Light, not just heat, might spur water to evaporate

If real, the effect might be occurring naturally all over the world

Green light means “go.” That might apply to evaporating water molecules too.

Visible light, especially that of a greenish hue, might spur water to evaporate, researchers report in the Nov. 7 Proceedings of the National Academy of Sciences. In experiments, water evaporating under visible light showed a higher evaporation rate than possible based on heat alone.

Coupled with other observations, they say, the finding suggests that when light shines on water, individual particles of light, or photons, can sever the bonds that connect water molecules, releasing clusters of molecules into the air.

In the new study, the researchers shone light on water contained in porous hydrogels, materials that greedily sop up water. The proposed effect occurs where air meets water, and the hydrogels the researchers studied contain innumerable crannies where the two meet, allowing the water to be cleaved off and escape. In some cases, the evaporation rate was more than double the expectation based on heat. What’s more, the evaporation rate varied with the wavelength of the light. Green light produced the highest evaporation rate.

What happens when AI eats itself?

A Virus that Generates Electricity 

Melting a bacteriophage’s coat of proteins turns it into a tiny power plant, which could fire up the discovery of new bioengineered devices.

Our bodies are alive with electrical signals that allow us to contract muscles and sense the world. The complex brain orchestrates these processes, but it turns out that even simpler biological entities generate electricity. In a new study published in Advanced Materials, researchers reported that a bioengineered virus generated electricity when exposed to heat, a phenomenon known as pyroelectricity. By working with viruses, the researchers hope to better understand bioelectricity in the human body and apply this knowledge to power novel biomaterials.

The M13 bacteriophage, a rod-shaped virus that infects bacteria, is adorned in a molecular coat, woven from nearly 3,000 copies of a helical protein. The protein is positively charged on the inside and negatively charged on the outside, but the arrangement of the thick protein coat balances out the charges. 

Over a decade ago, a research team put the squeeze on the coat proteins, which caused the bacteriophage to exhibit piezoelectricity—the ability to transform mechanical force into electricity.  When the researchers applied pressure to the viruses, the coat proteins changed shape, breaking the charge symmetry and becoming polarized, which generated an electric field and induced a current.

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In this new study,  the researchers addressed whether they could similarly use heat to shift the charge and generate electricity. They edited the genetic code of the viruses to include a specific protein sequence that is attracted to nickel. This way, the viruses would bind to and stand straight up on a thin nickel-coated plate, like a city block of skyscrapers. Then, they blasted these viral cities with heat, either with fire or a laser. As the proteins melted and unfolded, the proteins’ charges became unbalanced, generating voltage. The heat induced a polarization change, and the polarization change induced the electric potential.

Although the naturally occurring helical protein produces some pyroelectricity, the researchers wanted to see if they could give the molecule some added spark. To do this, they genetically altered the bacteriophage to add a string of glutamate, a negatively charged building block of proteins, into the outside of the coat protein.^1,4 When the researchers turned up the heat, the added glutamate amplified the polarization change, more than doubling the pyroelectricity of the normal protein.

“The very fact that they can genetically mutate the virus and make them pyroelectric—it's fascinating work, according to some physicists.

To demonstrate the practical applications of their supercharged virus, the research team generated electrical signatures that flag the presence of hazardous chemicals. To do this, they engineered the protein coat to bind xylene. Then when they heat blasted the bacteriophages, the proteins shapeshifted and produced more electricity. By detecting this difference in electricity, the authors say that the viruses could act as biosensors for harmful gases. 

1. Kim H, et al. Virus-based pyroelectricity. Adv Mater. 2023;35(46):e2305503.
2. Piccolino M. Luigi Galvani and animal electricity: Two centuries after the found.... Trends Neurosci. 1997;20(10):443-448.
3. Lee BY, et al. Virus-based piezoelectric energy generation. Nat Nanotechnol. 2012;7(6):351-356.
4. Lee JH, et al. Vertical self-assembly of polarized phage nanostructure for energy .... Nano Lett. 2019;19(4):2661-2667.

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To kill malaria-carrying mosquitoes efficiently, just add soap!

Could the solution to the decades-long battle against malaria be as simple as soap? In a new study published in PLOS Neglected Tropical Diseases, scientists  have made a compelling case for it.

A research team has found that adding small quantities of liquid soap to some classes of pesticides can boost their potency by more than 10-fold. The discovery is promising news as malaria-carrying mosquitoes display an increasing resistance to current insecticides.

Both laboratory tests and field trials have shown that neonicotinoids, a special class of insecticide, are a promising alternative to target populations showing resistance to existing insecticides. Neonicotinoids, however, do not kill some mosquito species unless their potency is boosted. In this case, the researchers say, soap is the boosting substance.

Colince Kamdem et al, Vegetable oil-based surfactants are adjuvants that enhance the efficacy of neonicotinoid insecticides and can bias susceptibility testing in adult mosquitoes, PLoS Neglected Tropical Diseases (2023).

Nanoplastics promote conditions for Parkinson's across various lab models, study shows

Nanoplastics interact with a particular protein that is naturally found in the brain, creating changes linked to Parkinson's disease and some types of dementia.

In a study appearing Nov. 17 in Science Advances,  researchers report that the findings create a foundation for a new area of investigation, fueled by the timely impact of environmental factors on human biology.

Parkinson's disease has been called the fastest growing neurological disorder in the world. Numerous lines of data suggest environmental factors might play a prominent role in Parkinson's disease, but such factors have for the most part not been identified till now.

Improperly disposed plastics have been shown to break into very small pieces and accumulate in water and food supplies, and were found in the blood of most adults in a recent study.

This new study suggests that the emergence of micro and nanoplastics in the environment might represent a new toxin challenge with respect to Parkinson's disease risk and progression. This is especially concerning given the predicted increase in concentrations of these contaminants in our water and food supplies.

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Researchers found that nanoparticles of the plastic polystyrene—typically found in single use items such as disposable drinking cups and cutlery—attract the accumulation of the protein known as alpha-synuclein.

The study's most surprising findings are the tight bonds formed between the plastic and the protein within the area of the neuron where these accumulations are congregating, the lysosome.

Researchers said the plastic-protein accumulations happened across three different models performed in the study—in test tubes, cultured neurons, and mouse models of Parkinson's disease. The questions remain about how such interactions might be happening within humans and whether the type of  plastic might play a role.

While microplastic and nanoplastic contaminants are being closely evaluated for their potential impact in cancer and autoimmune diseases, the striking nature of the interactions the researchers could observe in their models suggest a need for evaluating increasing nanoplastic contaminants on Parkinson's disease and dementia risk and progression.

Zhiyong Liu et al, Anionic nanoplastic contaminants promote Parkinson's disease–associated α-synuclein aggregation, Science Advances (2023). DOI: 10.1126/sciadv.adi8716. www.science.org/doi/10.1126/sciadv.adi8716

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No evidence for widespread transmission of viruses by African bats, says study

The scientific community and the public alike have often been presented with portrayals of bats as carriers of numerous dangerous viruses that are passed onto humans. In a paper published in Biology Letters, an international team of biologists, virologists and conservationists challenge this narrative surrounding bats.

