Expansion Rate: The Hubble Tension

Selective removal of aging cells opens new possibilities for treating age-related diseases

A research team  has achieved a significant breakthrough in the treatment of age-related diseases. Their cutting-edge technology offers a promising new approach by selectively removing aging cells, without harming normal healthy cells. This groundbreaking development is poised to redefine the future of health care and usher in a new era of targeted therapeutic interventions.

Aging cells, known as senescent cells, contribute to various inflammatory conditions and age-related ailments as humans age. To address this issue, the research team focused on developing a technology that could precisely target and eliminate aging cells, while sparing normal healthy cells. In their study, the team designed organic molecules that selectively target receptors overexpressed in the membranes of aging cells. By leveraging the higher levels of reactive oxygen species (ROS) found in aging cells, these molecules promote the formation of disulfide bonds and create oligomers that bind together. The research is published in the Journal of the American Chemical Society.

Through self-assembly of these oligomers, the researchers successfully created artificial proteins with a stable α-helix secondary structure. These protein-like nanoassemblies exhibited strong binding affinity to the mitochondrial membranes of aging cells, leading to membrane disruption and subsequent cell self-destruction.

"The selective removal of aging cells by targeting the mitochondria and inducing dysfunction has been successfully demonstrated in their experiments. This approach represents a new paradigm for treating age-related diseases.

This innovative technology offers several advantages, including minimal toxicity concerns and a wide therapeutic window by specifically targeting organelles within cells. It opens up exciting possibilities for designing preclinical and clinical trials in the future.

Sangpil Kim et al, Supramolecular Senolytics via Intracellular Oligomerization of Peptides in Response to Elevated Reactive Oxygen Species Levels in Aging Cells, Journal of the American Chemical Society (2023). DOI: 10.1021/jacs.3c06898

Rivers are rapidly warming, losing oxygen: Aquatic life at risk, study finds

Rivers are warming and losing oxygen faster than oceans, according to a  study published in the journal Nature Climate Change. The study shows that of nearly 800 rivers, warming occurred in 87% and oxygen loss occurred in 70%.

The study also projects that within the next 70 years, river systems, especially in the American South, are likely to experience periods with such low levels of oxygen that the rivers could "induce acute death" for certain species of fish and threaten aquatic diversity at large.

Scientists know that a warming climate has led to warming and oxygen loss in oceans, but did not expect this to happen in flowing, shallow rivers. They found that rivers are warming up and deoxygenating faster than oceans, which could have serious implications for aquatic life—and the lives of humans. 

Widespread deoxygenation in warming rivers, Nature Climate Change (2023). DOI: 10.1038/s41558-023-01793-3

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Electrons from Earth may be forming water on the moon

A team of researchers, led by a University of Hawai'i (UH) at Mānoa planetary scientist, discovered that high energy electrons in Earth's plasma sheet are contributing to weathering processes on the moon's surface and, importantly, the electrons may have aided the formation of water on the lunar surface. The study was published in Nature Astronomy.

Skepticism about claim human ancestors nearly went extinct

Could the lives of the eight billion people currently on Earth have depended on the resilience of just 1,280 human ancestors who very nearly went extinct 900,000 years ago?

That is the finding of a recent study which used genetic analysis modeling to determine that our ancestors teetered on the brink of annihilation for nearly 120,000 years.

However, scientists not involved in the research have criticized the claim, one telling AFP there was "pretty much unanimous" agreement among population geneticists that it was not convincing.
None denied that the ancestors of humans could have neared extinction at some point, in what is known as a population bottleneck.

But experts expressed doubts that the study could be so precise, given the extraordinarily complicated task of estimating population changes so long ago, and emphasized that similar methods had not spotted this massive population crash.

It is extremely difficult to extract DNA from the few fossils of human relatives dating from more than a couple of hundred thousand years ago, making it hard to know much about them.

But advances in genome sequencing mean that scientists are now able to analyze genetic mutations in modern humans, then use a computer model that works backwards in time to infer how populations changed—even in the distant past.

The study, published in the journal Science earlier this month, looked at the genomes of more than 3,150 modern-day humans.

The Chinese-led team of researchers developed a model to crunch the numbers, which found that the population of breeding human ancestors shrank to about 1,280 around 930,000 years ago.

99 percent of ancestors wiped out?
"About 98.7 percent of human ancestors were lost" at the start of the bottleneck.
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The bottleneck, potentially caused by a period of global cooling, continued until 813,000 years ago, the study said.

Then there was a population boom, possibly sparked by a warming climate and "control of fire", it added.

The researchers suggested that inbreeding during the bottleneck could explain why humans have a significantly lower level of genetic diversity compared to many other species.

The population squeeze could have even contributed to the separate evolution of Neanderthals, Denisovans and modern humans, all of which are thought to have potentially split from a common ancestor roughly around that time, the study suggested.

It could also explain why so few fossils of human ancestors have been found from the period.

However, archaeologists have pointed out that some fossils dating from the time have been discovered in Kenya, Ethiopia, Europe and China, which may suggest that our ancestors were more widespread than such a bottleneck would allow.
The hypothesis of a global crash does not fit in with the archaeological and human fossil evidence.
In response, the study's authors said that hominins then living in Eurasia and East Asia may not have contributed to the ancestry of modern humans.

"The ancient small population is the ancestor of all modern humans. Otherwise we would not carry the traces in our DNA.
Some experts are "extremely skeptical" that the researchers had accounted for the statistical uncertainty involved in this kind of analysis. They said it will "never be possible" to use genomic analysis of modern humans to get such a precise number as 1,280 from that long ago, emphasizing that there are normally wide ranges of estimations in such research.

The authors of the paper said their range was between 1,270 and 1,300 individuals—a difference of just 30.
But sceptics say that the paper was unconvincing".

Our ancestors may have neared extinction at some point but the ability of modern genomic data to infer such an event was "very weak"they say.

"It's probably one of those questions that we're not going to answer in the near future."
Source: AFP

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Notorious fungus Aspergillus fumigatus completely scrambles its genome after just one bout of sex

 Researchers have found that Aspergillus fumigatus produces more meiotic crossovers than any other organism. This means that the fungus can establish its complex resistance mechanism after just one cycle of sexual reproduction. The discovery uncovers a possible cause of the rapid spread of hard-to-treat fungal infections.

It also makes it difficult to identify the source of an infection with a resistant fungus. 

Aspergillus fumigatus is naturally widespread in our environment. In fact, we inhale the spores of this fungus every day. For healthy people, this causes no problems. But it can be dangerous for seriously ill patients.

For example, it's risky for people who are in the ICU, or receiving chemotherapy, or those who have undergone an organ transplant. Infections caused by Aspergillus fumigatus are therefore treated medically with azoles, which are antifungal agents. The problem is that the fungus is increasingly resistant to this treatment, and this can be fatal to patients.

One of the causes of the resistance mechanism in the fungus is believed to be the frequent use of azoles in agriculture. Farmers and horticulturists may not use azoles specifically to combat Aspergillus fumigatus, but they do use them to tackle other fungi. Exposure to azoles has enabled Aspergillus fumigatus to develop a resistance mechanism. Compost heaps, where the fungus naturally thrives, are particular hotspots for resistance selection. And that eventually works its way into hospitals. Even patients who have never been treated with an azole can already be carrying an azole-resistant fungus.

There are isolates that have many  genetic differences to those of the fungus at the farm, but also many similarities. This may be due to the sexual reproduction of the fungus, which the researchers looked at in their PLoS Biology study.

The researchers  focused on the number of crossovers per chromosome. In humans, that would be three to four on average. This results in combinations of genes from either parent remaining strongly linked. But in Aspergillus fumigatus, they detected up to 30 crossovers. That's the highest number ever found in an organism.

This means that a single act of sexual reproduction leads to a 'complete reshuffling' of the genome—the genetic makeup of the organism. "This causes enormous variation in the population, even within a relatively limited environment.

It makes it very difficult to identify the transmission route of an infection, from the environment to a patient. The fungus can also efficiently reproduce asexually as well as sexually. So you could simultaneously find the fungus with identical genomes in isolates located thousands of kilometers apart. That makes it very challenging to figure out the transmission of this fungus.

Ben Auxier et al, The human fungal pathogen Aspergillus fumigatus can produce the highest known number of meiotic crossovers, PLOS Biology (2023). DOI: 10.1371/journal.pbio.3002278

Why bats carry viruses that have higher fatality rates in humans than those from other mammals

A small team of biologists and evolutionists reports why bats carry viruses that cause higher fatality rates when jumping to humans than those that come from any other mammal. In their study, reported on the open-access site PLOS Biology, the group used data from past research efforts to model the growth of viruses within bat populations as well as their spread to other animals.

