Bid to end deadly cooking methods which stoke global warming
Fifty countries are meeting in France today to discuss the lack of access to clean cooking methods worldwide which causes millions of deaths every year and fuels global warming.
Some 2.3 billion people across 128 countries breathe in harmful smoke when they cook on basic stoves or over open fires, according to an International Energy Agency (IEA)-African Development Bank (ADB) report that sounded the alarm last year.
It said 3.7 million people a year die prematurely from harmful cooking practices, with children and women most at risk.
The IEA said the "unprecedented" Paris gathering aims to be "a moment of changing the direction". The problem "touches on gender, it touches on forestry, it touches on climate change, it touches on energy, it touches on health.
A third of the world cooks with fuels which produce harmful fumes when burned, including wood, charcoal, coal, animal dung and agricultural waste.
They pollute indoor and outdoor air with fine particlesthat penetrate the lungs and cause multiple respiratory and cardiovascular problems, including cancer and strokes.
These cooking practices are the third highest cause of premature deaths in the world and the second highest in Africa. In young children , they are a major cause of pneumonia, experts say.
They also prevent women and children from accessing education or earning a wage, as they spend hours looking for fuel.
Greenhouse gas emissions from using basic stoves and deforestation from collecting wood also contribute hugely to global warming.
Switching to clean cooking methods, such as LPG or electric cooking, would save 1.5 billion tonnes of CO2a year by 2030—roughly the amount emitted by ships and planes last year, according to the IEA.
IEA also recommends strong national leadership as well as grassroots efforts to change social norms.
This New Plastic Disappears When You Don't Need It Anymore
The plastic that eats itself
Our reliance on plastic has become a huge problem, which is why researchers are excited about a new type of material – one that comes with built-in biodegrading capabilities, due to the bacterial spores living inside it. The new self-digesting plastic combines thermoplastic polyurethane (TPU) and Bacillus subtilis bacteria, which had to be engineered to survive the high temperatures involved in plastic production. By repeatedly exposing the spores to increasing levels of heat, the team of researchers behind this new work found that the bacteria could eventually cope with the temperatures of 135 degrees Celsius (275 degrees Fahrenheit) required to mix the bacterial spores and TPU together. Past efforts to find ways to degrade plastics, fast, have often sourced bacterial enzymes and fungi from soils and compost heaps where those microbes are naturally abundant. But this new material needs only the bacterial spores inside it, reawakened with some nutrients and moisture, to start breaking down.
A minimal cognitive architecture reproduces control of human decision-making processes
Neuroscientists and psychologists have been trying to pinpoint the processes behind human decision-making for decades. While their efforts led to numerous interesting insights, the intricacies of complex decision-making remain poorly understood.
Researchers at the Paris Brain Institute carried out a study aimed at better understanding how the human brain allocates its resources when making decisions. Their paper, published in Communications Psychology, introduces an architecture that operates the online metacognitive control of decisions (oMCD), a theoretical construct describing why and how the brain choses to stop of continue deliberating.
Past studies have found that humans do not always invest their maximum mental efforts when making decisions. This can lead to various widely documented errors and cognitive biases (i.e., recurring deviations from rational thinking).
So when making a decision, what determines the amount of mental effort we invest in decisions?
Previous behavioral research suggested that, for certain kinds of decisions (so-called 'evidence-based' decisions), this may be done by balancing decision confidence (which tends to increase with mental effort) with the cost of mental effort. This then triggered the question: can this work for all kinds of decisions?
To address this question, researchers should first demonstrate that a confidence-based control policy eventually yields mental effort investments resembling those of optimal control policies that are specific to different kinds of decisions. This was one of the primary objectives of this work.
Researchers approached this problem in many different ways.
In the context of this study, the researchers effectively provided two lines of evidence. The first one is theoretical in essence. Specifically, we rely on so-called Markov Decision Processes (MDPs) to demonstrate that confidence-based control policies are quasi-optimal for a broad class of decisions."
After having identified the non-trivial quantitative properties of confidence-based control policies, the researchers set out to determine whether these properties can be found in empirical data gathered in experiments where humans completed decision-making tasks. The properties they specifically sought for included three-way interactions between the values of different options, decision times and the reported confidence in a decision.
In brief, they identified a minimal cognitive architecture for quasi-optimal decision control (in terms of how much effort is invested). Importantly, this architecture may generalize over most, if not all, kinds of decision types. This implies that a single brain system may operate decision control, irrespective of the type of decision.
Juliette Bénon et al, The online metacognitive control of decisions, Communications Psychology (2024). DOI: 10.1038/s44271-024-00071-y.
Why subsequent bouts of dengue are worse than a first-time infection
A massive upsurge in dengue cases marked by multiple outbreaks is occurring worldwide and raising new questions about who is at elevated risk of severe forms of the mosquito-transmitted disease.
Incidence of the infection has increased by orders of magnitude throughout the so-called dengue belt, which encompasses Central and South America, Sub-Saharan Africa, Southeast Asia and swaths of the South Pacific, home to densely populated islands. Dengue, without question, is the most widespread and rapidly increasing vector-borne disease in the world, according to the World Health Organization.
The story is similar in other dengue-affected areas of the world where lapses in vector control have conspired with global climate change to create an explosion of bloodthirsty mosquitoes, swarms of them moving into regions once considered dengue-free. Only female mosquitoes feed on blood, they're in constant need of the nutrients in it to nurture their eggs.
Now, more than two decades of dengue surveillance is answering a slew of questions at a time when the world needs guidance most.
Findings from the research have revealed how various subgroups—what virologists call subtypes—of the dengue virus influence future risk of severe infection. It has been known for years that those who become infected in subsequent outbreaks, after a usually mild bout with a first-time infection, are at significant risk of severe disease in later dengue exposures. New research finally has analyzed more than 15,000 cases to discern why that is so.
Writing in Science Translational Medicine, a global team of scientists has explained how the four dengue viral subtypes—DENV-1, 2, 3, and 4—influence the risk of repeated severe infections. The findings provide a new framework for disease monitoring and lay the foundation for vaccination strategies as the new dengue immunizations emerge.
The team also underscored how dengue, a pernicious tropical malady, can be understood within the context of other common viral diseases that circle the globe.
The ability of viruses, such as SARS-CoV- 2 and influenza, to continuously change their genetic structurein response to the selective pressure of population immunity complicates control efforts.
In the case of dengue virus, an arbovirus that infects more than 100 million people each year, the situation is even more complex. Individuals with high dengue virus antibody titers are protected from infection and developing severe disease.
However, individuals with sub-neutralizing antibody titers have been shown to have the highest risk of severe disease, through multiple hypothesized mechanisms including antibody-dependent enhancement.
A dengue infection can be tricky. Some patients who have weathered an infection but get infected in a subsequent outbreak can have more severe symptoms the second time around. Yet, most research on repeat dengue infections has regarded each of the serotypes as no different from the other. An assessment of each serotype's genetic differences was needed to provide a clearer picture of potential risks.
To develop that clearer picture, researchers studied each serotype in more than 15,000 patients' infections as a way to peel away much of the mystery surrounding why first-time dengue illnesses are traditionally milder than subsequent ones.
To determine how each of the viral serotypes affects the risk of severe disease, the researchers analyzed viral genetic data. The team also studied cases of patients hospitalized for dengue to determine which viral subtype caused their infections. Researchers gathered data from 21 years of dengue surveillance, ranging from 1994 to 2014, in a children's hospital in Bangkok, encompassing 15,281 individual cases. This allowed them to find repeat cases and each viral subtype in all infections.