Contrary to widely held beliefs, this comprehensive review of published studies finds no evidence, outside of Marburg and Sosuga virus, that African bat species serve as reservoirs or bridging hosts for viruses that spillover to humans and cause significant disease.

The research team,  examined the available literature, specifically focusing on viruses detected in bats in Africa. They meticulously reviewed 162 papers published between 1978 and 2020 and, based on data from more than 80,000 individual bats from 167 bat species, did not find substantial evidence that any bat species, other than the Egyptian rousette, plays a central role in the transmission of viruses to humans in this region.

The researchers found no evidence to support the prevailing narrative that bats harbour viruses that are transmitted to humans. On the contrary, their findings reveal only two bat-virus systems in which transmission is clearly documented.

The findings highlight the need for a more nuanced and informed approach to public discourse surrounding the role of wildlife in disease emergence." The authors thus propose a scheme to aid standardized evaluation of virus hosts in the future and call for greater interdisciplinary collaborations in bat-virus studies.

The researchers also state that instead of broadly stating bats harbour the Marburg virus, it is more accurate to specify that the Egyptian rousette, a specific bat species, hosts the Marburg virus. This phrasing preserves accuracy and avoids incorrectly associating all bat species with the Marburg virus.

This  will contribute to a more accurate understanding of the complex dynamics between wildlife, particularly bats, and human health.

Their study also raises concerns about the impact of reiterated research communication linking bats and viruses, based on missing evidence, on the public perception of bats, as well as human-bat conflicts and bat conservation efforts. Fear and active prosecution of bats are increasing dramatically and it is likely that populations are declining.

 Careful and scientifically sound communication of results as well as balancing potential risks against benefits will be crucial to allow humans and bats to live side by side in our changing world. The implications of this research extend beyond Africa, encouraging a more thoughtful and evidence-based approach to the study of zoonotic diseases worldwide.

For The First Time, an Eerie Green Glow Has Been Detected in The Night Sky of Mars

For the first time, a soft green glow has been detected in the night sky of Mars that we'd be able to see with our human eyes.

As it orbits Mars, the European Space Agency's (ESA) ExoMars Trace Gas Orbiter mission has spotted the Martian night sky glowing in light in the optical spectrum.

And the light is so bright in the polar regions that human explorers might even be able to use it to see, if the night is clear of clouds. These observations are unexpected and interesting for future trips to the Red Planet.

Actually, nightglow is a relatively common phenomenon in the atmospheres of the Solar System. A number of things can cause our atmosphere to emit its own light at night, but few things more than our own Sun. During the day, sunlight splits apart molecules in a process called photodissociation. However, on the night side of the atmosphere, away from the harsh radiation of the Sun, the loose atoms can recombine into molecules, releasing their excess energy as photons as they do so.

Here on Earth, the nightglow is visible from space as layers of green, golden, and even reddish light, depending on the molecules involved.

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But on other planets, things are a little less spectacular, at least to human eyes. The nightglow on Venus is infrared. On Jupiter, the glow is more ultraviolet (and apparently variable).

On Mars, infrared and ultraviolet nightglow have been seen. Scientists have even seen dayglow caused by the atmospheric absorption and release of energy from solar radiation in the visible spectrum on Mars (although you wouldn't be able to see it yourself, as a Mars explorer; daylight is simply too bright).

But "No nightglow spectrum has been observed so far in the visible domain," the researchers write. "Scattered solar light hinders such measurements from Earth's ground and no space-borne instrument has observed the Mars visible nightglow."
Between altitudes of 40 and 60 kilometers (25 to 37 miles), visible nightglow was spotted at the south pole during its Martian winter.

This, the researchers say, is the result of oxygen atoms transported from the sunny Martian day combining into dioxygen (O2), emitting a glow in the process – one bright enough to be seen from the ground.

This O₂ nightglow should be observable from a Martian orbiter as well as from the Martian surface with the naked eye under clear sky conditions," the researchers write.

https://www.nature.com/articles/s41550-023-02104-8

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New research maps 14 potential evolutionary dead ends for humanity and ways to avoid them

For the first time, scientists have used the concept of evolutionary traps on human societies at large. They find that humankind risks getting stuck in 14 evolutionary dead ends, ranging from global climate tipping points to misaligned artificial intelligence, chemical pollution, and accelerating infectious diseases.

The evolution of humankind has been an extraordinary success story. But the Anthropocene—the proposed geological epoch shaped by us humans—is showing more and more cracks. Multiple global crises, such as the COVID-19 pandemic, climate change, food insecurity, financial crises, and conflicts have started to occur simultaneously in something which scientists refer to as a polycrisis.

Humans are incredibly creative as a species. We are able to innovate and adapt to many circumstances and can cooperate on surprisingly large scales. But these capabilities turn out to have unintentional consequences. Simply speaking, you could say that the human species has been too successful and, in some ways, too smart for its own future good.

The  new study published as part of a larger assessment in the journal Philosophical Transactions of the Royal Society B. The assessment gathers insights from a wide range of different scientific disciplines across the natural and social sciences and humanities, to understand how the Anthropocene evolved and how global sustainability can continue to evolve in the future.

The new study shows how humanity could get stuck in "evolutionary traps"—dead ends that occur from initially successful innovations. In a first scoping effort, they identify 14 of these, including the simplification of agriculture, economic growth that does not deliver benefits for humans or the environment, the instability of global cooperation, climate tipping points, and artificial intelligence.

Evolutionary traps are a well-known concept in the animal world. Just like many insects are attracted by light, an evolutionary reflex that can get them killed in the modern world, humankind is at risk of responding to new phenomena in harmful ways.

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The simplification of agricultural systems is an example of such a trap. Relying on a few highly productive crops such as wheat, rice, maize, and soya, has meant that calories produced have skyrocketed over the past century. But it also meant that the food system has become very vulnerable to environmental change, such as weather extremes, or new diseases.

Of the 14 evolutionary traps, 12 are in an advanced state, meaning that humankind is on the verge of getting stuck to a degree where it becomes very difficult to get out. What's more, societies are continuing to move in the wrong direction in 10 of these 14.

Alarmingly, these evolutionary traps tend to reinforce each other. If societies get stuck in one dead end, they are more likely to get stuck in others as well. The two dead ends which currently are less advanced are the autonomy of technology—AI and robotics—and a loss of social capital through digitalization.

The new assessment also looks into why societies struggle so hard to move out of these traps.

The evolutionary forces that created the Anthropocene do not work well at the global level. In today's global systems, social and environmental problems grow in places that seem distant to the societies that could prevent them. Also, addressing them often requires global collaboration on a scale that many evolutionary forces often do not align well with.

This does not mean that humanity is doomed to fail, argue the researchers. But we must start to transform our societies actively. So far, the Anthropocene has to a large extent been an unconscious byproduct of other evolutionary processes.

"It's time for humans to become aware of the new reality and to collectively move where we want to as a species. We have the capability to do that and are already seeing signs of such movements. Our creativity, and our power to innovate and collaborate equip us with the perfect tools to actively design our future. We can break out of dead ends and business-as-usual, but for that, we must nurture the capacity for collective human agency and design settings where it can flourish.

A very simple thing that everybody can do is to engage more in nature and society while also learning about both the positive and negative global consequences of our own local actions.