Prior research has shown that when a virus jumps from bats to humans, the results can be deadlier for humans than when viruses jump from other mammals. The reason has been a matter of debate.

In this new effort, the team used data from prior research efforts, along with mathematics and modeling, to show that it is due to an innate tolerance for inflammation in bats, which, the researchers suggest, arose with their ability to fly.

To come to this conclusion, the research team first obtained data from other studies about the impact of several viruses on the immune systems of bats that had also jumped to humans. They then used that data in a mathematical model to show how a virus optimizes its chances of survival (by spreading from host to host before a host dies) by balancing transmission gains with degree of virulence. They found that a key feature of bat physiology—its ability to fly—was related to its tolerance for inflammation. This was pertinent because it made the bat more tolerant of viruses when infected. That allowed for a high growth rate of viruses in bats. And that, the researchers point out, is why the same virus would be more deadly in humans—we have a lower tolerance for inflammation. A lower tolerance, they note, leads to more grave symptoms, such as lungs that are no longer able to process enough air.

The research team extended their study to include 19 other mammals as a way to predict viral growth and the likely impact of a jump to humans in a general sense. They found reason to think that there is a low probability of a lethal virus that spreads easily from bats or other mammals to humans.

 Cara E. Brook et al, Reservoir host immunology and life history shape virulence evolution in zoonotic viruses, PLOS Biology (2023). DOI: 10.1371/journal.pbio.3002268

World falling dangerously short of climate goals: UN

A world facing catastrophic climate change is perilously off course in meeting goals for slashing carbon pollution and boosting finance for the developing world, according to the UN's first official progress report out Friday.

The 2015 Paris treaty has successfully driven climate action, but "much more is needed now on all fronts," said the report, which will underpin a crucial climate summit in Dubai at the end of the year.

"The world is not on track to meet the long-term goals of the Paris Agreement," including capping global warming at 1.5 degrees Celsius above mid-19th century levels, the report said.

Achieving net zero carbon emissions by 2050—another Paris goal—will also require phasing out the burning of all fossil fuels whose emissions cannot be captured or compensated.

The stocktake report also says that clean power must be dramatically ramped up, according to the first UN scorecard of the world's progress in meeting Paris Agreement climate goals.

"Scaling up renewable energy and phasing out all unabated fossil fuels are indispensable elements of just energy transitions to net zero emissions," it said.

"Unabated" refers to the absence of any technology that removes carbon emissions, either at the source or from the atmosphere.

Emissions have already peaked in developed and a few developing countries, but are continuing to rise in many of the world's largest economies.

The global stocktake report is a call for radical and immediate action to meet the goals of the Paris Agreement. 

The stocktake also highlights the need to rapidly and radically scale up financial support to developing nations so they can adapt to climate amplified weather disasters that are already eating away at their economies.

Source: News Agencies

Matter found to comprise 31% of the total amount of matter and energy in the universe

One of the most interesting and important questions in cosmology is, "How much matter exists in the universe?" An international team of scientists has now succeeded in measuring the total amount of matter for the second time. Reporting in The Astrophysical Journal, the team determined that matter makes up 31% of the total amount of matter and energy in the universe, with the remainder consisting of dark energy.

Cosmologists think that only about 20% of the total matter is made of regular or 'baryonic' matter, which includes stars, galaxies, atoms, and life. About 80% is made of dark matter, whose mysterious nature is not yet known but may consist of some as-yet-undiscovered subatomic particles.

The team used a well-proven technique to determine the total amount of matter in the universe, which is to compare the observed number and mass of galaxy clusters per unit volume with predictions from numerical simulations.

The number of clusters observed at the present time, the so-called 'cluster abundance,' is very sensitive to cosmological conditions and, in particular, the total amount of matter. A higher percentage of the total matter in the universe would result in more clusters being formed. But it is difficult to measure the mass of any galaxy cluster accurately as most of the matter is dark, and we cannot see it directly with telescopes.

To overcome this difficulty, the team was forced to use an indirect tracer of cluster mass. They relied upon the fact that more massive clusters contain more galaxies than less massive clusters (mass richness relation: MRR). Because galaxies consist of luminous stars, the number of galaxies in each cluster can be utilized as a way of indirectly determining its total mass.

By measuring the number of galaxies in each cluster in their sample from the Sloan Digital Sky Survey, the team was able to estimate the total mass of each of the clusters. They were then able to compare the observed number and mass of galaxy clusters per unit volume against predictions from numerical simulations.

The best-fit match between observations and simulations was with a universe consisting of 31% of the total matter, a value that was in excellent agreement with that obtained using cosmic microwave background (CMB) observations from the Planck satellite. Notably, CMB is a completely independent technique.

They have succeeded in making the first measurement of matter density using the MRR, which is in excellent agreement with that obtained by the Planck team using the CMB method.

This work further demonstrates that cluster abundance is a competitive technique for constraining cosmological parameters and complementary to non-cluster techniques such as CMB anisotropies, baryon acoustic oscillations, Type Ia supernovae, or gravitational lensing.

 Mohamed H. Abdullah et al, Constraining Cosmological Parameters Using the Cluster Mass–Richness Relation, The Astrophysical Journal (2023). DOI: 10.3847/1538-4357/ace773

Something Is Suppressing The Growth of The Universe, Physicists Say

Seen through a giant's eyes, our Universe's galaxies cling like foam to the surface of an eternal ocean, drawing into clumps and strings around inky voids. This sparkling web has taken eons to come together, congealing gradually under gravity's guidance out of what was, billions of years ago, an evenly-spread fog of white-hot particles fresh out of the Big Bang's oven.

Slow as this growth seems to us mere mortals, University of Michigan physicists Nhat-Minh Nguyen, Dragan Huterer, and Yuewei Wen want to slow it down even further, fixing one of science's most vexing problems in the process.
Their suggested tweak to the model that currently best describes our Universe could resolve a significant conflict in observations of space's expanding waistline.

Complain as you might that you can't get something for nothing these days, there's more empty space up there today than there was yesterday. Something is causing nothingness to grow, squeezing its way into the gaps between galaxies to gently push the large scale structure of the Universe apart at an ever increasing rate.
Since we don't know what is behind this mysterious shoving, we refer to it as dark energy.

"If gravity acts like an amplifier enhancing matter perturbations to grow into large-scale structure, then dark energy acts like an attenuator damping these perturbations and slowing the growth of structure," says Nguyen, the lead author of an investigation into the large-scale structure's growth.

"By examining how cosmic structure has been clustering and growing, we can try to understand the nature of gravity and dark energy."

The precise rate of expansion, known as the Hubble constant (H0), isn't at all clear. Measure the way certain kinds of exploding stars retreat into the distance, you might get an acceleration of 74 kilometers per second per megparsec. Using the 'light echo' of stretched radiation still bouncing about after the Big Bang – the cosmic microwave background (CMB) – H0 is closer to around 67 kilometers per second.

That might not seem like much of a difference, but the discrepancy has persisted through enough investigations that it can no longer be dismissed as some trivial error.
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Researchers took a fresh look at the flat ΛCDM concordance cosmology model as a potential source of mistaken assumptions. If cosmology was a game of chess, this would be the board and pieces as laid out on general relativity's tiles, moved by dark energy's push, and aligned by dark matter's gravitational influences.

Rewinding the chess pieces we see today, we can effectively see how the game began, from a momentary blink of rapid inflation to a time where the first stars collapse, to the formation of galaxies and their eventual emergence into gargantuan, interconnected threads.
If for some reason this process deviated from what's predicted by the concordance model, impeding the growth of the Universe's large-scale structure, the tension between the different measures of the Universe's accelerating expansion would vanish.

The researchers used a combination of measurements involving ripples in the cosmic web, gravitational lensing events, and details in the cosmic microwave background to come to a statistically convincing conclusion that the cosmic web is growing slower than the flat ΛCDM concordance cosmology model predicts.

"The difference in these growth rates that we have potentially discovered becomes more prominent as we approach the present day," says Nguyen.

"These different probes individually and collectively indicate a growth suppression. Either we are missing some systematic errors in each of these probes, or we are missing some new, late-time physics in our standard model."