Based on the pediatric patients' hospital records, researchers discovered a link between hospitalization and the order in which patients became infected with different dengue-virus serotypes. They were also able to determine which combinations of viral subtypes pointed to mild or severe forms of dengue. For instance, people who became infected with serotypes that were very similar, such as DENV-3 and DENV-4, or very different serotypes as in the case of DENV-1 and DENV-4, tended to have a lower risk of severe disease during the second infection.
Patients who were infected with serotypes that were only moderately different had a higher risk of severe symptoms in subsequent infections. The highest risk group in this category involved patients who had an initial infection with DENV-2 followed by a subsequent infection triggered by DENV-1.
The new research adds clarity to a disease risk that may seem paradoxical to the lay public. For example, most people infected with dengue virus for the first time develop extremely mild signs of the disease or none at all. But for those who do get sick, soaring fever, headache, body aches, nausea and rash are the primary symptoms, and they intensify in severe manifestations of the infection.
For more than a century a severe bout with dengue has been known as breakbone fever because of the intensity of the pain and accompanying muscle spasms.
The virus is carried in the tropics and subtropics by Aedes aegypti and Aedes albopictus mosquitoes, which are endemic in the dengue belt. But while the belt, which runs through latitudes 35-degrees North and 35-degrees South, has traditionally been home to dengue-carrying mosquitoes, the arthropods have been extending their range northward as global climate change intensifies, scientists say.
These findings suggest that immune imprinting helps determine dengue disease risk and provides a pathway to monitor the changing risk profile of populations and to quantifying risk profiles of candidate vaccines.
Lin Wang et al, Antigenic distance between primary and secondary dengue infections correlates with disease risk, Science Translational Medicine (2024). DOI: 10.1126/scitranslmed.adk3259
Artificial intelligence tool detects sex-related differences in brain structure
Artificial intelligence (AI) computer programs that process MRI results show differences in how the brains of men and women are organized at a cellular level, a new study shows. These variations were spotted in white matter, tissue primarily located in the human brain's innermost layer, which fosters communication between regions.
The work appears in Scientific Reports.
Men and women are known to experience multiple sclerosis, autism spectrum disorder, migraines, and other brain issues at different rates and with varying symptoms. A detailed understanding of how biological sex impacts the brain is therefore viewed as a way to improve diagnostic tools and treatments. However, while brain size, shape, and weight have been explored, researchers have only a partial picture of the brain's layout at the cellular level.
The new study used an AI technique called machine learning to analyze thousands of MRI brain scans from 471 men and 560 women. Results revealed that the computer programs could accurately distinguish between biological male and female brains by spotting patterns in structure and complexity that were invisible to the human eye.
The findings were validated by three different AI models designed to identify biological sex using their relative strengths in either zeroing in on small portions of white matter or analyzing relationships across larger regions of the brain.
These findings provide a clearer picture of how a living, human brain is structured, which may in turn offer new insight into how many psychiatric and neurological disorders develop and why they can present differently in men and women.
For the research, researchers started by feeding AI programs existing data examples of brain scans from healthy men and women and also telling the machine programs the biological sex of each brain scan. Since these models were designed to use complex statistical and mathematical methods to get "smarter" over time as they accumulated more data, they eventually "learned" to distinguish biological sex on their own. Importantly, the programs were restricted from using overall brain size and shape to make their determinations.
According to the results, all of the models correctly identified the sex of subject scans between 92% and 98% of the time. Several features in particular helped the machines make their determinations, including how easily and in what direction water could move through brain tissue.
These results highlight the importance of diversity when studying diseases that arise in the human brain.
If, as has been historically the case, men are used as a standard model for various disorders, researchers may miss out on critical insight.
While the AI tools could report differences in brain-cell organization, they could not reveal which sex was more likely to have which features.
According to the researchers, the team next plans to explore the development of sex-related brain structure differences over time to better understand environmental, hormonal, and social factors that could play a role in these changes.
Deep Learning with Diffusion MRI as in vivo Microscope Reveals Sex-related Differences in Human White Matter Microstructure, Scientific Reports (2024).
Analysis suggests people with more copies of ribosomal DNA have higher risks of developing disease
Ribosomal DNA (rDNA) is present in hundreds of copies in the genome, but has not previously been part of genetic analyses. A new study of 500,000 individuals indicates that people who have more copies of rDNA are more likely to develop inflammation and diseases during their lifetimes.
Standard genetic analysis techniques have not studied areas of the human genome that are repetitive, such as ribosomal DNA (rDNA), a fundamental part of the molecular mechanism which makes proteins in cells.
A new study has discovered that genetic disposition to disease can be found in these previously understudied areas of the genome.
The results, published in Cell Genomics, suggest that wider genome analysis could bring opportunities for preventative diagnostics, novel therapeutics, and greater insight into the mechanism of different human diseases.
In this study, samples from 500,000 individuals in the UK Biobank project were analyzed. Researchers used new whole genome sequencing (WGS) techniques to identify differences in numbers of copies of rDNA in each sample, and compared them with other health metrics and medical records. The researchers found that the number of copies of rDNA in an individual showed strong statistical association with well-established markers of systemic inflammation—such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII). These statistically significant associations were seen in the genomes of individuals of different ethnicities, suggesting a common indicator for risks of future disease.
rDNA copy number was also linked with an individual's kidney function within the sample of individuals of European ancestry. A similar effect was seen in samples from other ancestries, but further research using larger sample sizes will be needed to confirm this connection.
This research highlights the importance of analyzing the whole genome to better understand the factors impacting on our health. This study is also an example of how having access to large biobanks allows us to make unexpected discoveries, and provides new avenues for harnessing the power of genetics to understand human diseases.
Geneticists have long struggled to fully explain the genetic basis of many common complex traits and diseases. This work suggests that at least part of this missing heritability resides in difficult to sequence regions of the genome such as those encoding ribosomal copy number variation.
Scientists develop sticky pesticide to combat pest insects
Researchers have engineered a biological barrier that protects plants from diseases and pests. It concerns a sticky substance that is sprayed on leaves, to which pests stick.
The researchers hope that this insect glue will help to reduce the use of toxic chemical pesticides. They published their findings in the Proceedings of the National Academy of Sciences.
In the search for alternatives, scientists turned to nature for inspiration. The carnivorous sundew plant has so-called glandular hairs that secrete a sticky substance to catch insects. The researchers wanted to mimic this to protect the plants and crops in a natural way.
The researchers succeeded in their endeavor.
They transformed vegetable rice oil into a yellow, sticky substance by blowing air over it and grinding it into small particles using a laboratory blender. This results in beads of about one millimeter in diameter that are as sticky as duct tape. The size matches one of the common pest insect: thrips. By catching these insects, plants stay healthier and are less likely to become infected with fungi that the thrips carry with them.
So far, the researchers mainly focused on this type of pest, but the insect glue may also work against other pests, such as the Suzuki fruit fly that currently threatens cherry cultivation. At the same time, the drops are small enough that beneficial insects, such as pollinators, do not get stuck.
Unlike chemical pesticides, insects are unlikely to develop resistance against this adhesive, the researchers think.
Insects have already evolved so that they avoid adhesion, for example through hairs on their body and a bumpy surface. Increasing their body size remains one of the few escape methods from this sticky trap. That is not nearly as easy as developing tolerance to a chemical substance. If it happens at all, it takes many generations and only happens if the insect glue is used on a large scale.
