g., snorting).

In addition, injecting drugs is also associated with higher rates of infectious diseases and overdose. To better understand how route of drug administration impacts the brain's response to the drug, researchers conducted a double-blind, randomized, counterbalanced clinical trial using simultaneous PET/fMRI imaging.

Part 1

This study showed that when participants received methylphenidate orally, the rate of dopamine increases peaked more than an hour after administration. Comparatively, when participants received an intravenous injection of methylphenidate, the rate of dopamine increases peaked much faster—within 5 to 10 minutes of the administration.

Through the fMRI, researchers observed that one brain region, the  ventromedial prefrontal cortex,  was less active after both oral and intravenous administration of the study drug. However, two brain regions, the dorsal anterior cingulate cortex and the insula, which are part of the brain's salience network, were activated only after receiving the injection of methylphenidate, the more addictive route of drug administration. These same areas of the brain were not activated after taking methylphenidate orally, the route with lower addiction potential. This finding was consistent among all 20 research participants.

The salience network attributes value to things in our environment and is important for recognizing and translating internal sensations—including the subjective effects of drugs. This research adds to a growing body of evidence documenting the important role that the salience network appears to play in substance use and addiction. For instance, studies have shown that people who experience damage to the insula, part of the brain's salience network, can have a complete remission of their addiction.

 P Manza, et al. Neural circuit selective for fast but not slow dopamine increases in drug reward, Nature Communications (2023). DOI: 10.1038/s41467-023-41972-6. www.nature.com/articles/s41467-023-41972-6

Part 2

 Willow bark extract has broad-spectrum antiviral effect

We need safe, sustainable antiviral options to treat the outbreaks of the future. Scientists  have now shown that an extract of willow bark—a plant that has already provided several medicines, including the precursor to modern aspirin—has a broad-spectrum antiviral effect in cell sample experiments.

The extract worked both on enveloped coronaviruses, which cause colds as well as COVID-19, and non-enveloped enteroviruses, which cause infections such as flu and meningitis. There are no clinically approved drugs that work against enteroviruses directly, so this extract could be a future game-changer.

The scientists had previously tested willow bark extract on enteroviruses, and found it was highly successful. In this new study, they expanded the remit of their research to look at additional kinds of virus and to try to understand the mechanism of the extract's action.

Willow (Salix spp.) bark hot extracts inhibit both enveloped and nonenveloped viruses: study on its anti-coronavirus and anti-enterovirus activities, Frontiers in Microbiology (2023). DOI: 10.3389/fmicb.2023.1249794

Cheetahs become more nocturnal on hot days. Climate change may trigger fights among predators

Changing temperatures can impact the behavior patterns of large carnivore species and also the dynamics among species.

Cheetahs are usually daytime hunters, but the speedy big cats will shift their activity toward dawn and dusk hours during warmer weather, a new study finds.

Unfortunately for endangered cheetahs, that sets them up for more potential conflicts with mostly nocturnal competing predators such as lions and leopards, say the authors of research published recently in the journal Proceedings of the Royal Society B.

While cheetahs only eat fresh meat, lions and leopards will sometimes opportunistically scavenge from smaller predators.

Lions and leopards normally kill prey themselves, but if they come across a cheetah's kill, they will try to take it. The cheetahs will not fight the larger cats, they will just leave.

Hunting at different times of the day is one long-evolved strategy to reduce encounters between the multiple predator species. But the new study found that on the hottest days, when maximum daily temperatures soared to nearly 45 degrees Celsius (113 degrees Fahrenheit), cheetahs became more nocturnal—increasing their overlapping hunting hours with rival big cats by 16%.

There's a greater chance for more unfriendly encounters and less food for the cheetahs because of global warming. 

Kasim Rafiq et al, Increasing ambient temperatures trigger shifts in activity patterns and temporal partitioning in a large carnivore guild, Proceedings of the Royal Society B: Biological Sciences (2023). DOI: 10.1098/rspb.2023.1938

Engineered 'living materials' could help clean up water pollution one day

This is how the scientists described their work:

After we prepared the hydrogel, we embedded photosynthetic—or sunlight-capturing—bacteria called cyanobacteria into the gel.

The cyanobacteria embedded in the material still needed to take in light and carbon dioxide to perform photosynthesis, which keeps them alive. The hydrogel was porous enough to allow that, but to make the configuration as efficient as possible, we 3D-printed the gel into custom shapes—grids and honeycombs. These structures have a higher surface-to-volume ratio that allow more light, CO₂ and nutrients to come into the material.
Like all other bacteria, cyanobacteria has different genetic circuits, which tell the cells what outputs to produce. Our team genetically engineered the bacterial DNA so that the cells created a specific enzyme called laccase.

The laccase enzyme produced by the cyanobacteria works by performing a chemical reaction with a pollutant that transforms it into a form that's no longer functional. By breaking the chemical bonds, it can make a toxic pollutant nontoxic. The enzyme is regenerated at the end of the reaction, and it goes off to complete more reactions.

 Debika Datta et al, Phenotypically complex living materials containing engineered cyanobacteria, Nature Communications (2023). DOI: 10.1038/s41467-023-40265-2

Blood cancer treatment could be transformed by discovery

Engineered yeast breaks new record: a genome with over 50% synthetic DNA

Scientists have created a strain of brewer’s yeast (Saccharomyces cerevisiae) whose genome is more than half synthetic. Seven-and-a-half chromosomes were synthesized or stitched together in the laboratory. To make sure the genome was stable, biologists removed repetitive regions of DNA and sequestered all genes for transfer RNAs — essential for protein synthesis — in a single ‘neochromosome’. It’s a milestone for the Sc2.0 consortium, whose aim is to create yeast with a fully synthetic genome.

https://www.sciencedirect.com/science/article/pii/S0092867423011303...

https://www.cell.com/cell-genomics/fulltext/S2666-979X(23)00273-2?utm_source=Live+Audience&utm_campaign=3a61cb3609-briefing-dy-20231109&utm_medium=email&utm_term=0_b27a691814-3a61cb3609-50323416

Using bacteria to make lunar soil more fertile

A team of agronomists and biotechnicians  has found that adding bacteria to simulated lunar regolith increased the amount of phosphate in the soil for use by plants. In their study, published in the journal Communications Biology, the group added three types of bacteria to samples of volcanic material and then tested them for acidity and their ability to grow plants.

