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

Worrying about the present and future of our warming planet has also provoked rising anxiety, depression and even post-traumatic stress—particularly for people already struggling with these disorders, psychologists have warned.

In the first 10 months of the year, people searched online for the term "climate anxiety" 27 times more than during the same period in 2017, according to data from Google Trends cited by the BBC this week.

Source: 

The Lancet and AFP

Part 4

Chocolate discharges the same chemical in your body as when you feel love.
Chocolate raises levels of phenylethylamine (PEA), “the love chemical”. This chemical gets our hearts pumping, increases blood pressure, heart, and respiratory rates, and increases feelings of joy
Chocolate releases this neurochemical of pleasure in our brains. Dopamine kick starts a brain messenger chemical called DARP-32 that activates hormones. This is the chemical that surges through us when we are embraced by someone we love.
Chocolate contains tryptophan, a precursor to serotonin. Serotonin is our other feel good chemical. It diminishes anxiety and increases our ability to fight stress. Many antidepressants work by increasing serotonin levels.
So those who are not in love go eat chocolates and be happy.

How to make waves eat themselves
Physicists have demonstrated that two cavities carved into the side of a channel can totally dissipate the energy of incoming waves. In a model set-up with real water, researchers were able to achieve ‘perfect absorption’ — in which the waves completely cancelled themselves out as they bounced off the cavity walls — with waves of a frequency of 2.9 Hertz. The finding hints at the possibility of designing structures to protect coastlines or harvest wave energy.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.204002

Meta AI develops a non-invasive method to decode speech from brain activity

Recent technological advancements have opened invaluable opportunities for assisting people who are experiencing impairments or disabilities. For instance, they have enabled the creation of tools to support physical rehabilitation, to practice social skills, and to provide daily assistance with specific tasks.

Recent technological advancements have opened invaluable opportunities for assisting people who are experiencing impairments or disabilities. For instance, they have enabled the creation of tools to support physical rehabilitation, to practice social skills, and to provide daily assistance with specific tasks. Researchers at Meta AI recently developed a promising and non-invasive method to decode speech from a person's brain activity, which could allow people who are unable to speak to relay their thoughts via a computer interface. Their proposed method, presented in Nature Machine Intelligence, merges the use of an imaging technique and machine learning.

Alexandre Défossez et al, Decoding speech perception from non-invasive brain recordings, Nature Machine Intelligence (2023). DOI: 10.1038/s42256-023-00714-5.

Scientists discover rare six-planet system that moves in strange synchrony

Scientists have discovered a rare sight in a nearby star system: Six planets orbiting their central star in a rhythmic beat. The planets move in an orbital waltz that repeats itself so precisely that it can be readily set to music.

A rare case of an "in sync" gravitational lockstep, the system could offer deep insight into planet formationand evolution.

The analysis, led by UChicago scientist Rafael Luque, was published Nov. 29 in Nature.

The six planets orbit a star known as HD110067, which lies around 100 light-years away in the northern constellation of Coma Berenices.

In 2020, NASA's Transiting Exoplanet Survey Satellite (TESS) detected dips in the star's brightness that indicated planets were passing in front of the star's surface. Combining data from both TESS and the European Space Agency's CHaracterizing ExOPlanet Satellite (Cheops), a team of researchers analyzed the data and discovered a first-of-its-kind configuration.

While multi-planet systems are common in our galaxy, those in a tight gravitational formation known as "resonance" are observed by astronomers far less often.

In this case, the planet closest to the star makes three orbits for every two of the next planet out—called a 3/2 resonance—a pattern that is repeated among the four closest planets. Among the outermost planets, a pattern of four orbits for every three of the next planet out (a 4/3 resonance) is repeated twice.

And these resonant orbits are rock-solid: The planets likely have been performing this same rhythmic dance since the system formed billions of years ago, the scientists said.