After application, the sticky substance remains on the leaves for three months and cannot be washed off by rain. That is long enough to control pests until harvest. By spraying the insect glue on crops before the fruits develop, farmers minimize the chance of the pesticide getting onto the food. However, contact with food cannot be ruled out.
The advantage of this pesticide over chemical pesticides is that you can see the small, yellow drops. You can wash it off with water and dish soap. If you do ingest some of it, it is probably not harmful. As it is derived from vegetable oil.
But scientists still need to investigate how (un)healthy it is exactly.
Ralph van Zwieten et al, Mimicking natural deterrent strategies in plants using adhesive spheres, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2321565121
Scientists discover blood proteins that may give cancer warning seven years before diagnosis
Two studies have discovered proteins in the blood that could warn people of cancer more than seven years before it is diagnosed.
Scientists identified 618 proteins linked to 19 different types of cancer, including 107 proteins in a group of people who blood was collected at least seven years before diagnosis. The team has discovered that these proteins could be involved at the very earliest stages of cancer, where it could be prevented.
They think that some of these proteins could be used to detect cancer much earlier than is currently possible. In the future, this could help treat the disease at a much earlier stage or prevent it altogether.
The papers, titled "Identifying proteomic risk factors for cancer using prospective and exome analyses of 1,463 circulating proteins and risk of 19 cancers in the UK Biobank" and "Identifying therapeutic targets for cancer among 2,074 circulating proteins and risk of nine cancers," are published inNature Communications.
In these studies, the team used a powerful technique called proteomics. Proteomics allows scientists to analyze a large set of proteins in tissue samples at a single point in time, to see how they interact with each other and find any important differences in proteins between different tissue samples.
In the first study, scientists analyzed blood samples from UK Biobank that had been taken from more than 44,000 people, including over 4,900 people who subsequently had a cancer diagnosis.
Using proteomics, the team analyzed a set of 1,463 proteins from a single sample of blood from each person. They compared the proteins of people who did and did not go on to be diagnosed with cancer to look for important differences between them and find out which ones were linked to cancer risk. The scientists also identified 182 proteins that differed in the blood three years before a cancer diagnosis took place.
In the second study, the scientists looked at genetic datafrom over 300,000 cancer cases to do a deep dive into which blood proteins were involved in cancer development and could be targeted by new treatments.
The scientists found 40 proteins in the blood that influenced someone's risk of getting 9 different types of cancer. While altering these proteins may increase or decrease the chances of someone developing cancer, the scientists also found that in some cases this may lead to unintended side effects.
However, the team stressed that they will need to do further research to find out the exact role these proteins play in cancer development, which of the proteins are the most reliable ones to test for, which tests could be developed to detect the proteins in the clinic, and which drugs could target these proteins.
Identifying proteomic risk factors for cancer using prospective and exome analyses of 1,463 circulating proteins and risk of 19 cancers in the UK Biobank,Nature Communications(2024).www.nature.com/articles/s41467-024-48017-6
Karl Smith-Byrne et al, Identifying therapeutic targets for cancer among 2074 circulating proteins and risk of nine cancers,Nature Communications(2024).DOI: 10.1038/s41467-024-46834-3
Scientists generate heat over 1,000°C with solar power instead of fossil fuel
Instead of burning fossil fuels to smelt steel and cook cement, researchers in Switzerland want to use heat from the sun. The proof-of-concept study, published May 15 in the journal Device, uses synthetic quartz to trap solar energy at temperatures over 1,000°C (1,832°F), demonstrating the method's potential role in providing clean energy for carbon-intensive industries.
Glass, steel, cement, and ceramics are at the very heart of modern civilization, essential for building everything from car engines to skyscrapers. However, manufacturing these materials demands temperatures over 1,000°C and relies heavily on burning fossil fuels for heat. These industries account for about 25% of global energy consumption.
Researchers have explored a clean-energy alternative using solar receivers, which concentrate and build heat with thousands of sun-tracking mirrors. However, this technology has difficulties transferring solar energy efficiently above 1,000°C.
To boost the efficiency of solar receivers, the researchers turned to semitransparent materials such as quartz, which can trap sunlight—a phenomenon called the thermal-trap effect. The team crafted a thermal-trapping device by attaching a synthetic quartz rod to an opaque silicon disk as an energy absorber.
When they exposed the device to an energy flux equivalent to the light coming from 136 suns, the absorber plate reached 1,050°C (1,922°F), whereas the other end of the quartz rod remained at 600°C (1,112°F).
Using a heat transfer model, the team also simulated the quartz's thermal-trapping efficiency under different conditions. The model showed that thermal trapping achieves the target temperature at lower concentrations with the same performance, or at higher thermal efficiency for equal concentration.
Gut bacteria enhance cancer immunotherapy in mouse study
Roughly one in five cancer patients benefit from immunotherapy—a treatment that harnesses the immune system to fight cancer. Such an approach to beating cancer has seen significant success in lung cancer and melanoma, among others. Optimistic about its potential, researchers are exploring strategies to improve immunotherapy for cancers that don't respond well to the treatment, with the hope of benefiting more patients.
Cancer immunotherapy employs the body's immune cells to target and destroy tumors. One such treatment uses immune checkpoint inhibitor drugs to unleash the immune system by releasing the natural brakes that keep immune T cells quiet, a feature that prevents the body from harming itself. But some tumors fight back to suppress the attacking immune cells, damping the effectiveness of such inhibitors.
Now, researchers have found, in mice, that a strain of gut bacteria—Ruminococcus gnavus—can enhance the effects of cancer immunotherapy. The study, which appears May 17 in Science Immunology, suggests a new strategy of using gut microbes to help unlock immunotherapy's untapped cancer-fighting potential.
R. gnavus has been found in gut microbiota of cancer patients who respond well to immunotherapy. In clinical trials, fecal transplants from such individuals have helped some unresponsive patients reap immunotherapy's benefits.
A team of medical researchers has developed a technique to freeze and thaw brain tissue without causing damage. In their study, published in the journal Cell Reports Methods, the group tested bathing brain organoid tissue in candidate chemicals before freezing them using liquid nitrogen.
Prior research has shown that no matter how quickly brain matter is frozen, the freezing and thawing process always causes tissue damage. This has made it more difficult for researchers to study brain matter because research must be conducted immediately after obtaining a tissue sample. In this new effort, the team found a way around this problem by soaking the tissue in a special solution before freezing.
The work involved dipping or soaking brain organoids (brain tissue grown from stem cells) in candidate compounds and then freezing and thawing them to see how they fared. After many attempts, they found one combination of solutions that worked best—a mix of ethylene glycol, methylcellulose DMSO and Y27632. They named the solution mix MEDY.
The research team then tested MEDY under a variety of conditions to see how well it prevented damage from freezing. The conditions involved changing variables, such as the age of the organoids prior to freezing and how long they were soaked in a MEDY solution. They then allowed the organoids to resume growing after they were thawed for up to 150 days.
The researchers found little difference between organoids that had been frozen and those that had not—even those that had been frozen for as long as 18 months.
As a final test, the research team used their technique on a sample of brain tissue obtained from a live human patient and found that it worked just as well.
The research team suggests that their technique should allow researchers to store brain tissue samples on a scale large enough to allow for new types of brain and nervous system research.
Weiwei Xue et al, Effective cryopreservation of human brain tissue and neural organoids, Cell Reports Methods (2024). DOI: 10.1016/j.crmeth.2024.100777
Microplastics may slow the rate at which carbon is pulled from the sea surface to the depths
Plastics in the ocean do more harm than suffocate turtles, fish and other marine life.
