With just a tablespoon of blood, researchers aim to transform cancer treatment

Researchers  have developed a new blood test that provides unprecedented insight into a patient's cancer make-up, potentially allowing doctors to better select treatment options that will improve patient outcomes.

The technology was outlined in a study published recently in Nature.

The first-of-its-kind blood test analyzes the DNA that metastatic cancers shed into the bloodstream, known as circulating tumor DNA or ctDNA. By sequencing the entire genome of this ctDNA, the test reveals characteristics that are unique to each patient's cancer, giving physicians new tools to develop more personalized treatment plans.

With only a few drops of blood, we can now uncover critical information about a person's overall disease and how best to manage their cancer. This test has the potential to help clinicians choose better tailored treatment options and to more efficiently detect treatment resistance, allowing clinicians to adjust clinical care as needed.

 Alexander Wyatt, Deep whole-genome ctDNA chronology of treatment-resistant prostate cancer, Nature (2022). DOI: 10.1038/s41586-022-04975-9. www.nature.com/articles/s41586-022-04975-9

Mouse study shows dopamine released in brain in response to hydration

A team of researchers  has found that a certain part of the brain releases dopamine in response to hydration. In their paper published in the journal Nature, the group describes experiments they conducted with thirsty mice.

Prior research has shown that certain parts of the brain release dopamine, a chemical compound, as a means of providing pleasurable feedback to other parts of the brain. It is released during sex, for example, or when a person eats something they like, particularly foods that are sweet or fatty. In this new effort, the researchers have found that another part of the brain releases dopamine—this time when the brain is hydrated.

Noting that many animals have learned to determine which foods contain more water, the researchers wondered if there was a feedback mechanism in the brain prompting them to eat those foods that would provide more water, leading to more hydration in their brains. To find out, they turned to mice.

The experiments involved restricting water in test mice and using technology that allowed them to focus on the ventral tegmental area (VTA) in the brain. In one experiment, thirsty mice were given unlimited access to water for five minutes while the researchers monitored brain waves emanating from the VTA—a means of measuring how much, if any, dopamine was being produced. As expected, dopamine production levels rose as soon as the mice began drinking. But the researchers were then surprised to find that 10 minutes later, the dopamine levels rose again—coinciding with the amount of time it took for the water they had been drinking to reach their brain. The researchers then repeated the experiment but added salt to the water—the second bump in dopamine was much smaller due to the dehydrating impact of the salt.

James C. R. Grove et al, Dopamine subsystems that track internal states, Nature (2022). DOI: 10.1038/s41586-022-04954-0

Nanomembrane system could help diagnose diseases by isolating biomarkers in tears

Going to the doctor might make you want to cry, and according to a new study, doctors could someday put those tears to good use. In ACS Nano, researchers report a nanomembrane system that harvests and purifies tiny blobs called exosomes from tears, allowing researchers to quickly analyze them for disease biomarkers. Dubbed iTEARS, the platform could enable more efficient and less invasive molecular diagnoses for many diseases and conditions, without relying solely on symptoms.

Diagnosing diseases often hinges on assessing a patient's symptoms, which can be unobservable at early stages, or unreliably reported. Identifying molecular clues in samples from patients, such as specific proteins or genes from vesicular structures called exosomes, could improve the accuracy of diagnoses. However, current methods for isolating exosomes from these samples require long, complicated processing steps or large sample volumes. Tears are well-suited for sample collection because the fluid can be collected quickly and non-invasively, though only tiny amounts can be harvested at a time. So,  researchers wondered if a nanomembrane system, which they originally developed for isolating exosomes from urine and plasma, could allow them to quickly obtain these vesicles from tears and then analyze them for disease biomarkers.

The researchers successfully distinguished between healthy controls and patients with various types of dry eye disease based on a proteomic assessment of extracted proteins. Similarly, iTEARS enabled researchers to observe differences in microRNAs between patients with diabetic retinopathy and those that didn't have the eye condition, suggesting that the system could help track disease progression. The team says that this work could lead to a more sensitive, faster and less invasive molecular diagnosis of various diseases—using only tears.

Liang Hu et al, Discovering the Secret of Diseases by Incorporated Tear Exosomes Analysis via Rapid-Isolation System: iTEARS, ACS Nano (2022). DOI: 10.1021/acsnano.2c02531

Nanomembrane system could help diagnose diseases by isolating biomarkers in tears

Going to the doctor might make you want to cry, and according to a new study, doctors could someday put those tears to good use. In ACS Nano, researchers report a nanomembrane system that harvests and purifies tiny blobs called exosomes from tears, allowing researchers to quickly analyze them for disease biomarkers. Dubbed iTEARS, the platform could enable more efficient and less invasive molecular diagnoses for many diseases and conditions, without relying solely on symptoms.

Diagnosing diseases often hinges on assessing a patient's symptoms, which can be unobservable at early stages, or unreliably reported. Identifying molecular clues in samples from patients, such as specific proteins or genes from vesicular structures called exosomes, could improve the accuracy of diagnoses. However, current methods for isolating exosomes from these samples require long, complicated processing steps or large sample volumes. Tears are well-suited for sample collection because the fluid can be collected quickly and non-invasively, though only tiny amounts can be harvested at a time. So, researchers wondered if a nanomembrane system, which they originally developed for isolating exosomes from urine and plasma, could allow them to quickly obtain these vesicles from tears and then analyze them for disease biomarkers.

The team modified their original system to handle the low volume of tears. The new system, called "Incorporated Tear Exosomes Analysis via Rapid-isolation System" (iTEARS), separated out exosomes in just 5 minutes by filtering tear solutions over nanoporous membranes with an oscillating pressure flow to reduce clogging. Proteins from the exosomes could be tagged with fluorescent probes while they were still on the device and then transferred to other instruments for further analysis. Nucleic acids were also extracted from the exosomes and analyzed.

The researchers successfully distinguished between healthy controls and patients with various types of dry eye disease based on a proteomic assessment of extracted proteins. Similarly, iTEARS enabled researchers to observe differences in microRNAs between patients with diabetic retinopathy and those that didn't have the eye condition, suggesting that the system could help track disease progression. The team says that this work could lead to a more sensitive, faster and less invasive molecular diagnosis of various diseases—using only tears.

Liang Hu et al, Discovering the Secret of Diseases by Incorporated Tear Exosomes Analysis via Rapid-Isolation System: iTEARS, ACS Nano (2022). DOI: 10.1021/acsnano.2c02531

Woodpeckers' heads act more like stiff hammers than safety helmets

Scientists had long wondered how woodpeckers can repeatedly pound their beaks against tree trunks without doing damage to their brains. This led to the notion that their skulls must act like shock-absorbing helmets. Now, researchers reporting in the journal Current Biology on July 14 have refuted this notion, saying that their heads act more like stiff hammers. In fact, their calculations show that any shock absorbance would hinder the woodpeckers' pecking abilities.

Sam Van Wassenbergh, Erica J. Ortlieb, Maja Mielke, Christine Böhmer, Robert E. Shadwick, Anick Abourachid. Woodpeckers minimize cranial absorption of shocks. Current Biology, 2022; DOI: 10.1016/j.cub.2022.05.052

Quantum computer works with more than zero and one

Computers work with zeros and ones, also known as binary information. This approach has been so successful that computers now power everything from ATMs to self-driving cars and planes and it is hard to imagine a life without them.