As several countries make plans to send humans back to the moon, they must address several issues—one of the most basic is figuring out a way to feed people working there for an extended period of time. The obvious solution is for workers to grow their own food. But that presents problems, as well, such as how to transport soil for growing edible plants from Earth to the moon.

Some have suggested that moon soil, known as lunar regolith, might be treated to make it amenable to plant growth. Last year, a team in the U.S. showed that it is possible to grow plants in lunar regolith by growing a small number of weeds called thale cress in real lunar soil samples. That test showed that lunar soil can work, but not well enough for plants to mature and produce food. In this new study, the research team found that adding microbes to lunar soil can improve its ability to host plant life. To test the possibility of using microbes such as bacteria to make lunar regolith more hospitable to plant life, the research team obtained samples of volcanic material from a mountain in China—testing showed it to be a reasonable stand-in for regolith. The researchers then added one of three types of bacteria to three test pots filled with the volcanic material: Pseudomonas fluorescens, Bacillus megaterium and Bacillus mucilaginosus. After cultivating the bacteria in the soil samples, the researchers tested the samples to see the effects. They found that the addition of all three types of bacteria had made the soil samples more acidic, which resulted in reducing the pH level of the soil. That dissolved the insoluble phosphate-containing minerals in the soil, which released phosphorus, making it available for plants.

Yitong Xia et al, Phosphorus-solubilizing bacteria improve the growth of Nicotiana benthamiana on lunar regolith simulant by dissociating insoluble inorganic phosphorus, Communications Biology (2023). DOI: 10.1038/s42003-023-05391-z

Relieving stress in insulin-producing cells protects against type 1 diabetes

Removing a gene that manages stress within insulin-producing beta cells draws helpful attention from the immune system, protecting mice predisposed to type 1 diabetes from developing the disease, a new  study shows.

The study also found that changes discovered in the modified mouse beta cells are also present in human beta cells that manage to survive the widespread beta-cell death that characterizes type 1 diabetes.

This gives the researchers hope that their findings, published in the journal Cell Metabolism, may point to a potential new treatment that could be administered very early in the development of diabetes. 

When we eat, our beta cells produce about 1 million molecules of insulin every minute to help maintain normal blood glucose levels. That is a big and stressful job, especially for a part of these beta cells called the endoplasmic reticulum.

The endoplasmic reticulum is like the cell's warehouse staff. It folds the insulin protein molecules that a beta cell produces, packing them for shipping to other parts of the body. If something goes wrong with the protein folding process, the shipping process backs up or even stops, stressing the endoplasmic reticulum. A stress-response gene called Atf6 perks up when a cell is struggling with unfolded proteins. But if Atf6 can't resolve the protein-folding problem, prolonged stress will eventually kill the cell.

Scientists bred a line of diabetes-predisposed mice without the Atf6 gene in their beta cells. Instead of meeting their typical fate, those mice were protected from diabetes. Analysis of the genes expressed by their beta cells suggested the cells entered a state called senescence far ahead of schedule.

Senescence is a period of the cell's life cycle in which it stops dividing and halts other normal cellular business. Senescing cells can cause problems for neighboring cells by releasing inflammatory messaging molecules that trigger an immune system response.

When researchers removed—knocked-out—the Atf6 gene in the beta cells in the pancreas of their mouse model of type 1 diabetes, and they did not become diabetic. Instead of dying off, these cells unexpectedly appear to go into an early senescence state that initiated a beneficial immune response and helped the cells survive an autoimmune attack.

DNA damage, stress and aging can kick off senescence, which can draw an immune system response that cleans up the senescent cells. If the immune system fails to clear these cells, they accumulate and cause chronic inflammation and disease.

The beta cells without Atf6 exhibit transient senescence and start releasing this group of proteins, including leukemia inhibitory factor, or LIF, that recruits protective immune cells called M2 macrophages.

Part 1

Even more exciting is how closely the new study's results in mice appear to be reflected in human cells.

With a blood test, doctors can identify people who are at high-risk of developing type 1 diabetes months in advance of the death of their beta cells.

That may be a perfect timeframe for a treatment based on pharmacological inhibition of Atf6 or induction of LIF and other secreted proteins. If we can get there in time to protect these cells with transient senescence, the onset of diabetes might be prevented.

Hugo Lee et al, Stress-induced β cell early senescence confers protection against type 1 diabetes, Cell Metabolism (2023). DOI: 10.1016/j.cmet.2023.10.014

Part 2

Earth's Moon: Why One Side Always Faces Us

Astronomers find dozens of massive stars fleeing the Milky Way

The Milky Way can't hold onto all of its stars. Some of them get ejected into intergalactic space and spend their lives on an uncertain journey. A team of astronomers took a closer look at the most massive of these runaway stars to see what they could find out how they get ejected.

When astronomers observe a field of stars in the Milky Way, one of the things they measure is the velocity distribution. The overall velocity distribution of the stellar population reflects the rotation of the galaxy. And when a star isn't harmonized with the galaxy's rotation, it catches astronomers' attention.

A team of astronomers working with two catalogues of massive stars found a whole bunch of stars moving differently than the galaxy. They're runaway stars that are on their way out of the galaxy.

Nobody knows how many runaway stars are on their way out of our galaxy, but astronomers keep finding more of them. Some estimates say there are 10 million runaway stars fleeing the Milky Way, but we don't know for sure. It may depend on the mechanism that drives them away, and that's something astrophysicists don't fully understand. A new study aims to shed some light on the runaway star phenomenon by looking specifically at massive stars.

A relevant fraction of massive stars are runaway stars. These stars move with a significant peculiar velocity with respect to their environment.

