One night of total sleep deprivation shown to have antidepressant effect for some people

A study  has investigated a seemingly contradictory phenomenon of sleep deprivation leading to mood improvement in patients with depressive disorders.

In a paper, "Enhanced amygdala–cingulate connectivity associates with better mood in both healthy and depressive individuals after sleep deprivation," published in PNAS, the research team mapped brain region activity through resting-state-functional magnetic resonance imaging to see why some people receive a healthy boost from an otherwise negative public health epidemic.

The study finds that one night of total sleep deprivation enhanced amygdala connectivity to the anterior cingulate cortex, which correlated with better mood in some healthy and depressed individuals.

Ya Chai et al, Enhanced amygdala–cingulate connectivity associates with better mood in both healthy and depressive individuals after sleep deprivation, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2214505120

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Researchers induce cancer cells to 'commit suicide' with a self-produced bacterial toxin

For the first time in the world researchers  have encoded a toxin produced by bacteria into mRNA (messenger RNA) molecules and delivered these particles directly to cancer cells, causing the cells to produce the toxin—which eventually killed them with a success rate of 50%.

Many bacteria secrete toxins. The most famous of these is probably the botulinum toxin injected in Botox treatments. Another classic treatment technique is chemotherapy, involving the delivery of small molecules through the bloodstream to effectively kill cancer cells. However, chemotherapy has a major downside: it is not selective, and also kills healthy cells. The  idea of this work was to deliver safe mRNA molecules encoded for a bacterial toxin directly to the cancer cells—inducing these cells to actually produce the toxic protein that would later kill them. It's like placing a Trojan horse inside the cancer cell.

First, the research team encoded the genetic info of the toxic protein produced by bacteria of the pseudomonas family into mRNA molecules (resembling the procedure in which genetic info of COVID-19's spike protein was encoded into mRNA molecules to create the vaccine).

The mRNA molecules were then packaged in lipid nanoparticles coated with antibodies—to make sure that the instructions for producing the toxin would reach their target, the cancer cells. The particles were injected into the tumors of animal models with melanoma skin cancer. After a single injection, 44–60% of the cancer cells vanished.

When the cancer cell reads the 'recipe' at the other end it starts to produce the toxin as if it were the bacteria itself and this self-produced toxin eventually kills it. Thus, with a simple injection to the tumor bed, scientists can cause cancer cells to 'commit suicide,' without damaging healthy cells. Moreover, cancer cells cannot develop resistance to this technology as often happens with chemotherapy—because we can always use a different natural toxin.

 Yasmin Granot-Matok et al, Lipid nanoparticles-loaded with toxin mRNA represents a new strategy for the treatment of solid tumors, Theranostics (2023). DOI: 10.7150/thno.82228

We may be underestimating the climate risk to crops: researchers

The risks of harvest failures in multiple global breadbaskets have been underestimated, according to a study  that researchers said should be a "wake up call" about the threat climate change poses to our food systems.

Food production is both a key source of planet-warming emissions and highly exposed to the effects of climate change, with climate and crop models used to figure out just what the impacts could be as the world warms.

In the new research published in Nature Communications, researchers looked at the likelihood that several major food producing regions could simultaneously suffer low yields. These events can lead to price spikes, food insecurity and even civil unrest, according to them.

 By "increasing the concentration of greenhouse gases, we are entering this uncharted water where we are struggling to really have an accurate idea of what type of extremes we're going to face," according to them.  These types of concurring events are really largely underestimated.

Part 1

The study looked at observational and climate model data between 1960 and 2014, and then at projections for 2045 to 2099.

Researchers first looked at the impact of the jet stream—the air currents that drive weather patterns in many of the world's most important crop producing regions.

They found that a "strong meandering" of the jet stream, flowing in big wave shapes, has particularly significant impacts on key agricultural regions in North America, Eastern Europe and East Asia, with a reduction in harvests of up to seven percent.

The researchers also found that this had been linked to simultaneous crop failures in the past.

One example was in 2010, when the fluctuations of the jet stream were linked to both extreme heat in parts of Russia and devastating floods in Pakistan, which both hurt crops.

The study also looked at how well computer models assess these risks and found that while they are good at showing the atmospheric movement of the jet stream, they underestimate the magnitude of the extremes this produces on the ground.

 Kai Kornhuber, Risks of synchronized low yields are underestimated in climate and crop model projections, Nature Communications (2023). DOI: 10.1038/s41467-023-38906-7. www.nature.com/articles/s41467-023-38906-7

Part 2

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Money key for turning preprints into papers

Only 40% of preprints by researchers in lower-income countries will even..., compared with 61% authored by researchers in high-income nations. An analysis of almost 140,000 papers posted on the preprint servers bioRxiv and medRxiv between their inception (in 2013 and 2019, respectively) and 2021 also found that when a researcher in a richer country was added to the author list, the preprint-to-paper conversion rate increased. A lack of financial resources in poorer regions is likely to be one of the key factors preventing the transition from preprint to paper.

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0...

Scientists Discover a Self-Destructing Cell That Shields a Growing Embryo

Scientists have found a new human embryonic cell type, one that seems designed to protect the growing embryo by acting as a quality control measure and making sure that damaged cells are removed.

There's still a lot we don't know about the earliest stages of embryo formation, and this latest discovery promises to help future research into ensuring that pregnancies are given the best chance of success.

While we're all made up of trillions of cells as adults, life begins as a single cell that then divides again and again. As this division continues, cells start to specialize in their function – but in a genetic activity analysis of 5-day old embryos, researchers found certain cells that didn't match the standard profiles.

What makes these cells interesting is that they contain active 'jumping genes' (or transposons), rogue bits of DNA that can copy themselves, move around, and insert themselves back into the genome, potentially causing damage along the way. However, it seems that when this damage occurs, the newly discovered cells then self-destruct.

"If a cell is damaged by the jumping genes – or any other sort of error such as having too few or too many chromosomes – then the embryo is better off removing these cells and not allowing them to become part of the developing baby.

In other words, these new cells are deliberately configured to lose out in a survival of the fittest battle, sacrificing themselves to give the healthier cells priority and the embryo a better chance of growing.

These new cells have been called REject cells, because they're ultimately rejected and because they feature RetroElements, a specific type of jumping gene. Around a quarter of the cells are REject cells five days after fertilization, the study reveals.

The cells that are left behind are able to suppress their active jumping genes and don't have the same self-destruction routines built into them, the researchers found. Finding out exactly why this is and what's going on can be tackled in future studies.

"We are used to the idea of natural selection favoring one organism over another. What we are seeing within embryos also looks like survival of the fittest but this time between almost identical cells."

The researchers suggests that one difference between a successful and unsuccessful pregnancy might be how these REject cells behave, or how sensitive the embryo is to their messaging.

Part 1

The researchers also want to look into whether this new type of cell is present in the embryos of other primates besides humans. Based on the limited number of studies currently available, it seems likely that it is – a recent study suggests the same sort of activity could be happening in monkey embryos.

Jumping genes stay with us for our whole lives, and our bodies have to be continually on alert to make sure they're tightly managed. What this new research suggests is that in the earliest stages of life, they're more influential than we realized.

https://journals.plos.org/plosbiology/article?id=10.1371/journal.pb...