Orbitally resonant systems are extremely important to find because they tell astronomers about the formation and subsequent evolution of the planetary system. Planets around stars tend to form in resonance but can be easily perturbed. For example, a very massive planet, a close encounter with a passing star, or a giant impact event can all disrupt the careful balance.

As a result, many of the multi-planet systems known to astronomers are not in resonance but look close enough that they could have been resonant once. However, multi-planet systems preserving their resonance are rare.

Rafael Luque, A resonant sextuplet of sub-Neptunes transiting the bright star HD 110067, Nature (2023). DOI: 10.1038/s41586-023-06692-3. www.nature.com/articles/s41586-023-06692-3

Nanodiamonds can block tumor metastasis in mice, study shows

Nanodiamonds are 2–8 nm carbon nanoparticles, which can be easily functionalized with various chemical groups like carboxylic groups or drugs. Previous research has shown that actively dividing cells are more likely to absorb nanodiamonds and that epithelial cells treated with carboxylic nanodiamonds lose the ability to migrate across cell-permeable cellulose membranes.

Researchers explored whether nanodiamonds might block tumor metastasis, a process that requires cell migration to new areas. The research is published in the journal PNAS Nexus. 

The authors treated B16F10 melanoma cells with carboxylic nanodiamonds in culture and tested their ability to migrate and invade across polycarbonate membranes with 8-µm pores. The authors found that the nanodiamonds blocked the ability of melanoma cells to migrate, while untreated tumor cells were able to pass through the membrane.

Based on gene expression evidence, the authors hypothesize that the tiny carbon nanodiamonds may inhibit the breaking away of cancer cells from the primary tumor mass—as well as block subsequent steps of metastasis such as the physical movement of cells and their ability to enter blood vessels.

According to the authors, nanodiamonds should be further explored as a possible therapeutic agent for cancer metastasis.

 Sushreesangita P Behera et al, Carboxyl nanodiamonds inhibit melanoma tumor metastases by blocking cellular motility and invasiveness, PNAS Nexus (2023). DOI: 10.1093/pnasnexus/pgad359

Reducing fatal bird collisions

A mineral produced by plate tectonics has a global cooling effect, study finds

Geologists have found that a clay mineral on the seafloor, called smectite, has a surprisingly powerful ability to sequester carbon over millions of years.

Under a microscope, a single grain of the clay resembles the folds of an accordion. These folds are known to be effective traps for organic carbon. 

Now, the researchers have shown that the carbon-trapping clays are a product of plate tectonics: When oceanic crust crushes against a continental plate, it can bring rocks to the surface that, over time, can weather into minerals including smectite. Eventually, the clay sediment settles back in the ocean, where the minerals trap bits of dead organisms in their microscopic folds. This keeps the organic carbon from being consumed by microbes and expelled back into the atmosphere as carbon dioxide.

Over millions of years, smectite can have a global effect, helping to cool the entire planet. Through a series of analyses, the researchers showed that smectite was likely produced after several major tectonic events over the last 500 million years. During each tectonic event, the clays trapped enough carbon to cool the Earth and induce the subsequent ice age.

The findings are the first to show that plate tectonics can trigger ice ages through the production of carbon-trapping smectite.

"Palaeozoic cooling modulated by ophiolite weathering through organic carbon preservation", Nature Geoscience (2023). DOI: 10.1038/s41561-023-01342-9

Brain waves usually found in sleep can protect against epileptic activity

Slow waves that usually only occur in the brain during sleep are also present during wakefulness in people with epilepsy and may protect against increased brain excitability associated with the condition, finds a new study by researchers.

The researchers examined electroencephalogram (EEG) scans from electrodes in the brains of 25 patients with focal epilepsy (a type of epilepsy characterized by seizures arising from a specific part of the brain), while they carried out an associative memory task.

The electrodes had been placed in the patients' brains to localize abnormal activity and inform surgical treatment.