While there are no obvious contenders for what might put the brakes on the growth of the cosmic web, future measurements of the Universe's large scale structure might at least hint at whether there's a need to explore the idea further.
The Universe has taken 13.7 billion years to look this good. We can stand to wait a few more years to work out the secrets to such fine looking cosmological wrinkles.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.111001

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Can a vitamin transform natural killer cells into a cancer therapy? Scientists think the answer is yes

Cancer patients appeared to benefit from natural killer cells obtained from donors in an experimental method of treating cancer that involved an aggressive army of immune system fighters endowed with the ability to home in on malignant cells and destroy them.

The natural killer cells were pre-treated with nicotinamide, a compound widely known to most people as niacin, or vitamin B₃. It's a substance with a special affinity for natural killer cells, enhancing their capacity to annihilate cancers. Once primed in the laboratory, these natural killers are ready to be unleashed against formidable targets. The evolving methodology has shown promise in a preliminary study aimed at forcing hard-to-treat cancers of the blood into remission.

Prior to the new research, which is published in Science Translational Medicine, attempts by other teams to use natural killer cell infusions as a therapeutic for leukemias, lymphomas and other blood malignancies, weren't always effective. Doctors were confronted with a problem: some people simply didn't respond to the investigational treatment, which was offered after standard therapy failed.

Now, in a unique take on this emerging form of cancer treatment, medical scientists have devised a way to boost the effectiveness of natural killer cells, enhancing their role as a therapeutic. The innovative approach boosted the impact of natural killer cells and brought about remissions in patients with otherwise recalcitrant cancers.

The combination of nicotinamide-enhanced natural killer cells and monoclonal antibody treatment was safe in 30 patients, including 20 with relapsed or difficult-to-treat non-Hodgkin lymphoma. Among 19 patients with non-Hodgkin lymphoma, 11 demonstrated a complete response and three had a partial response within 28 days of treatment. Nicotinamide appears to protect the natural killer cells from oxidative stress, while enhancing their ability to home in on lymph nodes, the scientists found.

Frank Cichocki et al, Nicotinamide enhances natural killer cell function and yields remissions in patients with non-Hodgkin lymphoma, Science Translational Medicine (2023). DOI: 10.1126/scitranslmed.ade3341

 The energy costs of information processing in biological systems

The behaviors, physiology and existence of living organisms is supported by countless biological processes, which entail the communication between cells and other molecular components. These molecular components are known to transmit information to each other in various ways, for instance via processes know as diffusion and electrical depolarization or by exchanging mechanical waves.

Researchers recently carried out a study aimed at calculating the energetic cost of this transfer of information between cells and molecular components. Their paper, published in Physical Review Letters, introduces a new tool that could be used to study cellular networks and better understand their function.

 They had tried to experimentally determine how much energy neurons spend when sending information. They  found that this energy expenditure ranged between 10⁴-10⁷ K_BT/bit depending on details, which is far higher than the 'fundamental' bound of ~ K_BT/bit, sometimes called the the Landauer bound which must be paid to erase a bit of information.

A further objective of the recent study was to determine whether optimizing these energetic costs could shed light on the reasons why molecular systems communicate with each other using distinct physical mechanisms in different situations. For instance, while neurons typically communicate with each other via electrical signals, other types of tells can communicate via the diffusion of chemicals.

They wanted to understand in what regime each of these (and others) would be best in terms of an energy cost per bit.

 Samuel J. Bryant et al, Physical Constraints in Intracellular Signaling: The Cost of Sending a Bit, Physical Review Letters (2023). DOI: 10.1103/PhysRevLett.131.068401

Q: Why are the climate activists vandalizing art and museums?

Answer: "How do you feel when you see something beautiful and priceless art work apparently being destroyed before your eyes? Do you feel outraged? Good. Where is that feeling when you see the planet being destroyed?"

• A statement by a Just Stop Oil activist, who had taken part in vandalizing a work by Vermeer in The Hague

Lily Kinyon et al, When, where, and which climate activists have vandalized museums, npj Climate Action (2023). DOI: 10.1038/s44168-023-00054-5

Study finds significant chemical exposures in women with cancer

In a sign that exposure to certain endocrine-disrupting chemicals may be playing a role in cancers of the breast, ovary, skin and uterus, researchers have found that people who developed those cancers have significantly higher levels of these chemicals in their bodies.

While it does not prove that exposure to chemicals like PFAS (per- and poly-fluoroalkyl substances) and phenols (including BPA) led to these cancer diagnoses, it is a strong signal that they may be playing a role and should be studied further.

The study showed that particularly for women, higher exposure to PFDE, a long-chained PFAS compound, had double the odds of a previous melanoma diagnosis; women with higher exposure to two other long-chained PFAS compounds, PFNA and PFUA, had nearly double the odds of a prior melanoma diagnosis.

The study showed a link between PFNA and a prior diagnosis of uterine cancer; and women with higher exposure to phenols, such as BPA (used in plastics) and 2,5-dichlorophenol (a chemical used in dyes and found as a by-product in wastewater treatment), had higher odds of prior ovarian cancer diagnoses.

The study concludes that Since PFAS make up thousands of chemicals, one way to reduce exposures is for EPA to regulate PFAS as a class of chemicals, rather than one at a time.

Cathey, A.L et al, Exploratory profiles of phenols, parabens, and per- and poly-fluoralkyl substances among NHANES study participants in association with previous cancer diagnoses, Journal of Exposure Science & Environmental Epidemiology (2023). DOI: 10.1038/s41370-023-00601-6

Scientists Invented a Super-Slippery Toilet That Nothing Sticks to

The traditional porcelain and ceramic toilet bowls could be on the way out, if a new3D printed design from scientists  catches on – with the key benefit being the ultra slippery surface.

Poop that clings to the toilet bowl is not only unpleasant for bathroom visitors and cleaners alike, it actually wastes a significant amount of water as more flushes are required to dislodge the stuff.

It was this problem that the scientists wanted to tackle by making a non-stick toilet bowl. They used a mixture of plastic and hydrophobic sand grains for their material, fused together with laser-based 3D printing techniques, in a design that was around a tenth the size of a standard toilet bowl.

The abrasion-resistant super-slippery flush toilet, or ARSFT, was shown to repel synthetic feces, as well as multiple substances that the scientists tested. Nothing was able to get a grip on the surface, and everything slid straight down, much like the slippery pitcher plants that inspired the toilet design.

The as-prepared ARSFT remains clean after contacting with various liquids such as milk, yogurt, highly sticky honey, and starch gel mixed congee, demonstrating excellent repellence to complex fluids," write the researchers in their published paper.

https://onlinelibrary.wiley.com/doi/abs/10.1002/adem.202300703

Research finds ponds release more greenhouse gas than they store

Though human-made ponds both sequester and release greenhouse gases, when added up, they may be net emitters, according to two related studies by  researchers.

The studies begin to quantify the significant effects that both human-made and natural ponds have on the global greenhouse gas budget, measurements that aren't well understood. Global climate models and predictions rely on accurate accounting of greenhouse gas emissions and carbon storage.

In the study, the researchers examined the past management activities, while also taking sediment cores and measurements of sediment thickness for each of the 22 study ponds. They measured the amount of carbon in the sediment, extrapolated those measurements to the overall pond, and divided that number by the age of the pond to arrive at the amount of carbon sequestered annually per square meter, a number on the same order of magnitude as wetlands and mangroves, and more than lakes. They also found that carbon burial rates were influenced by aquatic plants (those large enough to be seen), fish and additions of high nitrogen levels relative to phosphorus, nutrients that may not get renewed in a static pond and become limited. The right kinds and ratios of added nutrients promote plant growth, which use carbon for cells, and are deposited on the pond floor when plants die.

The  researchers also measured gas emissions from the ponds approximately every two weeks over the course of ice-free period in 2021.

The researchers found that methane—a greenhouse gas 25 times more potent than carbon dioxide—accounted for most of the gas emitted annually, and carbon dioxide and methane emissions varied greatly by season.

Ponds absorbed CO2 during early summer months when plants were growing, and emitted it later in the year, when plants decomposed. Methane was emitted throughout warm months, but week-to-week shifts in emissions were high, pointing to the need for frequent sampling for accurate accounting.

Part 1

The researchers found that when water was stratified (a layer of warm water sitting on top of cold bottom waters), methane built up and led to overall higher emissions than when water was mixed by wind or sudden cooling. That's because micro-organisms on the pond bed that produce methane require low-oxygen conditions that is disrupted by mixing.