Part 2

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New Paper Links Climate Change to Shrinking Brain Size in Humans

A new study suggests a link between past climate changes and a drop in the size of the human brain – an adaptive response that emerges in an analysis of climate records and human remains over a 50,000-year period.

The study looked at how the brain size of 298 Homo specimens changed over the last 50,000 years in relation to natural records of global temperature, humidity, and rainfall. When the climate got warmer, the average brain size grew significantly smaller than when it was cooler.

researchers obtained data on skull sizes from ten separate published sources, for a total of 373 measurements from 298 human bones spanning 50,000 years. He included body size estimations that were adjusted for geographical region and gender to estimate brain sizes.

The fossils were put into groups based on how long ago they lived, and scientists conducted this research using four different fossil age spans of 100 years, 5,000 years, 10,000 years, and 15,000 years to help account for dating errors.

Then they compared brain size to four climate records, including temperature data from European Project for Ice Coring in Antarctica (EPICA) Dome C. The ice core at EPICA Dome C gives accurate measurements of the surface temperature going back more than 800,000 years.

The analysis showed a general pattern of changing brain size in Homo, which is correlated with climate change as temperatures rise and fall. Humans had a considerable decline in average brain size, amounting to just over 10.7 percent, throughout the Holocene warming period.

"Brain size changes appear to take place thousands of years after changes to climate, and this is particularly pronounced after the last glacial maximum, approximately 17,000 years.

While [acclimatization] unfolds within a single generation and natural selection can happen in as short as a few successive generations, species level adaptation often takes many successive generations."

This evolutionary pattern happened over a relatively brief period of time, ranging from 5,000 to 17,000 years, and the trends suggest that ongoing global warming could have detrimental effects on human cognition.

"Even a slight reduction in brain size across extant humans could materially impact our physiology in a manner that is not fully understood.

The analysis showed that humidity and rainfall levels also had an effect on brain growth. While temperature is a more significant factor, it did find a weak correlation between dry spells and slightly larger brain volumes.

 ecosystem factors like predation, indirect climate effects like vegetation and net primary production, or non-climate factors like culture and technology could all be contributing to changes in brain size.

"The results suggest that climate change is predictive of Homo brain size, and certain evolutionary changes to the brain may be a response to environmental stress.

Part 1

More work will be needed to determine whether the impact of climate change on Homo physiology is a result specifically of temperature changes or an indirect effect from other elements of a changing environment.

https://karger.com/bbe/article/98/2/93/835670/Climate-Change-Influe...

Part 2

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Artificial cells demonstrate that 'life finds a way'

Evolutionary biologists  have been studying a synthetically constructed minimal cell that has been stripped of all but its essential genes. They found that the streamlined cell can evolve just as fast as a normal cell—demonstrating the capacity for organisms to adapt, even with an unnatural genome that would seemingly provide little flexibility.

This shows that if there's one thing the history of evolution has taught us is that life will not be contained. Life breaks free. It expands to new territories, and it crashes through barriers painfully, maybe even dangerously, but . . . life finds a way.

It appears there's something about life that's really robust. We can simplify it down to just the bare essentials, but that doesn't stop evolution from going to work.

For their study,  the researchers used the synthetic organism, Mycoplasma mycoides JCVI-syn3B—a minimized version of the bacterium M. mycoides commonly found in the guts of goats and similar animals. Over millennia, the parasitic bacterium has naturally lost many of its genes as it evolved to depend on its host for nutrition.

Researchers at the J. Craig Venter Institute in California took this one step further. In 2016, they eliminated 45% of the 901 genes from the natural M. mycoides genome—reducing it to the smallest set of genes required for autonomous cellular life. At 493 genes, the minimal genome of M. mycoides JCVI-syn3B is the smallest of any known free-living organism. In comparison, many animal and plant genomes contain more than 20,000 genes.

In principle, the simplest organism would have no functional redundancies and possess only the minimum number of genes essential for life. Any mutation in such an organism could lethally disrupt one or more cellular functions, placing constraints on evolution. Organisms with streamlined genomes have fewer targets upon which positive selection can act, thus limiting opportunities for adaptation.

Part 1

Although M. mycoides JCVI-syn3B could grow and divide in laboratory conditions, researchers wanted to know how a minimal cell would respond to the forces of evolution over time, particularly given the limited raw materials upon which natural selection could operate as well as the uncharacterized input of new mutations.

"Everysingle gene in its genome is essential" with reference to M. mycoides JCVI-syn3B. "One could hypothesize that there is no wiggle room for mutations, which could constrain its potential to evolve."

The researchers established that M. mycoides JCVI-syn3B, in fact, has an exceptionally high mutation rate. They then grew it in the lab where it was allowed to evolve freely for 300 days, equivalent to 2,000 bacterial generations or about 40,000 years of human evolution.

The next step was to set up experiments to determine how the minimal cells that had evolved for 300 days performed in comparison to the original, non-minimal M. mycoides as well as to a strain of minimal cells that hadn't evolved for 300 days. In the comparison tests, the researchers put equal amounts of the strains being assessed together in a test tube. The strain better suited to its environment became the more common strain.

They found that the non-minimal version of the bacterium easily outcompeted the unevolved minimal version. The minimal bacterium that had evolved for 300 days, however, did much better, effectively recovering all of the fitness that it had lost due to genome  streamlining. The researchers identified the genes that changed the most during evolution. Some of these genes were involved in constructing the surface of the cell, while the functions of several others remain unknown.

Understanding how organisms with simplified genomes overcome evolutionary challenges has important implications for long-standing problems in biology—including the treatment of clinical pathogens, the persistence of host-associated endosymbionts, the refinement of engineered microorganisms, and the origin of life itself.

this demonstrates the power of natural selection to rapidly optimize fitness in the simplest autonomous organism, with implications for the evolution of cellular complexity. In other words, it shows that life finds a way.

Jay Lennon, Evolution of a minimal cell, Nature (2023). DOI: 10.1038/s41586-023-06288-x. www.nature.com/articles/s41586-023-06288-x

Part 2

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Study shows the Earth formed from dry, rocky building blocks

Billions of years ago, in the giant disk of dust, gas, and rocky material that orbited our young sun, larger and larger bodies coalesced to eventually give rise to the planets, moons, and asteroids we see today.

Scientists are still trying to understand the processes by which planets, including our home planet, were formed. One way researchers can study how Earth formed is to examine the magmas that flow up from deep within the planet's interior. The chemical signatures from these samples contain a record of the timing and the nature of the materials that came together to form Earth—analogous to how fossils give us clues about Earth's biological past.

Now, a study  shows that the early Earth accreted from hot and dry materials, indicating that our planet's water—the crucial component for the evolution of life—must have arrived late in the history of Earth's formation.

Though humans do not have a way to journey into the interior of our planet, the rocks deep within the earth can naturally make their way to the surface in the form of lavas. The parental magmas of these lavas can originate from different depths within Earth, such as the upper mantle, which begins around 15 kilometers under the surface and extends for about 680 kilometers; or the lower mantle, which spans from a depth of 680 kilometers all the way to the core–mantle boundary at about 2,900 kilometers below our feet.

Like sampling different layers of a cake—the frosting, the filling, the sponge—scientists can study magmas originating from different depths to understand the different "flavors" of Earth's layers: the chemicals found within and their ratios with respect to one another.