Massive early-type OB stars are the most luminous stars in the Milky Way. OB stars are not only massive and young, they're extremely hot. They form in loosely organized groups with one another called OB associations. Because they're young and hot, they don't last long. They're important in astronomy because they're so massive and energetic and because many of them explode as supernovae. That's why there are specific catalogues dedicated to them.

Part 1

Why do massive stars make up such a high proportion of runaway stars? There are two competing theories that attempt to explain runaway stars, and both involve massive stars. One is the dynamical ejection scenario (DES), and the other is the binary supernova scenario (BSS).

OB stars often form in binary pairs. In the BSS, one star explodes as a supernova, and the explosion kicks the other star. If the situation is right, the surviving star is given enough energy in the right direction that it can escape from its bond with its partner, which is now a neutron star or a black hole. It can also escape the gravitational pull of the Milky Way. If that happens, it begins its long journey into intergalactic space.

In the DES, there's no dramatic supernova explosion. Instead, a star in a compact, densely packed region experiences gravitational interactions with other stars. Encounters between binary and single stars can produce runaways, and so can encounters between two binary pairs. The OB associations where O-type and B-type stars tend to form are the types of dense environments that can trigger runaway stars. Since most of these stars are massive, most of the runaway stars are, too.

Scientists have been wondering about the two scenarios and debating them for decades. Both scenarios can produce stars with enough velocity to escape the galaxy. In studying their sample of 175 runaway stars, the researchers found that their data favors one explanation over the other.

The higher percentages and higher velocities found for O-type compared to Be-type runaways underline that the dynamical ejection scenario is more likely than the binary supernova scenario.

The percentages of spectral types represented in runaway stars help explain their conclusion. 25% of the O-type stars in their sample are runaways versus 5% of the Be-type. Other studies have come up with different numbers, but as the researchers point out, there is agreement in the sense that the percentage of runaway O stars is significantly higher than for B or Be stars.

Previous research shows that O-type runaway stars have higher velocities than B and Be-type stars. Previous research also shows that dynamical ejection often results in faster, more massive runaways than the binary supernova scenario. 

M. Carretero-Castrillo et al, Galactic runaway O and Be stars found using Gaia DR3, Astronomy & Astrophysics (2023). DOI: 10.1051/0004-6361/202346613. On arXiv: DOI: 10.48550/arxiv.2311.01827

Part 2

**

World's First Entire Eye Transplant

How animals get their stripes and spots

Nature has no shortage of patterns, from spots on leopards to stripes on zebras and hexagons on boxfish. But a full explanation for how these patterns form has remained elusive.

Now engineers  have shown that the same physical process that helps remove dirt from laundry could play a role in how tropical fish get their colorful stripes and spots. Their findings were published Nov. 8 in the journal Science Advances.

Biologists have previously shown that many animals evolved to have coat patterns to camouflage themselves or attract mates. While genes encode pattern information like the color of a leopard’s spots, genetics alone do not explain where exactly the spots will develop, for example.

In 1952, before biologists discovered the double helix structure of DNA, Alan Turing, the mathematician who invented modern computing, proposed a bold theory of how animals got their patterns.

Turing hypothesized that as tissues develop, they produce chemical agents. These agents diffuse through tissue in a process similar to adding milk to coffee. Some of the agents react with each other, forming spots. Others inhibit the spread and reaction of the agents, forming space between spots. Turing’s theory suggested that instead of complex genetic processes, this simple reaction-diffusion model could be enough to explain the basics of biological pattern formation.

Surely Turing’s mechanism can produce patterns, but diffusion doesn’t yield sharp patterns.

Where particles  form sharply defined stripes,  the process known as diffusiophoresis plays a role in nature’s pattern formation.

Diffusiophoresis happens when a molecule moves through liquid in response to changes, such as differences in concentrations, and accelerates the movement of other types of molecules in the same environment. While it may seem like an obscure concept to non-scientists, it’s actually how laundry gets clean.

One recent study showed that rinsing soap-soaked clothes in clean water removes the dirt faster than rinsing soap-soaked clothes in soapy water. This is because when soap diffuses out of the fabric into water with lower soap concentration, the movement of soap molecules draws out the dirt. When the clothes are put in soapy water, the lack of a difference in soap concentration causes the dirt to stay in place.

The movement of molecules during diffusiophoresis, as researchers observed in their simulations, always follows a clear trajectory and gives rise to patterns with sharp outlines. To see if it may play a role in giving animals their vivid patterns, researchers ran a simulation of the purple and black hexagonal pattern seen on the ornate boxfish skin using only the Turing equations. The computer produced a picture of blurry purple dots with a faint black outline. Then the team modified the equations to incorporate diffusiophoresis. The result turned out to be much more similar to the bright and sharp bi-color hexagonal pattern seen on the fish.

The research team’s theory suggests that when chemical agents diffuse through tissue as Turing described, they also drag pigment-producing cells with them through diffusiophoresis—just like soap pulls dirt out of laundry. These pigment cells form spots and stripes with a much sharper outline.

 Benjamin Alessio et al, Diffusiophoresis-Enhanced Turing Patterns, Science Advances (2023). DOI: 10.1126/sciadv.adj2457. www.science.org/doi/10.1126/sciadv.adj2457

New antifungal molecule kills fungi without toxicity in human cells, mice

A new antifungal molecule, devised by tweaking the structure of prominent antifungal drug Amphotericin B, has the potential to harness the drug’s power against fungal infections while doing away with its toxicity, researchers  reported in the journal Nature.

Amphotericin B, a naturally occurring small molecule produced by bacteria, is a drug used as a last resort to treat fungal infections. While AmB excels at killing fungi, it is reserved as a last line of defense because it also is toxic to the human patient – particularly the kidneys.

This work is a demonstration that, by going deep into the fundamental science, you can take a billion-year head start from nature and turn it into something that hopefully is going to have a big impact on human health.