When the results from the all the present studies are considered together, ponds are net emitters of greenhouse gases, due to methane release overwhelming the amount of carbon stored in the sediments. But the findings also offer the possibility of reducing methane emissions with bubblers or underwater circulators. If we could reduce that methane number, we could potentially flip these ponds from being net emitters to net sinks, but we have to get a handle on that methane.

Meredith A. Holgerson et al, High rates of carbon burial linked to autochthonous production in artificial ponds, Limnology and Oceanography Letters (2023). DOI: 10.1002/lol2.10351

Nicholas E. Ray et al, High Intra‐Seasonal Variability in Greenhouse Gas Emissions From Temperate Constructed Ponds, Geophysical Research Letters (2023). DOI: 10.1029/2023GL104235

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Yogurt may be the next go-to garlic breath remedy

It turns out yogurt may have a previously unknown benefit: eliminating garlic odors.

A new study conducted in a lab—with follow-up human breath tests being planned—showed that whole milk plain yogurt prevented almost all of the volatile compounds responsible for garlic's pungent scent from escaping into the air.

Researchers tested the garlic deodorizing capacity of yogurt and its individual components of water, fat and protein to see how each stood up to the stink. Both fat and protein were effective at trapping garlic odors, leading the scientists to suggest high-protein foods may one day be formulated specifically to fight garlic breath.

For each treatment experiment, the researchers placed equal amounts of raw garlic in glass bottles and confirmed the cluster of offending sulfur-based volatiles were released in concentrations that would be detected by the human nose. They used mass spectrometry to measure levels of the volatile molecules in gaseous form present before and after each treatment.

Results showed that yogurt alone reduced 99% of the major odor-producing raw garlic volatiles. When introduced separately, the fat, water and protein components of yogurt also had a deodorizing effect on raw garlic, but fat and protein performed better than water.

In the case of fat, a higher quantity of butter fat was more effective at deodorization. The proteins studied included different forms of whey, casein and milk proteins, all of which were effective at deodorizing garlic—likely because of their ability to trap the volatile molecules before they were emitted into the air. A casein micelle-whey protein complex performed the best.

Additional experiments involving changing the pH of the yogurt to make it less acidic—from 4.4 pH to 7 pH—reduced the yogurt's deodorization effect on the garlic. Changing the pH of water, on the other hand, did not make any difference in water's deodorization effect.

Manpreet Kaur et al, Effect of Yogurt and Its Components on the Deodorization of Raw and Fried Garlic Volatiles, Molecules (2023). DOI: 10.3390/molecules28155714

How brain cells die in Alzheimer’s

Entire Branches on Tree of Life Are Dying, Scientists Warn

Like the comet striking the dinosaurs – in slower motion, but just as deadly – human activity is hacking off entire branches from the tree of life, a new study confirms.

"It is changing the trajectory of evolution globally and destroying the conditions that make human life possible," ecologists warn in their new paper.

"It is an irreversible threat to the persistence of civilization and the livability of future environments for Homo sapiens."

This rate is 35 times higher than previous genus-level extinctions.

Without human influence, it would have taken 18,000 years for the same number of genera to have met their end. Other studies have also found similarly high extinction rates for plant, fungi, and invertebrate life as well.

"[The sixth mass extinction] is causing rapid mutilation of the tree of life, where entire branches (collections of species, genera, families, and so on) and the functions they perform are being lost," explain the researchers.

The biosphere we live within is extremely interconnected, so loss of species groups that play particular functions within their interconnected-living web can have severe cascading consequences.

What's more, this rate of genera loss is set to increase, they calculate. If we continue on our current trajectory and all current endangered genera are snuffed from existence by 2100, the equivalent 300-year-loss since 1800 would have taken 106,000 years at normal background levels of extinction.

The most vulnerable species are usually the most unique, yet overlooked on the planet. Along with them we'll lose millions of years of evolutionary history, which can never be repeated, as well as the loss of critical functions they performed that helped keep all the surrounding biological cycles chugging on like a well oiled machine.

Climate change alone is creating a massive destabilization across these systems, scattering critical timing of ecosystem services like pollination, reducing the types of species and allowing new ones to invade more easily.

From plastics, to pesticides, habitat loss and poaching, we're not allowing the life around us to catch a break.

"Immediate political, economic, and social efforts of an unprecedented scale are essential if we are to prevent these extinctions and their societal impacts. What happens in the next two decades will very likely define the future of biodiversity

https://www.pnas.org/doi/10.1073/pnas.2306987120

Part 2

Spider silk is spun by silkworms for the first time, offering a green alternative to synthetic fibers

Scientists  have synthesized spider silk from genetically modified silkworms, producing fibers six times tougher than the Kevlar used in bulletproof vests.

The study, published September 20 in the journal Matter, is the first to successfully produce full-length spider silk proteins using silkworms. The findings demonstrate a technique that could be used to manufacture an environmentally friendly alternative to synthetic commercial fibers such as nylon.

Silkworm silk is presently the only animal silk fiber commercialized on a large scale, with well-established rearing techniques. Consequently, employing genetically modified silkworms to produce spider silk fiber enables low-cost, large-scale commercialization.

Scientists have eyed spider silk as an enticingly sustainable alternative to synthetic fibres, which can release harmful microplastics into the environment and are often produced from fossil fuels that generate greenhouse gas emissions. But turning to nature for alternatives isn't without challenges.

Previously developed processes for spinning artificial spider silk have struggled to apply a surface layer of glycoproteins and lipids to the silk to help it withstand humidity and exposure to sunlight—an anti-aging "skin layer" that spiders apply to their webs.

Genetically modified silkworms offer a solution to this problem, say the researchers  since silkworms coat their own fibers with a similar protective layer.

The exceptionally high mechanical performance of the fibers produced in this study holds significant promise in this field. This type of fiber can be utilized as surgical sutures, addressing a global demand exceeding 300 million procedures annually.

The spider silk fibers could also be used to create more comfortable garments and innovative types of bulletproof vests and they may have applications in smart materials, the military, aerospace technology, and biomedical engineering.

 Qing Meng, High-strength and ultra-tough whole spider silk fibers spun from transgenic silkworms, Matter (2023). DOI: 10.1016/j.matt.2023.08.013. www.cell.com/matter/fulltext/S2590-2385(23)00421-6

Researchers make sand that flows uphill

Engineering researchers  have discovered that sand can actually flow uphill.

The team's findings were published recently in the journal Nature Communications. A corresponding video shows what happens when torque and an attractive force  is applied to each grain—the grains flow uphill, up walls, and up and down stairs.

"After using equations that describe the flow of granular materials,"  say the authors of the paper, "we were able to conclusively show that these particles were indeed moving like a granular material, except they were flowing uphill."

The researchers say the highly unusual discovery could unlock many more lines of inquiry that could lead to a vast range of applications, from health care to material transport and agriculture.

Uphill granular flow of microrobotic microrollers

But to understand how these grains are flowing uphill, the researchers calculated what the stresses are that cause them to move in that direction. If you have a negative angle of repose, then you must have cohesion to give a negative coefficient of friction. These granular flow equations were never derived to consider these things, but after calculating it, what came out is an apparent coefficient of friction that is negative.

Increasing the magnetic force increases the cohesion, which gives the grains more traction and the ability to move faster. The collective motion of all those grains, and their ability to stick to each other, allows a pile of sand particles to essentially work together to do counterintuitive things—like flow up walls, and climb stairs. The team is now using a laser cutter to build tiny staircases, and is taking videos of the material ascending one side and descending the other. A single microroller couldn't overcome the height of each step. But working together, they can.

 Samuel R. Wilson-Whitford et al, Microrollers flow uphill as granular media, Nature Communications (2023). DOI: 10.1038/s41467-023-41327-1

How bats evolved to avoid cancer

A new paper titled "Long-read sequencing reveals rapid evolution of immunity and cancer-related genes in bats" in Genome Biology and Evolution shows that rapid evolution in bats may account for the animals' extraordinary ability to both host and survive infections as well as avoid cancer.

Bats are exceptional among mammals for not only their ability to fly, but also for their long lives, low cancer rates, and robust immune systems. The ability of bats to tolerate viral infections may stem from unusual features of their innate immune response.

These characteristics make bats an interesting animal to investigate, because they may have implications for human health. For example, by better understanding the mechanisms of the bat immune system that allow bats to tolerate viral infections, researchers may be better able to prevent disease outbreaks from animals to people. Comparative genomic analyses of bats and cancer-susceptible mammals may eventually provide new information on the causes of cancer and the links between cancer and immunity.