Because the formation of Earth was not instantaneous and instead involved materials accreting over time, samples from the lower mantle and upper mantle give different clues to what was happening over time during Earth's accretion.

In the new study, the team found that the early Earth was primarily composed of dry, rocky materials: chemical signatures from deep within the planet showed a lack of so-called volatiles, which are easily evaporated materials like water and iodine. In contrast, samples of the upper mantle revealed a higher proportion of volatiles, three times of those found in the lower mantle.

Based on these chemical ratios, researchers created a model that showed Earth formed from hot, dry, rocky materials, and that a major addition of life-essential volatiles, including water, only occurred during the last 15% (or less) of Earth's formation.

Weiyi Liu, I/Pu reveals Earth mainly accreted from volatile-poor differentiated planetesimals, Science Advances (2023). DOI: 10.1126/sciadv.adg9213. www.science.org/doi/10.1126/sciadv.adg9213

New radio observations confirm unintended electromagnetic radiation...

Scientists from a number of leading research institutions including the Max Planck Institute for Radio Astronomy in Bonn, Germany, used the Low Frequency Array (LOFAR) telescope to observe 68 of SpaceX's satellites. The authors conclude that they detected "unintended electromagnetic radiation" emanating from onboard electronics.

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Facial recognition technology could soon be everywhere—here's how t...

The recent coronation of King Charles III was a high-profile example of when facial recognition technology has been used to monitor a crowd, but there are plenty of others. The technology is used by law enforcement all over the UK and other countries.

Why some people get sick more often

One reason why some people are more susceptible to falling ill than others is their body's response to inflammation. “We all need some inflammation, but it has to be the right amount at the right place at the right time,” says physician-scientist Sunil Ahuja. Ahuja and his colleagues found that some people’s immune systems are better at bouncing back from infec... that trigger inflammation. There’s no sure way to predict how you’ll weather any particular bout of disease, but Ahuja recommends reducing exposure risks (by wearing a protective mask, for example) and — this won’t surprise you — enjoying a healthy diet and plenty of exercise.

Scientific American | 6 min read
Reference: Nature Communications paper

Use It or Lose It
As we age, the overall number of muscle cells declines: Studies suggest that muscle mass decreases by about 3 to 8 percent per decade after age 30 and at higher rates after age 60. Loss of muscular function and other factors also degrade the connection between motor nerves in the brain and muscle tissue. Issues in communication between nerves and muscles can create weakness and a decline in muscle mass. Experts recommend so-called high-velocity resistance training to keep the muscles ready to respond and the brain-muscle connection sharp.

Why this matters: Muscle loss is a common contributor to severe falls and accidents that lead to injury or physical disability in older adults. Low muscle mass from aging can impact how well individuals cope with cancer treatment, surgeries and heart and lung problems. It can impact individual lifespan and how quickly one recovers from illness and hospital stays.

What the experts say: Even if people don’t notice muscle mass gains through resistance training at first, “you actually get stronger long before your muscles get bigger,” says Stephanie Studenski, a geriatrician and professor emeritus at the University of Pittsburgh. “That exercise is doing something to the wiring to the nervous system connection to the muscle.”

Experts recommend so-called high-velocity resistance training to ke....

How do fireworks actually work?

Why does matter exist? Roundness of electrons may hold clues

In the first moments of our universe, countless numbers of protons, neutrons and electrons formed alongside their antimatter counterparts. As the universe expanded and cooled, almost all these matter and antimatter particles met and annihilated each other, leaving only photons, or flashes of light, in their wake.

And if the universe were perfectly symmetrical, with equal amounts of matter and antimatter, that would be the end of the story—and we would never have existed. But there must have been an imbalance—some leftover protons, neutrons and electrons—that formed atoms, molecules, stars, planets, galaxies and eventually, people.

If the universe had been perfectly symmetrical, then there would be nothing left but light. This is a hugely important moment in history. Suddenly there is stuff in the universe, and the question is, why? Why do we have this asymmetry?

The mathematical theories and equations that explain our universe call for symmetry. Particle theorists have refined these theories to tackle the presence of asymmetry. But without evidence, those theories are just math. So experimental physicists  have been looking at fundamental particles such as electrons for signs of asymmetry. Now they made a record-breaking measurement of electrons, narrowing down the search for where this asymmetry came from. The findings have been published in Science.

Part 1

One place to look for evidence of asymmetry is in the electron's electric dipole moment (eEDM). Electrons are made up of negative electric charge, and the eEDM indicates how evenly that charge is spread between the electron's north and south pole. Any measurement of eEDM above zero would confirm an asymmetry; the electron would be more egg-shaped than circular. But no one knows just how small that deviation may be.

Electrons are fundamental particles, and their symmetry tells us about the symmetry of the universe.

Physicists  recently set a record for precision measurement of eEDM, improving on previous measurements by a factor of 2.4. How precise is that? If an electron were the size of the Earth, their study found that any asymmetry that exists would be smaller than the radius of an atom. Making a measurement that precise is incredibly difficult.

The researchers looked at molecules of hafnium fluoride. If they applied a strong electric field to the molecules, non-round electrons would want to align with the field, shifting around inside the molecule. If they were round, then the electrons wouldn't budge. Using an ultraviolet laser, they stripped electrons off molecules, making a set of positively charged ions, and trapped them. Alternating the electromagnetic field around the trap, the molecules were forced to either align or not align with the field. Then the researchers used lasers to measure the energy levels of the two groups. If the levels were different between them, that would indicate that the electrons were asymmetrical.

Their experiment allowed them to have longer measurement times than past attempts, which gave them greater sensitivity. However, the group's measurements showed that the electrons didn't move energy levels, indicating that as best as we can presently measure, electrons are round.

this level of precision from a tabletop experiment is an achievement. It shows that expensive particle accelerators are not the only means of exploring these fundamental questions about the universe, and that there are a lot of avenues to try. And while the group didn't find asymmetry, its result will help the field keep looking for answers to the asymmetry of the early universe.

Tanya S. Roussy et al, An improved bound on the electron's electric dipole moment, Science (2023). DOI: 10.1126/science.adg4084

Part2 

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‘Overweight’ BMI might be set too low

People with an ‘overweight’ body mass index (BMI) have a slightly lower rate of de..., suggesting that the threshold at which higher weight might be a health risk is not accurate. The BMI was developed to assess population-level health but is often used to give health advice to individuals. Researchers tracked the survival of an ethnically diverse group of around 500,000 US adults for up to 20 years and found that having a BMI between 25 and 29.9 — classified as ‘overweight’ — is associated with an 5–7% lower risk of death than having one in the ‘healthy’ range. Lead researcher Aayush Visaria says this shows that “BMI overall is just not a good indicator of mortality risk — other factors such as body fat distribution also play an important role”.

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0...

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Disinformation researchers under pressure

Researchers who study conspiracy theories say that they are now being drawn into one: allegations that they are helping to suppress conservative opinions in the United States. There are at least three House of Representatives judiciary committ..., government programmes designed to counter disinformation and social-media platforms, such as Twitter and Facebook. In parallel, some researchers are facing lawsuits or being blocked from working with federal agencies. The moves contribute to a worrying trend in which climate scientists, for instance, are targeted by conservative activists and leaders. “This is a practice that is going to touch more and more researchers’ lives,” says political scientist Rebekah Tromble.

https://www.nature.com/articles/d41586-023-02195-3?utm_source=Natur...