Building on this success, today's quantum computers are also designed with binary information processing in mind. The building blocks of quantum computers, however, are more than just zeros and ones. However, restricting them to binary systems prevents these devices from living up to their true potential.

A research team  now succeeded in developing a quantum computer that can perform arbitrary calculations with so-called quantum digits (qudits), thereby unlocking more computational power with fewer quantum particles. Their study is published in Nature Physics.

Although storing information in zeros and ones is not the most efficient way of doing calculations, it is the simplest way. Simple often also means reliable and robust, so binary information has become the unchallenged standard for classical computers.

In the quantum world, the situation is quite different. In the Innsbruck quantum computer, for example, information is stored in individual trapped Calcium atoms. Each of these atoms naturally has eight different states, of which typically only two are used to store information. Indeed, almost all existing quantum computers have access to more quantum states than they use for computation.

The physicists from Innsbruck have now developed a quantum computer that can make use of the full potential of these atoms, by computing with qudits. Contrary to the classical case, using more states does not make the computer less reliable. Quantum systems naturally have more than just two states and the researchers showed that they can control them all equally well.

Martin Ringbauer, A universal qudit quantum processor with trapped ions, Nature Physics (2022). DOI: 10.1038/s41567-022-01658-0. www.nature.com/articles/s41567-022-01658-0

Horizontal Gene Transfer Happens More Often Than Anyone Thought

DNA passed to and from all kinds of organisms, even across kingdoms, has helped shape the tree of life, to a large and undisputed degree in microbes and also unexpectedly in multicellular fungi, plants, and animals.

https://www.the-scientist.com/features/horizontal-gene-transfer-hap...

SARS-CoV-2 Could Use Nanotubes to Infect the Brain

While the study did show a potential way that neurons could be infected, the researchers didn’t show evidence that ACE2-positive cells could infect the types of epithelial cells that compose the blood-brain barrier. They also didn’t directly show that blood-brain barrier cells could form TNTs and transfer the virus to neurons. “Are blood-brain barrier cells capable of inducing these bridges?” scientists now will have to answer this Q.

Tunneling nanotubes provide a route for SARS-CoV-2 spreading

https://www.science.org/doi/10.1126/sciadv.abo0171

https://www.the-scientist.com/news-opinion/sars-cov-2-could-use-nan...

Part 2

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Engineering team develops process to make implants safer

An interdisciplinary team of researchers have developed a new plasma-enabled process that could limit the proliferation of toxins from implants into a patient's bloodstream. 

In their published paper,  the authors explain that a major challenge of developing nanoparticle-modified biomedical implant material is to stably attach metallic nanoparticles on different surfaces—particularly polymer surfaces.

For years, scientists have achieved synthesis of metallic nanoparticles in aqueous solutions using both chemical and biological (plant extracts) reducing agents. The challenge of attaching metallic nanoparticles is especially difficult in cases involving hydrophobic polymeric biomaterials, which most polymeric biomaterials fall under.

To address this challenge, Thomas and his team developed a plasma-enabled process called plasma electroless reduction. The PER process allows researchers to deposit gold and silver nanostructures on different 2D and 3D polymer material surfaces, such as cellulose paper, polypropylene-based facemasks and 3D printed polymer scaffolds.

It is well known that there are toxicity issues offered by the rapid and premature release of the metallic nanostructures from the implant material into the bloodstream. This issue could be addressed only by ensuring the stable anchoring of the metallic nanostructures on implant surfaces. This has inspired us to optimize our PER process by conducting systematic and in-depth investigation of concentration of the metallic precursor followed by sonication wash before cell culture in vitro.

The team  was able to successfully anchor silver nanoparticles on the surface of 3D printed polymers without any rapid release into the surroundings. The team's additive manufacturing expertise also allowed them to design smaller 3D scaffold wafers that will fit into the well of a 96-well plate.

This systematic optimization of making uniform metal nanostructures on 3D scaffolds with cytocompatibility and potential antibacterial properties will be highly relevant and can potentially make an impact on the future development of biocompatible scaffolds, especially for osteomyelitis disease.

Vineeth M. Vijayan et al, Plasma Electroless Reduction: A Green Process for Designing Metallic Nanostructure Interfaces onto Polymeric Surfaces and 3D Scaffolds, ACS Applied Materials & Interfaces (2022). DOI: 10.1021/acsami.2c01195

How Climate Patterns Thousands of Miles Away Affect US Bird Migration

Scientists blunt the impact of natural killer cells to improve vaccine effectiveness

Scientists have discovered that the body's own natural killer cells can suppress the immune benefits of therapeutic vaccines, a problem that can affect inoculations against chronic viral infections and cancer.

Indeed, the scientific literature is replete with examples of otherwise effective vaccines sometimes proving impotent. Increasingly, the reasons are pointing to an enemy within the body itself: a friend that transforms into a foe.

Scientists have been investigating the conundrum and have turned to an animal model to decipher how natural killer cells inadvertently blunt the benefits of vaccines.

In Science Translational Medicine, researchers report that natural killer cells can react so overwhelmingly after vaccination that they negatively impact a critical constituent of the immune response—CD8+T cells. This vital population can become overworked and exhausted, they found, a phenomenon that causes vaccination to have little effectiveness.

Therapeutic vaccines for chronic infections have reduced efficacy because of the presence of exhausted T cells and [an] environment that limits vaccine response. The problem invariably begins with the aggression of natural killer cells.

Working with a mouse model, scientists have found that a combination treatment can boost robust immune responses after vaccination by acting on natural killer cells. The strategy, the team said, may eventually prove useful in the design and improvement of therapeutic vaccines for chronic viral infections and cancers.

Mariana O. Diniz et al, NK cells limit therapeutic vaccine–induced CD8 + T cell immunity in a PD-L1–dependent manner, Science Translational Medicine (2022). DOI: 10.1126/scitranslmed.abi4670

Researchers identify how cells move faster through mucus than blood

Researchers  have discovered that certain cells move surprisingly faster in thicker fluid—think honey as opposed to water, or mucus as opposed to blood—because their ruffled edges sense the viscosity of their environment and adapt to increase their speed.

Their combined results in cancer and fibroblast cells—the type that often creates scars in tissues—suggest that the viscosity of a cell's surrounding environment is an important contributor to disease, and may help explain tumor progression, scarring in mucus-filled lungs affected by cystic fibrosis, and the wound-healing process.

The study, "Membrane ruffling is a mechanosensor of extracellular fluid viscosity," published today in Nature Physics, sheds new light on cell environments, an under-explored area of research.

The study found that the thicker the surrounding environment, the stronger the cells adhere to the substrate and the faster they move—much like walking on an icy surface with shoes that have spikes, versus shoes with no grip at all.