Studies of bats and other organisms complement studies based on mouse models; mice are more amenable than bats to experimental manipulation but exhibit fewer characteristics with implications for human disease.

So researchers sequenced the genomes of two bat species, the Jamaican fruit bat and the Mesoamerican mustached bat, and carried out a comprehensive comparative genomic analysis with a diverse collection of bats and other mammals.

The researchers found genetic adaptations in six DNA repair-related proteins and 46 proteins in bats that were cancer-related, meaning that researchers have previously found that such proteins suppress cancer. Notably, the study found that these altered cancer-related genes were enriched more than two-fold in the bat group compared to other mammals.

By generating these new bat genomes and comparing them to other mammals scientists continue to find extraordinary new adaptations in antiviral and anticancer genes. These investigations are the first step towards translating research on the unique biology of bats into insights relevant to understanding and treating aging and diseases, such as cancer, in humans.

Armin Scheben et al, Long-read sequencing reveals rapid evolution of immunity and cancer-related genes in bats, Genome Biology and Evolution (2023). DOI: 10.1093/gbe/evad148

Chameleon-inspired coating could cool and warm buildings through the seasons

As summer turns to fall, many people will be turning off the air conditioning and firing up heaters instead. But traditional heating and cooling systems are energy-intensive, and because they typically run on fossil fuels, they aren't sustainable. Now, by mimicking a desert-dwelling chameleon, a research team reporting in Nano Letters has developed an energy-efficient, cost-effective coating. The material could keep buildings cool in the summers—or warm in the winters—without additional energy.

Many desert creatures have specialized adaptations to allow them to survive in harsh environments with large daily temperature shifts. For example, the Namaqua chameleon of southwestern Africa alters its color to regulate its body temperature as conditions change. The critters appear light gray in hot temperatures to reflect sunlight and keep cool, then turn a dark brown once they cool down to absorb heat instead.

This unique ability is a naturally occurring example of passive temperature control—a phenomenon that could be adapted to create more energy-efficient buildings. But many systems, such as cooling paints or colored steel tiles, are only designed to keep buildings either cool or warm, and can't switch between "modes."

Inspired by the Namaqua chameleon, researchers wanted to create a color-shifting coating that would adapt as outside temperatures fluctuate. To make the coating, researchers mixed thermochromic microcapsules, specialized microparticles and binders to form a suspension, which they sprayed or brushed onto a metal surface. When heated to 68 degrees Fahrenheit, the surface began to change from dark to light gray. Once it reached 86 degrees, the light-colored film reflected up to 93% of solar radiation. Even when heated above 175 degrees for an entire day, the material showed no signs of damage. Next, the team tested it alongside three conventional coatings—regular white paint, a passive radiative cooling paint and blue steel tiles—in outdoor tests on miniature, doghouse-sized buildings throughout all four seasons.

Part 1

• In winter, the new coating was slightly warmer than the passive radiative cooling system, though both maintained similar temperatures in warmer conditions.
• In summer, the new coating was significantly cooler than the white paint and steel tiles.
• During spring and fall, the new coating was the only system that could adapt to the widely fluctuating temperatures changes, switching from heating to cooling throughout the day.

The researchers say that this color-changing system could save a considerable amount of energy for regions that experience multiple seasons, while still being inexpensive and easy to manufacture.

"Warm in Winter and Cool in Summer" Scalable Biochameleons Inspired Temperature Adaptive Coating with Easy Preparation and Construction, Nano Letters (2023). DOI: 10.1021/acs.nanolett.3c02733

Part 2

Nanotechnology in the fight against viruses

Newly emerging and recurrent cases of viral infections constitute a significant problem and a huge challenge to public health. Most countries prevent or control acute viral infections through widespread vaccination and improved sanitation. As a result, measles, yellow fever, and rabies cases rarely occur now.

But these days very frequently, new viral infections, symptoms and infections are being  reported. But researchers are trying to fight these viral infections with nanotechnology that can solve current problems related to the prevention, treatment, and diagnosis of viral infections.

Most attention is paid to the synthesis of new drugs and vaccines based on nanocarriers, with increased effectiveness and reduced side effects, the design of personal protective equipment (masks, gloves, medical clothing) and self-disinfecting surfaces, as well as strategies for the development of nanobiosensors enabling early detection of viral infection.

The results of research conducted on a laboratory scale are very promising. However, when thinking about the commercialization of medical products based on nanotechnology, one should consider how their cost can be reduced and how they can be made more reliable compared to existing solutions.

This is one such paper: Joanna Goscianska et al, Nanoscience versus Viruses: The SARS‐CoV‐2 Case, Advanced Functional Materials (2021). DOI: 10.1002/adfm.202107826

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Deep sea mystery of the Lebensspuren

Regeneration across complete spinal cord injuries reverses paralysis

When the spinal cords of mice and humans are partially damaged, the initial paralysis is followed by the extensive, spontaneous recovery of motor function. However, after a complete spinal cord injury, this natural repair of the spinal cord doesn't occur and there is no recovery. Meaningful recovery after severe injuries requires strategies that promote the regeneration of nerve fibers, but the requisite conditions for these strategies to successfully restore motor function have remained elusive till recently.

Five years ago, some researchers demonstrated that nerve fibres can be regenerated across anatomically complete spinal cord injuries. But they also realized this wasn't enough to restore motor function, as the new fibers failed to connect to the right places on the other side of the lesion.

Now the scientists used state-of-the-art equipment to run in-depth analyses and identity which type of neuron is involved in natural spinal-cord repair after partial spinal cord injury.

Their  observations using single-cell nuclear RNA sequencing not only exposed the specific axons that must regenerate, but also revealed that these axons must reconnect to their natural targets to restore motor function.

Their discovery informed the design of a multipronged gene therapy. The scientists activated growth programs in the identified neurons in mice to regenerate their nerve fibers, upregulated specific proteins to support the neurons' growth through the lesion core, and administered guidance molecules to attract the regenerating nerve fibers to their natural targets below the injury.

Mice with anatomically complete spinal cord injuries regained the ability to walk, exhibiting gait patterns that resembled those quantified in mice that resumed walking naturally after partial injuries. This observation revealed a previously unknown condition for regenerative therapies to be successful in restoring motor function after neurotrauma.

Scientists now think a complete solution for treating spinal cord injury will require both approaches—gene therapy to regrow relevant nerve fibers, and spinal stimulation to maximize the ability of both these fibers and the spinal cord below the injury to produce movement.

While many obstacles must still be overcome before this gene therapy can be applied in humans, the scientists have taken the first steps towards developing the technology necessary to achieve this feat in the years to come.

Jordan W. Squair et al, Recovery of walking after paralysis by regenerating characterized neurons to their natural target region, Science (2023). DOI: 10.1126/science.adi6412. www.science.org/doi/10.1126/science.adi6412

Smart speaker lets users mute different areas of a room

In virtual meetings, it's easy to keep people from talking over each other. Someone just hits mute. But for the most part, this ability doesn't translate easily to recording in-person gatherings. In a bustling cafe, there are no buttons to silence the table beside you.

The ability to locate and control sound—isolating one person talking from a specific location in a crowded room, for instance—has challenged researchers, especially without visual cues from cameras.

A team of researchers has developed a shape-changing smart speaker, which uses self-deploying microphones to divide rooms into speech zones and track the positions of individual speakers. With the help of the team's deep-learning algorithms, the system lets users mute certain areas or separate simultaneous conversations, even if two adjacent people have similar voices.

Like a fleet of Roombas, each about an inch in diameter, the microphones automatically deploy from and then return to a charging station. This allows the system to be moved between environments and set up automatically. In a conference room meeting, for instance, such a system might be deployed instead of a central microphone, allowing better control of in-room audio.

Creating Speech Zones Using Self-distributing Acoustic Swarms, Nature Communications (2023). DOI: 10.1038/s41467-023-40869-8. www.nature.com/articles/s41467-023-40869-8

Turning a cockroach into a cyborg without injuring it

Where do spammers get your details?

Each time you enter your email address or phone number into an e-commerce website, you may be handing it to spammers. But sometimes you may even receive spam from entities you don't recognize. That's because businesses will often transfer customers' contact information to related companies, or sell their data to third parties such as data brokers.

Some entities also use "address-harvesting" software to search the internet for electronic addresses that are captured in a database. The collector then uses these addresses directly, or sells them to others looking to send spam.

Most countries have prohibitions.