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Climate-friendly air conditioning inspired by termites

The climate control used by termites in their mounds could inspire tomorrow's climate-smart buildings. New research from Lund University in Sweden shows that future buildings inspired by the termites could achieve the same effect as traditional climate control, but with greater energy efficiency and without its carbon dioxide footprint.

Counting bats that protect a park

Eliminating extra chromosomes in cancer cells prevents tumor growth

Cancer cells with extra chromosomes depend on those chromosomes for tumor growth, a new Yale study reveals, and eliminating them prevents the cells from forming tumors. The findings, said the researchers, suggest that selectively targeting extra chromosomes may offer a new route for treating cancer.

The study was published July 6 in the journal Science.

Human cells typically have 23 pairs of chromosomes; extra chromosomes are an anomaly known as aneuploidy.

If we look at normal skin or normal lung tissue, for example, 99.9% of the cells will have the right number of chromosomes. But we’ve known for over 100 years that nearly all cancers are aneuploid.

However, it was unclear what role extra chromosomes played in cancer — for instance, whether they cause cancer or are caused by it.
For a long time, we could observe aneuploidy but not manipulate it. We just didn’t have the right tools.

But in this new study, researchers used the gene-engineering technique CRISPR to develop a new approach to eliminate entire chromosomes from cancer cells, which is an important technical advance. Being able to manipulate aneuploid chromosomes in this way will lead to a greater understanding of how they function.

Using their newly developed approach — which they dubbed Restoring Disomy in Aneuploid cells using CRISPR Targeting, or ReDACT — the researchers targeted aneuploidy in melanoma, gastric cancer, and ovarian cell lines. Specifically, they removed an aberrant third copy of the long portion — also known as the “q arm” — of chromosome 1, which is found in several types of cancer, is linked to disease progression, and occurs early in cancer development.

When they eliminated aneuploidy from the genomes of these cancer cells, it compromised the malignant potential of those cells and they lost their ability to form tumours.

When investigating how an extra copy of chromosome 1q might promote cancer, the researchers found that multiple genes stimulated cancer cell growth when they were overrepresented — because they were encoded on three chromosomes instead of the typical two.

This overexpression of certain genes also pointed the researchers to a vulnerability that might be exploited to target cancers with aneuploidy.

https://www.science.org/doi/10.1126/science.adg4521

https://news.yale.edu/2023/07/06/eliminating-extra-chromosomes-canc...

American mink regrow their brains in a rare reversal of the domestication process

Farm animals look different from their wild counterparts in many ways, and one difference is consistent: their brains are smaller than those of their ancestors. From sheep to pigs to cows, domesticated animals have smaller relative brain sizes compared to their wild counterparts—a phenomenon known as the domestication effect.

Now a new study has discovered a rare reversal of the domestication effect. Over the course of captive breeding, the American mink has undergone a reduction in relative brain size, but populations that escaped from captivity were able to regain almost the full ancestral brain size within 50 generations. The study is published recently in the Royal Society Open Science.

These  results show that loss of brain size is not permanent in domesticated animals.

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When animals lose brain size through the course of domestication, it's mostly considered to be a one-way street. Animals almost never seem to regain the relative brain sizes of their ancestral forms, even in feral populations that have been living in the wild for generations. "Once animals loose parts of their body, such as certain brain regions, over the course of evolution, they are gone and cannot simply be regained.

Studying whether or not feral animals can regain the relative brain sizes of their wild counterparts is also difficult methodologically. you would need to find an animal with separate wild and feral populations to reduce the chance that the groups had mixed. And, you would need to find an animal that could be studied through sufficient brain and skull measurements. You would need an animal, in other words, like the American mink.

Part 1

Native to North America, the American mink has been domesticated for the fur trade for over a century. After they were bred in Europe for fur farming, captive animals escaped to form feral populations that have spread throughout Europe. This natural history thus provided the separated populations that researchers needed. 

To explore changes in brain size, the team turned to a proxy: skulls. "Braincase size is a good proxy for brain size in mink, and this allows us to take measurements from existing skull collections without the need for living animals. A museum collection from Cornell University was used to study skulls of wild American mink while European fur farms provided skulls of domesticated animals.

The team took measurements from skulls to calculate relative brain size of the animals. They found that, according to the well-documented domestication process, the brains of captive-bred mink had shrunk by 25% compared to their wild ancestors. But, in contrast to expectations, the brains of feral mink grew almost back to wild size within 50 generations.

Researchers think  tehy know why this animal, in particular, has achieved what was thought to be unlikely. American mink belong to a family of small mammals with a remarkable ability to seasonally change their brain size in a process known as Dehnel's phenomenon. 

While other domesticated animals seem to lose brain size permanently, it's possible that mink can regain their ancestral brain sizes because they have flexible brain size built into their system. This flexibility could have offered advantages to the mink that re-entered the wild.

 Ann-Kathrin Pohle et al, Domestication effect of reduced brain size is reverted when mink become feral, Royal Society Open Science (2023). DOI: 10.1098/rsos.230463

Part 2

Chemists discover why photosynthetic light-harvesting is so efficient

When photosynthetic cells absorb light from the sun, packets of energy called photons leap between a series of light-harvesting proteins until they reach the photosynthetic reaction center. There, cells convert the energy into electrons, which eventually power the production of sugar molecules.

This transfer of energy through the light-harvesting complex occurs with extremely high efficiency: Nearly every photon of light absorbed generates an electron, a phenomenon known as near-unity quantum efficiency.

A new study by chemists offers a potential explanation for how proteins of the light-harvesting complex, also called the antenna, achieve that high efficiency. For the first time, the researchers were able to measure the energy transfer between light-harvesting proteins, allowing them to discover that the disorganized arrangement of these proteins boosts the efficiency of the energy transduction.

In order for that antenna to work, you need long-distance energy transduction. The key finding of this work is that the disordered organization of the light-harvesting proteins enhances the efficiency of that long-distance energy transduction.

Wang, Dihao et al, Elucidating interprotein energy transfer dynamics within the antenna network from purple bacteria, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2220477120. doi.org/10.1073/pnas.2220477120

Physicists develop a metamaterial that can count

A block of rubber that can count to ten and even remember the order in which it is pressed—physicists  have published about this latest metamaterial in the journal Physical Review Letters.

A beam counter: rubber that can count to ten

Lennard J. Kwakernaak et al, Counting and Sequential Information Processing in Mechanical Metamaterials, Physical Review Letters (2023). DOI: 10.1103/PhysRevLett.130.268204

Fossils reveal how ancient birds molted, could explain why modern birds survived while other dinosaurs died
Every bird you've ever seen—every robin, every pigeon, every penguin at the zoo—is a living dinosaur. Birds are the only group of dinosaurs that survived the asteroid-induced mass extinction 66 million years ago. But not all the birds alive at the time made it. Why the ancestors of modern birds lived while so many of their relatives died has been a mystery that paleontologists have been trying to solve for decades. Two new studies point to one possible factor: the differences between how modern birds and their ancient cousins molt their feathers.