Jian Liu, Membrane ruffling is a mechanosensor of extracellular fluid viscosity, Nature Physics (2022). DOI: 10.1038/s41567-022-01676-y. www.nature.com/articles/s41567-022-01676-y

Natural clean-up: Bacteria can remove plastic pollution from lakes

A study of 29 European lakes has found that some naturally-occurring lake bacteria grow faster and more efficiently on the remains of plastic bags than on natural matter like leaves and twigs.

The bacteria break down the carbon compounds in plastic to use as food for their growth.

The scientists say that enriching waters with particular species of bacteria could be a natural way to remove plastic pollution from the environment.

The effect is pronounced: the rate of bacterial growth more than doubled when plastic pollution raised the overall carbon level in lake water by just 4%.

The results suggest that the plastic pollution in lakes is 'priming' the bacteria for rapid growth— the bacteria are not only breaking down the plastic but are then more able to break down other natural carbon compounds in the lake.

Lake bacteria were found to favor plastic-derived carbon compounds over natural ones. The researchers think this is because the carbon compounds from plastics are easier for the bacteria to break down and use as food.

The scientists caution that this does not condone ongoing plastic pollution. Some of the compounds within plastics can have toxic effects on the environment, particularly at high concentrations.

Eleanor Sheridan, Plastic pollution fosters more microbial growth in lakes than natural organic matter, Nature Communications (2022). DOI: 10.1038/s41467-022-31691-9. www.nature.com/articles/s41467-022-31691-9

Research breakthrough in mystery child hepatitis

Researchers reported a breakthrough this week in mysterious hepatitis cases affecting young children, finding the serious liver condition was linked to co-infection of two common viruses, but not the coronavirus.

The World Health Organization (WHO) has reported at least 1,010 probable cases, including 46 that required transplants and 22 deaths from the illness dating back to last October.

Previous theories had centered on a spike in commonly found adenovirus infections being behind the cases.

But in two new studies carried out independently and simultaneously in Scotland and London, scientists found another virus, AAV2 (adeno-associated virus 2) played a significant role and was present in 96 percent of all patients examined.

AAV2 is not normally known to cause disease and cannot replicate itself without another "helper" virus being present.

Both teams concluded that co-infection with either AAV2 and an adenovirus, or sometimes the herpes virus HHV6, offered the best explanation for the severe liver disease.

The presence of the AAV2 virus is associated with unexplained hepatitis in children. also cautioned it was not yet certain whether AAV2 was causing the disease or was rather a biomarker for underlying adenovirus infection that is harder to detect but was the main pathogen.

Both papers have been posted online to "preprint" servers and still await peer review before they are published in journals.

https://media.gosh.nhs.uk/documents/MEDRXIV-2022-277963v1-Breuer.pdf

https://www.medrxiv.org/content/10.1101/2022.07.19.22277425v1

https://medicalxpress.com/news/2022-07-breakthrough-mystery-child-h...

FNDs

Scientists discover new 'origins of life' chemical reactions

Four billion years ago, the Earth looked very different than it does today, devoid of life and covered by a vast ocean. Over the course of millions of years, in that primordial soup, life emerged. Researchers have long theorized how molecules came together to spark this transition. Now, scientists have discovered a new set of chemical reactions that use cyanide, ammonia and carbon dioxide—all thought to be common on the early earth—to generate amino acids and nucleic acids, the building blocks of proteins and DNA.

In addition to giving researchers insight into the chemistry of the early earth, the newly discovered chemical reactions are also useful in certain manufacturing processes, such as the generation of custom labeled biomolecules from inexpensive starting materials.

Because the new reaction is relatively similar to what occurs today inside cells—except for being driven by cyanide instead of a protein—it seems more likely to be the source of early life, rather than drastically different reactions, the researchers say. The research also helps bring together two sides of a long-standing debate about the importance of carbon dioxide to early life, concluding that carbon dioxide was key, but only in combination with other molecules.

In the process of studying their chemical soup, the researchers discovered that a byproduct of the same reaction is orotate, a precursor to nucleotides that make up DNA and RNA. This suggests that the same primordial soup under the right conditions, could have given rise to a large number of the molecules that are required for the key elements of life.

 Ramanarayanan Krishnamurthy, Prebiotic synthesis of α-amino acids and orotate from α-ketoacids potentiates transition to extant metabolic pathways, Nature Chemistry (2022). DOI: 10.1038/s41557-022-00999-w. www.nature.com/articles/s41557-022-00999-w

Part 1

Earlier this year, Krishnamurthy's group showed how cyanide can enable the chemical reactions that turn prebiotic molecules and water into basic organic compounds required for life. Unlike previously proposed reactions, this one worked at room temperature and in a wide pH range. The researchers wondered whether, under the same conditions, there was a way to generate amino acids, more complex molecules that compose proteins in all known living cells.

In cells today, amino acids are generated from precursors called α-keto acids using both nitrogen and specialized proteins called enzymes. Researchers have found evidence that α-keto acids likely existed early in Earth's history. However, many have hypothesized that before the advent of cellular life, amino acids must have been generated from completely different precursors, aldehydes, rather than α-keto acids, since enzymes to carry out the conversion did not yet exist. But that idea has led to debate about how and when the switch occurred from aldehydes to α-keto acids as the key ingredient for making amino acids.

After their success using cyanide to drive other chemical reactions, Krishnamurthy and his colleagues suspected that cyanide, even without enzymes, might also help turn α-keto acids into amino acids. Because they knew nitrogen would be required in some form, they added ammonia—a form of nitrogen that would have been present on the early earth. Then, through trial and error, they discovered a third key ingredient: carbon dioxide. With this mixture, they quickly started seeing amino acids form.

If you mix only the keto acid, cyanide and ammonia, it just sits there. As soon as you add carbon dioxide, even trace amounts, the reaction picks up speed.

Part 2

Engineers develop stickers that can see inside the body

Ultrasound imaging is a safe and noninvasive window into the body's workings, providing clinicians with live images of a patient's internal organs. To capture these images, trained technicians manipulate ultrasound wands and probes to direct sound waves into the body. These waves reflect back out to produce high-resolution images of a patient's heart, lungs, and other deep organs.

Currently, ultrasound imaging requires bulky and specialized equipment available only in hospitals and doctor's offices. But a new design by MIT engineers might make the technology as wearable and accessible as buying Band-Aids at the pharmacy.

In a paper appearing recently in Science, the engineers present the design for a new ultrasound sticker—a stamp-sized device that sticks to skin and can provide continuous ultrasound imaging of internal organs for 48 hours.

The researchers applied the stickers to volunteers and showed the devices produced live, high-resolution images of major blood vessels and deeper organs such as the heart, lungs, and stomach. The stickers maintained a strong adhesion and captured changes in underlying organs as volunteers performed various activities, including sitting, standing, jogging, and biking.

The current design requires connecting the stickers to instruments that translate the reflected sound waves into images. The researchers point out that even in their current form, the stickers could have immediate applications: For instance, the devices could be applied to patients in the hospital, similar to heart-monitoring EKG stickers, and could continuously image internal organs without requiring a technician to hold a probe in place for long periods of time.

If the devices can be made to operate wirelessly—a goal the team is currently working toward—the ultrasound stickers could be made into wearable imaging products that patients could take home from a doctor's office or even buy at a pharmacy.