 Peter Søgaard Jørgensen et al, Evolution of the polycrisis: Anthropocene traps that challenge global sustainability, Philosophical Transactions of the Royal Society of London (B ) (2023). DOI: 10.1098/rstb.2022.0261

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(a) System dynamics associated with three major groups of Anthropocene traps, global traps, technology traps and structural traps (including temporal and connectivity traps). Two reinforcing feedback loops are indicated with R and interactions between dynamics across groups oftraps are indicated with colored superscript letters (color of causal node) and stippled lined arrows. Credit: Philosophical Transactions of the Royal Society B

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Early-life stress changes more genes in the brain than a head injury

A surprising thing happened when researchers began exploring whether early-life stress compounds the effects of a childhood head injury on health and behavior later in life. In an animal study, stress changed the activation level of many more genes in the brain than were changed by a bump to the head.

It's already known that head injuries are common in young kids, especially from falling, and can be linked to mood disorders and social difficulties that emerge later in life. Adverse childhood experiences are also very common, and can raise risk for disease, mental illness and substance misuse in adulthood.

Researchers found many, many, many more genes were differentially expressed as a result of their early life stress manipulation than their traumatic brain injury manipulation in animals.

Stress is really powerful, and we shouldn't understate the impact of early life stress on the developing brain, according to them. 

The research poster was presented Nov. 12, 2023 at Neuroscience 2023, the annual meeting of the Society for Neuroscience.

https://www.sfn.org/meetings/neuroscience-2023

Brightest flash ever disturbed Earth's atmosphere last year

Last year the brightest flash of light ever seen in the night sky disturbed Earth's upper atmosphere in a way that has never before detected before.

A massive burst of gamma rays from an enormous cosmic explosion around two billion light years away arrived at Earth on October 9, 2022, lighting up telescopes around the world.

Quickly nicknamed the "BOAT"—for Brightest Of All Time—the flash lasted just seven minutes but its afterglow was visible to amateur astronomers for seven hours.

The flash activated lightning detectors in India and triggered instruments that normally study explosions on the sun called solar flares. It also affected long wave radio communications in the lower ionosphere, a section of Earth's upper atmosphere around 60 to 350 kilometers (37 to 217 miles) above the surface. The BOAT also affected the upper ionosphere—the very first time a gamma-ray burst has been observed in this section of the atmosphere.

From 350 to 950 kilometers above Earth, near the edge of the space, the upper ionosphere is where radiation from the sun turns into charged particles that form an important electric field.

Researchers found a shape in the electric field that had never been observed before.

The research would help scientists understand the potential threat that other gamma-ray bursts could pose in the future. The worst-case scenario would be if such a powerful blast came from much closer to home—say, within our own Milky Way galaxy. That could "completely erase" Earth's ozone layer.

This would expose everything on the surface to the full might of the sun's ultraviolet radiation, potentially wiping out life on Earth. There has previously been speculation that past gamma-ray bursts could have caused ancient mass extinction events.

But It is also possible that the ionosphere would absorb all the gamma rays and "nothing would happen" to those of us on the ground.

The blast came from the direction of the constellation Sagitta and traveled an estimated 1.9 billion years to reach Earth. It is now 2.4 billion light years away because of the expansion of the universe. On average, more than one gamma-ray-burst reaches Earth every day. But one with the brightness of the BOAT is estimated to come around once every 10,000 years.

Mirko Piersanti, Evidence of an upper ionospheric electric field perturbation correlated with a gamma ray burst, Nature Communications (2023). DOI: 10.1038/s41467-023-42551-5. www.nature.com/articles/s41467-023-42551-5

Why does even a small amount of red wine give some people headaches?

 For some people, drinking red wine even in small amounts causes a headache. Typically, a "red wine headache" can occur within 30 minutes to three hours after drinking as little as a small glass of wine.

In a new study, scientists examined why this happens—even to people who don't get headaches when drinking small amounts of other alcoholic beverages. Researchers think that a flavanol found naturally in red wines can interfere with the proper metabolism of alcohol and can lead to a headache. The study was published in the journal Scientific Reports.

This flavanol is called quercetin and it is naturally present in all kinds of fruits and vegetables, including grapes. It's considered a healthy antioxidant and is even available in supplement form. But when metabolized with alcohol, it can be problematic.

When it gets in your bloodstream, your body converts it to a different form called quercetin glucuronide. In that form, it blocks the metabolism of alcohol. As a result, people can end up accumulating the toxin acetaldehyde. Acetaldehyde is a well-known toxin, irritant and inflammatory substance. Researchers know that high levels of acetaldehyde can cause facial flushing, headache and nausea.

The medication disulfiram prescribed to alcoholics to prevent them from drinking causes these same symptoms. That's because the drug also causes the toxin to build up in the body when normally an enzyme in the body would break it down. About 40% of the East Asian population also has an enzyme that doesn't work very well, allowing acetaldehyde to build up in their system.

 When susceptible people consume wine with even modest amounts of quercetin, they develop headaches, particularly if they have a preexisting migraine or another primary headache condition.

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Levels of this flavanol can vary dramatically in red wine

Quercetin is produced by the grapes in response to sunlight. If you grow grapes with the clusters exposed, such as they do in the Napa Valley for their cabernets, you get much higher levels of quercetin. In some cases, it can be four to five times higher.

Levels of quercetin can also differ depending on how the wine is made, including skin contact during fermentation, fining processes and aging.

Scientists are testing this hypothesis  now .

 Inhibition of ALDH2 by Quercetin Glucuronide Suggests a New Hypothesis to Explain Red Wine Headaches, Scientific Reports (2023).

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World's richest 1% emit as much carbon as bottom two-thirds: report

The richest one percent of the global population are responsible for the same amount of carbon emissions as the world's poorest two-thirds, or five billion people, according to an analysis published Sunday by the nonprofit Oxfam International.

While fighting the climate crisis is a shared challenge, not everyone is equally responsible and government policies must be tailored accordingly, according to the report.

It says, the richer you are, the easier it is to cut both your personal and your investment emissions. You don't need that third car, or that fourth holiday, or you don't need to be invested in the cement industry." 

Climate Equality: A Planet for the 99%", was based on research compiled by the Stockholm Environment Institute (SEI) and it examined the consumption emissions associated with different income groups up to the year 2019.
Among the key findings of this study are that the richest one percent globally—77 million people—were responsible for 16 percent of global emissions related to their consumption.

That is the same share as the bottom 66 percent of the global population by income, or 5.11 billion people.
Source: 2023 AFP

What is a sonar pulse and how can it injure humans under water?
Light doesn't travel well underwater—even in clear waters, you can see perhaps some tens of meters. Sound, however, travels very well and far underwater. This is because water is much denser than air, and so can respond faster and better to acoustic pressure waves—sound waves.

Because of these properties, ships use sonar to navigate through the ocean and to "see" underwater. The word "sonar" stands for sound navigation and ranging.

Sonar equipment sends out short acoustic (sound) pulses or pings and then analyzes the echoes. Depending on the timing, amplitude, phase, and direction of the echoes the equipment receives, you can tell what's underwater—the seafloor, canyon walls, coral, fishes, and of course, ships and submarines.