A new study shows that microplastics may reduce the ability of the ocean to help offset the climate crisis by slowing down the rate at which carbon is taken from the sea surface to the depths.
For millennia, the ocean has been part of a carbon sink process in which dead phytoplankton clump together and fall into the deep ocean in showers of what look like "marine snow". The resulting carbon sequestration is a marine version of how trees and plants on terrestrial Earth take carbon from the atmosphere and store it in soil.
But new research shows that microplastics in the ocean are slowing the process down by making the "marine snow" more buoyant. Plastics want to float. If phytoplanktons grow on microplastics in biofilms, instead of as free living organisms, that changes the buoyancy of the phytoplankton when they die.
Basically, the plastics are slowing down the sinking rate of the marine snow, which is potentially reducing the efficiency with which the ocean can remove carbon dioxide from the atmosphere.
So microplastics could be a threat to global scale processes, such as the carbon cycle that is so important for all life.
Kai Ziervogel et al, Microbial interactions with microplastics: Insights into the plastic carbon cycle in the ocean, Marine Chemistry (2024). DOI: 10.1016/j.marchem.2024.104395
A high-fat diet promotes cancer progression by inducing gut microbiota–mediated leucine production
Researchers have found a link between diet, a type of gut bacterium and breast cancer. The study, published on 6 May in theProceedings of the National Academy of Science, found that a high-fat diet increased the number ofDesulfovibriobacteria in the guts of mice, suppressing their immune systems and accelerating tumour growth.
Researchers say the finding could spark new ideas for therapies for breast cancer, the most common malignancy affecting women worldwide.
Mice that are fed a high-fat diet often serve as a proxy for human obesity in animal studies. The team found that mice consuming a high-fat diet had more Desulfovibrio bacteria and had elevated levels of a type of cell that suppresses the immune system, myeloid-derived suppressor cells (MDSCs), which originate in the bone marrow. This suggested to the researchers that higher numbers of Desulfovibrio bacteria and a suppressed immune system were linked;
High-fat-diet mice also had higher levels of the amino acid leucine circulating in their blood than did mice fed a normal diet. Knowing that leucine can be made by some kinds of gut bacteria, the team treated the mice with antibiotics that killed Desulfovibrio. This caused both MDSC and leucine levels to return to normal.
Armed with this information, the researchers went back to the blood samples that they had taken from the people with breast cancer. As anticipated, those with a BMI of more than 24 had higher levels of leucine, more immunosuppressive MDSCs and survived fewer years post-treatment than those with a lower BMI.
In other words,Desulfovibriobacteria, benefiting from a high-fat diet, made excess leucine. This caused a spike in the numbers of MDSCs, which suppress the immune system and allow tumours to grow.
Digging disrupts natural processes that keep soil healthy and productive. Minimising cultivation is desirable when trying to grow plants in ways that have the least environmental impact.
Digging the soil bulldozes a number of structures underground. Drainage channels created by worms are destroyed, important fungal networks are broken and carbon that’s been locked in the soil is released into the atmosphere.
Digging also brings weed seeds closer to the surface, causing them to sprout more readily.
Benefits don’t necessarily include better crops, although some gardeners have reported higher yields.
Charles Dowding, a champion of no-dig gardening, compared side-by-side beds over eight years. One was dug, the other wasn’t. He reported 100kg of additional produce from the no-dig bed.
So how does a no-dig garden grow? Instead of cultivating the soil, no-dig gardeners cover their beds with a layer of mulch or well-rotted organic matter, either from their own compost bins or the garden centre.
If the ground is weedy, simply cover it with a few sheets of cardboard.
Then add another layer of compost on top (this is sometimes known as lasagne gardening).
The weeds will be smothered and plants root into the soil below, which will be enriched by the activity of worms carrying the compost into the underlying soil.
Discovery may explain why Egyptian pyramids were built along long-lost Ahramat branch of the Nile
Some 31 pyramids in Egypt, including the Giza pyramid complex, may originally have been built along a 64-km-long branch of the river Nile which has long since been buried beneath farmland and desert. The findings, reported in a paper in Communications Earth & Environment, could explain why these pyramids are concentrated in what is now a narrow, inhospitable desert strip.
The Egyptian pyramid fields between Giza and Lisht, built over a nearly 1,000-year period starting approximately 4,700 years ago, now sit on the edge of the inhospitable Western Desert, part of the Sahara. Sedimentary evidence suggests that the Nile used to have a much higher discharge, with the river splitting into several branches in places. Researchers have previously speculated that one of these branches may have flown by the pyramid fields, but this has not been confirmed.
Eman Ghoneim and colleagues studied satellite imagery to find the possible location of a former river branch running along the foothills of the Western Desert Plateau, very near to the pyramid fields. They then used geophysical surveys and sediment cores to confirm the presence of river sediments and former channels beneath the modern land surface, indicating the presence of a former branch, which they propose naming "Ahramat" (meaning pyramids in Arabic).
The authors suggest that an increased build-up of windblown sand, linked to a major drought which began approximately 4,200 years ago, could be one of the reasons for the branch's migration east and eventual silting up.
The discovery may explain why these pyramid fields were concentrated along this particular strip of desert near the ancient Egyptian capital of Memphis, as they would have been easily accessible via the river branch at the time they were built. Additionally, the authors found that many of the pyramids had causeways that ended at the proposed riverbanks of the Ahramat branch, which they suggest is evidence the river was used for transporting construction materials.
The findings reiterate the importance of the Nile as a highway and cultural artery for ancient Egyptians, and also highlight how human society has historically been affected by environmental change, according to the authors.
Future research to find more extinct Nile branches could help prioritize archaeological excavations along their banks and protect Egyptian cultural heritage, they add.
Quantum Breakthrough Could Charge Batteries in a Snap
Batteries based on the wave-like nature of charged particles could revolutionize energy storage, potentially cramming in more power at a faster rate than conventional electrochemical cells could ever hope to manage. A new protocol developed by a team of physicists from National Cheng Kung University could transform the basic principles of a fast-charging quantum battery into a practical system, demonstrating ways the superposition of a battery may be used to store energy quickly and efficiently.
Fundamental to quantum physics is the principle that all bits of matter have a wave-like identity that spreads out through space and time.
As counterintuitive as it is to our experience of reality, these waves represent the properties of an object – whether it's an electron, a molecule, a cat, or a whole planet – as a spectrum of possibility referred to as its superposition.
In recent years, researchers have pondered whether one or more objects in a superposition have something in common with the chaotic zip and bounce of heated material in an engine. Tapping into this quantum phenomenon could even provide new ways to transfer and hold energy.
It's a nice idea in concept, but transforming the theory behind quantum heat engines into a working device requires identifying suitable processes that don't waste a whole lot of energy.
The researchers experimentally evaluated two approaches to using the superposition of a particle to charge a hypothetical quantum battery to determine whether its fuzzy state is indeed transferring energy.
In place of an actual battery, the team simply used a trapped ion in a superposition state known as a qubit, which can gain energy as it passes through a reflective space that constrains the kinds of waves passing through.
Sending the ion through a device that split its wave into two beams, the team compared the battery's ability to store energy as separated waves passed through multiple entry points into a single cavity, and then into multiple cavities.
Not only did they find the ion's superposition really can allow for efficient charging, they found the 'many doorways, one room' approach induced an interference effect that could theoretically lead to what they call a "perfect charging phenomenon", which allows a complete conversion of stored energy to work from the quantum battery at any point in the charging process.