Chonghe Wang et al, Bioadhesive ultrasound for long-term continuous imaging of diverse organs, Science (2022). DOI: 10.1126/science.abo2542. www.science.org/doi/10.1126/science.abo2542

Philip Tan et al, Seeing inside a body in motion, Science (2022). DOI: 10.1126/science.adc8732. www.science.org/doi/10.1126/science.adc8732

Alarm as Earth hits 'Overshoot Day' Thursday: NGOs

Mankind marks a dubious milestone Thursday (yesterday), the day by which humanity has consumed all earth can sustainably produce for this year, with NGOS warning the rest of 2022 will be lived in resource deficit.

The date—dubbed "Earth Overshoot Day"—marks a tipping point when people have used up "all that ecosystems can regenerate in one year", according to the Global Footprint Network and WWF.

From January 1 to July 28, humanity has used as much from nature as the planet can renew in the entire year. That's why this July 28 is Earth Overshoot Day.

The Earth has a lot of stock, so we can deplete Earth for some time but we cannot overuse it for ever. It's like with money; we can spend more than we earn for some time until we're broke."

It would take 1.75 Earths to provide for the world's population in a sustainable way, according to the measure, which was created by researchers in the early 1990s.

Global Footprint Network said Earth Overshoot Day has fallen ever sooner over the last 50 years.

Source: News Agencies

Promising evidence of deuterium forming into a metallic state at high pressure

A trio of researchers at the French Alternative Energies and Atomic Energy Commission has shown promising evidence of deuterium forming into a metallic state at high pressure. In their paper published in the journal Physical Review Letters, researchers describe the process they used to pressurize a deuterium sample and test it for a transition state. Theory suggests that all elements should transition to a metallic state if subjected to strong enough pressure. This is because at some point, their electrons will become delocalized. But modeling, much less demonstrating, such transition points has proven to be difficult. Early research looking for the transition state of hydrogen led to theories that it would reach a metallic state when hydrogen molecules disassociated completely. That led to many efforts to see if such theories were true—sadly, none were successful. Then in 2000, a team at Cornell University calculated that hydrogen should transition at 410 GPa. In 2020, the researchers of the current study used a diamond anvil cell to compress a sample of hydrogen to 425 GPa and used synchrotron infrared absorption and Raman spectroscopy to measure the band gap of the material. They found a sudden drop from 0.6eV to 0.1eV at 80K, comprising promising evidence of hydrogen forming into a metallic state as theorized. A short time later, physicist Alexander Goncharov suggested that transitions should happen more easily under conditions where quantum motion could allow for some atoms to tunnel from one place to another. Noting that deuterium nuclei are heavier than hydrogen, the researchers reasoned that they should be less delocalized than protons and thus should require more pressure to transition. To find out if that was the case, the team reran their 2020 effort, only this time, they used deuterium instead of hydrogen. They found the band gap decreased in ways similar to the hydrogen experiment, but it did so at 460 GPa, possibly confirming the theory. The researchers noted that they also saw nothing that would indicate molecular disassociation had occurred in either experiment.

Paul Loubeyre et al, Compression of D2 to 460 GPa and Isotopic Effects in the Path to Metal Hydrogen, Physical Review Letters (2022). DOI: 10.1103/PhysRevLett.129.035501

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Just add water to activate a disposable paper battery

A water-activated disposable paper battery is presented in a proof-of-principle study in Scientific Reports. The authors suggest that it could be used to power a wide range of low-power, single-use disposable electronics—such as smart labels for tracking objects, environmental sensors and medical diagnostic devices—and minimize their environmental impact. The battery, devised by Gustav Nyström and colleagues, is made of at least one cell measuring one centimeter squared and consisting of three inks printed onto a rectangular strip of paper. Sodium chloride salt is dispersed throughout the strip of paper and one of its shorter ends has been dipped in wax. An ink containing graphite flakes, which acts as the positive end of the battery (cathode), is printed onto one of the flat sides of the paper while an ink containing zinc powder, which acts as the negative end of the battery (anode), is printed onto the reverse side of the paper. Additionally, an ink containing graphite flakes and carbon black is printed on both sides of the paper, on top of the other two inks. This ink connects the positive and negative ends of the battery to two wires, which are located at the wax-dipped end of the paper. When a small amount of water is added, the salts within the paper dissolve and charged ions are released. These ions activate the battery by dispersing through the paper, resulting in zinc in the ink at the negative end of the battery releasing electrons. Attaching the wires to an electrical device closes the circuit so that electrons can be transferred from the negative end—via the graphite and carbon black-containing ink, wires and device—to the positive end (the graphite-containing ink) where they are transferred to oxygen in the surrounding air. These reactions generate an electrical current that can be used to power the device.

Part 1

To demonstrate the ability of their battery to run low-power electronics, the authors combined two cells into one battery and used it to power an alarm clock with a liquid crystal display. Analysis of the performance of a one-cell battery revealed that after two drops of water were added, the battery activated within 20 seconds and, when not connected to an energy-consuming device, reached a stable voltage of 1.2 volts. The voltage of a standard AA alkaline battery is 1.5 volts. After one hour, the one-cell battery's performance decreased significantly due to the paper drying. However, after two more drops of water were added, it maintained a stable operating voltage of 0.5 volts for more than one additional hour.

The authors propose that the biodegradability of paper and zinc could enable their battery to minimize the environmental impact of disposable, low-power electronics. They suggest that the sustainability of the battery can be further increased by minimizing the amount of zinc used within the ink, which also allows the amount of electricity the battery generates to be precisely controlled.

Gustav Nyström, Water activated disposable paper battery, Scientific Reports (2022). DOI: 10.1038/s41598-022-15900-5. www.nature.com/articles/s41598-022-15900-5

Part 2

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Scientists confirm COVID tied to wildlife sales at Chinese market

An international team of researchers has confirmed that live animals sold at the Huanan Seafood Wholesale Market were the likely source of the COVID-19 pandemic that has claimed 6.4 million lives since it began nearly three years ago.

“Rigorously combining all available evidence surrounding the emergence of SARS-CoV-2 clearly demonstrates that the virus jumped at least twice from animals to humans at the Huanan market,” said Dr. Marc Suchard, UCLA Fielding School of Public Health professor of biostatistics. “Identifying multiple transmission events finally puts to rest a single origin from elsewhere.”

Co-led by Suchard and Dr. Michael Worobey (University of Arizona), Dr. Joel Wertheim (UCSD) and Dr. Kristian Andersen (Scripps Research Institute), international teams of researchers have traced the start of the pandemic to the market in Wuhan, China, where foxes, raccoon dogs, and other live mammals susceptible to the virus were sold immediately before the pandemic began. Their findings were published Tuesday in two peer-reviewed papers in the journal Science, after being previously released in pre-print versions in February.

The publications, which have since gone through peer review and include additional analyses and conclusions, virtually eliminate alternative scenarios that have been suggested as origins of the pandemic. Moreover, the authors conclude that the first spread to humans from animals likely occurred in two separate transmission events in the Huanan market in late November 2019.