Most vessels—from small, private boats to large commercial tankers—use sonar. However, compared to your off-the-shelf sonar used for finding fish, navy sonars are stronger.
The effects of sonar on divers
We don't hear well underwater—no surprise since we've evolved to live on land. Having said that, you would hear a sonar sound underwater (a mid-to-high pitch noise) and would know you've been exposed.
When it comes to naval sonars, human divers have rated the sound as "unpleasant to severe" at levels of roughly 150dB re 1 µPa (decibel relative to a reference pressure of one micro pascal, the standard reference for underwater sound). This would be, perhaps, very roughly 10km away from a military sonar. Note that we can't compare sound exposure under water to what we'd receive through the air because there are too many physical differences between the two.

Human tolerance limits are roughly 180dB re one µPa, which would be around 500m from military sonar. At such levels, humans might experience dizziness, disorientation, temporary memory and concentration impacts, or temporary hearing loss.
At higher received levels, closer ranges, or longer exposures, you might see more severe physiological or health impacts. In extreme cases, in particular, for impulsive, sudden sound (which sonar is not), sound can cause damage to tissues and organs.
What does sonar do to marine animals?
Some of the information on what noise might do to humans underwater comes from studies and observations of animals.

While they typically don't have outer ears (except for sea lions), marine mammals have inner ears that function similarly to ours. They can receive hearing damage from noise, just like we do. This might be temporary, like the ringing ears or reduced sensitivity you might experience after a loud concert, or it can be permanent.

Marine mammals living in a dark ocean rely on sound and hearing to a greater extent than your average human. They use sound to navigate, hunt, communicate with each other and to find mates. Toothed whales and dolphins have evolved a biological echo sounder or biosonar, which sends out series of clicks and listens for echoes. So, interfering with their sounds or impacting their hearing can disrupt critical behaviors.

Finally, sound may also impact non-mammalian fauna, such as fishes, which rely on acoustics rather than vision for many of their life functions.

https://theconversation.com/what-is-a-sonar-pulse-and-how-can-it-in...

AWEsome Waves in Earth’s Airglow

A wearable robot that assists people with walking

In recent years, roboticists have introduced increasingly advanced systems, which could open exciting new possibilities for surgery, rehabilitation, and health care assistance. These robotic systems are already helping to improve the quality of life of many people with disabilities, as well as patients who suffered physical

trauma or underwent medical procedures.

Researchers recently introduced a new wearable robot designed to specifically assist humans who have difficulties walking due to aging, muscle weakness, surgeries or specific medical conditions. This robot, presented in a paper published in Science Robotics, was found to improve balance, while also reducing the energy spent while walking (the so-called metabolic cost). 

In contrast with other robotic systems for hip abduction assistance proposed in the past, the robot now created  focuses on the frontal plane. This is the frontal part of the human body, known to support movements and lateral stability while walking.

Juneil Park et al, Effect of hip abduction assistance on metabolic cost and balance during human walking. Science Robotics (2023). DOI: 10.1126/scirobotics.ade0876.

High temperatures may have caused over 70,000 excess deaths in Europe in 2022

The burden of heat-related mortality during the summer of 2022 in Europe may have exceeded 70,000 deaths according to a study .

The authors of the study, published in The Lancet Regional Health—Europe, revised upwards initial estimates of the mortality associated with record temperatures in 2022 on the European continent. The study is titled "The effect of temporal data aggregation to assess the impact of changing temperatures in Europe: an epidemiological modelling study."

Ballester J et al, The effect of temporal data aggregation to assess the impact of changing temperatures in Europe: an epidemiological modelling study, The Lancet Regional Health—Europe (2023). DOI: 10.1016/j.lanepe.2023.100779

Babies as young as four months show signs of self-awareness: Study

Babies as young as four months old can make sense of how their bodies interact with the space around them, according to new research.

The findings, published in Scientific Reports, shed new light on how self-awareness develops. Experts  showed babies a ball on a screen moving towards or away from them. When the ball was closest to them on the screen, the babies were presented with a 'touch' (a small vibration) on their hands while their brain activity was being measured.  The researchers found that from just four months old, babies show enhanced somatosensory (tactile) brain activity when a touch is preceded by an object moving toward them.

These findings indicate that even in the first few months of life, before babies have even learned to reach for objects, the multisensory brain is wired up to make links between what babies see and what they feel. This means they can sense the space around them and understand how their bodies interact with that space. This is sometimes referred to as peripersonal space.

Of course, humans do this all the time as adults, using our combined senses to perceive where we are in space and making predictions about when we will touch an object or not. But now that we know that babies in the early stages of their development begin to show signs of this, it opens up questions about how much of these abilities are learned or innate.

Visual objects approaching the body modulate subsequent somatosensory processing at 4 months of age, Scientific Reports (2023). DOI: 10.1038/s41598-023-45897-4

Unearthing how a carnivorous fungus traps and digests worms

A new analysis sheds light on the molecular processes involved when a carnivorous species of fungus known as Arthrobotrys oligospora senses, traps and consumes a worm. 

A. oligospora usually derives its nutrients from decaying organic matter, but starvation and the presence of nearby worms can prompt it to form traps to capture and consume worms. A. oligospora is just one of many species of fungi that can trap and eat very small animals.

When A. oligospora first senses a worm, the findings suggest, DNA replication and the production of ribosomes (structures that build proteins in a cell) both increase. Next, the activity increases of many genes that encode proteins that appear to assist in the formation and function of traps, such as secreted worm-adhesive proteins and a newly identified family of proteins dubbed "trap enriched proteins" (TEP).

Finally, after A. oligospora has extended filamentous structures known as hyphae into a worm to digest it, the activity is boosted by genes coding for a variety of enzymes known as proteases—in particular, a group known as metalloproteases. Proteases break down other proteins, so these findings suggest that A. oligospora uses proteases to aid in worm digestion.

These findings could serve as a foundation for future research into the molecular mechanisms involved in A. oligospora predation and other fungal predator-prey interactions.

Lin H-C, de Ulzurrun GV-D, Chen S-A, Yang C-T, Tay RJ, Iizuka T, et al. (2023) Key processes required for the different stages of fungal carnivory by a nematode-trapping fungus. PLoS Biology (2023). DOI: 10.1371/journal.pbio.3002400

How bloodstain 'tails' can point to significant, additional forensic details

Most of us know that evidence left at a crime scene, such as blood, can often reveal information that is key to investigating and understanding the circumstances around a crime—and that scientific methods can help interpret that information.

In the journal Physics of Fluids, a group of scientists   demonstrated how bloodstains can yield even more valuable details than what is typically gathered by detectives, forensic scientists, and crime scene investigators. By examining the protrusions that deviate from the boundaries of otherwise elliptical bloodstains, the researchers studied how these "tails" are formed. The article is titled "Bloodstain tails: Asymmetry aids reconstruction of oblique impact".

These protrusions are typically only used to get a sense of the direction that the drop traveled, but are otherwise neglected.

In fact, previous studies have primarily focused on larger blood drops falling vertically on flat surfaces or on inclined surfaces where gravity can reshape and obscure the tails. By contrast, the new study involved a series of high-speed experiments with human blood droplets with diameters of less than a millimeter impacting horizontal surfaces at various angles.