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They also demonstrated the process as scalable, with the interference effect persisting even when sending more than one qubit through the cavity.
By carrying out the process on the IBM Quantum Platform and IonQ's quantum hardware, the team demonstrated a proof-of-concept for their protocol, showing a similar system could have the potential to be an energy-effective way of rapidly charging and extracting power from a quantum system. Though a qubit can simulate the fundamental physics, new methods will be needed to turn the protocol into something more practical and battery-like, meaning it will be a while before you'll be recharging your electric moped in an eyeblink.
Still, the experiment shows there's nothing in the laws of physics that says we can't exploit the quantum landscape for long-life, rapid-charging energy storage.
Composition of gut microbiota could influence decision-making
The way we make decisions in a social context can be explained by psychological, social, and political factors. But what if other forces were at work? Scientists show that changes in gut microbiota can influence our sensitivity to fairness and how we treat others. Their findings are published in the journal PNAS Nexus.
The intestinal microbiota—i.e., all the bacteria, viruses and fungi that inhabit our digestive tract—plays a pivotal role in our bodies, well beyond digestive function. Recent research underscores its impact on cognition, stress, anxiety, depressive symptoms, and behaviour; mice raised in a sterile environment, for example, have difficulty interacting with other individuals.
While these findings are promising, most of this research is carried out on animals and cannot be extrapolated to humans. Nor does it allow us to understand what neuronal, immune, or hormonal mechanisms are at work in this fascinating dialogue between brain and intestine: researchers observe a link between the composition of the microbiota and social skills but do not know precisely how one controls the other.
The available data suggests that the intestinal ecosystem communicates with the central nervous system via various pathways, including the vagus nerve. It might also use biochemical signals that trigger the release of neurotransmitters, such as dopamine and serotonin, which are essential for proper brain function.
To determine whether the composition of the human gut microbiota could influence decision-making in a social setting, researchers used behavioural tests—including the famous "ultimatum game" in which one player is given a sum of money he must split (fairly or unfairly) with a second player, who is free to decline the offer if s/he deems it insufficient. In that case, neither player receives any money. Refusing the sum of money is equivalent to what we call "altruistic punishment," i.e., the impulse to punish others when a situation is perceived as unfair: for the second player, restoring equality (no one receives any money) sometimes feels more important than obtaining a reward. The ultimatum game is then used as an experimental way of measuring sensitivity to fairness.
To fully exploit this effect, the researchers recruited 101 participants. For seven weeks, 51 took dietary supplements containing probiotics (beneficial bacteria) and prebiotics (nutrients that promote the colonization of bacteria in the gut), while 50 others received a placebo. They all participated in an ultimatum game during two sessions at the beginning and end of the supplementation period. Part 1
The study's results indicate that the group that received the supplements was much more inclined to reject unequal offers at the end of the seven weeks, even when the money split was slightly unbalanced. Conversely, the placebo group behaved similarly during the first and second test sessions. Moreover, the behavioral change in the supplemented group was accompanied by biological changes: the participants who, at the start of the study, had the greatest imbalance between the two types of bacteria that dominate the gut flora (Firmicutes and Bacteroidetes) experienced the most significant change in the composition of their gut microbiota with the intake of supplements. In addition, they also showed the greatest sensitivity to fairness during the tests. The researchers also observed a sharp drop in their levels of tyrosine, a dopamine precursor, after the seven-week intervention. For the first time, a causal mechanism is emerging: the composition of the gut microbiota could influence social behavior through the precursors of dopamine, a neurotransmitter involved in brain reward mechanisms.
"It's too early to say that gut bacteria can make us less rational and more receptive to social considerations," conclude the researchers. However, these new results clarify which biological pathways we must look at. The prospect of modulating the gut microbiota through diet to positively influence decision-making is fascinating. We need to explore this avenue very carefully.
Marie Falkenstein et al, Impact of the gut microbiome composition on social decision-making, PNAS Nexus (2024). DOI: 10.1093/pnasnexus/pgae166
Rusting Rivers: The Alarming Impact of Permafrost Thaw on Arctic Rivers
In this video, researchers reveal the startling discovery of over 75 streams and rivers in Alaska's Brooks Range turning orange due to metals released in permafrost thaw. Researchers delve into the consequences of this phenomenon, its impact on aquatic ecosystems and local communities, and the ongoing research efforts to understand and mitigate these changes.
As incidence of cancer increases globally, the use of cancer drugs is also growing at a rate of approximately 10 percent per year in developed countries. Pharmaceuticals significantly contribute to the improvement of human health; however, their environmental impacts have also become a major concern.
Cancer drugs in our ecosystems Among the many molecules used to treat cancers are cytostatics.
As defined by the United States' National Institutes of Health (NIH), a cystostatic is "a substance that slows or stops the growth of cells, including cancer cells, without killing them."
When a cancer patient takes these drugs, the chemicals in them, including cytostatics, are eventually evacuated through the patients' solid and liquid waste.
A patients' waste ends up in the hospital or domestic wastewater system, where the chemicals in it are not entirely eliminated by end of pipe wastewater treatment plants. These chemicals can then find their way into aquatic ecosystems, and even our drinking water supply, at varying concentrations.
Cytostatic drugs are now classified as contaminants of emerging concern (CECs) due to their hazardous environmental impact.
The message is clear: this problem is only going to get worse as more people use cancer drugs. The continuous release of pharmaceuticals into aquatic ecosystems (even at low levels) can reduce surface water quality, endanger biodiversity and disrupt ecosystem functioning. They have a toxic impact on aquatic flora and fauna, especially the fish.
Scientists Confirm Microplastics Now Detected in Human Testicles
We can now add testicles to the list of places where microplastics have managed to spread – alongside human placentas, ancient rocks, clogged arteries, blue whales, baby poop, the wilderness of Antarctica, near the peak of Mount Everest, and the bottom of the ocean.
Research led by the University of New Mexico looked at testicular tissue taken from both dogs and humans, finding microplastics in every sample, with an abundance almost three times higher in humans than in dogs. The team found an average 122.63 micrograms of microplastics per gram of tissue in canines, and 329.44 micrograms per gram in people.
Besides giving us another sobering reminder of how plastic pollution is penetrating every part of our bodies, the study raises some concerning questions in regards to how these microscopic fragments might impact male fertility.
Male and female mice exhibit different empathic behaviors to others' pain
Social interactions are multi-faceted experiences that entail understanding the emotional states of others and responding appropriately. Neuroscientists and psychologists have been studying social interactions for decades, in the hope of understanding their neural and behavioral underpinnings.
A team of researchers recently carried out a study exploring how male and female mice respond to the pain of other mice. Their findings, published in Neuron, suggest that there are both neurobiological and behavioural differences between the two sexes, specifically in relation to their empathic responses.
Recognizing the affective states of social counterparts and responding appropriately fosters successful social interactions.
The primary objective of the recent study was to delve deeper into how male and female mammals respond to another animal in pain, both in terms of their behavior and brain activity. To do this, they carried out a series of experiments on mice, where two mice were placed in lateral chambers, while an observing mouse was placed in the central section of a common cage.