One study – “The Huanan Seafood Wholesale Market in Wuhan was the early epicenter of the COVID-19 pandemic” - scrutinized the locations of the first known COVID-19 cases, as well as swab samples taken from surfaces at various locations at the market. The other – “The molecular epidemiology of multiple zoonotic origins of SARS-CoV-2” - focused on genomic sequences of SARS-CoV-2 from samples collected from COVID-19 patients during the first weeks of the pandemic in China.

Along with Suchard, a physician who also teaches at the David Geffen School of Medicine at UCLA, UCLA post-doctoral scholars Andrew Magee and Karthik Gangavarapu co-authored this work.

The first paper examined the geographic pattern of COVID-19 cases in the first month of the outbreak, December 2019. The team was able to determine the locations of almost all of the 174 COVID-19 cases identified by the World Health Organization that month, 155 of which were in Wuhan.

Analyses showed that these cases were clustered tightly around the Huanan market, whereas later cases were dispersed widely throughout Wuhan – a city of 11 million people. Notably, the researchers found that a striking percentage of early COVID patients with no known connection to the market – meaning they neither worked there nor shopped there – turned out to live close-by.

Part 1

Fossil-fuel emissions hamper carbon dating

The burning of fossil fuels has officially shifted the composition of carbon isotopes in the air of the Northern Hemisphere enough to cancel out a useful signal from nuclear-weapons testing. This could cause a headache for archaeologists, because modern items now look like objects from the early twentieth century in terms of radiocarbon dating. The development means that forensic scientists will no longer be able to use radiocarbon fingerprints to pinpoint the ages of materials such as ivory, antiques and wine. “If you’re working in forensics or detecting fakes, this is a really sad moment.

Carbon dating hampered by rising fossil-fuel emissions

How soft sounds might dull pain in mice

Scientists engineer DNA 'receipt book' to store cells' history

New evidence hints at the role of gut microbiota in autistic spectrum disorder

Autism spectrum disorder (ASD) is a neurological and developmental condition that affects how humans communicate, learn new things and behave. Symptoms of ASD can include difficulties in interacting with others and adapting to changes in routine, repetitive behaviors, irritability and restricted or fixated interests for specific things.

While symptoms of autism can emerge at any age, the first signs generally start to show within the first two years of a child's life. People with ASD can encounter numerous challenges, which can be addressed through support services, talk therapy and sometimes medication.

To this day, neuroscientists and medical researchers have not identified the primary causes of ASD. Nonetheless, past findings suggest that it could be caused by the interaction of specific genes with environmental factors.

Interestingly, recent neuroscience studies have found that the biological makeup of the gut could contribute to some of the most characteristic symptoms of ASD. More specifically, experiments on mice suggest that the pathway between gut bacteria  and the central nervous system can affect social behaviors.

Building on previous findings, researchers at University of Rome 'Tor Vergata' and University of Calabria have recently carried out a new study on mice, investigating the effects of transplanting fecal microbiota gathered from autistic donors to mice. Their results, published in Neuroscience, provide further evidence that links gut microbiota with social behaviors typical of ASD.

Scientists examined two different groups of mice. Mice in the first group (i.e., the experimental group) received transplanted microbiota originating from the gut of children with ASD, while mice in the other (i.e., the control group) were exposed to VPA, a synthetic compound with anticonvulsant properties, while in their mothers' wounds.

Contextually, FMT accounted for elevated expression levels of the pro-inflammatory factors IL-1β, IL-6, COX-1 and TNF-α in both brain and small intestine.

observed that the mice who received the ASD microbiota exhibited unusual behaviors while completing different maze tests that are widely used in neuroscience studies. Their behaviors could be linked to those observed in children and adults with ASD.

The recent findings gathered by this team of researchers seem to confirm previous results in the field, suggesting that gut microbiota can indeed play a role in social behaviors. In the future, they could inspire new research in this area and contribute to the testing and gradual introduction of treatments for autism that also consider diet and gut health.

Modifications of behavior and inflammation in mice following transplant with fecal microbiota from children with autism. Neuroscience(2022). DOI: 10.1016/j.neuroscience.2022.06.038.

Why people struggle to recognise the faces of people from different racial backgrounds

Cognitive psychologists think they have discovered the answer to a 60-year-old question as to why people find it more difficult to recognize faces from visually distinct racial backgrounds than they do their own.

This phenomenon named the other-race effect (ORE) was first discovered in the 1960s and has consistently been demonstrated through the face inversion effect (FIE) paradigm, where people are tested with pictures of faces presented in their usual upright orientation and inverted upside down. Such experiments have consistently shown that the FIE is larger when individuals are presented with faces from their own race as opposed to other race faces. It has prompted decades of debate as to the underlying factors, with social scientists historically taking the view that it's indicative of how people are less motivated to engage and differentiate members of other races, thus leading to a weaker memory for them. Cognitive scientists, on the other hand, propose that it is based on the comparative lack of visual experience that people have with other-race individuals, which then results in reduced perceptual expertise with other-race faces. Now, a team in the Department of Psychology at Exeter, using direct electrical current brain stimulation, has found that the ORE would appear to be caused by a lack of cognitive visual expertise and not by social bias.

Published in the journal Scientific Reports, the research was conducted at Exeter's Washington Singer Laboratories, and used a non-invasive transcraniaL direct current stimulation (tDCS) procedure, specifically formulated to impair a person's ability to recognize upright faces. This was applied to the participants' dorsolateral prefrontal cortex, via a pair of sponges attached to their scalp.

Ciro Civile et al, Transcranial direct current stimulation (tDCS) eliminates the other-race effect (ORE) indexed by the face inversion effect for own versus other-race faces, Scientific Reports (2022). DOI: 10.1038/s41598-022-17294-w

Phantom vibration syndrome

Scientists reveal how detergents actually work
Scientists have discovered the precise way detergents break biological membranes, which could increase our understanding of how soaps work to kill viruses like COVID-19.
Detergents play a role in everyday life, from removing tough stains and cleaning messy hands to fixing sticky locks. On the nanoscale, they are extremely destructive, and only a few droplets in water can rupture and kill living organisms. This property has led to their widespread use and many soap formulations have been developed to kill disease-carrying viruses, including COVID-19.
Understanding the precise molecular-level mechanisms through which detergents work may help us better design antiviral agents that can combat disease at the earliest possible stage.
For the study, the scientists looked at the detergent Tween-20, which is a key protective ingredient in many products such as handwashes.Detergent molecules like Tween-20 are shaped like an ice cream cone. At the top of the cone is a region that interacts strongly with water, and at the bottom a group of atoms repel water and form a pointed tail. When you wash your hands with soap, an army of detergent molecules surround the bacteria and viruses on your skin, and in an attempt to escape the surrounding water, they scurry towards and bombard them, tails first, squeezing their membrane envelopes and breaking them apart.The chemical properties of detergents have been studied in detail, but until now the precise, molecular level details of the interaction have been difficult to assess because of a lack of tools and techniques capable of capturing the entire process.Researchers  have now developed a series of methods to try and learn more about these important interactions. They  created a series of highly-controllable membrane balls, and they used a molecular nanoruler known as single-molecule FRET (fluorescence resonance energy transfer), to measure how constituents of the membranes move apart during their interaction with detergents.They discovered that after Tween-20 binds to the membranes, the balls expand significantly and pores form on their surface before they completely fragment.To confirm their findings, the researchers used computer simulations to model how the membranes evolved.The experimental results from different approaches matched up extremely well, and the molecular dynamics simulations allowed scientists to extract otherwise hidden physics governing the process.
Lara Dresser et al, Tween-20 Induces the Structural Remodeling of Single Lipid Vesicles, The Journal of Physical Chemistry Letters (2022). DOI: 10.1021/acs.jpclett.2c00704