This new study shows that  the precise flow that determines the tail length differs from the flow responsible for the size and shape of the elliptical portion of the stain. "In other words, the tail lengths encompass additional independent information that can help analysts reconstruct where the blood drop actually came from."

Indeed, the tail length can reflect information about the size, impact speed, and impact angle of the blood drop that formed the stain. When measured for several blood stains in a stain pattern, the trajectories of the drops can be backtracked to their presumed origin.

Incorporating tail length into standard bloodstain analyses will produce more robust evidentiary information.

"Knowing the origin of the blood stains at a crime scene can help detectives determine whether a victim was standing or sitting, or help corroborate or question a witness's testimony.

Garam Lee et al, Bloodstain tails: Asymmetry aids reconstruction of oblique impact, Physics of Fluids (2023). DOI: 10.1063/5.0170124

Gut microbes help alleviate constipation

Scientists have identified the genes in the probiotic Bifidobacteria longum responsible for improving gut motility. A research team reporting November 21 in the journal Cell Host & Microbe found that B. longum strains possessing the abfA cluster of genes can ameliorate constipation through enhanced utilization of an indigestible fiber called arabinan in the gut.

The researchers established the causal link between a genetic variant—the abfA cluster—to the key functional difference of probiotic B. longum in multiple model organisms, including mice and humans, and provided mechanistic and ecological insights into how a single gene cluster can affect the gut motility of hosts through arabinan metabolism.

Peter Kuffa et al, Fiber-deficient diet inhibits colitis through the regulation of the niche and metabolism of a gut pathobiont, Cell Host & Microbe (2023). DOI: 10.1016/j.chom.2023.10.016

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Solar panels vs planting forests: Which reduces climate change faster?

Photovoltaic fields outperform afforestation as a global climate-change mitigation strategy, according to a study published in the journal PNAS Nexus.

The World Is Running Out of Male Sea Turtles

Green sea turtles are already an endangered species, mainly due to humans hunting them, harvesting their eggs, degrading their habitats, or entangling them in garbage (fishing nets) of some kind.

But they also face another, more insidious threat from people: the loss of male hatchlings from the species.

You probably already know that this is partly caused by rising temperatures due to climate change – but a new study has now unveiled another human-caused problem driving this trend.

During this research work, when the hatchlings emerged, researchers recorded their sex and tested them for 18 heavy metals like cadmium and chromium, plus organic pollutants like polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs).

These contaminants are all known or suspected to function as 'xenoestrogens' or molecules that bind to the receptors for female sex hormones. Female turtles accumulate these contaminants at their foraging sites. As eggs develop within her, they absorb the contaminants that she accumulated and sequester them in the liver of the embryos, where they can stay for years after hatching.

the study found varying sex ratios among the different clutches, but most nests yielded predominantly female hatchlings, the researchers report.

And the degree of female bias in each nest showed an association with xenoestrogen levels in the hatchlings, they discovered: higher pollutant levels in hatchlings' livers correlated with a greater female bias in their nest.

More research is still needed to clarify whether these pollutants are contributing to differences in sex ratio, but the association already warrants concern, researchers say.

https://www.frontiersin.org/articles/10.3389/fmars.2023.1238837/full

Part 2

Chlorine disinfectant is no more effective than water at killing off hospital superbug, new study shows

One of the primary chlorine disinfectants currently being used to clean hospital scrubs and surfaces does not kill off the most common cause of antibiotic-associated sickness in health care settings globally, according to a new study.

Research has shown that spores of Clostridioides difficile, commonly known as C. diff, are completely unaffected despite being treated with high concentrations of bleach used in many hospitals. In fact, the chlorine chemicals are no more effective at damaging the spores when used as a surface disinfectant—than using water with no additives. Writing in the journal Microbiology, the study's authors say susceptible people working and being treated in clinical settings might be unknowingly placed at risk of contracting the superbug.

As a result, and with incidence of biocide overuse only serving to fuel rises in antimicrobial resistance (AMR) worldwide, they have called for urgent research to find alternative strategies to disinfect C. diff spores in order to break the chain of transmission in clinical environments.

 Clostridioides difficile spores tolerate disinfection with Sodium hypochlorite disinfectant and remain viable within surgical scrubs and gown fabrics, Microbiology (2023). DOI: 10.1099/mic.0.001418

This sea worm's posterior swims away, and now scientists know how

Life always finds ways to surprise us. The presence of a unique reproductive mechanism in some annelid worms or segmented worms is one such surprise. In a process called stolonization, the posterior body part with gonads of the syllid worm detaches from its original body. The detached part is called the stolon, and it is full of gametes (eggs or sperm).

The stolon swims around by itself and spawns when it meets the opposite sex. Swimming autonomously would not only protect the original body from environmental dangers but could also help its gametes disperse over larger distances.

To swim autonomously, the stolons develop their own eyes, antennae, and swimming bristles while still attached to their original body. But how does the stolon head form in the middle of the original body?

Part 1

Careful histological and morphological observations revealed that the stolon formation starts with the maturation of gonads in the posterior end. Then forms a head in the anterior part of the developing stolon. Sense organs such as eyes and antennae, and swimming bristles form soon after. Before the stolon detaches, it develops nerves and a 'brain' to sense and behave independently.

To understand the development of stolon's head, researchers investigated the developmental gene expression patterns of the sexually maturing worms. A well-known group of head formation genes are known to define the head region of various animals. They found that these genes are expressed more in the head region of the stolon. Typically, the head formation genes are not expressed as much in the middle of the body. But during gonad development in syllids, head formation genes are highly expressed in the middle of the posterior end of the original body.

This shows how normal developmental processes are modified to fit the life history of animals with unique reproductive styles.

Morphological, Histological and Gene-Expression Analyses on Stolonization in the Japanese Green Syllid, Megasyllis nipponica (Annelida, Syllidae), Scientific Reports (2023). DOI: 10.1038/s41598-023-46358-8

Part 2

Researchers pinpoint brain area where people who are blind recognize faces identified by sound

Using a specialized device that translates images into sound, neuroscientists  showed that people who are blind recognized basic faces using the part of the brain known as the fusiform face area, a region that is crucial for the processing of faces in sighted people.

It's been known for some time that people who are blind can compensate for their loss of vision, to a certain extent, by using their other senses.

This study tested the extent to which this plasticity, or compensation, between seeing and hearing exists by encoding basic visual patterns into auditory patterns with the aid of a technical device researchers refer to as a sensory substitution device. With the use of functional magnetic resonance imaging (fMRI), they can determine where in the brain this compensatory plasticity is taking place.

Face perception in humans and nonhuman primates is accomplished by a patchwork of specialized cortical regions. How these regions develop has remained controversial. Due to their importance for social behavior, many researchers think that the neural mechanisms for face recognition are innate in primates or depend on early visual experience with faces.

The new results  from people who are blind imply that fusiform face area development does not depend on experience with actual visual faces but on exposure to the geometry of facial configurations, which can be conveyed by other sensory modalities.