These researchers spent years exploring AmB in hopes of making a derivative that can kill fungi without harm to humans. In previous studies, they developed and leveraged a building block-based approach to molecular synthesis and teamed up with a group specializing in molecular imaging tools called solid-state nuclear magnetic resonance. They  uncovered the mechanism of the drug: AmB kills fungi by acting like a sponge to extract ergosterol from fungal cells.

The researchers also found that that AmB similarly kills human kidney cells by extracting cholesterol, the most common sterol in people. The researchers also resolved the atomic-level structure of AmB sponges when bound to both ergosterol and to cholesterol.

Using this structural information along with functional and computational studies, they achieved a significant breakthrough in understanding how AmB functions as a potent fungicidal drug. This provided the insights to modify AmB and tune its binding properties, reducing its interaction with cholesterol and thereby reducing the toxicity.

Part 1

 They began synthesizing and testing derivatives with slight changes to the region that binds to ergosterol and cholesterol, while also boosting the kinetics of the ergosterol-removing process to maintain efficacy.

 The researchers tested the most promising derivatives – first with in vitro assays, quickly assessing the efficacy in killing fungi; then moving to cell cultures and eventually live mice, assessing toxicity.

The researchers tested this molecule against over 500 different clinically relevant pathogen species in four different locations. And this molecule completely surprised us by either mimicking or surpassing the efficacy of current clinically available antifungal drugs.

The researchers tested AM-2-19 in human blood and kidney cells to screen for toxicity. They also tested AM-2-19 in mouse models of three common, stubborn fungal infections and saw high efficacy.

Maji, A. et al. Tuning sterol extraction kinetics yields a renal-sparing polyene antifungal. Nature https://doi.org/10.1038/s41586-023-06710-4 (2023).

Part 2

Semantic hearing: Future of intelligent hearables

Liver cells age differently depending on where they are in the organ

 People age at different rates. But what about inside of a living body? Do all cells age in the same way? And does the location of a cell in the organ make a difference to the ageing process? Researchers  have now shown in the liver of mice that liver cells age differently depending on where they are located in the organ.

The liver is largely made up of a single type of cell, the hepatocyte. Depending on where they are in the liver, they have different roles. Near the portal vein, where fresh, oxygen-rich blood enters the liver, hepatocytes use the oxygen to process fats in their mitochondria and produce energy. In contrast, carbohydrates are broken down in the less oxygen-rich regions of the liver. "In the liver, the position of the hepatocyte in the organ plays a crucial role. That's why the liver was the perfect model for us to investigate whether location also makes a difference in ageing.

The location of the liver cells has a strong influence on the ageing process. In the region of the liver where the liver cells use oxygen for energy production in their mitochondria, this process deteriorates significantly with age. In the central, oxygen-deprived area of the liver, however, the researchers found no change in the mitochondria, but a change in the cells' fat metabolism.

It is important where a cell ages. They age differently depending on where they are located and what their function is, according to these researchers. 

https://www.mpg.de/21085057/1109-balt-location-location-location-15...

Each of Your Nostrils Smells The World Uniquely, Study Reveals

It's not immediately noticeable to us, but our two nostrils are actually working independently in some ways and appear to have their own separate sense of smell.

That's the conclusion of a new study from researchers in the US that could teach us much more about the brain and how senses are processed. The findings build on earlier studies in animals and humans, indicating that our brains might be capable of processing each nostril's input individually as well as synthesizing them into one complete whole.

To look more closely at smelling in stereo, the researchers from the University of Pennsylvania, the Barrow Neurological Institute, and Ohio State University enlisted the help of 10 epilepsy patients who had already had electrodes implanted in their brains.

One of three different scents, as well as a control consisting of pure air, was puffed into either nostril or both together in each trial. After several seconds, the subject was asked to identify the smell, then state which nostril they used to detect it - left, right, or both. Meanwhile, the researchers collected data on the brain's response via the electrodes.

What's more, smelling through two nostrils together created two distinct bursts of activity. Though the time delay between them was very short, it was there, and the researchers suggest that this again points to the nostrils not always being in unison. Two nostrils were better than one when it came to identifying odors and identifying them more quickly, which hints that there's definitely some benefit to having two nostrils rather than one – as with eyes and ears. The analysis concentrated on the piriform cortex (PC) brain region, where the sense of smell is handled and interpreted. As we already know, our different senses are closely interconnected too, which means the findings may have implications beyond smell.

https://www.cell.com/current-biology/fulltext/S0960-9822(23)01379-9

Forests with multiple tree species are 70% more effective as carbon sinks than monoculture forests, study finds

To slow the effects of climate change, conserve biodiversity, and meet the sustainable development goals, replanting trees is vital. Restored forests store carbon within the forest's soil, shrubs, and trees. Mixed forests are especially effective at carbon storage, as different species with complementary traits can increase overall carbon storage.

Compared to single-species forests, mixed forests are also more resilient to pests, diseases, and climatic disturbances, which increases their long-term carbon storage potential. The delivery of other ecosystem services is also greater in mixed species forests, and they support higher levels of biodiversity.

Although the benefits of diverse forest systems are well known, many countries' restoration commitments are focused on establishing monoculture plantations. Given this practice, an international team of scientists has compared carbon stocks in mixed planted forests to carbon stocks in commercial and best-performing monocultures, as well as the average of monocultures.

Diverse planted forests store more carbon than monocultures—upwards of 70%. Researchers also found the greatest increase in carbon storage relative to monocultures in four-species mixtures.

The mixed planted forests assessed in the study ranged in species richness from two to six species. In the data set the scientists worked with, four-species mixtures were the most effective carbon sinks. One such mix was made up from different broadleaf trees. Mixes with two species also had greater above-ground carbon stocks than monocultures and stored up to 35% more carbon. 

Accordingly, the researchers were able to show that diversification of forests enhances carbon storage. Altogether, above-ground carbon stocks in mixed forests were 70% higher than in the average monoculture. The researchers also found that mixed forests had 77% higher carbon stocks than commercial monocultures, made up of species bred to be particularly high yielding.