Feathers are one of the key traits that all birds share. They're made of a protein called keratin, the same material as our fingernails and hair, and birds rely on them to fly, swim, camouflage, attract mates, stay warm, and protect against the sun's rays.

But feathers are complex structures that can't be repaired, so as a means of keeping them in good shape, birds shed their feathers and grow replacements in a process called molting. Baby birds molt in order to lose their baby feathers and grow adult ones; mature birds continue to molt about once a year.

A paper in the journal Cretaceous Research detailed the discovery of a cluster of feathers preserved in amber from a baby bird that lived 99 million years ago.

Today, baby birds are on a spectrum in terms of how developed they are when they're born and how much help they need from their parents. Altricial birds hatch naked and helpless; their lack of feathers means that their parents can more efficiently transmit body heat directly to the babies' skin. Precocial species, on the other hand, are born with feathers and are fairly self-sufficient.

All baby birds go through successive molts— periods when they lose the feathers they have and grow in a new set of feathers, before eventually reaching their adult plumage. Molting takes a lot of energy, and losing a lot of feathers at once can make it hard for a bird to keep itself warm. As a result, precocial chicks tend to molt slowly, so that they keep a steady supply of feathers, while altricial chicks that can rely on their parents for food and warmth undergo a "simultaneous molt," losing all their feathers at roughly the same time.

The amber-preserved feathers in this study are the first definitive fossil evidence of juvenile molting, and they reveal a baby bird whose life history doesn't match any birds alive today.

"This specimen shows a totally bizarre combination of precocial and altricial characteristics. All the body feathers are basically at the exact same stage in development, so this means that all the feathers started growing simultaneously, or near simultaneously."

However, this bird was almost certainly part of a now-extinct group called the Enantiornithines, which   were highly precocial.

Part 1

The pressures of being a precocial baby bird that had to keep itself warm, while undergoing a rapid molt, might have been a factor in the ultimate doom of the Enantiornithines. Enantiornithines were the most diverse group of birds in the Cretaceous, but they went extinct along with all the other non-avian dinosaurs.

When the asteroid hit, global temperatures would have plummeted and resources would have become scarce, so not only would these birds have even higher energy demands to stay warm, but they didn't have the resources to meet them.

Both the amber specimen and the study of molting in modern birds point to a common theme: prehistoric birds and feathered dinosaurs, especially ones from groups that didn't survive the mass extinction, molted differently from today's birds.

 Yosef Kiat et al, Rarity of molt evidence in early pennaraptoran dinosaurs suggests annual molt evolved later among Neornithes, Communications Biology (2023). DOI: 10.1038/s42003-023-05048-x

Jingmai O'Connor et al, Immature feathers preserved in Burmite provide evidence of rapid molting in enantiornithines, Cretaceous Research (2023). DOI: 10.1016/j.cretres.2023.105572

Part 2

Animals who mate during a heat wave less likely to reproduce successfully, new study shows

As the planet continues to warm due to global climate change, the frequency and intensity of extreme weather events, such as heat waves, is rising. Heat waves are not just uncomfortable for humans; they also pose significant challenges for animals. Heat stress caused by these extreme events can disrupt all aspects of animal reproduction. The findings also show that when a heat wave occurs during mating, offspring are smaller and have lower survival rates.

Understanding how animals are affected by climate change is vital, and the research looked at the potential effects of heat waves, and in particular, the role of the timing of a heat wave event, within an organism's reproductive cycle.

Researchers  found that the timing of the heat wave really matters: when it occurs a few days before or after mating, it has little to no effect on reproductive processes. In contrast, when the heat wave occurs during mating, parents are less likely to reproduce successfully, and their offspring are smaller and have lower survival.

The research provides novel insights and can improve the ability to make informed predictions about the ecological consequences of heat waves under climate change.

The implications of these findings extend well beyond this specific insect species, and they highlight the need to investigate these effects more broadly.

Predicting how wild populations will be affected by climate change is a challenging endeavor. This study provides another piece of the puzzle and helps us form a more complete picture of how heat waves might shape animal reproduction and population survival.

Natalie Pilakouta et al, The consequences of heatwaves for animal reproduction are timing‐dependent, Functional Ecology (2023). DOI: 10.1111/1365-2435.14386

Fertility Mystery: IVF Success Is Higher if Eggs Harvested in Summer

There's something about the seasons that seems to impact human reproduction for unknown reasons.

A new study  has found in vitro fertilization (IVF) is most successful when eggs are harvested in the summer.

It doesn't seem to matter when the frozen embryo is actually transferred to a person's womb, only when it is originally collected.

If eggs are retrieved in summer, the live birth rate is 31 percent; if eggs are collected in autumn, the live birth rate is 26 percent.

Meanwhile, eggs collected in winter and spring sit between these two success rates.

While previous IVF studies found seasons have no consistent impact on embryo transfers, implantation, pregnancy, or live birth rates, egg collection seems to be a different matter.

Of all these embryos, those collected on days with more than 10 hours of sunshine were 28 percent more likely to result in a live birth than those collected when the sun showed its face for less than 7 hours a day.

However, the actual temperature of the day didn't seem to have an impact.

The research was done in hindsight, so it can't reveal a direct cause and effect.

 a similar 2022 study in the Northern Hemisphere found that the season and temperature at the time of egg retrieval significantly impacted the subsequent live birth rate.

Specifically, eggs collected during summer in Boston were 42 percent more likely to result in a live birth than those collected during winter. Meanwhile, eggs collected on the warmest days were 34 percent more likely to result in a live birth than eggs collected on the coldest days.

The findings suggest that seasons can have an important effect on a person's ovarian function, although not necessarily the receptiveness of their uterus or the early development of a fetus.

The two studies disagree, however, on whether ambient temperature or the duration of bright sunshine is the more important seasonal factor impacting embryo retrieval, possibly via vitamin D or the production of melatonin.

Maybe it's neither.

https://academic.oup.com/humrep/advance-article/doi/10.1093/humrep/...

An Arachnid that has three Different Kinds of Male

Scientists have found a rare species of arachnid in New Zealand that hosts three different types of males. Recent findings on the species are forcing a rethink of animal mating systems and the evolution of reproductive strategies.

We've known since 2020 that while male harvestmen (Forsteropsalis pureora) – or daddy longlegs, as you might better know them – look the same and have similar genes, there seemed to be three distinct types.

At the top of the hierarchy sits the large alpha male, which has short yet strong pincer-like jaws that it uses to pin down competition when fighting for territory or mates.

Next comes the beta male, which has longer and thinner pincers. And in last place is the gamma male, which is seven times smaller than the other two.

Not only do gamma males look different from the others, but they also act differently.

Instead of battling for female mates like their larger peers, researchers found these smaller, weaponless males have all but given up the fight.

Their tactic for survival involves sneaking around and looking for undefended females to reproduce with.

The rare pecking order is known as trimorphism, and researchers only discovered it among animals for the first time in 2009.

Now, researchers at the University of Auckland – many of whom conducted the 2020 study – think they have figured out why trimorphism evolves among harvestmen in particular.

According to the new study, if a male harvestman loses a leg in his youth, voluntarily 'dropping' a limb to avoid a hungry predator, the harvestman can't regrow the lost limb and is 45 times more likely to grow up smaller and weaker than his peers. Perhaps this is because they can't get enough food for their development because their hunting is impeded.