If the receiver consented to these types of messages, the prohibition does not apply. When you buy goods or services from a company, you will often see a request to click on a "yes" button to receive marketing promotions. Doing so means you have consented. On the other hand, if your phone or inbox are hit by commercial messages you haven't agreed to receive, that is a breach of the Spam Act by the sender. If you originally signed up to receive the messages, but then unsubscribed and the messages kept coming after five business days, that is also illegal. Senders must also include a functioning unsubscribe facility in every commercial message they send. Spammers can be penalized for breaches of the Spam Act.

It's worth noting that messages from political parties, registered charities and government bodies aren't prohibited—nor are messages from educational institutions to students and former students. So while you might consider these messages as "spam", they can legally be sent freely without consent. Factual messages (without marketing content) from businesses are also legal as long as they include accurate sender details and contact information.

Part 1

If you want to stop spam,

1. use a spam filter and block spammers—email and telecommunications providers often supply useful tools as part of their services
2. unsubscribe from any emails you no longer want to receive—even if you originally agreed to receive them
3. remove as much of your contact details from websites as you can and always restrict the sharing of your personal information (such as name, birth date, email address and mobile number) when you can—beware of pre-ticked boxes asking for your consent to receive marketing emails
4. install cybersecurity updates for your devices and software as you get them
5. always think twice about opening emails or clicking on links, especially for messages promising rewards or asking for personal information—if it looks too good to be true, it probably is
6. use multi-factor authentication to access online services so even if a scam compromises your login details, it will still be difficult for hackers to break into your accounts
7. report spam to your email and telecommunications providers.

Source: https://theconversation.com/why-do-i-get-so-much-spam-and-unwanted-...

Brain sensitivity to insulin may be modulated by menstrual cycle

A combined team of diabetes specialists  has found evidence that suggests brain sensitivity to insulin may be modulated by the menstrual cycle in women.

In their study, reported in the journal Nature Metabolism, the group conducted a clinical trial involving monitoring the insulin levels of female volunteers.

Prior research has suggested that the presence of insulin in the brain can lead to changes in eating behavior, whole-body metabolism and fat storage. How this works is not well understood. Making things even murkier, as the researchers note, is that virtually all prior research in this area has involved testing the impact of insulin on the brains of men.

In this new effort, the research team sought to learn more about the impact of insulin on women's brains. To that end, they conducted a clinical trial that involved testing the impact of insulin on the brains of 11 female volunteers during two time periods; during their first day of ovulation, and just after they had ovulated.

To measure the impact of insulin on their brains, the volunteers underwent hyperinsulinemic-euglycemic clamps—a procedure that can be used to measureinsulin sensitivity. Some of the women were also given intranasal insulin doses during the procedure while others received a placebo. The researchers found that during the first day of ovulation, the brain was more sensitive to the insulin, but not during the days just after ovulation.

Next, the research team administered MRI scans to 15 different female volunteers to learn more about the impact of insulin on the hypothalamus during menstrual cycles. They found the same results—the women exhibited higher hypothalamus sensitivity to insulin just prior to the onset of ovulation but not afterward. The researchers suggest their findings explain why so many women experience hunger just prior to getting their period, why their metabolism slows and why weight gain is so much more likely. The researchers suggest that the female body reacts this way as a means of storing up energy to sustain a pregnancy, should it occur.

 Julia Hummel et al, Brain insulin action on peripheral insulin sensitivity in women depends on menstrual cycle phase, Nature Metabolism (2023). DOI: 10.1038/s42255-023-00869-w

Nils B. Kroemer, Metabolic tuning during the menstrual cycle, Nature Metabolism (2023). DOI: 10.1038/s42255-023-00867-y

New research adds evidence to the benefits of ginger supplements for treating autoimmune diseases

New research has revealed a potentially important role ginger supplements can play in controlling inflammation for people living with autoimmune diseases.

The research published in JCI Insight focused on studying the impact of ginger supplementation on a type of white blood cell called the neutrophil. The study was especially interested in neutrophil extracellular trap (NET) formation, also known as NETosis, and what it may mean for controlling inflammation.

The study found ginger consumption by healthy individuals makes their neutrophils more resistant to NETosis. This is important because NETs are microscopic spider web-like structures that propel inflammation and clotting, which contribute to many autoimmune diseases, including lupus, antiphospholipid syndrome and rheumatoid arthritis.

There are a lot of diseases where neutrophils are abnormally overactive. Now researchers found that ginger can help to restrain NETosis, and this is important because it is a natural supplement that may be helpful to treat inflammation and symptoms for people with several different autoimmune diseases.

In a clinical trial, the researchers found that daily intake of a ginger supplement for seven days (20 mg of gingerols/day) by healthy volunteers boosted a chemical inside the neutrophil called cAMP. These high levels of cAMP then inhibited NETosis in response to various disease-relevant stimuli.

There are not a lot of natural supplements, or prescription medications for that matter, that are known to fight overactive neutrophils. Researchers think ginger may have a real ability to complement treatment programs that are already underway. The goal is to be more strategic and personalized in terms of helping to relieve people's symptoms.

 Ginger intake suppresses neutrophil extracellular trap formation in autoimmune mice and healthy humans, JCI Insight (2023).

https://insight.jci.org/articles/view/172011

Urban light pollution linked to smaller eyes in birds: Study

 The bright lights of big cities could be causing an evolutionary adaptation for smaller eyes in some birds, a new study indicates.

Researchers found that two common songbirds, the Northern Cardinal and Carolina Wren, that live year-round in the urban core of San Antonio, Texas, had eyes about 5% smaller than members of the same species from the less bright outskirts. Researchers found no eye-size difference for two species of migratory birds, the Painted Bunting and White-eyed Vireo, no matter which part of the city they lived in for most of the year.

The findings, published in Global Change Biology, have implications for conservation efforts amid the rapid decline of bird populations.

This study shows that residential birds may adapt over time to urban areas, but migratory birds are not adapting, probably because where they spend the winter—they are less likely to have the same human-caused light and noise pressures. It may make it more difficult for them to adjust to city life during the breeding season.

Todd M. Jones, Alfredo P. Llamas, Jennifer N. Phillips. Phenotypic signatures of urbanization? Resident, but not migratory, songbird eye size varies with urban‐associated light pollution levels. Global Change Biology, 2023; DOI: 10.1111/gcb.16935

Why You Didn't Get Your Dad's Mitochondria

Virtually every animal on Earth can thank their mother for the energy that fuels each of their cells. The power is generated in a part of the cell known as the mitochondria, and this organelle is made entirely from a genetic recipe laid out in your mother's DNA.

A father's mitochondrial DNA, or mtDNA, plays no part. Yet the precise point at which dad's mitochondrial genes are given the heave-ho isn't a clear-cut story, with different studies supporting a breakdown in the egg's cytoplasm, and a severe edit in the sperm as it's being formed. A recent study that sequenced the genes in human sperm cells could detect no intact mtDNA before fertilization, lending support to an early chop. While each sperm cell contained about 100 mitochondria of its own, a team of researchers  found no trace of male mtDNA within the mitochondria. The sperm also lacked the transcription factors needed to maintain mtDNA. "We conclude," the authors write, "that the mature human spermatozoa are essentially devoid of mtDNA, consistent with maternal inheritance of the mitochondrial genome in mammals."

Of course, male sex cells still contribute nuclear DNA to their offspring, and the human nuclear genome is billions of times larger than the mitochondrial genome. Even still, mutations in the latter genome are associated with a diversity of diseases and aging processes, which suggests it is quite important for health and function.

So why is it only mom's mtDNA that gets passed down?

Part 1

So why is it only mom's mtDNA that gets passed down?

One hypothesis has to do with the mitochondrial genome's relatively high mutation rate compared to the nuclear genome. Each cell in the body contains numerous mitochondria, which get separated into daughter cells the parent cell splits.

Because sperm cells rapidly churn through their energy trying to reach a human egg for fertilization, their mtDNA – if it did exist – would probably accumulate a bunch of mutations.

Eggs pass on really good mtDNA at least partly because they don't use mitochondria as a source of energy.

The findings do not explain why, in rare circumstances, scientists have found mtDNA transmission in some humans that looks as though it came from both the father and the mother. But it might help experts better understand some fertility disorders, which can be passed down through eggs or sperm. In recent years, scientists have started to find ways to target specific mutations in mitochondrial DNA so they aren't inherited by offspring. Worldwide, in fact, several children have been born with DNA from three different people, after their parents sought cutting-edge mitochondrial replacement therapy. The incredibly unique babies have nuclear DNA that derives from the fertilization of a sperm and an egg, like any other child, but their mitochondrial DNA comes from the egg of a separate female donor. "Maternal inheritance of mtDNA is a major paradigm that guides the existence and evolution of the vast majority of species," the authors of the recent study conclude, "however, the molecular basis of this phenomenon and its benefits have remained unclear."