One of the mice in the lateral chamber was given an injection that caused abdominal pain, while the other two were not administered anything. The researchers monitored the behavior of the mouse in the central part of the cage, who could explore the environment freely and thus whether to interact with the other mice and in what ways. Initially, both male and female mice moved in their surroundings, displaying similar exploratory behaviors. Yet after a while, particularly towards the end of each experimental trial, the team found that male mice exhibited more grooming behaviors, while female mice demonstrated a social preference for the mouse that was in pain, as they spent more time in its proximity and sniffing it. "We show that male and female mice emit distinct olfactory cues after experiencing distress," the researchers wrote. "These cues activate distinct neural circuits in the piriform cortex (PiC) and evoke sexually dimorphic empathic behaviours on observers. Specifically, the PiC → PrL pathway is activated in female observers, inducing a social preference for the distressed counterpart. Conversely, the PiC → MeA pathway is activated in male observers, evoking excessive self-grooming behaviors." This distinct neural pathway that the researchers found to be activated in male observers originated from non-overlapping PiC neuron populations with different gene expression signatures. Notably, these gene expression signatures are regulated by transcription factors and sex hormones. Overall, their observations suggest that male and female mice are biologically inclined to respond differently to other mice in pain. While females are more likely to get closer to a peer who is in pain, males tend to respond to another's pain with excessive self-grooming. The results of this study could soon be explored further and validated in additional experiments. In the future, they could pave the way for the discovery of new neural processes underpinning sex-specific social behaviours.
Shunchang Fang et al, Sexually dimorphic control of affective state processing and empathic behaviors, Neuron (2024). DOI: 10.1016/j.neuron.2024.02.001
Body lice may be bigger plague spreaders than previously thought
A new laboratory study suggests that human body lice are more efficient at transmitting Yersinia pestis, the bacterium that causes plague, than previously thought, supporting the possibility that they may have contributed to past pandemics.
Y. pestis has been the culprit behind numerous pandemics, including the Black Death of the Middle Ages that killed millions of people in Europe. It naturally cycles between rodents and fleas, and fleas sometimes infect humans through bites; thus, fleas and rats are thought to be the primary drivers of plague pandemics. Body lice—which feed on human blood—can also carry Y. pestis, but are widely considered to be too inefficient at spreading it to contribute substantially to outbreaks. However, the few studies that have addressed lice transmission efficiency have disagreed considerably.
To help clarify the potential role of body lice in plague transmission, Bland and colleagues conducted a series of laboratory experiments in which body lice fed on blood samples containing Y. pestis. These experiments involved the use of membrane feeders, which simulate warm human skin, enabling scientists to study transmission potential in a laboratory setting.
They found that the body lice became infected with Y. pestis and were capable of routinely transmitting it after feeding on blood containing levels of the pathogen similar to those found in actual human plague cases.
They also found that Y. pestis can infect a pair of salivary glands found in body lice known as the Pawlowsky glands, and lice with infected Pawlowsky glands transmitted the pathogen more consistently than lice whose infection was limited to their digestive tract. It is thought that Pawlowsky glands secrete lubricant onto the lice's mouthparts, leading the researchers to hypothesize that, in infected lice, such secretions may contaminate mouthparts with Y. pestis, which may then spread to humans when bitten. These findings suggest that body lice may be more efficient spreaders of Y. pestis than previously thought, and they could have played a role in past plague outbreaks.
Bland DM, Long D, Rosenke R, Hinnebusch BJ (2024) Yersinia pestis can infect the Pawlowsky glands of human body lice and be transmitted by louse bite. PLoS Biology (2024). DOI: 10.1371/journal.pbio.3002625
Nightmares could be an early warning sign of an autoimmune diseaseflare-up– new study
Nightmares coming before autoimmune diseases have been found in other neurological diseases. Descriptions of flare-related nightmares in our study often involved being attacked, trapped, crushed or falling. Many were very distressing. One person described them as: “Horrific, like murders, like skin coming off people, horrific.” Another important finding was that these nightmares often came before a disease flare-up, particularly in people who then had hallucinations as part of their disease pattern. This was more likely in people with lupus than the other rheumatological diseases such as inflammatory arthritis. This wasn’t unexpected as lupus is known to affect the brain in some cases. Of the patients also reporting hallucinations, 61% of lupus patients and 34% with other autoimmune rheumatological diseases reported increasing disrupted sleep (mostly nightmares) just before their hallucinations.
Newborns whose mother spoke in a mix of languages during pregnancy are more sensitive to a range of sound pitches
It's well established that babies in the womb hear and learn about speech, at least in the third trimester. For example, newborns have been shown to already prefer the voice of their mother, recognize a story that had been repeatedly told to them while in the womb, and tell apart their mother's native language.
What wasn't known until now was how developing fetuses learn about speech when their mother speaks to them in a mix of languages. Yet this is common: there are 3.3 billion bilingual people (43% of the population) worldwide, and in many countries, bilingualism or multilingualism is the norm.
Researchers showed that exposure to monolingual or a bilingual speech has different effects at birth on 'neural encoding' of voice pitch and vowel sounds: that is, how information about these aspects of speech has been initially learned by the fetus.
At birth, newborns from bilingual mothers appear more sensitive to a wider range of acoustic variation of speech, whereas newborns from monolingual mothers seem to be more selectively tuned to the single language they have been immersed in.
Exposure to bilingual or monolingual maternal speech during pregnancy affects the neurophysiological encoding of speech sounds in neonates differently, Frontiers in Human Neuroscience (2024). DOI: 10.3389/fnhum.2024.1379660
Exposure to endocrine-disrupting chemicals in utero associated with higher odds of metabolic syndrome in children
The term 'metabolic syndrome' (MetS) encompasses a group of factors, such as abdominal obesity, hypertension and insulin resistance, that together increase the risk of cardiovascular disease and type 2 diabetes.
A new study suggests that prenatal exposure to a combination of endocrine disrupting chemicals (EDCs) is associated with poorer metabolic health in childhood, which in turn may contribute to an increased risk of metabolic syndrome in adulthood.
EDCs are chemical substances that are so named because of their ability to interfere with the functioning of our hormonal system, growth, energy balance and metabolism and whose exposure, given their ubiquity in our environment, is difficult to escape.
Previous studies have already shown a link between individual exposure to some of these compounds during the prenatal phase and some of the factors that make up the metabolic syndrome, particularly obesity and blood pressure.
The study involved 1,134 mothers and their children from six European countries (Spain, France, Greece, Lithuania, Norway and the United Kingdom), all volunteers from the HELIX (Human Early Life Exposome) cohort. Prenatal exposure to a total of 45 endocrine disruptors was analyzed through blood and urine samples collected from the mothers during pregnancy or from the umbilical cord after birth.
Later, when the children were between 6 and 11 years old, they were followed up, including a clinical examination, interview and collection of biological samples. This yielded data on waist circumference, blood pressure, cholesterol, triglycerides and insulin levels, which were aggregated to obtain a risk index for metabolic syndrome.
Statistical analysis showed that mixtures of metals, perfluoroalkylated and polyfluoroalkylated substances (PFAS), organochlorine pesticides and flame retardants (or PBDEs) were associated with a higher risk of metabolic syndrome. In the case of metals, the association observed was mainly due to the effect of mercury, the main source of which is the intake of large fish.
PFASs are one of the most widely used families of chemical compounds, being used in pesticides, paints, non-stick pans or fast food packaging, among many other common uses. Because of their persistence, they are also known as the "forever chemicals." Also very persistent are organochlorine pesticides, which were already banned in Europe in the 1970s, but to which we are still widely exposed due to their permanence in the environment.
Researchers also observed that associations were stronger in girls for mixtures of PFASs and polychlorinated biphenyls (PCBs), while boys were more susceptible to exposure to parabens. Since endocrine disruptors interfere with sex steroid hormones, these differences fall within what would be expected.