During the task, participants were presented with 27 pairs of images that remained on a screen for six seconds. The images were in nine groups of three—each group featuring a picture of a person, a place and an object. In each case, participants had to remember which images had been grouped together. EEG data were recorded continuously throughout the task.

After reviewing the EEG data, the team found that the brains of people with epilepsy were producing slow waves—lasting less than one second—while they were awake and taking part in the task.

The occurrence of these "wake" slow waves increased in line with increases in brain excitability and decreased the impact of epileptic spikes on brain activity.

In particular, there was a decrease in the "firing" of nerve cells, which the researchers say could protect against epileptic activity.

Wake slow waves in focal human epilepsy impact network activity and cognition, Nature Communications (2023). DOI: 10.1038/s41467-023-42971-3

As dengue expands beyond the global 'dengue belt,' scientists dispel conventional wisdom about the disease

Unknowns, dangers and surprises persist about dengue viral infection and now an assumption once accepted as conventional wisdom about immunity to the mosquito-borne disease may be incorrect.

Dengue is a devastating viral infection transmitted to humans through the bite of Aedes aegypti mosquitoes—flying hypodermic needles that descend prolifically during significant outbreaks. Many dengue epidemics tend to occur in urban settings, scientists say. Dengue viral infection can cause a severe headache, high fever, nausea, vomiting, swollen glands, and rash. Still, and perhaps most surprisingly, many people who are infected have no symptoms at all. In rare cases, however, dengue disease can be fatal.

New research involving epidemiological models and data from more than 4,400 people in Nicaragua suggests that it's time immunologists developed a new framework to understand population immunity to dengue. For decades, it was believed that once you were infected with dengue virus, the immunity lasted for life. The dogma persisted in the face of observational data, which found that people who were previously infected were more susceptible to severe dengue if infected again.

But an international collaborative group of researchers has now conclusively shown that immunity not only wanes, it tends to wax and wane—a discovery that reveals dengue infection to be far more complex than previously thought.

According to them, Infection with multiple dengue virus serotypes is thought to induce enduring protection against dengue disease. However, long-term antibody waning has been observed after repeated dengue infection. The waning of antibodies inevitably was followed by a boosting of antibodies when the next epidemic came along.

This discovery allowed the construction of a new model that best describes population vulnerability to dengue infection, especially amid the known periodicity—the cyclic nature—of dengue outbreaks.

When it comes to dengue, people are not permanently immune but susceptible to infection, then immune and ultimately susceptible again. Hence, the researchers  newly proposed a model: "susceptible-infected-recovered-susceptible."

Rosemary A. Aogo et al, Effects of boosting and waning in highly exposed populations on dengue epidemic dynamics, Science Translational Medicine (2023). DOI: 10.1126/scitranslmed.adi1734

New research suggests cellular stress in the placenta may be possible cause of preeclampsia

Preeclampsia is a mysterious condition that occurs in about one of 10 pregnancies without any early warning signs. After 20 weeks or more of normal blood pressure during the pregnancy, patients with preeclampsia will begin to experience elevated blood pressure and may also have increased levels of protein in their urine due to hypertension reducing the filtering power of the kidneys. Prolonged hypertension due to preeclampsia can lead to organ damage and life-threatening complications for mothers and fetuses.

There is no cure for the underlying causes of preeclampsia, so physicians focus on managing and monitoring patients' blood pressure to allow for as close to a full-term gestation as possible. With severe disease, pre-term deliveries are necessary.

For those who get it earlier on, it can be terrifying and life-changing, potentially including a long hospital stay before delivery and significant supportive care for the infant in the NICU afterwards.

Now scientists have published results on a study of one of the emerging theories for what causes preeclampsia in Science Advances.

The experiments focus on a particular layer of cells of the placenta called the syncytiotrophoblast (STB), which is a key part of the barrier between the mother and developing fetus. This blockade helps keep a mother's fully formed immune system from reacting to the fetus and potentially responding as if the fetus was a foreign threat such as a viral or bacterial invader.