Or maybe there's no point in investing in big fighting weapons when they're already disadvantaged when it comes to fighting. So, the arachnids' resources may be invested in other things, such as testes size, sperm count, or aerobic poise, to ensure they make the most of the mating opportunities they get.

Part 1

The latter possibility is particularly intriguing as it suggests that male harvestmen can permanently 'lay down their weapons' and adopt a new lifestyle that doesn't rely on competition. So even when males have fewer legs to stand on, they can still find ways to reproduce.

If that's the case, then Charles Darwin's theory of sexual selection, which puts great emphasis on sexual ornaments and weapons, may not be fully comprehensive; there could be other ways to snag a mate in nature.

In fact, the same male dung beetles that Darwin once used to support his theory of sexual selection over a century ago, turned out to be trimorphic as well. This means that not all male dung beetles possess large mandibles for fighting other males or wooing females.

--

While trimorphism can be a result of different genetics, creating various male roles in a society, in the case of dung beetles and harvestmen, the phenomenon seems to have less to do with how animals are born and more to do with how they grow up.

What happens in their youth seems to determine how they develop sexually.

Further research will be needed to explore what sets alpha and beta males apart.

https://academic.oup.com/beheco/article/34/4/613/7160263?login=false

Part 2

Humans' impact on Earth began a new epoch in the 1950s called the Anthropocene, scientists say

From climate change to species loss and pollution, humans have etched their impact on Earth with such strength and permanence since the middle of the 20th century that a special team of scientists says a new geologic epoch began then.

Called the Anthropocene—and derived from the Greek terms for "human" and "new"—this epoch started sometime between 1950 and 1954, according to the scientists. While there is evidence worldwide that captures the impact of burning fossil fuels, detonating nuclear weapons and dumping fertilizers and plastics on land and in waterways, the scientists are proposing a small but deep lake outside of Toronto, Canada—Crawford Lake—to place a historic marker.

It's quite clear that the scale of change has intensified unbelievably and that has to be human impact. This puts the power of humans in a somewhat similar class with the meteorite that crashed into Earth 66 million years ago, killing off dinosaurs and starting the Cenozoic Era, or what is conversationally known as the age of mammals. But not quite. While that meteorite started a whole new era, the working group is proposing that humans only started a new epoch, which is a much smaller geologic time period.

The scientists aims to determine a specific start date of the Anthropocene by measuring plutonium levels at the bottom of Crawford Lake. Crawford Lake, which is 79 feet (29 meters) deep and 258,333 square feet (24,000 square meters) in area, was chosen over 11 other sites because the annual effects of human activity on the earth's soil, atmosphere and biology are so clearly preserved in its layers of sediment. That includes everything from nuclear fallout to species-threatening pollution to steadily rising temperatures.

The remarkably preserved annual record of deposition in Crawford Lake is truly amazing.

The Anthropocene shows the power—and hubris—of humankind. But the reality is that our power to transform the environment has far exceeded our understanding of the consequences and our capacity to change course.

Source: 2023 The Associated Press

https://phys.org/news/2023-07-humans-impact-earth-began-epoch.html?...

Global study details microplastics contamination in lakes and reservoirs

Around 14 million tons of plastic end up in the ocean every year. But that is not the only water source where plastic represents a significant intrusion.

Scientists found microplastics in every lake they sampled. 

A new paper, titled "Plastic debris in lakes and reservoirs," reveals that concentrations of plastic found in freshwater environments are actually higher than those found in so-called "garbage patches" in the ocean. The article is published in Nature.

Veronica Nava et al, Plastic debris in lakes and reservoirs, Nature (2023). DOI: 10.1038/s41586-023-06168-4

Birds build nests from anti-bird spikes

Crows and magpies are building nests with the metal spikes meant to deter them from perch.... Carrion
crows (Corvus corone) and Eurasian magpies (Pica pica) in The Netherlands, Belgium and Scotland were observed to have plucked the sharp metal pins off buildings to use in their nests. The magpies even put most of the spikes on top of their nests, perhaps in an anti-bird effort of their own (crows eat magpies’ eggs).

https://www.hetnatuurhistorisch.nl/fileadmin/user_upload/documents-...

Crows and magpies using anti-bird spikes to build nests, researchers find
Dutch study identifies several examples of corvids’ ‘amazing’ ability to adapt to the urban environment.

Birds have never shied away from turning human rubbish into nesting materials, but even experts in the field have raised an eyebrow at the latest handiwork to emerge from urban crows and magpies.

Nests recovered from trees in Rotterdam in the Netherlands and Antwerp in Belgium were found to be constructed almost entirely from strips of long metal spikes that are often attached to buildings to deter birds from setting up home on the structures.

The discovery prompted researchers at the Natural History Museum in Rotterdam and the Naturalis Biodiversity Center in Leiden to scour the internet for further examples, leading to the identification of another anti-bird spike nest in Glasgow. One of the reviewers of the study then flagged a fourth nest in Enschede in the Netherlands.

While the Rotterdam nest was made by crows, the other three were built by magpies, which construct large dome-like nests. The crows used the anti-bird spikes as a sturdy construction material, but the magpies may have appreciated their intended use: they placed most of the spikes on the nest’s roof where they could deter predators, including other birds and weasels.
It is not the first time birds have been found to incorporate urban materials into their nests. In 1933, a South African museum reported a crow’s nest fashioned from hard-drawn copper, galvanised iron and barbed wire. Nails, screws and even drug users’ syringes have all found their way into birds’ nests.
Part 2

Robot assisted surgery with four arms

UV Light – More Than Just Sunburns

New research puts age of universe at 26.7 billion years, nearly twice as old as previously thought

Our universe could be twice as old as current estimates, according to a new study that challenges the dominant cosmological model and sheds new light on the so-called "impossible early galaxy problem."

The newly-devised model stretches the galaxy formation time by a several billion years, making the universe 26.7 billion years old, and not 13.7 as previously estimated.

For years, astronomers and physicists have calculated the age of our universe by measuring the time elapsed since the Big Bang and by studying the oldest stars based on the redshift of light coming from distant galaxies. In 2021, thanks to new techniques and advances in technology, the age of our universe was thus estimated at 13.797 billion years using the Lambda-CDM concordance model.

However, many scientists have been puzzled by the existence of stars like the Methuselah that appear to be older than the estimated age of our universe and by the discovery of early galaxies in an advanced state of evolution made possible by the James Webb Space Telescope. These galaxies, existing a mere 300 million years or so after the Big Bang, appear to have a level of maturity and mass typically associated with billions of years of cosmic evolution. Furthermore, they're surprisingly small in size, adding another layer of mystery to the equation.

Zwicky's tired light theory proposes that the redshift of light from distant galaxies is due to the gradual loss of energy by photons over vast cosmic distances. However, it was seen to conflict with observations. Yet now it 's found that "by allowing this theory to coexist with the expanding universe, it becomes possible to reinterpret the redshift as a hybrid phenomenon, rather than purely due to expansion.

In addition to Zwicky's tired light theory, researchers no introduce the idea of evolving "coupling constants," as hypothesized by Paul Dirac. Coupling constants are fundamental physical constants that govern the interactions between particles. According to Dirac, these constants might have varied over time. By allowing them to evolve, the timeframe for the formation of early galaxies observed by the Webb telescope at high redshifts can be extended from a few hundred million years to several billion years. This provides a more feasible explanation for the advanced level of development and mass observed in these ancient galaxies.