Josef Rauschecker et al, Sound-encoded faces activate the left fusiform face area in the early blind, PLoS ONE (2023). journals.plos.org/plosone/arti … journal.pone.0286512

Wi-Fi for nerve signals
Researchers have charted a long-distance ‘wireless’ nerve network in Caenorhabditis elegans worms for the first time. The nervous system can be thought of as a web of neurons that pass on messages through direct links, called synapses. But neurons can also communicate over longer distances by releasing molecules called neuropeptides, which are intercepted by other neurons some distance away. Incorporating both ‘wired’ synaptic connections and wireless signalling better predicts how signals travel in the worm than does a model using synaptic connections alone.

https://www.nature.com/articles/d41586-023-03619-w?utm_source=Live+...

Randi, F., Sharma, A. K., Dvali, S. & Leifer, A. M. Nature 623, 406–414 (2023).

Ripoll-Sánchez, L. et al. Neuron 111, 3570–3589 (2023).

Wang, H. et al. Science 382, eabq8173 (2023).

How to keep polio from coming back

Poliovirus is close to being eliminated: it could be gone within three years. But eradication is not extinction. The next challenge will be keeping it at bay. In rare cases, the oral poliovirus vaccine can itself seed a polio outbreak. But withdrawing that vaccine will leave people unprotected. The inactivated poliovirus vaccine doesn’t have the same flaw, but it doesn’t block transmission, so a broad vaccination programme would have to continue. And we will have to be sure that polio can never escape from a research institute or vaccine-manufacturing facility. Finally, a very tiny — but unknown — number of people have immune-deficiency disorders that mean they can carry and spread polio without knowing it, for years.

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Study uncovers no compelling evidence that air purifiers prevent re...

The COVID pandemic led to many calls for improved indoor air quality with claims that doing so would reduce the risk of the virus spreading. However, the real-world evidence to support these claims has been lacking, and studies undertaken during the pandemic have not yet been reported.

Space Communication: beaming messages via laser

Beaming messages via laser across a distance of almost 16 million kilometers or 10 million miles is no longer fiction.

That's about 40 times farther than the Moon is from Earth, and it's the first time that optical communications have been sent across such a distance. Traditionally, we use radio waves to talk to distant spacecraft – but higher frequencies of light, such as near infrared, offer an increase in bandwidth and therefore a huge boost in data speed. If we're going to be able to send high-definition video messages to and from Mars without a significant delay, then this is the tech we need. The test is part of NASA's Deep Space Optical Communications (DSOC) experiment, and the successful establishment of the comms link is known as 'first light'.

https://www.jpl.nasa.gov/missions/deep-space-optical-communications...

Study shows plants use air channels to create a directional light signal and regulate phototropism

Plants have no visual organs, so how do they know where light comes from? In an original study combining expertise in biology and engineering, scientists  uncovered that a light-sensitive plant tissue uses the optical properties of the interface between air and water to generate a light gradient that is "visible" to the plant. These results have been published in the journal Science.

The majority of living organisms (micro-organisms, plants and animals) have the ability to determine the origin of a light source, even in the absence of a sight organ comparable to the eye. This information is invaluable for orienting oneself or optimal positioning in the environment.

Perceiving where light is coming from is particularly important for plants, which use this information to position their organs, a phenomenon known as phototropism. This enables them to capture more of the sun's rays, which they then convert into chemical energy through the process of photosynthesis, a vital process that is necessary for the production of nearly all of the food we eat.

Although the photoreceptor that initiates phototropism has long been known, the optical properties of photosensitive plant tissue have until now remained a mystery. A multidisciplinary study uncovered a surprising tissue feature allowing plants to detect directional light cues.

Part 1

It all started with the observation of a mutant of the model species Arabidopsis thaliana, the thale cress, whose stem was surprisingly transparent.

 These plants failed to respond to light correctly. The  biologists in the group then decided to call on the skills of their  colleagues in other fields in order to further compare the specific optical properties of the mutant versus wild-type samples.

They found that the natural milky appearance of the stems of young wild plants was in fact due to the presence of air in intercellular channels precisely located in various tissues. In the mutant specimens, the air is replaced by an aqueous liquid, giving them a translucent appearance.

But what purpose do such air-filled channels serve? They enable the photosensitive stem to establish a light gradient that can be "read" by the plant. The plant can then determine the origin of the light source. This phenomenon is due to the different optical properties of air and water, which make up the majority of living tissue.

More specifically, air and water have different refractive indices. This leads to light scattering as it passes through the seedling.

Thanks to their research, the scientists have revealed a novel mechanism that enables living organisms to perceive where the light is coming from, enabling them to position their organs such as leaves in a way that optimizes light capture for photosynthesis. The study also provided a better understanding of the formation of air-filled intercellular channels, which have a range of functions in plants, in addition to the formation of light gradients.

Ganesh M. Nawkar et al, Air channels create a directional light signal to regulate hypocotyl phototropism, Science (2023). DOI: 10.1126/science.adh9384. www.science.org/doi/10.1126/science.adh9384

Part 2

Biohybrid microrobots could remove micro- and nano-plastics from aquatic environments

Micro and nano plastics are harmful tiny particles derived from the disintegration of plastic waste released into the water. These particles have been found to disrupt aquatic ecosystems, for instance, delaying the growth of organisms, reducing their food intake, and damaging fish habitats.

Devising effective technologies to effectively remove these tiny particles is of utmost importance, as it could help to protect endangered species and their natural environments. These technologies should be carefully designed to prevent further pollution and destruction; thus, they should be based on environmentally friendly materials.

Researchers recently developed biohybrid microrobots that could remove micro- and nano-plastics from polluted water without causing further pollution. These robots, presented in a paper published in Advanced Functional Materials, integrate biological materials, specifically algae, with environmentally friendly materials that respond to external magnetic fields. 

The new robots they created, dubbed magnetic algae robots (MARs), consist of a combination of algae and environmentally friendly magnetic nanoparticles.

These robots operate under the influence of an external magnetic field, enabling precise control over their movement. The negative surface charge of MARs is attributed to the presence of -COOH groups on the surface of algae cells. In contrast, the selected micro/nano plastics carry a positive surface charge. This positive-negative interaction facilitates electrostatic attraction, thereby promoting the targeted capture and removal of micro/nano plastics by the MARs.

The unique composition of the robots created by the researchers makes them both non-polluting and responsive to externally applied magnetic fields. This could allow them to sustainably retrieve nano- and micro-sized plastic particles from aquatic environments.

 Xia Peng et al, Biohybrid Magnetically Driven Microrobots for Sustainable Removal of Micro/Nanoplastics from the Aquatic Environment, Advanced Functional Materials (2023). DOI: 10.1002/adfm.202307477

Reactivating silenced fetal hemoglobin genes could counter sickle cell–related diseases

Researchers from multiple institutions  have found a way to use gene editing to reactivate dormant fetal oxygen-transporting proteins in adult blood cells to potentially reverse a wide range of blood disorders.

In a paper, "Base editing of the HBG promoter induces potent fetal hemoglobin expression with no detectable off-target mutations in human HSCs," published in Cell Stem Cell, the team compares gene editing techniques while formulating a method that could have important clinical applications.