The barrier also works in reverse to keep the fetus's growing immune system from reacting to its mother's cells and tissues. The study's authors investigated the hypothesis that an abnormal amount of cellular and molecular stresses to the STB can damage the placenta and lead to preeclampsia.

Part 1

By comparing "normal" placentas with placentas from pregnancies where patients suffered from preeclampsia, investigators demonstrated that preeclampsia was associated with higher levels of cellular stresses in the STB layer on the placenta. Additionally, the researchers found a hyperactive level of activity of the Gαq protein known to play a role in transmitting signals related to the levels of several hormones present in excessive amounts during preeclampsia.

So, can preeclampsia be prevented? While today the answer is no, MCW scientists now are one step closer with these experimental results. And they are continuing to work as a team to achieve this goal through additional studies.

Megan Opichka et al, Mitochondrial-Targeted Antioxidant Attenuates Preeclampsia-Like Phenotypes Induced by Syncytiotrophoblast-Specific Gαq Signaling, Science Advances (2023). DOI: 10.1126/sciadv.adg8118. www.science.org/doi/10.1126/sciadv.adg8118

Part 2

New discovery: Stunning River of Stars Flowing Through Space

A stunning river of stars has been spotted flowing through the intergalactic space in a cluster of galaxies about 300 million light years away.

Such bridges are known as stellar streams; and, at a length of 1.7 million light-years, the newly named Giant Coma Stream is the longest we've ever seen. And that's not all: the faint river is the first of its kind ever seen outside of a galaxy.

https://www.aanda.org/articles/aa/full_html/2023/11/aa46780-23/aa46...

Dolphins can detect electrical fields

Two captive bottlenose dolphins (Tursiops truncatus) have now proved to researchers at the University of Rostock and Nuremberg Zoo in Germany that they can reliably sense weak electric fields in the water with their long snouts.

The discovery hints at the possibility that some marine mammals really can sniff out the electric currents of small prey buried in the sand. They might even use the skill to sense Earth's magnetic field.

To date, only one other 'true' placental mammal on Earth has been found to possess electroreceptors. Little more than a decade ago, scientists demonstrated that the common Guiana dolphin (Sotalia guianensis) evolved its own unique system of electroreception – one that is inherently different to fish, amphibians, and monotremes, like platypuses and echidnas.

Experiments now suggest that adult bottlenose dolphins and Guiana dolphins can both do something oddly similar with a line of sensitive pores on their snouts, called vibrissal crypts. These little holes used to hold juvenile whiskers, and they are extremely sensitive.

In experiments, bottlenose dolphins were able to use these ex-whisker pits to sense very weak electric fields as low as 2.4 and 5.5 microvolts per centimeter – a detection threshold that the researchers say is "in the same order of magnitude as those in the platypus" and also similar to Guiana dolphins.

https://journals.biologists.com/jeb/article/226/22/jeb245845/334721...

Food Preserving Technique May Have Sparked Human Brain Growth: Researchers

Researchers propose that a taste for fermented morsels may have triggered a surprising jump in the growth rate of our ancestors' brains.

In fact, a shift from a raw diet to one that included food items already partially broken down by microbes may have been a crucial event in our brain's evolution, according to a perspective study by evolutionary neuroscientists.

The brain sizes of our ancestors, the Australopiths, were similar to those of chimpanzees (Pan troglodytes) and bonobos (Pan paniscus). The human lineage's brain expansion accelerated with Homo's emergence and continued through Homo sapiens and Homo neanderthalensis.

How did our ancestors, with brains about the size of chimpanzees, manage to harness the power of external fermentation?