For such a foundational part of life, it's incredible we don't know more about where our genes come from.

https://www.nature.com/articles/s41588-023-01505-9

Part 2

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RNA has been recovered from an extinct species for the first time

A new study shows the isolation and sequencing of more than a century-old RNA molecules from a Tasmanian tiger specimen preserved at room temperature in a museum collection. This resulted in the reconstruction of skin and skeletal muscle transcriptomes from an extinct species for the first time.

The researchers note that their findings have relevant implications for international efforts to resurrect extinct species, including both the Tasmanian tiger and the wooly mammoth, as well as for studying pandemic RNA viruses.

The Tasmanian tiger, also known as the thylacine, was a remarkable apex carnivorous marsupial that was once distributed all across the Australian continent and the island of Tasmania. This extraordinary species found its final demise after European colonization, when it was declared as an agricultural pest and a bounty of £1 per each full-grown animal killed was set by 1888. The last known living Tasmanian tiger died in captivity in 1936 at the Beaumaris Zoo in Hobart, Tasmania. Recent efforts in de-extinction have focused on the Tasmanian tiger, as its natural habitat in Tasmania is still mostly preserved, and its reintroduction could help recovering past ecosystem equilibriums lost after its final disappearance. However, reconstructing a functional living Tasmanian tiger not only requires a comprehensive knowledge of its genome (DNA) but also of tissue-specific gene expression dynamics and how gene regulation worked, which are only attainable by studying its transcriptome (RNA). Resurrecting the Tasmanian tiger or the wooly mammoth is not a trivial task, and will require a deep knowledge of both the genome and transcriptome regulation of such renowned species, something that only now is starting to be revealed.

The researchers behind this study have sequenced, for the first time, the transcriptome of the skin and skeletal muscle tissues from a 130-year-old desiccated Tasmanian tiger specimen preserved at room temperature in the Swedish Museum of Natural History in Stockholm. This led to the identification of tissue-specific gene expression signatures that resemble those from living extant marsupial and placental mammals. The recovered transcriptomes were of such good quality that it was possible to identify muscle- and skin-specific protein coding RNAs, and led to the annotation of missing ribosomal RNA and microRNA genes, the later following MirGeneDB recommendations.

Emilio Marmol-Sanchez et al, Historical RNA expression profiles from the extinct Tasmanian tiger, Genome Research (2023). DOI: 10.1101/gr.277663.123

Cross-species virus transmission found in several species of small furry animals

Research led by multiple institutions in China has examined how small, furry, viral vectors affect the spread and evolution of viruses. They report the identification of 669 viruses, including 534 novel viruses, greatly expanding our knowledge of the mammalian virome, including previously unknown coronaviruses and orthorubulaviruses.

In their paper, "Host traits shape virome composition and virus transmission in wild small mammals," published in Cell, the team used meta-transcriptomic sequencing of internal organ and fecal samples from 2,443 wild bats, rodents, and shrews from four Chinese habitats. Viruses were identified in nearly all animals studied.

Researchers identified viruses related to known human or domestic animal pathogens (e.g., Rotavirus A, Seoul virus, Wenzhou mammarenavirus), including coronaviruses, which have caused diseases like SARS and COVID-19. There were also newly identified viruses from the orthorubulaviruses, porcine epidemic diarrhea virus (PEDV), swine acute diarrhea syndrome coronaviruses (SADS-CoVs), and SARS-related coronaviruses.

The study provided robust evidence of cross-species virus transmission. For instance, viruses were found in multiple species of wild small mammals, indicating that these viruses can move between different animal species, potentially including humans.

The team observed cross-species virus transmission at taxonomic levels across species, genus, family, and order, where the same virus was found in three or more mammalian species. Viruses with multi-organ distributions within hosts were more likely to be found in other host species. This suggests that if a virus is present in multiple internal organs, it has a higher chance of spreading to other species.

Bats are often considered to harbor more viruses than rodents. Of the animals sampled in the study, bats did have the highest richness, followed by rodents and shrews. While the total number of viruses identified in bats was more than that in rodents, the average number of viruses identified per species of bats and rodents was similar.

Yan-Mei Chen et al, Host traits shape virome composition and virus transmission in wild small mammals, Cell (2023). DOI: 10.1016/j.cell.2023.08.029

Scam awareness found to be best defense for older adults facing fraudster phone calls

Research  has looked into the susceptibility of older adults to scammers. In a paper, "Vulnerability of Older Adults to Government Impersonation Scams," published in JAMA Network Open, researchers tested 644 older adults with an experiment designed to mimic a government impersonation scam.

Participants averaged age 85.6 and were part of the Rush Memory and Aging Project (MAP), an ongoing cohort study of common chronic conditions related to aging. As part of the experiment, they were exposed to deceptive materials through mailers, emails, and phone calls by a live agent, mimicking a government impersonation scam.

Results were classified by three engagement groups: no engagement, engagement with skepticism, and conversion (those who engaged without skepticism).

Of the 644 participants, 441 (68.5%) did not engage, 97 (15.1%) engaged but raised skepticism, and 106 (16.4%) comprised the conversion group. Of those converted, nearly three-quarters provided personal information.

The research revealed that factors like cognition, financial literacy, and awareness of fraud scams were associated with the type of engagement. Those in the skeptical engagement group had the highest cognitive scores and financial literacy, while the conversion group had the lowest scam awareness.

According to the Federal Trade Commission, phone calls are the most common and most effective method used by fraudsters for targeting older adults.

Lei Yu et al, Vulnerability of Older Adults to Government Impersonation Scams, JAMA Network Open (2023). DOI: 10.1001/jamanetworkopen.2023.35319

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AI predicts sea surface temperature cooling during tropical cyclones

Tropical cyclones are extreme weather events, characterized by a circular form and formation over warm tropical oceans experiencing low atmospheric pressure, high winds and heavy rain. Tropical storms exceed 39 miles per hour (mph), while hurricanes experience sustained winds of 74mph and above.

The warm waters fuel the continuation of the cyclone, consequently cooling the surface of the ocean, and high wind speeds increase currents. The latter results in mixing of the layers of the ocean, bringing deeper and cooler water to the surface. In doing so, this can help to reduce the warm water fuel to cyclones, causing them to slow down or even cease altogether.

New research published in Geophysical Research Letters has turned towards technology to model the effects of tropical cyclones on oceans, in particular sea surface temperatures. This is important as the temperature can impact wider ecosystem responses, as well as the organisms that call the oceans home.

The machine learning-based random forest method used data from a 20-year period beginning in 1998 to train the system and help predict the evolution of sea surface temperature over time and space within the northwest Pacific Ocean (equator to 30°N, 100–160°E), one of the most active zones for tropical cyclones.

The research work showed that stronger intensity, larger and slower-moving tropical cyclones in areas with a shallow mixed ocean layer tend to have a greater cooling effect on the surface waters. Storm intensity and speed have a greater local effect, while the overall size of the cyclone, pre-storm ocean mixed layer depth and sea surface temperature impact the cooling effect over a larger area. 

Hongxing Cui et al, Predicting Tropical Cyclone‐Induced Sea Surface Temperature Responses Using Machine Learning, Geophysical Research Letters (2023). DOI: 10.1029/2023GL104171

Antimatter falls downward like normal matter: Study reveals gravity's effect on matter's elusive twin

Physicists studying antihydrogen—an anti-proton paired with an antielectron, or positron—have conclusively shown that gravity pulls it downward and does not push it upward. At least for antimatter, antigravity doesn't exist.

The experimental results have been reported in the Sept. 28 issue of the journal Nature by a team representing the Antihydrogen Laser Physics Apparatus (ALPHA) collaboration at the European Center for Nuclear Research (CERN) in Geneva, Switzerland.

The gravitational acceleration of antimatter that the team comes up with is close to that for normal matter on Earth: 1 g, or 9.8 meters per second per second (32 feet per second per second). More precisely, it was found to be within about 25% (one standard deviation) of normal gravity.

It surely accelerates downwards, and it's within about one standard deviation of accelerating at the normal rate.