Young mixed planted forests store more carbon than monocultures—a meta-analysis, Frontiers in Forests and Global Change (2023). DOI: 10.3389/ffgc.2023.1226514

Physicists trap electrons in a 3D crystal for the first time

 Electrons move through a conducting material like commuters at the height of Manhattan rush hour. The charged particles may jostle and bump against each other, but for the most part they’re unconcerned with other electrons as they hurtle forward, each with their own energy.

But when a material’s electrons are trapped together, they can settle into the exact same energy state and start to behave as one. This collective, zombie-like state is what’s known in physics as an electronic “flat band,” and scientists predict that when electrons are in this state they can start to feel the quantum effects of other electrons and act in coordinated, quantum ways. Then, exotic behavior such as superconductivity and unique forms of magnetism may emerge.

Now, physicists have successfully trapped electrons in a pure crystal. It is the first time that scientists have achieved an electronic flat band in a three-dimensional material. With some chemical manipulation, the researchers also showed they could transform the crystal into a superconductor — a material that conducts electricity with zero resistance.

The electrons’ trapped state is possible thanks to the crystal’s atomic geometry. The crystal, which the physicists synthesized, has an arrangement of atoms that resembles the woven patterns in “kagome,” the Japanese art of basket-weaving. In this specific geometry, the researchers found that rather than jumping between atoms, electrons were “caged,” and settled into the same band of energy.

The researchers say that this flat-band state can be realized with virtually any combination of atoms — as long as they are arranged in this kagome-inspired 3D geometry. The results, published in Nature, provide a new way for scientists to explore rare electronic states in three-dimensional materials. These materials might someday be optimized to enable ultraefficient power lines, supercomputing quantum bits, and faster, smarter electronic devices.

https://news.mit.edu/2023/physicists-trap-electrons-3d-crystal-firs...

The Remains of an Ancient Planet Lie Deep Within Earth

Mind-Altering Cat Parasite May Trigger Frailty in Older People

An infamous parasite primarily carried by cats, Toxoplasma gondii, could be responsible for increased frailty in older adults, a new study reveals.

The discovery, made by an international team of researchers, adds to what we already know about T. gondii: that it can cause flu-like symptoms in many, and more serious issues such as seizures in people with weaker immune systems. "We often think of T. gondii infection as relatively asymptomatic, but this study highlights that for some people it may have significant health consequences later on.

The research team suspected that the parasite may be one of the causes of 'inflammaging', or persistent age-related inflammation that contributes to frailty. Blood tests from 601 Spanish and Portuguese adults aged over 65 were analyzed for measures of frailty, including unintentional weight loss, tiredness, and loss of mental sharpness. While there wasn't an association found between T. gondii infections and frailty, among those who had been infected by T. gondii, people who produced a higher number of antibodies to fight it were more likely to show signs of being frail. To put it another way, there are signs of a link between a more severe immune reaction to this parasite, and a greater likelihood of being more frail in old age. It's not enough to prove cause and effect, but it seems there might be something going on. On the inflammaging front, those with a stronger response to T. gondii (perhaps through a more widespread infection, or multiple infections) also had higher levels of certain biomarkers of inflammation, suggesting another potential link there.

Considering infection rates for T. gondii rise as people get older, and that it can lie dormant and undetected in a human body for several decades, the researchers say we need to be even more careful when it comes to avoiding infection. That can come through exposure to T. gondii eggs (in a cat's litter box, for example, or water that they've contaminated), or through eating undercooked meat that's been infected by the parasite. Keeping cats indoors and avoiding strays can help too.

https://academic.oup.com/biomedgerontology/advance-article/doi/10.1...

All fireworks, including the green ones, are bad ! Did you know that Deepavali fireworks cause more distress than happiness? So we celebrate Diwali without any fireworks! All these years I never ever touched even a single one. We have been celebrating  Deepavali with fun and happiness minus fireworks for the past few years. Before somebody asks me 'How can there be fun without fireworks?', I want to add I had fun because I didn't contribute to the pollution. I didn't send out a toxic concoction into the atmosphere that rains down heavily into lakes, rivers, seas, fields and houses. I am not responsible for someone developing hypothyroidism, anemia or cancer. And I am extremely happy because of this! Fireworks get their flamboyance from a variety of chemicals, many of which are toxic to humans. From the gunpowder that fuels their flight to the metallic compounds that colour their explosions, fireworks often contain carcinogenic or hormone-disrupting substances that can seep into soil and water, not to mention the lung-clogging smoke they release and plastic debris they scatter. Almost all the major cities in India that have measured Deepavali festival-raised pollution levels recently sounded alarm bells. Some people justify their acts of using fireworks by saying that these harmful gases released into the atmosphere actually kill mosquitoes and other harmful insects! But these insects might already have developed resistance to these chemicals. Moreover, if they are harmful to some living beings, they would equally be harmful to the other ones (human beings) too! First the ever evolving fireworks tempt you and make you buy them at sky-rocketing prices causing distress to your earning loved ones. Fire accidents are quite common during this festival. The flying fire bits also get into unprotected eyes and burn eye parts, especially the cornea leading to blindness. Apart from causing agony to the animal life, the loud noises also increase hearing distress and the toxic smoke released into the atmosphere can get lodged in people's lungs and enhance asthmatic symptoms and severe breathing problems in human beings. Anybody considering him/her-self environmentally conscious and responsible will never go anywhere near these fireworks as they pose a serious environmental and health danger from heavy metals and other toxic firework fallout. So celebrate Diwali without fireworks like we do. 

Our Galaxy's Heart Is Pulsing With a Mysterious Signal

Compared to some other galaxies out there, the supermassive black hole at the heart of the Milky Way isn't a particularly active one. It's not guzzling down scads of material, and it's not blasting giant jets of plasma into space. Even a relatively peaceful supermassive black hole, however, is a wild, savage beast, and our own – named Sagittarius A* – has been recorded doing some pretty strange things. And now there's a new one: astrophysicists Gustavo Magallanes-Guijón and Sergio Mendoza of National Autonomous University of Mexico have recorded it sort of… pulsing. Every 76 minutes, like clockwork, the gamma-ray flux of Sgr A fluctuates. This, the researchers say, is similar in periodicity to changes in the black hole's radio and X-ray emission too, suggesting an orbital motion of something whirling madly around the black hole.

https://arxiv.org/abs/2311.05875

Exoplanet Types: Worlds Beyond Our Solar System

Data reveal possible reason some exoplanets are shrinking

A new study could explain the "missing" exoplanets between super-Earths and sub-Neptunes.