Researchers suggest that hominids with lower cognitive abilities and smaller brains may have adapted to fermentation much earlier than proposed alternative alternative explanations for this gut-to-brain energy redirection, like animal hunting and fire-based cooking.
Fermentation has many advantages associated with cooked foods, such as softer textures, increased caloric content, improved nutrient absorption, and defense against harmful microorganisms.
The researchers emphasize the need for empirical research to support or refute their hypothesis, such as microbiological studies, comparative analyses, and genetic and genomic investigations.

https://www.nature.com/articles/s42003-023-05517-3

Part 2

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Brain implants revive cognitive abilities long after traumatic brain injury in clinical trial

A lady in her final semester of college, planning to apply to law school, when she suffered a traumatic brain injury in a car accident. The injury so compromised her ability to focus she struggled in a job sorting mail.

She couldn't remember anything . Her left foot dropped, so she'd trip over things all the time. She was always in car accidents. And she had no filter—she'd get pissed off really easily.

Her parents learned about research being conducted at Stanford Medicine and reached out; she was accepted as a participant. In 2018, physicians surgically implanted a device deep inside her brain, then carefully calibrated the device's electrical activity to stimulate the networks the injury had subdued. The results of the clinical trial were published Dec. 4 in Nature Medicine. She noticed the difference immediately. When she was asked to list items in the produce aisle of a grocery store, she could rattle off fruits and vegetables. Then a researcher turned the device off, and she couldn't name any. Since the implant she hadn't  had any speeding tickets she said. She doesn't trip anymore. She can remember how much money is in her bank account. She  wasn't able to read earlier, but after the implant she bought a book, 'Where the Crawdads Sing,' and loved it and remembered it. And she doesn't have that quick temper." For her and four others, the experimental deep-brain-stimulation device restored, to different degrees, the cognitive abilities they had lost to brain injuries years before. The new technique, developed by Stanford Medicine researchers and collaborators from other institutions, is the first to show promise against the long-lasting impairments from moderate to severe traumatic brain injuries.

Nicholas Schiff, Thalamic deep brain stimulation in traumatic brain injury: a phase 1, randomized feasibility study, Nature Medicine (2023). DOI: 10.1038/s41591-023-02638-4. www.nature.com/articles/s41591-023-02638-4

Toxic chemicals in  whales and dolphins are exceeding safe limits

Almost half of marine mammals around the UK are being poisoned by banned chemicals.

The compounds, once used in pesticides, flame retardants and coolants, are having significant impacts on the health and reproduction of the animals.

The UK's whales and dolphins are full of toxins—and it might only get worse.

Despite many being banned almost 20 years ago, levels of persistent organic pollutants (POPs) remain high in the oceans. In fact, these chemicals may breach safe limits in as many as half of all marine mammals living around the UK, based on a new study of stranded animals.

While the researchers found that levels of six key POPs are declining, they're concerned that the chemicals currently contained in coastal landfill sites could increasingly leak out as flooding, extreme weather and coastal erosion are enhanced by climate change.

What is alarming is this can happen anywhere in the world.

Rosie S. Williams et al, Spatiotemporal Trends Spanning Three Decades Show Toxic Levels of Chemical Contaminants in Marine Mammals, Environmental Science & Technology (2023). DOI: 10.1021/acs.est.3c01881

Cracked Piece of Metal Heals Itself in Experiment 

Scientists observed a metal healing itself, something never seen before. If this process can be fully understood and controlled, we could be at the start of a whole new era of engineering.

In a study published in July, a research team  was testing the resilience of the metal, using a specialized transmission electron microscope technique to pull the ends of the metal 200 times every second. They then observed the self-healing at ultra-small scales in a 40-nanometer-thick piece of platinum suspended in a vacuum. Cracks caused by the kind of strain described above are known as fatigue damage: repeated stress and motion that causes microscopic breaks, eventually causing machines or structures to break. Amazingly, after about 40 minutes of observation, the crack in the platinum started to fuse back together and mend itself before starting again in a different direction.

https://www.nature.com/articles/s41586-023-06223-0

Eye scans can provide crucial insights into kidney health, study finds

3D eye scans can reveal vital clues about kidney health that could help to track the progression of disease, research suggests. The advance could revolutionize the monitoring of kidney disease, which often progresses without symptoms in the early stages.