Researchers discover one of the largest known bacteria-to-animal gene transfers inside a fruit flyA fruit fly genome is not just made up of fruit fly DNA—at least for one fruit fly species. New research shows that one fruit fly species contains whole genomes of a kind of bacteria, making this finding the largest bacteria-to-animal transfer of genetic material ever discovered. The new research also sheds light on how this happens.
Scientists used new genetic long-read sequencing technology to show how genes from the bacteria Wolbachia incorporated themselves into the fly genome up to 8,000 years ago.The researchers say their findings show that unlike Darwin's finches or Mendel's peas, genetic variation isn't always small, incremental, and predictable.In addition to the long reads, the researchers validated junctions between integrated bacteria genes and the host fruit fly genome. To determine if the bacteria genes were functional and not just DNA fossils, the researchers sequenced the RNA from fruit flies specifically looking for copies of RNA that were created from templates of the inserted bacterial DNA. They showed the bacteria genes were encoded into RNA and were edited and rearranged into newly modified sequences indicating that the genetic material is functional.
An analysis of the unique sequences revealed that the bacteria DNA integrated into the fruit fly genome in the last 8,000 years—exclusively within chromosome 4—expanding the chromosome size by making up about 20 percent of chromosome 4. Whole bacterial genome integration supports a DNA-based rather than an RNA-based mechanism of integration.
They also found nearly a complete second genome and much more with almost 10 copies of some bacterial genome regions.
Wolbachia is an intracellular bacteria that infects numerous types of insects. Wolbachia transmits its genes maternally through female egg cells. Some research has showed that these infections are more mutualistic than parasitic, giving insects advantages, such as resistance to certain viruses.

Eric S. Tvedte et al, Accumulation of endosymbiont genomes in an insect autosome followed by endosymbiont replacement, Current Biology (2022). DOI: 10.1016/j.cub.2022.05.024

Salt in sea spray found to be the reason for less lightning over tropical oceans

Novel Antibiotic kills bacteria via a new two-step mechanism

 Bioscientists use mixed-reality headset, custom software to measure vegetation in the field

How the genome is packed into chromosomes that can be faithfully moved during cell division

Researchers discovered a molecular mechanism that confers special physical properties to chromosomes in dividing human cells to enable their faithful transport to the progeny. They showed how a chemical modification establishes a sharp surface boundary on chromosomes, thus allowing them to resist perforation by microtubules of the spindle apparatus. The findings are published in the journal Nature.

When cells divide, they need to transport exactly one genome copy to each of the two daughter cells. Faithful genome segregation requires the packaging of extremely long chromosomal DNA molecules into discrete bodies so that they can be efficiently moved by the mitotic spindle, a filament system composed of thousands of microtubules. The new findings shed light on how mitotic chromosomes resist the constant pushing and pulling forces generated by the microtubules. Amidst this complex system, the distinct physical properties are conferred to the chromosomes by changing the levels of histone acetylation, a chemical modification within the chromatin fiber.
Prior work had shown that, in dividing cells, the chromatin fibers are folded into loops by a large protein complex called condensin. However, the role of condensin alone could not explain why chromosomes appear as dense bodies with a sharp surface rather than a loose structure resembling a bottlebrush. Some studies had suggested a role of histone acetylation in regulating the level of compaction during cell division, but the interplay of histone acetylation with condensin and its functional relevance remained unclear. This new work is now able to conceptually disentangle the two mechanisms.
The team varied the levels of condensin and histone acetylation to study their precise effects. Removing condensin disrupted the elongated shape of chromosomes in dividing cells and lowered their resistance to pulling forces but did not affect their level of compaction. Combining condensin depletion with a treatment that increases the levels of histone acetylation caused massive chromatin decompaction in dividing cells, and perforation of chromosomes by microtubules.

The researchers hypothesized that chromatin is organized as a swollen gel throughout most of the cell cycle (when it is relatively highly acetylated) and that this gel compacts to an insoluble form during cell division when the acetylation levels globally decrease. They then developed an assay to probe the solubility of chromatin by fragmenting mitotic chromosomes into small pieces. The fragments of mitotic chromosomes formed droplets of liquid chromatin, but when the acetylation level was increased, the chromatin fragments dissolved in the cytoplasm. These observations support a model where a global reduction of chromatin acetylation during mitosis establishes an immiscible chromatin gel with a sharp phase boundary, providing a physical basis for resistance against microtubule perforation.
With further experiments involving pure chromatin that was reconstituted in vitro, and by probing chromatin access by various soluble macromolecules, the team found that immiscible chromatin forms a structure dense in negative charge that excludes negatively charged macromolecules and microtubules. This study shows how DNA looping by the condensin complex cooperates with a chromatin phase separation process to build mitotic chromosomes that resist both pulling and pushing forces exerted by the spindle. The deacetylation of histones during cell division hence confers unique physical properties to chromosomes that are required for their faithful segregation.
Daniel Gerlich, A mitotic chromatin phase transition prevents perforation by microtubules, Nature (2022). DOI: 10.1038/s41586-022-05027-y. www.nature.com/articles/s41586-022-05027-y

Sterile mice produce rat sperm

Researchers generated rat sperm cells inside sterile mice using a technique called blastocyst complementation. The advance appears August 4 in the journal Stem Cell Reports.
This new study shows that scientists can use sterile animals as hosts for the generation of germ cells from other animal species.
Aside from a conceptual advancement, this notion can be utilized to produce endangered animal species gametes inside more prevalent animals. Other implications may involve an improved method to produce rat transgenic models for biomedical research.
Pluripotent stem cells (PSCs) provide a powerful tool for biomedical research, but the generation of gametes in the form of eggs or sperm cells from PSCs is a highly challenging endeavor. In prior studies, researchers used a technique called blastocyst complementation to generate rat organs in mice using PSCs and mutated mouse embryos that cannot produce specific organs. Building on this work, Bar-Nur and his collaborators wondered whether it would be possible to generate rat sperm inside mice that carry a genetic mutation that otherwise renders them sterile.

To test this idea, the researchers injected rat PSCs into mouse embryos to produce mouse-rat chimeras. An essential gene for sperm production was mutated in the mouse blastocysts. The rat stem cells developed together with the mouse cells, thereby generating a chimeric animal composed of genotypes from the two species. As a consequence of the genetic sterility-inducing mutation, an empty niche developed inside the testes, which enabled the rat cells to colonize them and exclusively generate rat sperm in mouse-rat chimeras. The sperm cells could fertilize rat egg cells, but the embryos did not develop normally or give rise to live offspring.

The interesting thing observed in this study was that all the sperm cells inside the chimeras were of rat origin. As such, the mouse host environment, which was sterile due to a genetic mutation, was still able to support efficient sperm cell production from a different animal species.