Some exoplanets seem to be losing their atmospheres and shrinking. In a new study using NASA's retired Kepler Space Telescope, astronomers find evidence of a possible cause: The cores of these planets are pushing away their atmospheres from the inside out.

The study is published in The Astronomical Journal.

Exoplanets (planets outside our solar system) come in a variety of sizes, from small, rocky planets to colossal gas giants. In the middle lie rocky super-Earths and larger sub-Neptunes with puffy atmospheres. But there's a conspicuous absence—a "size gap"—of planets that fall between 1.5 to 2 times the size of Earth (or in between super-Earths and sub-Neptunes) that scientists have been working to better understand.

Scientists have now confirmed the detection of over 5,000 exoplanets, but there are fewer planets than expected with a diameter between 1.5 and 2 times that of Earth. Exoplanet scientists have enough data now to say that this gap is not a fluke. There's something going on that impedes planets from reaching and/or staying at this size.

Researchers think that this gap could be explained by certain sub-Neptunes losing their atmospheres over time. This loss would happen if the planet doesn't have enough mass, and therefore gravitational force, to hold onto its atmosphere. So sub-Neptunes that aren't massive enough would shrink to about the size of super-Earths, leaving the gap between the two sizes of planets.

But exactly how these planets are losing their atmospheres has remained a mystery. Scientists have settled on two likely mechanisms: One is called core-powered mass loss; and the other, photoevaporation. The new study has uncovered new evidence supporting the first.

 Jessie L. Christiansen et al, Scaling K2. VII. Evidence For a High Occurrence Rate of Hot Sub-Neptunes at Intermediate Ages, The Astronomical Journal (2023). DOI: 10.3847/1538-3881/acf9f9

Microplastics found in clouds could affect the weather

From the depths of the seas to snow on mountains and even the air above cities, microplastics are turning up increasingly often. Now, in Environmental Science & Technology Letters, researchers have analyzed microplastics in clouds above mountains. They suggest that these tiny particles could play a role in cloud formation and, in turn, affect weather.

Microplastics—plastic fragments smaller than five millimeters—originate from a myriad of items used daily, such as clothing, packaging and car tires.

As research in the field evolves, scientists are not only detecting microplastics in the atmosphere but also investigating how they may play a role in cloud formation. For example, a group of researchers recently detected plastic granules, which had water-attracting surfaces, in Japanese mountaintop clouds.

So, to learn more, researchers set out to look for microplastics in mountain clouds, used computer models to figure out how they could have gotten there, and tested how the particles could have impacted—and been impacted by—the clouds.

Wang and the team first collected 28 samples of liquid from clouds at the top of Mount Tai in eastern China. Then they analyzed the samples and found:

• Low-altitude and denser clouds contained greater amounts of microplastics.
• Particles were made of common polymers, including polyethylene terephthalate, polypropylene, polyethylene, polystyrene and polyamide.
• The microplastics tended to be smaller than 100 micrometers in length, although some were as long as 1,500 micrometers.
• Older, rougher particles had more lead, mercury and oxygen attached to their surfaces, which the researchers suggest could facilitate cloud development.

Part 1

Research models suggested that airflow from highly populated inland areas, rather than from over the ocean or other nearby mountains, served as the major source of the fragments.

In laboratory experiments, the researchers demonstrated that microplastics exposed to cloud-like conditions—ultraviolet light and filtered cloud-sourced water—had smaller sizes and rougher surfaces than those exposed to pure water or air. Additionally, particles impacted by the cloud-like conditions had more lead, mercury and oxygen-containing groups.

These results suggest that clouds modify microplastics in ways that could enable the particles to affect cloud formation and the fate of airborne metals. However, more work is needed to fully understand how microplastics affect clouds and the weather.

Characterization of Microplastics in Clouds over Eastern China, Environmental Science & Technology Letters (2023). DOI: 10.1021/acs.estlett.3c00729. pubs.acs.org/doi/abs/10.1021/acs.estlett.3c00729

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Researchers discover alternative cosmic source of gold

Researchers have discovered that the explosion of a low-mass neutron star can be the alternative cosmic source for lanthanides and other heavy elements, including precious metals such as gold and platinum.

Neutron stars are the evolutionary end points of stars with a mass between 10 to 25 times that of the sun. After the final explosion, the star leaves behind a compact object with a mass comparable to the sun, and a diameter of about 20 km (the size of Manhattan). Such a compact object is stable enough to exist alone. But in a binary neutron star system, the interaction with the companion neutron star can trigger something dramatic. Traditionally, when two neutron stars are close enough, they merge and collide. This process is the major source of lanthanides and heavy elements in the universe. The collision can create the condition (known as the r-process) for the synthesis of these elements. The merger event was recently observed for the first time in 2017. However, it is highly uncertain if this channel alone is sufficient to explain the heavy elements in the cosmic scale. The team noticed that even without direct collision, the primary neutron star can lose mass to its companion neutron star by tidal force. Theoretical models expect that after shedding sufficient mass, the star becomes unstable, and it triggers uncontrolled pulsation and the later explosion.

The new results  confirm that the individual low mass neutron star is unstable, and it can explode. The chemical composition of the ejecta closely resembles the solar composition, especially in heavy elements. This suggests that this scenario could be another important method to explain the chemical element distribution in the universe.

This study sheds light on one of the fundamental questions about the universe: where all the chemical elements come from, and how did the universe evolve from only hydrogen and helium to a diversity of 118 elements. Lanthanides have close relations with modern technology. For example, neodymium is the main ingredient for manufacturing strong magnets. Heavy elements including precious metals, i.e., gold and platinum, are also abundantly produced by this channel.