Experts say the technology has the potential to support early diagnosis as current screening tests cannot detect the condition until half of the kidney function has been lost. Researchers used highly magnified images to detect changes to the retina—the layer of tissue at the back of the eye that senses light and sends signals to the brain. They found that the images offer a quick, non-invasive way to monitor kidney health.

The eye is the only part of the body where it is possible to view a key process called microvascular circulation—and this flow of blood through the body's tiniest vessels is often affected in kidney disease.

 investigated whether 3D images of the retina, taken using a technology called optical coherence tomography (OCT), could be used to identify and accurately predict the progression of kidney disease.

OCT scanners—used in most high street opticians—use  light waves to create a cross-sectional picture of the retina, displaying each individual layer, within a few minutes.

The team looked at OCT images from 204 patients at different stages of kidney disease, including transplant patients  alongside 86 healthy volunteers. They found that patients with chronic kidney disease had thinner retinas compared with healthy volunteers. The study also showed that thinning of the retina progressed as kidney function declined.

These changes were reversed when kidney function was restored following a successful transplant. Patients with the most severe form of the disease, who received a kidney transplant, experienced rapid thickening of their retinas after surgery.

This knowledge can be utilized in the future to identify the kidney ailments fast.

 Neeraj Dhaun et al, Choroidal & retinal thinning in chronic kidney disease are modifiable with treatment & independently associate with eGFR decline, Nature Communications (2023). www.nature.com/articles/s41467-023-43125-1

Harvesting water from air with solar power

More than 2.2 billion people currently live in water-stressed countries, and the United Nations estimates that 3.5 million die every year from water-related diseases. Because the areas most in need of improved drinking water are also located in some of the sunniest places in the world, there is strong interest in harnessing sunlight to help obtain clean water.

Researchers  developed a promising new solar-powered atmospheric water harvesting technology that could help provide enough drinking water for people to survive in those difficult, dryland areas.

Historically, researchers have faced challenges when injecting salt into hydrogels as the higher salt content reduced the swelling capacity of the hydrogel due to the salting-out effect. This led to salt leakage and the water absorption capacity decreased.

The researchers synthesized a super hygroscopic gel using plant derivatives and hygroscopic salts that was capable of absorbing and retaining an unparalleled amount of water. One kilogram of dry gel could adsorb 1.18 kilograms of water in arid atmospheric environments and up to 6.4 kilograms in humid atmospheric environments. This hygroscopic gel was simple and inexpensive to prepare and would consequently be suitable for large-scale preparation.

In addition, the team adopted a prototype with desorption and condensation chambers, configured in parallel. They employed a turbofan in the condensation chamber to increase the recovery of desorbed water to more than 90%.

In an outdoor prototype demonstration, the team found it released adsorbed water even in the morning or afternoon when the sun is weak. The system could also achieve simultaneous adsorption and desorption during the daytime.

The team is trying to work to achieve simultaneous adsorption and desorption using renewable energy  to maximize daily water yield per unit mass of adsorbent to further optimize the system's performance for practical applications in water generation.

Chengjie Xiang et al, Daytime air-water harvesting based on super hygroscopic porous gels with simultaneous adsorption-desorption, Applied Physics Reviews (2023). DOI: 10.1063/5.0160682

Replacing bone saws with smart lasers

Even back in 1957, when Gordon Gould coined the term "laser" (short for "Light Amplification by Stimulated Emission of Radiation"), he was already imagining the possibilities for its use in medicine. Surgeons would be able to make precise incisions without even touching the patient.