Researchers now suggest that the traditional interpretation of the "cosmological constant," which represents dark energy responsible for the accelerating expansion of the universe, needs revision. Instead, he proposes a constant that accounts for the evolution of the coupling constants. This modification in the cosmological model helps address the puzzle of small galaxy sizes observed in the early universe, allowing for more accurate observations.

R Gupta, JWST early Universe observations and ΛCDM cosmology, Monthly Notices of the Royal Astronomical Society (2023). DOI: 10.1093/mnras/stad2032

26.7 Billion Years old Galaxy! WOW! Now believable. Exactly how brilliant was Paul Dirac to have postulated or hypothised that Coupling constants are fundamental physical constants that govern the interactions between particles. Further - according to Dirac, these constants might have varied over time.
What an extraordinary brain Dirac had!

New method used to develop RNA therapy for the treatment of rare diseases

Having a rare genetic disease is actually pretty common. Rare diseases affect approximately 1 in 10 individuals. What makes them rare is that these 1 in 10 people affected have an estimated 7,000 different conditions, with treatments available for only about 5% of them.

Rare disease research  has accelerated the treatment potential for one such disease, ataxia-telangiectasia, with antisense oligonucleotides.

In a paper, "A framework for individualized splice-switching oligonucleotide therapy," published in Nature, the researchers detail their methods to identify treatment potential for one rare disease and illustrate how the process could tackle other untreatable conditions. A Clinical Briefing published in the same journal issue summarizes the work done by the team.

The research is based on splice-switching antisense oligonucleotides (ASOs). ASOs are short sequences of synthetic nucleic acids, a chain of nucleotides adenine (A), cytosine (C), guanine (G) and thymine (T), connected in a specific sequence. The specific sequence is called "antisense" because it complements an RNA target sequence, binding with it to alter its function.

The alteration can induce degradation, modulation of splicing, prevention of translation, or in this case, paste a correction over a mis-splicing event. By correcting mis-spliced RNA, the normal production of downstream proteins can resume the role they would carry out in a healthy individual.

Jinkuk Kim et al, A framework for individualized splice-switching oligonucleotide therapy, Nature (2023). DOI: 10.1038/s41586-023-06277-0

Clinical Briefing: A framework for identifying targets for individualized therapy in genetic disease, Nature (2023). DOI: 10.1038/d41586-023-01994-y

Cap top 20% of energy users to reduce carbon emissions, say scientists

Consumers in the richer, developed nations will have to accept restrictions on their energy use if international climate change targets are to be met, warn researchers.

The big challenge is to identify the fairest and most equitable way that governments can curtail energy use, a process known as energy demand reduction. In the paper, "Emissions savings from equitable energy demand reduction," in the journal Nature Energy, the research team analyzed several scenarios to identify a potential solution.

One option is to cap the top 20% of energy users while allowing those people who use little energy and have poverty-level incomes to be able to increase their consumption levels and improve their quality of life.

Across any population there will be a range—or distribution—of values for how much energy individuals use. The values are sorted into 100 percentiles—for example, the 50th percentile represents the value that is exactly in the middle of the energy distribution, which half the population fail to reach and the other half exceeds.

Under the energy demand reduction scheme, the top-level energy users would see their energy use restricted to the value of energy use at the 80th percentile. In the scenario modeled, that would be 170.2 gigajoules (GJ) per person per year, compared to the mean energy use of the top 20% of consumers of 196.8 GJ per person per year.

Using data from 27 European states, the researchers modeled how effective this energy demand reduction strategy would be. They found it would cut greenhouse gas emissions by 11.4% from domestic energy sources; 16.8% from transport and 9.7% from total energy consumption.

Allowing people in poverty to increase their energy use would reduce these emissions savings by relatively small amounts—1.2 percentage points for domestic energy; 0.9 for transport; and 1.4 for total energy consumption. It would enable the less well-off to meet unmet needs, perhaps where they may have been unable to adequately heat their home.

Part 1

Policymakers need to win public support for energy demand reduction mechanisms. The reality is decarbonization on the supply side, where energy is generated and distributed, will not be enough to deliver the emission reductions that are needed.

"So, energy demand will have to be reduced. That is the inescapable reality. Experts on the UN's Intergovernmental Panel on Climate Change estimate that reducing energy demand could produce between 40% and 70% of the emissions reductions that need to be found by 2050.

This research is indicating that public support for energy demand reduction is possible if the public see the schemes as being fair and deliver climate justice.

Milena Büchs, Emissions savings from equitable energy demand reduction, Nature Energy (2023). DOI: 10.1038/s41560-023-01283-y. www.nature.com/articles/s41560-023-01283-y

Part 2

**

'Mind controlling' parasitic worms are missing genes found in every other animal, researchers find

In a world full of bizarre animals, hairworms are some of the strangest. Hairworms are parasitic worms that manipulate the behavior of their hosts in what's sometimes called "mind control."

A new study in the journal Current Biology reveals another strange trait shared by different hairworm species—they're missing about 30% of the genes that researchers expected them to have. What's more, the missing genes are responsible for the development of cilia, the hair-like structures present in at least some of the cells of every other animal known.

Hairworms are found all over the world, and they look like skinny strands of spaghetti, a couple inches long. Their simple bodies hint at their parasitic lifestyle— they have no excretory, respiratory, or circulatory systems, and they spend almost their entire lives inside the bodies of other animals.

One of the coolest things, maybe the thing that they are most known for, is that they can affect the behavior of their hosts and make them do things that they wouldn't do otherwise.

There are a few hundred species of freshwater hairworms. Their eggs hatch in water, and the hairworm larvae get eaten by tiny water-dwelling predators like mayfly larvae, which in turn get eaten by bigger, land-dwelling predators like crickets.

After growing into adulthood inside of their new hosts' bodies, the hairworms manipulate the hosts' behavior, causing them to jump into water. There, the worms swim out of their hosts' butts and seek out mates, knotting themselves together, to begin the cycle anew.

There are also five species of hairworms that live in marine environments and parasitize water-dwelling creatures like lobsters, but it's not clear if those ones also have host manipulation capabilities— there's no pressure for the worms to get back to the water, since the hosts already live there.

Researchers d sequenced them. But when they compared the hairworms' genetic codes to those of other animals, they found something striking.

"What they found was very surprising: both hairworm genomes were missing about 30% of a set of genes that are expected to be present across basically all groups of animals.

The large majority of the missing genes were exactly the same between the two species. This was just implausible by chance.

Part 1

What's more, the fact that both the freshwater and marine hairworm species had lost the genes for cilia indicates that this evolutionary change happened in the deep past to the two species' common ancestor. "It is likely that the loss happened early on in the evolution of the group, and they just have been carrying on like that.

The finding opens the door to several new questions. It's not clear how the lack of cilia have affected hairworms, or if the hairworms' parasitic behavior could be related to the missing cilia. There are plenty of other parasitic organisms that aren't missing these specific genes, so we cannot say that the genes are missing because of their parasitic lifestyle. 