Although the researchers were able to generate rat sperm cells that morphologically appeared indistinguishable from normal rat sperm cells, these cells were immotile and the fertilization rates of rat eggs was significantly lower in comparison to rat sperm cells produced in rats. Nonetheless, the work provides a proof-of-principle that one can generate sperm cells of one animal species in another by mixing the two species in an artificially generated organism called a chimera. Using sterile mice for genetically modified rat PSCs may speed up the production of transgenic rats to model human diseases in biomedical research.

Ori Bar-Nur, Exclusive generation of rat spermatozoa in sterile mice utilizing blastocyst complementation with pluripotent stem cells, Stem Cell Reports (2022). DOI: 10.1016/j.stemcr.2022.07.005. www.cell.com/stem-cell-reports … 2213-6711(22)00364-2

Early-life acquisition of antimicrobial resistance in newborn children from low- and middle-income countries
Every year, almost 7 million potentially serious bacterial infections are estimated to occur in newborns, resulting in more than 550,000 annual neonatal deaths. Most of these infections and deaths happen in LMICs, where often scarce resources can limit the capacity to diagnose and treat sepsis. These problems are further complicated by the global rise of antimicrobial resistance (AMR), particularly the rapid spread of gram-negative bacteria that are resistant to antibiotics—including Klebsiella pneumoniae, Escherichia coli, and Enterobacter cloacae that are no longer susceptible to ß-lactam antibiotics, such as ampicillin and ceftazidime. AMR is already estimated to account for approximately 5 million deaths a year worldwide, and has been predicted to result in 10 million annual deaths by 2050.
Despite neonatal sepsis representing such a major health problem in LMICs, it is still unclear how, when, and where newborn babies acquire life-threatening infections. Furthermore, the factors associated with the presence of AMR in these cases are also still being elucidated. For example, there have been no studies in LMICs examining whether the presence of antibiotic-resistant bacteria in mothers is linked to the development of sepsis in their newborns.

In a new study published in Nature Microbiology, scientists decided to look at the presence of antibiotic resistance genes (ARGs) in the gut microbiota—the collection of microbes that are present in the human gut—of mothers and their babies from 7 LMICs in Africa and South Asia. As part of the "Burden of Antibiotic Resistance in Neonates from Developing Societies" study, or BARNARDS—a network of 12 clinical sites across Bangladesh, Ethiopia, India, Nigeria, Pakistan, Rwanda and South Africa—they recruited 35,040 mothers and 36,285 neonates. From these, they collected 18,148 rectal swabs (15,217 from mothers and 2,931 from neonates, including 626 with sepsis), which were used to grow the bacteria present in these samples and assess the presence of clinically important ARGs in the microbiota of mothers and their babies. The authors found that a large number of samples carried genes linked to antibiotic resistance, suggesting that AMR is far more widespread in these settings than previously anticipated.

For example, samples from around 1 in 5 neonates (18.5%) were positive for blaNDM, a gene that encodes New Delhi metallo-beta-lactamase, which is an enzyme that can destroy ß-lactam antibiotics including the commonly used carbapenems, resulting in the bacteria being resistant against this drug. Importantly, the researchers found that ARGs were present in neonates within hours of birth, indicating that initial colonization of the newborns with antibiotic-resistant bacteria occurred at birth or soon after, likely through contact with the mother or from the hospital environment.

Maria Carvalho, Antibiotic resistance genes in the gut microbiota of mothers and linked neonates with or without sepsis from low- and middle-income countries, Nature Microbiology (2022). DOI: 10.1038/s41564-022-01184-y. www.nature.com/articles/s41564-022-01184-y

Israeli scientists create the world's first 'Artificial Embryos' 

Robotic motion in curved space defies standard laws of physics

When humans, animals, and machines move throughout the world, they always push against something, whether it's the ground, air, or water. Until recently, physicists thought this to be a constant, following the law of conservation momentum. Now, researchers have proven the opposite—when bodies exist in curved spaces, it turns out that they can in fact move without pushing against something.

The findings were published in Proceedings of the National Academy of Sciences on July 28, 2022. In the paper, a team of researchers created a robot confined to a spherical surface with unprecedented levels of isolation from its environment, so that these curvature-induced effects would predominate.

The researchers found that as the robot changed its shape, it inched forward around the sphere in a way that could not be attributed to environmental interactions.

The researchers set out to study how an object moved within a curved space. To confine the object on the sphere with minimal interaction or exchange of momentum with the environment in the curved space, they let a set of motors drive on curved tracks as moving masses. They then connected this system holistically to a rotating shaft so that the motors always move on a sphere. The shaft was supported by air bearings and bushings to minimize the friction, and the alignment of the shaft was adjusted with the Earth's gravity to minimize the residual force of gravity.

From there, as the robot continued to move, gravity and friction exerted slight forces on it. These forces hybridized with the curvature effects to produce a strange dynamic with properties neither could induce on their own. The research provides an important demonstration of how curved spaces can be attained and how it fundamentally challenges physical laws and intuition designed for flat space. 

While the effects are small, as robotics becomes increasingly precise, understanding this curvature-induced effect may be of practical importance, just as the slight frequency shift induced by gravity became crucial to allow GPS systems to accurately convey their positions to orbital satellites. Ultimately, the principles of how a space's curvature can be harnessed for locomotion may allow spacecraft to navigate the highly curved space around a black hole.

Also because spacetime is very slightly curved, a device could actually move forward without any external forces or emitting a propellant—a novel discovery.

Shengkai Li et al, Robotic swimming in curved space via geometric phase, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2200924119

Dry lightning is cloud-to-ground (CG) lightning without any accompanied rainfall nearby.

Dry lightning sparks some of the most destructive and costly wildfires in California, study finds

A new study has found dry lightning outbreaks are the leading cause of some of the largest wildfire outbreaks in modern California history.

Researchers have developed the first long-term climatology of dry lightning—lightning which occurs with less than 2.5 mm of rainfall.

They found that moisture and instability high in the atmosphere—above a hot, dry, lower atmosphere—were key drivers of dry lightning across all regions in central and northern California and that widespread dry lightning outbreaks can occur anytime between May–October, even in "quiet" years for lightning activity.

Meteorological and geographical factors associated with dry lightning in central and northern California, Environmental Research: Climate (2022) DOI: 10.1088/2752-5295/ac84a0

https://phys.org/news/2022-08-lightning-destructive-costly-wildfire...

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Chances of climate catastrophe are ignored, scientists say

Experts are ignoring the worst possible climate change catastrophic scenarios, including collapse of society or the potential extinction of humans, however unlikely, a group of top scientists claim.

Eleven scientists from around the world are calling on the United Nations' Intergovernmental Panel on Climate Change, the world's authoritative climate science organization, to do a special science report on "catastrophic climate change" to "bring into focus how much is at stake in a worst-case scenario." In their perspective piece in Monday's Proceedings of the National Academy of Sciences they raise the idea of human extinction and worldwide societal collapse in the third sentence, calling it "a dangerously underexplored topic."