Before that could happen, however, there were—and still are—many hurdles to overcome. Manually controlled light sources have been superseded by mechanical and computer-controlled systems to reduce injuries caused by clumsy handling. Switching from continuous beams to pulsed lasers, which turn themselves rapidly on and off, has reduced the heat they produce. Technical advances allowed lasers to enter the world of ophthalmology in the early 1990s. Since then, the technology has moved on in other areas of medicine, too, but only in relatively few applications has it replaced the scalpel and the bone saw.

Safety concerns are the most important hurdle: how can we prevent injury to the surrounding tissue? How closely can the cutting depth be controlled so that deeper layers of tissue are not accidentally damaged?

Researchers  have just made an important contribution to the safe and precise use of lasers with their recent publication in the journal Lasers in Surgery and Medicine. They  developed a system that combines three functions: it cuts bone, controls the cutting depth and differentiates between different tissues.

These three functions are carried out by three lasers that are aligned to focus on the same spot. The first laser serves as a tissue sensor in that it scans the surroundings of the site where the bone is to be cut.

Pulses are sent with this laser to the surface at regular intervals, so to speak, vaporizing a tiny bit of tissue each time. The composition of this vaporized tissue is measured with a spectrometer. Each type of tissue has its own individual spectrum—its own signature. An algorithm processes this data and creates a kind of map that shows where the bones are located and where the soft tissue is.

Not until all of this has been completed does the second laser, which cuts bone, activate, and then only in places where bones rather than soft tissue are shown on the map that has just been generated. At the same time, the third laser—an optical system—measures the depth of the cut and checks that the cutting laser is not penetrating more deeply than planned. During the cutting phase, the tissue sensor also constantly monitors whether the correct tissue is being cut.

The special thing about this system is that it controls itself—without human interference.

The researchers have so far been testing their system on femur bones and tissue from pigs acquired from a local butcher. They were able to prove that their system works accurately down to fractions of a millimeter. The speed of the combined laser also approaches that of a conventional surgical procedure.

The research team is currently working on making the system smaller.

Arsham Hamidi et al, Multimodal feedback systems for smart laser osteotomy: Depth control and tissue differentiation, Lasers in Surgery and Medicine (2023). DOI: 10.1002/lsm.23732 Arsham Hamidi et al,

Towards miniaturized OCT-guided laser osteotomy: integration of fiber-coupled Er:YAG laser with OCT, Optics Continuum (2023). DOI: 10.1364/OPTCON.497483

Scientist Rebellion is composed of thousands of climate researchers, academics, and concerned citizens who are urging people to get involved in the effort to limit global overheating. As part of the COP 28 proceedings, Scientist Rebellion is urging people to sign an open letter pleading for governments to heed the climate science and take meaningful action while there is still time.

https://scientistrebellion.org/

https://cleantechnica.com/2023/12/05/1000-scientists-plead-for-publ...

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The first ever 1,000-qubit quantum chip

IBM has unveiled the first quantum computer with 1,121 superconducting qubits (qubits are the quantum equivalent of digital bits in a classical computer). Quantum computers could outperform classical computers in certain areas by exploiting phenomena such as entanglement and superposition. However, these quantum states are notoriously fickle and prone to error, so simply having more qubits does not necessarily make a system better. IBM says it will now focus on more error-resistant systems, rather than larger ones.

https://www.nature.com/articles/d41586-023-03854-1?utm_source=Live+...

Earliest mosquito was a bloodsucking male
The discovery of the earliest known fossil mosquitoes, preserved in Lebanese amber, had a sting in the tail: the insects were bloodsucking males. Today, only female mosquitoes eat blood, with males living on nectar and plant juices. The 125-million-year-old fossils have mouthparts that look perfect for piercing skin, as well as mate-grabbing appendages that confirm their sex. The finding could turn current thinking — that blood-sucking evolved after plant-eating — on its head. “We think now that, originally, the mosquito could be bloodsucking,” says palaeontologist and study co-author Dany Azar. “With the appearance of the flowering plant, this function could be just forgotten later on.”

https://www.sciencedirect.com/science/article/pii/S0960982223014483...