Fetal gamma (γ) globin is normally replaced by adult (β) hemoglobin during development. In an odd quirk of evolution, only humans and a few types of monkeys are known to switch from γ to β gene expression. The genes producing the fetal hemoglobin become silenced and dormant after the genetic switch by repressors such as BCL11A and ZBTB7A, whose binding motifs have been identified as targets for reactivation. β-hemoglobinopathies, including β-thalassemia and sickle cell disease, result from mutations in the HBB gene, leading to impaired β-globin production and resulting in anemia, impaired oxygen delivery to tissues and possible multi-organ tissue damage. The researchers experimentally discovered that reactivating γ-globin expression could be developed into a universal therapeutic strategy for these conditions.

Wenyan Han et al, Base editing of the HBG promoter induces potent fetal hemoglobin expression with no detectable off-target mutations in human HSCs, Cell Stem Cell (2023). DOI: 10.1016/j.stem.2023.10.007

Plastic waste in the water might be stopping, or interrupting, some shrimp-like creatures from reproducing
In a unique study, published in the journal Environmental Pollution,the ability of "shrimp-like" creatures to reproduce successfully was found to be compromised by chemicals found in everyday plastics.

Research showed that little critters, known as marine amphipod Echinogammarus marinus, changed their mating behavior when exposed to toxic plastic additives.

Until now, most research into plastic pollution has focused on visual plastics; what can get trapped in plastics and the dangers of ingesting large particles. Scientists now have taken a different approach and investigated the chemicals that are used as ingredients in plastics.
This unsuccessful mating behavior has serious repercussions, not only for the species being tested but potentially for the population as a whole. These animals form pairs to reproduce. Once they were exposed to a chemical, they would break apart from their mate and take much longer—in some cases days—to re-pair, and sometimes not at all.
These creatures make up a substantial amount of the diet of fish and birds. If they are compromised it will have an effect on the whole food chain.
There are more than 350,000 chemicals in use around the world in everyday products. Ten thousand of these are used to enhance plastics. Chemicals can be used to make plastics more flexible, add color, give sun protection or make plastic flameproof. About one-third of these chemicals are known to be toxic to human's immune, nervous or reproductive systems.
Although the animals we tested were exposed to much higher concentrations than you would normally find in the environment, the results indicate these chemicals can affect sperm count.

Bidemi Green-Ojo et al, Evaluation of precopulatory pairing behaviour and male fertility in a marine amphipod exposed to plastic additives, Environmental Pollution (2023). DOI: 10.1016/j.envpol.2023.122946

Death by Stem Cell: Developing New Cancer Therapies

Engineering stem cells to deliver cancer therapeutics directly to tumors, thereby increasing their efficacy.

While chemotherapy, surgery, and radiation therapy are traditional cancer treatments that can be applied individually or in combination, a patient’s response to these approaches depends on cancer type, location, heterogeneity, and drug resistance.2 Consequently, researchers need to develop novel therapies and delivery methods.

Some researchers are developing cancer therapeutics that use stem cells as delivery vectors to treat primary and metastatic brain and lung cancers. In a recently published Science Translational Medicine paper, some of them  showed an allogeneic twin stem cell system carrying oncolytic viral particles and immunomodulators to treat brain metastases.  A few weeks later, they also published a Stem Cells Translational Medicine paper, where they engineered mesenchymal stem cells to secrete a bi-functional molecule targeting two receptors in lung tumors, leading to cancer cell death.

1. Siegel RL, et al. Cancer statistics, 2023. CA Cancer J Clin. 2023;73(1):17-48.
2.  Debela DT, et al. New approaches and procedures for cancer treatment: Current perspec.... SAGE Open Med. 2021;9.
3.  Kanaya N, et al. Gene-edited and -engineered stem cell platform drives immunotherapy.... Sci Transl   Med. 2023;15(698):eade8732.
4.  Moleirinho S, et al. Fate and efficacy of engineered allogeneic stem cells targeting cel.... Stem Cells Transl Med. 2023;12(7):444-458.

Scientists Find 'Kill Switch' That Activates Cancer Cell Death in The Lab

Scientists have figured out a way to detonate the 'doors' that lead to the heart of cancerous tumors, blowing them wide open for drug treatments.

The strategy works by triggering a 'timer bomb' on the cells that line a tumor's associated blood vessels.

These vessels control access to the tumor tissue, and until they are opened, engineered immune cells can't easily gain entry to the cancer to fight it off. The timer bomb on these cells is actually a 'death' receptor, called Fas (or CD95). When activated by the right antibody, it triggers the programmed death of that cell.

In recent experiments using mouse models and human cell lines, scientists have at last identified specific antibodies that, when attached to Fas receptors, effectively trigger self-implosion. now that we've identified this epitope, there could be a therapeutic path forward to target Fas in tumors. The antibody that binds to this epitope (a specific part of the death receptor), essentially represents the kill switch for the cell. Once this immune checkpoint is blown open, other cancer therapies, like CAR-T therapy, can gain access to more of their targets, which are often clumped together and hidden within the tumor. CAR-T therapy works by programming a person's own white blood cells, called T-cells, to bind to and attack specific types of cancerous cells. These tailored immune cells, however, cannot usually get past the 'bystander' cells that lack the recognisable antigens usually used to target tumor cells. As a result, CAR-T therapy has only been approved to treat blood cancers or leukemia. It fails to provide consistent success against solid tumors till now. In recent experiments , scientists developed two engineered antibodies that were "supremely effective" at attaching to Fas receptors and causing bystander cells to self-implode. This was true in ovarian cancer models and many other tumor cell lines tested in the lab. The Fas ligand developed by researchers was able to engage two critical parts of the Fas receptor, which researchers say should be investigated further. These parts hold potential as future drug targets.

https://www.nature.com/articles/s41418-023-01229-7

Scientists finally work out what causes itching

The bilingual brain may be better at ignoring irrelevant information

People who speak two languages may be better at shifting their attention from one thing to another compared to those who speak one, according to a study published this month in the journal Bilingualism: Language and Cognition.

The study examined differences between bilingual and monolingual individuals when it comes to attentional control and ignoring information that isn't important at the time. 

Our results showed that bilinguals seem to be more efficient at ignoring information that's irrelevant, rather than suppressing—or inhibiting information. One explanation for this is that bilinguals are constantly switching between two languages and need to shift their attention away from the language not in use.

For example, if an English- and Spanish-speaking person is having a conversation in Spanish, both languages are active, but English is put on hold but always ready to be deployed as needed. Numerous studies have examined the distinctions between the two groups in broad cognitive mechanisms, which are mental processes that our brains use, like memory, attention, problem-solving, and decision-making.

The effects of speaking two languages on a person's cognitive control is often debated. Some of the literature says these differences aren't so pronounced, but that could be because of the tasks linguists use to research differences between bilinguals and monolinguals.

Now what about people who can speak several languages?

Grace deMeurisse et al, Bilingual attentional control: Evidence from the Partial Repetition Cost paradigm, Bilingualism: Language and Cognition (2023). DOI: 10.1017/S1366728923000731

Bacteria store 'memories' and pass them on for generations, study finds

Scientists have discovered that bacteria can create something like memories about when to form strategies that can cause dangerous infections in people, such as resistance to antibiotics and bacterial swarms when millions of bacteria come together on a single surface. The discovery—which has potential applications for preventing and combatting bacterial infections and addressing antibiotic-resistant bacteria—relates to a common chemical element bacterial cells can use to form and pass along these memories to their progeny over later generations.