The scientists said they aren't saying that worst is going to happen. They say the trouble is no one knows how likely or unlikely a "climate endgame" is and the world needs those calculations to battle global warming.

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Mystery cells that create blood stem cells in mammals identified

Imagine if one day blood transfusions from strangers were not needed because they could be produced from cells that line your own blood vessels' cells.

While that day is still some years off, medical researchers at UNSW Sydney have made an important first step by identifying—in mice—a mechanism that is used naturally in mammals to make blood from cells that line blood vessels.

It was already known that a process termed "endothelial to hematopoietic transition" takes place in mammalian embryos, whereby cells lining blood vessels (endothelial cells) change into blood stem cells.

But the identity of the cells that regulate this process had up until now been a mystery.

In a paper published recently in the journal Nature Cell Biology, a team of researchers describe how they solved this puzzle by identifying the cells in the embryo that can convert adult endothelial cells into blood stem cells. The cells—known as "Mesp1-derived PDGFRA+ stromal cells"—reside underneath the aorta.

While more research is needed before this can be translated into clinical practice, the discovery could be an important step in regenerative medicine by providing a potential new tool to generate engraftable hematopoietic stem cells.

Vashe Chandrakanthan et al, Mesoderm-derived PDGFRA+ cells regulate the emergence of hematopoietic stem cells in the dorsal aorta, Nature Cell Biology (2022). DOI: 10.1038/s41556-022-00955-3

Watch tiny electromechanical robots that are faster than cheetahs for their size

Methane satellites find landfills with the same climate impact as several hundred thousand cars

Methane is almost thirty times more powerful as a greenhouse gas than CO₂. Researchers from SRON Netherlands Institute for Space Research therefore scan the entire globe for large methane leaks. A landfill in Buenos Aires turns out to emit tens of tons of methane per hour, comparable to the climate impact of one and a half million cars. They also detect large emissions from landfills in India and Pakistan, identifying new low-hanging fruit in the battle against climate change. The work was published on August 10 in Science Advances.

Methane is the second largest anthropogenic contributor to the greenhouse effect, after CO₂. This is due to its large global warming potential over 100 years (GWP-100). Methane is almost 30 times more potent per ton as a greenhouse gas than CO₂. When methane is released through human activity—by oil installations, coal mines, cattle sheds or landfills—it can be made less harmful by flaring it and thereby converting it to CO₂. Even better, if you capture it, you can put it to good use in boilers or stoves. Researchers from SRON Netherlands Institute for Space Research have now used satellite data to locate a number of landfills that are low-hanging fruit in the fight against climate change. Four landfills in Argentina, India and Pakistan emit several or even tens of tons of methane per hour.

 Buenos Aires, Delhi, Lahore and Mumbai stood out, with urban emissions on average twice as high as estimated in global inventories. The landfill in Buenos Aires emits 28 tons of methane per hour, comparable to the climate impact of 1.5 million cars. The three other landfills are responsible for, respectively, three, six and 10 tons of methane per hour, which still amounts to the impact of 130,000 to 500,000 cars.

Methane is odorless and colorless, so leaks are notoriously difficult to detect. But satellites are ideally suited for this. Landfills are super-emitters that pump large amounts of methane into the atmosphere. That is painful to watch because you can solve it with relatively little effort. You could, for example, separate and compost the organic waste, which would drastically reduce methane production. And even in the case of mixed waste, you can still collect or flare the methane produced. Methane has a lifetime of only about 10 years in the atmosphere, so if we act now, we will quickly see results in the form of less global warming.

Joannes D. Maasakkers, Daniel J. Varon, Aldís Elfarsdóttir, Jason McKeever, Dylan Jervis, Gourav Mahapatra, Sudhanshu Pandey, Alba Lorente, Tobias Borsdorff, Lodewijck R. Foorthuis, Berend J. Schuit, Paul Tol, Tim A. van Kempen, Richard van Hees, Ilse Aben, 'Using satellites to uncover large methane emissions from landfills', Science Advances, 2022. science.org/doi/10.1126/sciadv.abn9683

Rainwater unsafe to drink due to chemicals: study

Rainwater everywhere on the planet is unsafe to drink due to levels of toxic chemicals known as PFAS that exceed the latest guidelines, according to a new study by scientists.

Commonly known as 'forever chemicals' because they disintegrate extremely slowly, PFAS (per- and polyfluoroalkyl substances) were initially found in packaging, shampoo or makeup but have spread to our entire environment, including water and air.

There is nowhere on Earth where the rain would be safe to drink, according to the measurements that scientists have taken now.

Even in Antarctica or the Tibetan plateau, the levels in the rainwater are above the drinking water guidelines that the US EPA (Environmental Protection Agency) proposed.

According to some studies, exposure can also lead to problems with fertility, development delays in children, increased risks of obesity or certain cancers (prostate, kidney and testicular), an increase in cholesterol levels.
—Planet 'irreversibly contaminated'—

We have made the planet inhospitable to human life by irreversibly contaminating it now so that nothing is clean anymore. And to the point that's it's not clean enough to be safe.

We have crossed a planetary boundary. And we have to learn to live with it.

 Per- and polyfluoroalkyl substances (PFAS) define a new planetary boundary for novel entities that has been exceeded, Environmental Science & Technology (2022). DOI: 10.1021/acs.est.2c02765

Study of OTC supplements shows some have very high levels of levodopa, which can lead to paranoia

A team of researchers  has found that over-the-counter supplements that are advertised as containing extracts from Mucuna pruriens, a type of bean that contains levodopa, sometimes contain high levels of levodopa. In their paper published in the journal JAMA Neurology, the group describes testing the levels of levodopa in several Mucuna pruriens–based supplements.

Levodopa (known more commonly as L-DOPA) is a type of amino acid that is commonly found in plants and animals. In humans, it serves as a precursor to several types of neurotransmitters, one of which is dopamine. In 1969, researchers discovered that giving L-DOPA to patients with Parkinson's disease could reduce their symptoms; therefore, it is widely used today. Prior research has also found that many patients with Parkinson's disease believe that higher doses of L-DOPA will further improve their condition, but doctors do not agree. Still, some people with the disease buy over-the-counter supplements containing Mucuna pruriens extracts because research has shown the beans contain L-DOPA. In addition to overriding established medical advice, taking such supplements can have negative effects on patients, such as the development of paranoia. In this new effort, the researchers sought to learn more about Mucuna pruriens supplements—specifically, the amount of levodopa they contain. They purchased 16 bottles of the supplements and tested them. They found that the supplements all had different amounts of levodopa and that the amounts did not match what were listed on the labels. They also found some of the supplements had more levodopa in them than prescription medications. The researchers suggest their findings should be a warning to Parkinson's patients—they have no way of knowing how much levodopa they are consuming if they take such supplements, which can wreak havoc with the treatment prescribed by their doctor. The researchers note that some people who do not have Parkinson's disease also purchase and consume the supplements, which can lead to paranoia, agitation, impulse control and sometimes psychosis. 

Pieter A. Cohen et al, Levodopa Content of Mucuna pruriens Supplements in the NIH Dietary Supplement Label Database, JAMA Neurology (2022). DOI: 10.1001/jamaneurol.2022.2184