 Chun-Ming Yip et al, R-process Nucleosynthesis of Subminimal Neutron Star Explosions, The Astrophysical Journal (2023). DOI: 10.3847/1538-4357/acf570

50 Years of Data Links Insecticides to Global Decline of Human Sperm Counts: Meta Analysis

Insecticide exposure has been linked to lower sperm concentration in adult men worldwide, according to a new review of 25 studies spanning almost 50 years. The research team  says it's the most thorough systematic review of the topic so far.

These are strong findings as their method takes into account each study's limitations, so their published paper recommends reducing exposure to the two types of insecticides studied to preserve male fertility and increase the changes of parenthood.

people are primarily exposed to insecticides through the consumption of contaminated food and water.

These commonly-used insecticides' main mode of toxicity is the inhibition of enzymes involved in the normal breakdown of neurotransmitters like acetylcholine.

The researchers note other studies have shown that semen quality is declining over time. A review in 2022 found that the average sperm count among participants, who were not considered infertile dropped by 51 percent between 1973 and 2018, from 101.2 million to 49 million per millilitre of semen.

There's a correlation between low sperm concentration and other factors of male health too, such as an increased risk of some cancers. However, finding two things to be related doesn't prove that one is responsible for or a result of the other, and we still don't know the mechanism behind the effects.

https://ehp.niehs.nih.gov/doi/10.1289/EHP12678

1 in 50 Million Chance: US Woman With Rare Double Uterus Is Pregnant in Both

 A 32-year-old woman from Alabama who was born with two uteruses is now pregnant in both.

Kelsey Hatcher, who is documenting her story on her Instagram account "doubleuhatchlings," knew from the age of 17 she has "uterus didelphys," a rare condition where a person has a double uterus, thought to affect about 0.3 percent of females.

It was during a routine eight-week ultrasound visit in May that the mother-of-three learned not only that she was having twins this time around – but that a fetus was present in each of her uteruses.

Most likely what happened is that she ovulated separately and had one egg come down each fallopian tube, meaning coming down on each side of the uterus, and then sperm traveled up on each separate uterus and fertilization occurred separately, according to her doctors. Both the fetuses are healthy.

Pregnancies in both uteruses are exceedingly rare – the odds were 1 in 50 million – with the last widely known case occurring in Bangladesh in 2019 when Arifa Sultana, then 20, gave birth to healthy twins 26 days apart.​

But the uteruses will contract at different times, which could be minutes, hours or even days apart, and the woman and her husband  are aware Cesarean sections – for one, or both – could be needed, depending on how things unfold.

Source: 

Agence France-Presse

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Kelsey's ultrasound shows both of her uteruses with a baby in each. Source: (doubleuhatchlings/Instagram)

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1.3 million lives lost every year in just seven countries: The devastating impact of tobacco revealed

Every year 1.3 million lives are lost to cancers caused by smoking tobacco across the UK, US and BRICS nations (Brazil, Russia, India, China and South Africa), according to a new study.

Researchers have found that together, the seven countries represented more than half of the global burden of cancer deaths every year. They concluded that smoking, as well as three other preventable risk factors—alcohol, overweight or obesity, and human papillomavirus (HPV) infections—caused almost 2 million deaths combined.

Researchers concluded that the four preventable risk factors resulted in over 30 million years of life lost each year. Smoking tobacco had by far the biggest impact—leading to 20.8 million years of life being lost, the study said.

Some of the other key findings from the study include:

• Preventable risk factors were associated with different cancer types in different places. For example, in India, there were more premature deaths from head and neck cancer in men, and gynecological cancer in women, but in every other country, tobacco smoking caused the most years of life to be lost to lung cancer.

• Researchers believe that this is due to differences in each of the countries—cervical screening is less comprehensive in India and South Africa than in other countries like the UK and US, which would explain why there are more premature deaths from gynecological cancers due to HPV infection in India and South Africa. The higher number of years of life lost to head and neck cancer in men in India could be explained by smoking habits being different to those in the UK, with the general population smoking different tobacco products.

• There are gender differences in the number of cancer deaths and years of life lost to different risk factors. Men have higher rates of years of life lost to smoking and drinking alcohol, because smoking and drinking rates tend to be higher in men. In China, India and Russia, rates of years of life lost to tobacco smoking and alcohol were up to nine times higher in men than women.

• Meanwhile, being overweight or obese, and HPV infection, led to more cancer deaths and years of life lost in women than in men. In South Africa and India, HPV led to particularly high rates of years of life lost with a large gender imbalance. Rates were 60 times higher in women than men in South Africa, and 11 times higher in India, which highlights the urgent need for improved access to cervical screening and the HPV vaccination in these countries.

• The differences in cancers linked to HPV infection are stark—mortality rates are six times higher in South Africa than in the UK and US. Cervical cancer has been largely prevented by screening in the UK and US, and is on track to be almost eliminated through HPV vaccination in the UK.

International burden of cancer deaths and years of life lost from cancer attributable to four major risk factors: a population-based study in Brazil, Russia, India, China, South Africa, the United Kingdom, and United States, eClinicalMedicine (2023).

New studies of brain activity explain benefits of electroconvulsive therapy

Electroconvulsive therapy (ECT), formerly known as electroshock therapy, involves inducing a brief seizure in the brain using controlled doses of electricity. While ECT is highly effective for certain mental illnesses, particularly depression, the reasons for its efficacy have long puzzled the fields of psychiatry and neuroscience.

Now, researchers  may have an answer. In two new studies published in Translational Psychiatry, they propose a new hypothesis that ECT alleviates depression symptoms by increasing aperiodic activity, a type of electrical activity in the brain that doesn't follow a consistent pattern and is generally considered to be the brain's background noise.

Electroconvulsive therapy has a great track record, but a bad reputation. The therapy is effective in up to 80% of patients who receive the treatment, most often for depression but occasionally for bipolar disorder or schizophrenia. However, despite this high success rate, electroconvulsive therapy is frequently associated with frightening images of people receiving painful, high voltage shocks.