Albert Einstein's theory of general relativity, though conceived before antimatter was discovered in 1932, treats all matter identically, implying that antimatter and matter respond the same to gravitational forces. All normal matter, such as protons, neutrons and electrons, have anti-particles that bear the opposite electrical charge and, when they encounter their normal matter counterpart, annihilate completely.

Part 1

An artist's conceptual rendering of the antihydrogen atoms contained within the magnetic trap of the ALPHA-g apparatus. As the field strength at the top and bottom of the magnetic trap is reduced, the antihydrogen atoms escape, touch the chamber walls and annihilate. Most of the annihilations occur beneath the chamber, showing that gravity is pulling the antihydrogen down.

Jeffrey Hangst, Observation of the effect of gravity on the motion of antimatter, Nature (2023). DOI: 10.1038/s41586-023-06527-1. www.nature.com/articles/s41586-023-06527-1

Anna Soter, Free-falling antihydrogen reveals the effect of gravity on antimatter, Nature (2023). DOI: 10.1038/d41586-023-02930-w , www.nature.com/articles/d41586-023-02930-w

Part 2

 Why our skin feels 'tight' after washing

When we wash our face with a cleanser, our skin can start to feel tight. With the application of a favorite moisturizer, that feeling often goes away. This perception of our skin might seem subjective, but researchers recently revealed the mechanism behind these feelings.

Their work, published in PNAS Nexus, demonstrates how mechanical changes at the outer surface of our skin translate into sensations and provides a quantitative approach for determining how people will perceive their skin after using a moisturizer or cleanser.

Our skin is the largest organ in our body and it's constantly exposed to the environment around us. The outermost layer of our skin—the stratum corneum—acts as a barrier to keep out unwanted chemicals and bacteria and to keep in moisture. When we use a harsh cleanser, it strips away some of the lipids that hold in moisture, causing the stratum corneum to contract. A good moisturizer increases the water content of the stratum corneum, causing it to swell.

 The mechanical forces created by this shrinking or swelling propagate through the skin to reach mechanoreceptors—sensory receptors that turn mechanical force into neurological signals—below the epidermis, which then fire off signals to the brain that we interpret as a feeling of skin tightness.

The researchers studied the effects of nine different moisturizing formulas and six different cleansers on donor skin samples from three locations on the human body—cheek, forehead, and abdomen. They measured changes in the stratum corneum in the lab and then fed that information into a sophisticated model of human skin to predict the signals that the mechanoreceptors would send.

Ross Bennett-Kennett et al, Sensory neuron activation from topical treatments modulates the sensorial perception of human skin, PNAS Nexus, (2023) DOI: 10.1093/pnasnexus/pgad292. academic.oup.com/pnasnexus/art … /2/9/pgad292/7278834

Ultrasound enables gene delivery throughout the brain

Researchers tested the safety and feasibility of gene delivery to multiple brain regions using a noninvasive, ultrasound-based technique in rodents, and their findings suggest that the efficiency of gene delivery improves within each targeted site when more sites are opened.

The work used focused ultrasound energy to safely make the blood-brain barrier permeable. The technique is known as focused ultrasound blood-brain barrier opening (FUS-BBBO). 

The procedure also permits the passage of proteins and other small molecules in the other direction—that is, from the brain into the bloodstream—where they can be readily sampled.

Many disorders affect large brain regions or the entire brain, but delivery of gene therapy to these regions is difficult. 

When a gene-delivery vector is injected into the brain with a needle, it often only diffuses a few millimeters. To treat the entire brain, one would need to perform thousands of injections, which would be difficult and possibly harmful. With FUS-BBBO, such surgical delivery could be circumvented.

Researchers now tested the efficiency and safety of opening 105 sites simultaneously with positive results in most regions of the brain. Surprisingly, their findings suggest that the efficiency of gene delivery improves within each targeted site when more sites are opened.

 Shirin Nouraein et al, Acoustically targeted noninvasive gene therapy in large brain volumes, Gene Therapy (2023). DOI: 10.1038/s41434-023-00421-1

An adhesive and stretchable epicardial patch to precisely monitor the heart's activity

Epicardial patches are carefully engineered tissue patches that can be placed near or on a patient's heart. These devices can help doctors to diagnose and treat a variety of heart conditions, including arrhythmia and heart attacks (i.e., myocardial infarctions).

In recent years, several engineers and medical researchers have been trying to develop these devices, yet many solutions proposed so far are not ideal. Specifically, most epicardial patches created so far are designed to be affixed onto the heart via a medical procedure known as "suturing," which can be both challenging and risky. Researchers recently developed an alternative epicardial patch that could be much easier to apply in clinical settings. This patch, introduced in Nature Electronics, is both stretchable and adhesive; thus, it does not need to be affixed onto a patient's heart through the suturing process.

Considering the highly irregular surface of the heart, the existing devices with low adhesiveness often become detached due to continuous cardiac contraction/relaxation in long term. To overcome such issues, facile and instantaneous and even robust adhesion to cardiac tissues is essential. Furthermore, when attached to the heart for an extended period, the materials used in epicardial devices should be exceptionally soft to avoid causing any tissue compression.

Researchers set out to develop a new adhesive epicardial patch that effectively overcomes the limitations of previously proposed designs. The patch they created now can be instantly attached to tissue on the heart's surface and could easily be fabricated on a large-scale.

Notably, their patch does not exert any unnecessary pressure on the heart's tissue for extended periods of time, which could improve both its safety and efficacy. It is comprised of three different but co-existing materials, namely a liquid-phase conducting composite, a network-shaped substrate, and an ionic adhesive.

The combination of these materials eliminates the need to suture the patch to the heart, making it easy to implement for medical professionals with varying degrees of experience, while also reducing the risk of complications associated with the suturing procedure.

 Heewon Choi et al, Adhesive bioelectronics for sutureless epicardial interfacing, Nature Electronics (2023). DOI: 10.1038/s41928-023-01023-w

Recessive genes make the carrot colour orange

A new study of the genetic blueprints of more than 600 types of carrot shows that three specific genes are required to give carrots an orange color. Surprisingly, these three required genes all need to be recessive, or turned off. The paper's findings shed light on the traits important to carrot improvement efforts and could lead to better health benefits from the vegetable.

Normally, to make some function, you need genes to be turned on. In the case of the orange carrot, the genes that regulate orange carotenoids—the precursor of vitamin A that have been shown to provide health benefits—need to be turned off.

According to the researchers, orange carrot could have resulted from white and yellow carrot crosses, as white and yellow carrots are at the base of the phylogenetic tree for the orange carrot. Also, carotenoids got their name because they were first isolated from carrots.

Population genomics identifies genetic signatures of carrot domestication and improvement and uncovers the origin of high carotenoid orange carrots, Nature Plants (2023). DOI: 10.1038/s41477-023-01526-6

Fire- safe fuel!

 Chemical engineers have designed a fuel that ignites only with the application of electric current. Since it doesn't react to flames and cannot start accidental fires during storage or transport, it is a "safe" liquid fuel.

The fuel we're normally using is not very safe. It evaporates and could ignite, and it's difficult to stop that. 

It is much easier to control the flammability of our fuel and stop it from burning when we remove voltage.

When fuel combusts, it is not the liquid itself that burns. Instead, it is the volatile fuel molecules hovering above the liquid that ignite on contact with oxygen and flame. Removing an oxygen source will extinguish the flame, but this is difficult to do outside of an engine.

If you throw a match into a pool of gasoline on the ground, it's the vapor of the gas that's burning. You can smell that vapor and you instantly know it's volatile. If you can control the vapour, you can control whether the fuel burns.

The base of the new fuel is an ionic liquid, which is a form of liquified salt. It is similar to the salt we use to flavour food, which is sodium chloride. The one researchers used for this project has a lower melting point than table salt, low vapour pressure, and is organic.

Once in the lab, the research team modified the ionic liquid's formula, replacing the chlorine with perchlorate. Then, they used a cigarette lighter to see if the resulting liquid would burn. 

Next the team tried an application of voltage followed by a lighter flame, which did ignite. Once they shut off the current, the flame was gone, and they were able to repeat that process over and over again—applying voltage, seeing smoke, lighting the smoke so it burned, then turning it off. It's a system they could start and stop very quickly.

Adding more voltage to the liquid resulted in larger flames with more energy output. As such the approach could also act like a metering or throttling system in an engine.

Prithwish Biswas et al, Electrochemical Modulation of the Flammability of Ionic Liquid Fuels, Journal of the American Chemical Society (2023). DOI: 10.1021/jacs.3c04820