These results suggest that exposure to widespread mixtures of endocrine disruptors during pregnancy may be associated with adverse metabolic health in both boys and girls. This association may contribute to the current increase in the prevalence of lifetime metabolic syndrome, which currently affects a quarter of the adult population, with upward trends evident even among young people Prenatal Exposure to Chemical Mixtures and Metabolic Syndrome Risk in Children, JAMA Network Open (2024). DOI: 10.1001/jamanetworkopen.2024.12040
Why the brain can robustly recognize images, even without colour
Even though the human visual system has sophisticated machinery for processing colour, the brain has no problem recognizing objects in black-and-white images. A new study offers a possible explanation for how the brain comes to be so adept at identifying both colour and colour-degraded images.
Using experimental dataand computational modeling, the researchers found evidence suggesting the roots of this ability may lie in development. Thework has been publishedinScience
Early in life, when newborns receive strongly limited colour information, the brain is forced to learn to distinguish objects based on their luminance, or intensity of light they emit, rather than their colour. Later in life, when the retina and cortex are better equipped to process colours, the brain incorporates colour information as well but also maintains its previously acquired ability to recognize images without critical reliance on colour cues.
The findings also help to explain why children who are born blind but have their vision restored later in life, through the removal of congenital cataracts, have much more difficulty identifying objects presented in black and white. Those children, who receive rich colour input as soon as their sight is restored, may develop an overreliance on colour that makes them much less resilient to changes or removal of colour information.
Researchers have observed that limitations in early sensory input can also benefit other aspects of vision, as well as the auditory system.
In 2022, they used computational models to show that early exposure to only low-frequency sounds, similar to those that babies hear in the womb, improves performance on auditory tasks that require analyzing sounds over a longer period of time, such as recognizing emotions.
Nanoparticle vaccines: A potential leap forward in veterinary medicine
Classical vaccines often rely on traditional technologies, such as live attenuated or inactivated pathogens, which carry inherent risks including reduced immunogenicity under certain conditions and potential safety concerns. This has spurred the need for innovative approaches that can provide safer and more effective prophylactic solutions in veterinary medicine.
Self-assembled protein nanoparticles (SAPNs) emerge as a cutting-edge solution, harnessing the power of nanotechnology to revolutionize vaccine design and implementation.
In an article published on 10 May 2024 in Animal Diseases, researchers at Zhejiang University's Institute of Preventive Veterinary Medicine, delve into the development and application of SAPNs and virus-like nanoparticles (VLPs), offering a detailed discussion of their potential in veterinary medicine.
The article focuses on various types of SAPNs, including natural and synthetically designed nanoparticles. These nanoparticles are tailored to enhance the immune system's ability to recognize and respond to pathogens more effectively.
Key highlights include the use of animal virus-derived nanoparticles and bacteriophage-derived nanoparticles, which have shown the potential to elicit strong cellular and humoral responses. The nanoparticles' ability to mimic pathogen structures enables them to trigger a more substantial immune reaction, potentially leading to long-lasting immunity.
Researchers have documented successes in using these nanoparticles to protect against diseases like foot-and-mouth disease and swine fever, showcasing their broad applicability and effectiveness.
Veterinary nanoparticle vaccines have broad implications, with the potential to extend the benefits beyond veterinary applications into human health. The enhanced safety and immunogenicity of these vaccines could lead to the development of advanced vaccines for human use.
Additionally, by reducing the environmental impact of livestock diseases, this technology may contribute to more sustainable agricultural practices globally.
Meiqi Sun et al, Toward innovative veterinary nanoparticle vaccines, Animal Diseases (2024). DOI: 10.1186/s44149-024-00119-w
How a world record 'squeeze' could offer comfort for dark matter hunters
Quantum engineers have developed a new amplifier that could help other scientists search for elusive dark matter particles.
Imagine throwing a ball. You'd expect science to be able to work out its exact speed and location at any given moment, right? Well, the theory of quantum mechanics says you can't actually know both with infinite precision at the same time.
It turns out that as you more precisely measure where the ball is, knowing its speed becomes less and less accurate.
This conundrum is commonly referred to as Heisenberg's uncertainty principle, named after the famous physicist Werner Heisenberg who first described it.
For the ball, this effect is imperceptible, but in the quantum world of small electrons and photons the measurement uncertainty suddenly becomes very significant.
That's the problem being addressed by a team of engineers who have developed an amplifying device that performs precise measurements of very weak microwave signals, and it does so through a process known as squeezing.
Squeezing involves reducing the certainty of one property of a signal in order to obtain ultra-precise measurements of another property.
The team of researchers have significantly increased the accuracy of measuring signals at microwave frequencies, like those emitted by your mobile phone, to the point of setting a new world record.
The precision of measuring any signal is fundamentally limited by noise. Noise is the fuzziness that creeps in and masks signals, which is something you may have experienced if you've ever ventured out of range when listening to AM or FM radio.
However, uncertainty in the quantum world means there is a limit as to how low noise can be made in a measurement.
Even in a vacuum, a space void of everything, the uncertainty principle tells us we must still have noise. We call this 'vacuum' noise. For many quantum experiments, vacuum noise is the dominant effect that prevents us from making more precise measurements.
The squeezer produced by the research team now can beat this quantum limit.
The device amplifies noise in one direction, so that noise in another direction is significantly reduced, or 'squeezed.' Think of the noise as a tennis ball, if we stretch it vertically, then it must reduce along the horizontal to maintain its volume. Researchers can then use the reduced part of the noise to do more precise measurements.
They showed that the squeezer is able to reduce noise to record low levels.
Squeezing is very difficult at microwave frequenciesbecause the materials used tend to destroy the fragile squeezed noise quite easily.
What they've done is a lot of engineering in order to remove sources of loss, which means utilizing very high-quality superconducting materials to build the amplifier.
And the team think that the new device could help speed up the search for notoriously elusive particles known as axions, which are so far only theoretical, but proposed by many as the secret ingredient of mysterious dark matter.
The squeezed noise itself could even be used in future quantum computers.
It turns out that squeezed vacuum noise is an ingredient to build a certain type of quantum computer. Excitingly, the level of squeezing they've achieved is not far off the amount needed to build such a system.
Arjen Vaartjes et al, Strong microwave squeezing above 1 Tesla and 1 Kelvin, Nature Communications (2024). DOI: 10.1038/s41467-024-48519-3
Atomic-resolution imaging shows why ice is so slippery
A team of physicists has uncovered the reason behind the slipperiness of ice. In their study, published in the journal Nature, the group used atomic force microscopy to get a closer look at the surface of ice at different temperatures.
Prior research and day-to-day experiences have shown that ice is slippery, even when temperatures are well below the freezing point. Research has suggested this is because of a pre-melt coating that develops at the surface, which serves as a lubricant.
In this new study, the research team used an atomic force microscope fitted with a carbon monoxide atom on its tip to get a better look at the structure of normal ice and its pre-melt coating.
The researchers began by chilling ice inside the microscope chamber to -150°C and then using the microscope to look at its atomic structure. They could see that the internal ice (known as ice Ih), and the ice at the surface were different.
The ice Ih, as expected, was arranged in stacked hexagons. The ice on the surface, by contrast, was only partially hexagonal. The researchers also found defects in the ice at the border between the two types of ice that occurred as the different ice shapes met one another.