A lot of people are surprised to learn that doctors still use electroconvulsive therapy, but the modern procedure uses highly controlled dosages of electricity and is done under anesthesia. It really doesn't look like what you see in movies or television.

While generally safe and effective, ECT does have drawbacks, including temporary confusion and cognitive impairment. It also requires multiple outpatient visits, which can present a barrier to some people who might otherwise benefit from the treatment.

Part 1

One of the reasons ECT isn't more popular is that for a lot of people, it's easier and more convenient to just take a pill. However, in people for whom medications don't work, electroconvulsive therapy can be life-saving. Understanding how it works will help us discover ways to increase the benefits while minimizing side effects.

The researchers used electroencephalography (EEG) scans to study the brain activity of patients who received ECT therapy for depression. They also looked at another similar form of treatment called magnetic seizure therapy, which induces a seizure with magnets instead of electrodes. Both therapies showed increased aperiodic activity levels in patients' brains post-treatment.

One of the functions of aperiodic activity in the brain is helping control how neurons turn on and off. Our neurons are constantly going through cycles of excitation and inhibition that correspond with different mental states. Aperiodic activity helps boost inhibitory activity in the brain, effectively slowing it down.

Something we see regularly in the EEG scans of people who receive electroconvulsive or magnetic seizure therapy is a slowing pattern in the brain's electrical activity. This pattern has gone unexplained for many years, but accounting for the inhibitory effects of aperiodic activity helps explain it. It also suggests that these two forms of therapy are causing similar effects in the brain.

 Translational Psychiatry (2023). doi.org/10.1038/s41398-023-02631-y

Translational Psychiatry (2023). doi.org/10.1038/s41398-023-02634-9

Part 2

Bear genes show circadian rhythms even during hibernation

The internal clocks of grizzly bears appear to keep ticking through hibernation, according to a genetic study. This persistence highlights the strong role of circadian rhythms in the metabolism of many organisms including humans.

The genetic study confirmed observational evidence that bears' energy production still waxes and wanes in a daily pattern even as they slumber for several months without eating. The researchers also found that during hibernation the amplitude of the energy production was blunted, meaning the range of highs and lows was reduced. The peak also occurred later in the day under hibernation than during the active season, but the daily fluctuation was still there.  

This underscores the importance of the circadian rhythms themselves—that they give organisms the flexibility to still function in a state as extreme as a hibernating bear.

Other research has shown that circadian rhythms, the 24-hour physical cycles common to most living animals on Earth, have ties to metabolic health. In humans, major disruptions to these patterns, such as occur in night shift work, have been linked to metabolic problems like weight gain and higher prevalence of diabetes.

Ellery P. Vincent et al, Circadian gene transcription plays a role in cellular metabolism in hibernating brown bears, Ursus arctos, Journal of Comparative Physiology B (2023). DOI: 10.1007/s00360-023-01513-5

How cell identity is preserved when cells divide

Every cell in the human body contains the same genetic instructions, encoded in its DNA. However, out of about 30,000 genes, each cell expresses only those genes that it needs to become a nerve cell, immune cell, or any of the other hundreds of cell types in the body.

Each cell's fate is largely determined by chemical modifications to the proteins that decorate its DNA; these modification in turn control which genes get turned on or off. When cells copy their DNA to divide, however, they lose half of these modifications, leaving the question: How do cells maintain the memory of what kind of cell they are supposed to be?

A new MIT study proposes a theoretical model that helps explain how these memories are passed from generation to generation when cells divide. The research team suggests that within each cell's nucleus, the 3D folding pattern of its genome determines which parts of the genome will be marked by these chemical modifications.

After a cell copies its DNA, the marks are partially lost, but the 3D folding allows each daughter cell to easily restore the chemical marks needed to maintain its identity. And each time a cell divides, chemical marks allow a cell to restore its 3D folding of its genome. This way, by juggling the memory between 3D folding and the marks, the memory can be preserved over hundreds of cell divisions.

 Jeremy A. Owen et al, Design principles of 3D epigenetic memory systems, Science (2023). DOI: 10.1126/science.adg3053. www.science.org/doi/10.1126/science.adg3053

Researchers help reduce lead levels in Madagascar drinking water

A team of engineers and public health experts helped residents reduce their exposure to lead—a major global environmental pollutant that causes more than 1 million premature deaths each year. By combining efforts to replace water pumps and educate city technicians, these researchers helped decrease the blood lead levels of 87 percent of the children tested during their study.

The lead concentrations of the water from the pumps exceeded the World Health Organization's recommended limit of lead in drinking water—10 micrograms per liter. In some cases, the water contained more than 10 times the recommended limit.

The families and children are drinking this water and using it to cook their meals.

In low- and middle-income countries, there is a lack of regulations and understandings of the harmful effects of lead, as well as other comorbidities, such as improper nutrition, that can increase childhood lead absorption.

The pumps are the primary source of water for more than three-quarters of the coastal area of Madagascar, where there are about 9,000 pumps because tap water is not always affordable or available for the city's 280,000 people. 

Part 1

They used social marketing—a process that focuses on changing behavior to improve health using strategies from the commercial marketing world—to create a faster, more cost-effective plan to directly educate the people responsible for the manufacturing and repairing of the pumps.

The researchers worked with local staff to build the capacity and skill set of technicians, while overseeing and facilitating work on the pumps to ensure they understood how to remove and replace the leaded pump components. Additionally, to understand the impact of this intervention, they worked with local health practitioners to measure blood lead levels of small children who drank water from the pumps before and after the leaded pump components were replaced.

Of the 55 children tested, 87 percent experienced a significant decrease in blood lead levels once leaded components were removed from the pumps.

Adaline M. Buerck et al, Reductions in Children's Blood Lead Levels from a Drinking-Water Intervention in Madagascar, Sub-Saharan Africa, Environmental Science & Technology (2023). DOI: 10.1021/acs.est.3c03774

Part 2

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