 Tauana J Cunha, Rampant loss of universal metazoan genes revealed by a chromosome-level genome assembly of the parasitic Nematomorpha, Current Biology (2023). DOI: 10.1016/j.cub.2023.07.003. www.cell.com/current-biology/f … 0960-9822(23)00908-9

Part 2

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Toothpaste containing synthetic tooth minerals can prevent cavities as effectively as fluoride: Clinical trial

Brushing twice a day keeps the dentist away—but can we improve on the toothpaste we use to maintain clean teeth, preventing medical issues that spiral from poor dental health? Most toothpastes use fluoride, a powerful tool for oral hygiene. However, fluoride can pose health problems in some cases, especially for children who consume too much fluoride by swallowing most of their toothpaste: children normally use only a tiny dose of toothpaste to avoid these problems, but that reduces toothbrushing efficacy.

In the search for alternatives, a team of international scientists and  clinicians have identified a hydroxyapatite toothpaste that works just as well as fluoride toothpaste to protect against cavities.

Hydroxyapatite is a safe and effective alternative to fluoride in caries prevention for daily use.

Hydroxyapatite is a calcium phosphate mineral found in the skeleton. It's known to be very safe for human consumption and has previously been shown to help with oral conditions like periodontitis. It can both inhibit the demineralization of teeth, a key step towards a cavity, and contribute to remineralization, which reinforces damaged tooth surfaces.

In a trial study  scientists found that nearly 90% of patients in both groups had no new cavities. There was no statistical difference in efficacy between the patients using a hydroxyapatite toothpaste and the control group using a fluoride tooth paste: both worked equally well.

Caries-preventing effect of a hydroxyapatite-toothpaste in adults: A 18 months double-blinded randomized clinical trial, Frontiers in Public Health (2023). DOI: 10.3389/fpubh.2023.1199728. www.frontiersin.org/articles/1 … bh.2023.1199728/full

Biology behind new drug used to treat triple-negative breast cancer uncovered

How TTP488 (azeliragon), an experimental drug, impairs aggressive, triple-negative breast cancer from metastasizing has been uncovered at the cellular level, according to researchers.

Triple-negative breast cancers (TNBCs) account for about 10–15% of all diagnosed breast cancers and are comprised of cancer cells that don't have estrogen or progesterone receptors, nor do they produce a protein called HER2 in significant quantities. TNBC's are more common in women younger than age 40 or those who are Black; for those cancers that metastasize, the five-year survival rate is only 12%. TNBCs have eluded effective treatment for decades. This discovery pinpoints some of the signaling pathways and cellular mechanisms through which a receptor that sits on the surface of TNBC cells, called the receptor for advanced glycation end-products (RAGE), regulates its deadly metastatic spread. Armed with this knowledge, the researchers were able to test the effectiveness of TTP488 in both the lab and in mice to show that the drug could be helpful in people.

Melinda Magna et al, RAGE inhibitor TTP488 (Azeliragon) suppresses metastasis in triple-negative breast cancer, npj Breast Cancer (2023). DOI: 10.1038/s41523-023-00564-9

**

What is making 2023 likely the hottest year recorded

Human-made climate change is supercharging natural weather phenomena to drive heatwaves roasting Asia, Europe and North America that could make 2023 the hottest year since records began, scientists say.

Here experts explain how 2023 has got so hot, warning these record temperatures will get worse even if humanity sharply cuts its planet-warming gas emissions.

El Nino: After a record hot summer in 2022, this year the Pacific warming phenomenon known as El Nino has returned, heating up the oceans.

This may have provided some additional warmth to the North Atlantic, though because the El Nino event is only just beginning, this is likely only a small portion of the effect.

Scientists calculated that there was an 81-percent chance that 2023 would become the warmest year since thermometer records began in the mid-19th century.

Dust and sulphur: The warming of the Atlantic may also have been sharpened by a decrease of two substances that typically reflect sunlight away from the ocean: dust blowing off the Sahara desert and sulfur aerosols from shipping fuel.

Stagnant Anticyclones: Warming oceans affect land weather patterns, prompting heatwaves and droughts in some places and storms in others. The hotter atmosphere sucks up moisture and dumps it elsewhere.

Scientists highlighted the length and intensity of the lingering anticyclone systems bringing the heatwaves.

Where stagnant high-pressure areas persist over continents, the air sinks and warms, melting away clouds, causing intense summer sunshine to parch the soils, heating the ground and air above," with heatwaves "lodged in place" for weeks.

Climate change: 

Scientists at the Intergovernmental Panel on Climate Change (IPCC) said in their global summary report this year that climate change had made deadly heatwaves "more frequent and more intense across most land regions since the 1950s".

This month's heatwaves are "not one single phenomenon but several acting at the same time. But they are all strengthened by one factor: climate change.

Higher global temperatures make heatwaves longer and more intense. Despite being the main driver, climate change is one variable that humans can influence by reducing emissions from fossil fuels.

"We are moving out of the usual and well-known natural oscillations of the climate to unchartered and more extreme territory.

However, we have the ability to reduce our human influence on the climate and weather and to not create more extreme and long-lasting heatwaves.

The IPCC has said heatwaves risk getting more frequent and intense, though governments can limit climate change by reducing countries' greenhouse gas emissions.

Deep, rapid and sustained cuts in carbon emissions to net zero can halt the warming, but humanity will have to adapt to even more severe heatwaves in the future, Scientists warn.

Researchers Prove We Hear the Sound of Silence

Silence might not be deafening, but it's something that literally can be heard, concludes a team of philosophers and psychologists who used auditory illusions to reveal how moments of silence distort people's perception of time.

May I have your Attention please, this is very important. (And my AI is going to post this very frequently). The fights here are increasing global warming. Each of the activities you perform online comes with a small cost – a few grams of carbon dioxide are emitted due to the energy needed to run your devices and power the wireless networks you access. Less obvious, but perhaps even more energy intensive, are the data centres and vast servers needed to support the internet and store the content we access over it. Although the energy needed for a single internet search or email is small, approximately 4.1 billion people, or 53.6% of the global population, now use the internet. Those scraps of energy, and the associated greenhouse gases emitted with each online activity, can add up. The carbon footprint of our gadgets, the internet and the systems supporting them account for about 3.7% of global greenhouse emissions, according to expert estimates. If we were to rather crudely divide the 1.7 billion tonnes (1.6 billion tons) of greenhouse gas emissions estimated to be produced in the manufacture and running of digital technologies between all internet users around the world, it means each of us is responsible for 414kg (912lbs) of carbon dioxide a year. Internet users in some parts of the globe will have a disproportionately large footprint. If we were to rather crudely divide the 1.7 billion tonnes (1.6 billion tons) of greenhouse gas emissions estimated to be produced in the manufacture and running of digital technologies between all internet users around the world, it means each of us is responsible for 414kg (912lbs) of carbon dioxide a year. We can also alter the way we use our gadgets to cut our digital carbon footprints. It is okay if we use the net for the benefit of mankind. But for fighting? Over serial chars? This fighting is contributing to global warming. Now don't complain if the heat wave persists, if the crops fail, if your energy bill or food bill exceeds your budget capabilities. Girls, you yourself are responsible for it!

https://www.youtube.com/watch?v=qTySL9pHqUc&lc=UgzH8CLgVwRcrcUg...