Researchers found that E. coli bacteria use iron levels as a way to store information about different behaviours that can then be activated in response to certain stimuli.

Scientists had previously observed that bacteria that had a prior experience of swarming (moving on a surface as a collective using flagella) improve subsequent swarming performance.

Bacteria don't have neurons, synapses or nervous systems, so any memories are not like the ones we have. They are more like information stored on a computer.

Bacteria don't have brains, but they can gather information from their environment, and if they have encountered that environment frequently, they can store that information and quickly access it later for their benefit.

It all comes back to iron, one of the most abundant elements on Earth. Singular and free-floating bacteria have varying levels of iron. Scientists observed that bacterial cells with lower levels of iron were better swarmers. In contrast, bacteria that formed biofilms, dense, sticky mats of bacteria on solid surfaces, had high levels of iron in their cells. Bacteria with antibiotic tolerance also had balanced levels of iron. These iron memories persist for at least four generations and disappear by the seventh generation.

Before there was oxygen in the Earth's atmosphere, early cellular life was utilizing iron for a lot of cellular processes. Iron is not only critical in the origin of life on Earth, but also in the evolution of life. It makes sense that cells would utilize it in this way.

Souvik Bhattacharyya et al, A heritable iron memory enables decision-making in Escherichia coli, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2309082120

Study unveils the engagement of different cortical networks while humans are unconscious

States of unconsciousness, such as those that occur during sleep or while under the effect of anesthesia, have been the focus of countless past neuroscience studies. While these works have identified some brain regions that are active and inactive when humans are unconscious, the precise contribution of each of these regions to consciousness remains largely unclear.

Researchers recently carried out a study aimed at better understanding the activity of different regions of the cortex, the outer layer of the mammalian brain, during different states of unconsciousness, namely sleep and general anesthesia. Their paper, published in Neuron, identifies distinct cortical networks that are engaged during different states of unconsciousness.

What happens in the human brain when we are unconscious? And, what happens when we cannot be awakened?

This recent study on the states of unconsciousness focuses on sleep versus general anesthesia induced by the drug propofol.

The researchers carried out their study on patients diagnosed with epilepsy who had electrodes implanted in their brains as part of their medical treatment. By recording brain activity inside the brain, these electrodes help doctors monitor and treat epileptic seizures. 

They found that, compared to when they were awake, during sleep the brain was uniformly affected across patients, presenting simpler and reduced brain connections, as well as larger variability in the recorded activity.

All measures were more pronounced during propofol-induced anesthesia, but the brain involvement was not uniform; the changes in prefrontal regions were particularly prominent.

This indicates that during different forms of unconsciousness distinct parts of the brain are involved in different ways. These new findings in turn imply that going from unconscious to conscious may use different mechanisms depending on the nature of the unconscious state.

 Rina Zelmann et al, Differential cortical network engagement during states of un/consciousness in humans, Neuron (2023). DOI: 10.1016/j.neuron.2023.08.007

Not just meteorite: New clues about the demise of dinosaurs

What wiped out the dinosaurs? A meteorite plummeting to Earth is only part of the story, a new study suggests. Climate change triggered by massive volcanic eruptions may have ultimately set the stage for the dinosaur extinction, challenging the traditional narrative that a meteorite alone delivered the final blow to the ancient giants.

Researchers delved into volcanic eruptions of the Deccan Traps—a vast and rugged plateau in Western India formed by molten lava. Erupting a staggering 1 million cubic kilometers of rock, it may have played a key role in cooling the global climate around 65 million years ago. The work took researchers around the world, from hammering out rocks in the Deccan Traps to analyzing the samples in England and Sweden. 

In the lab, the scientists estimated how much sulfur and fluorine was injected into the atmosphere by massive volcanic eruptions in the 200,000 years before the dinosaur extinction.

Remarkably, they found the sulfur release could have triggered a global drop in temperature around the world—a phenomenon known as a volcanic winter.

The research demonstrates that climatic conditions were almost certainly unstable, with repeated volcanic winters that could have lasted decades, prior to the extinction of the dinosaurs. This instability would have made life difficult for all plants and animals and set the stage for the dinosaur extinction event. 

Sara Callegaro et al, Recurring volcanic winters during the latest Cretaceous: Sulfur and fluorine budgets of Deccan Traps lavas, Science Advances (2023). DOI: 10.1126/sciadv.adg8284

How climate change impacts health

Extreme heat, air pollution and the increasing spread of deadly infectious diseases are just some of the reasons why the World Health Organization has called climate change the single biggest health threat facing humanity.

Global warming must be limited to the Paris Agreement target of 1.5 degrees Celsius "to avert catastrophic health impacts and prevent millions of climate change-related deaths", according to the WHO.

However, under current national carbon-cutting plans, the world is on track to warm up to 2.9°C this century, the UN said this week.

While no one will be completely safe from the effects of climate change, experts expect that most at risk will be children, women, the elderly, migrants and people in less developed countries which have emitted the least planet-warming greenhouse gases.

This year is widely expected to be the hottest on record. And as the world continues to warm, even more frequent and intense heat waves are expected to follow.

Part 1

Heat is believed to have caused more than 70,000 deaths in Europe during summer last year, researchers said this week, revising the previous number up from 62,000.

Worldwide, people were exposed to an average of 86 days of life-threatening temperatures last year, according to The Lancet Countdown report earlier this week.

The number of people over 65 who died from heat rose by 85 percent from 1991-2000 to 2013-2022, it added.

And by 2050, more than five times more people will die from the heat each year under a 2°C warming scenario, The Lancet Countdown projected.

More droughts will also drive rising hunger. Under the scenario of 2°C warming by the end of the century, 520 million more people will experience moderate or severe food insecurity by 2050.

Meanwhile, other extreme weather events such as storms, floods and fires will continue to threaten the health of people across the world.

Part 2

Almost 99 percent of the world's population breathes air that exceeds the WHO's guidelines for air pollution.

Outdoor air pollution driven by fossil fuel emissions kills more than four million people every year, according to the WHO.

It increases the risk of respiratory diseases, strokes, heart disease, lung cancer, diabetes and other health problems, posing a threat that has been compared to tobacco.

The damage is caused partly by PM2.5 microparticles, which are mostly from fossil fuels. People breathe these tiny particles into their lungs, where they can then enter the bloodstream.

While spikes in air pollution, such as extremes seen in India's capital New Delhi earlier this month, trigger respiratory problems and allergies, long-term exposure is believed to be even more harmful.

The changing climate means that mosquitoes, birds and mammals will roam beyond their previous habitats, raising the threat that they could spread infectious diseases with them.

Mosquito-borne diseases that pose a greater risk of spreading due to climate change include dengue, chikungunya, Zika, West Nile virus and malaria.

The transmission potential for dengue alone will increase by 36 percent with 2°C warming, The Lancet Countdown report warned.

Storms and floods create stagnant water that are breeding grounds for mosquitoes, and also increase the risk of water-borne diseases such as cholera, typhoid and diarrhea.

Scientists also fear that mammals straying into new areas could share diseases with each other, potentially creating new viruses that could then jump over to humans.

Part 3