The researchers then raised the temperaturein the chamber slightly, which resulted in more disorder as the differences in shape became more pronounced. The team then created a simulation showing how such disorder would impact the surface as a whole unit—it showed the disorder expanding all the way across the surface, giving the ice a liquid-like appearance that would be slippery if trod upon.
Jiani Hong et al, Imaging surface structure and premelting of ice Ih with atomic resolution, Nature (2024). DOI: 10.1038/s41586-024-07427-8
Bizarre bacteria scramble workflow of life Bacteria have stunned biologists by reversing the usual flow of information. Typically genes written in DNA serve as the template for making RNA molecules, which are then translated into proteins. Some viruses are known to have an enzyme that reverses this flow by scribing RNA into DNA. Now scientists have found bacteria with a similar enzyme that can even make completely new genes — by reading RNA as a template. These genes create protective proteins when a bacterium is infected by a virus. It should change the way we look at the genome.
Now, scientists have discovered an even weirder twist. A bacterial version of reverse transcriptase reads RNA as a template to make completely new genes written in DNA. These genes are then transcribed back into RNA, which is translated into protective proteins when abacterium is infected by a virus. By contrast, viral reverse transcriptases don’t make new genes; they merely transfer information from RNA to DNA.
The discovery that reverse transcriptase — which has previously been known only for copying genetic material — can create completely new genes has left other researchers gobsmacked.
How gut microbes drive tumour growth Scientists have long known that obese people have poorer cancer survival rates. Now they have some idea why. A high-fat diet increases the number of Desulfovibrio bacteria in the gut of mice. These release leucine, an amino acid, which encourages the proliferation of a kind of cell that suppresses the immune system. With a suppressed immune system, tumour growth can increase. In breast cancer patients, poorer outcomes were seen for women with higher body-mass index, who also had higher levels of Desulfovibrio bacteria in their gut and leucine in their blood. It’s a provocative finding that will open up new avenues that we should be thinking about.
Biggest risk factors for disease spread A meta-analysis of five ways that humanity’s environmental footprint spreads disease — biodiversity loss, chemical pollution, climate change, invasive species and deforestation/urbanization — suggests that conserving biodiversity, controlling invasive species and lowering greenhouse-gas emissions would reduce disease spread the most. This evidence can be used in international policy to spur action on climate change and biodiversity loss due to their negative impacts on disease.
Biologists observe recurring evolutionary changes, over time, in stick insects
A long-standing debate among evolutionary scientists goes something like this: Does evolution happen in a predictable pattern or does it depend on chance events and contingency? That is, if you could turn back the clock, as celebrated scientist Stephen Jay Gould (1941–2002) described in his famous metaphor, "Replaying the Tape of Life," would life on Earth evolve, once again, as something similar to what we know now, or would it look very, very different?
Now researchers report evidence of repeatable evolution in populations of stick insects in the paper "Evolution repeats itself in replicate long-term studies in the wild," in Science Advances.
The team examined three decades of data on the frequency of cryptic color-pattern morphs in the stick insect species Timema cristinae in ten naturally replicate populations in California. T. cristinae is polymorphic in regard to its body colour and pattern. Some insects are green, which allows the wingless, plant-feeding insect to blend in with California lilac (Ceanothus spinosus) shrubs. In contrast, green striped morphs disappear against chamise (Adenostoma fasciculatum) shrubs.
Hiding among the plants is one of T. christinae's key defenses as hungry birds, such as scrub jays, are insatiable predators of the stick insects.
Bird predation is a constant driver shaping the insects' organismal traits, including coloration and striped vs. non-striped.
Scientists observed predictable 'up-and-down' fluctuations in stripe frequency in all populations, representing repeatable evolutionary dynamics based on standing genetic variation.
A field experiment demonstrates these fluctuations involved negative frequency-dependent natural selection (NFDS), where cryptic colour patterns are more beneficial when rare rather than common. This is likely because birds develop a 'search image' for very abundant prey.
At short time scales, evolution involving existing variations can be quite predictable. You can count on certain drivers always being there, such as birds feeding on the insects.
But at longer time scales, evolutionary dynamics become less predictable.
The populations might experience a chance event, such as a severe droughtor a flooding event, that disrupts the status quo and thus, the predictable outcomes.
On long time scales, a new mutation in the species could introduce a rare trait. That's about as close to truly random as you can get.
Rare things are easily lost by chance, so there's a strong probability a new mutation could disappear before it gains a stronghold.
Indeed, another species of Timema stick insect that also feeds on chamise either never had or quickly lost the mutations making the cryptic stripe trait. Thus, the evolution of stripe is not a repeatable outcome of evolution at this long scale.
Replicated, long-term studies from natural populations, including research on the famous Darwin's finches, are rare.
Because most of this work is restricted to one or few populations, it is difficult to draw inferences on repeatability among multiple evolutionary independent populations.
Such studies are challenging to implement not only because they take concerted effort, but also because you can't rush time.
Fine air particles, less than 2.5 micrometers in diameter (PM2.5), are a major air pollutant linked to various health problems. These particles can travel deep into the lungs and even enter the bloodstream when inhaled. Recent research suggests a major health concern: PM2.5 exposure can also damage the digestive system, including the liver, pancreas, and intestines.
The work is published in the journal eGastroenterology. This recent research has been focused on how PM2.5 exposure triggers stress responses within the digestive system's cells. These stress responses involve specialized subcellular structures within cells called organelles, such as the endoplasmic reticulum (ER), mitochondria, and lysosomes. When PM2.5 disrupts these organelles, it creates a chain reaction within the cells that can lead to inflammation and other harmful effects.
The liver, a major organ for detoxification and metabolism, is particularly susceptible to PM2.5 damage. Studies have shown that PM2.5 exposure can lead to a cascade of problems within the liver, including inflammation, stress responses, and damage to the organelles, and disrupted energy metabolism. These effects can contribute to the development of non-alcoholic fatty liver disease (NASH) and type 2 diabetes.
PM2.5 exposure does not stop at the liver. It can also harm the pancreas and intestines. Studies have linked PM2.5 to an increased risk of pancreatic impairment in people with diabetes, as well as damage to intestinal cells and an increase in their permeability. This increased permeability can lead to a variety of digestive issues.
Researchers are exploring whether dietary or pharmaceutical interventions can mitigate PM2.5 damage. Interestingly, some studies suggest that certain nutrients, like monounsaturated fatty acids and vitamins, may offer some protection against the harmful effects of PM2.5.
Many plants and plant oils are high in monounsaturated fats but low in saturated fats. These include: oils from olives, peanuts, canola seeds, safflower seeds, and sunflower seeds, avocadoes, pumpkin seeds, sesame seeds, almonds, cashews, peanuts and peanut butter, pecans.
Air pollution is a complex issue with no easy solutions. While research continues mitigating PM2.5 exposure, the current understanding of its impact on the digestive system highlights the far-reaching consequences of air pollution on human health. It underscores the need for continued efforts to reduce air pollution levels and develop strategies to protect ourselves from its detrimental effects.
Big brands are 'failing to curb plastic sachet use'
Small plastic sachets commonly used in low- and middle-income countries must be phased out and packaging reuse systems promoted, urge campaigners and waste pickers, as new analysis reveals major corporations have failed to curb their use.
Pocket-sized individual portions of goods ranging from shampoo to instant coffee have become popular in lower-income communities for their affordability.
An estimated 855 billion sachets are sold globally each year with Southeast Asia consuming nearly half of the total and this figure projected to rise to 1.3 trillion by 2027, according to environmental groups.
But the convenience of sachets comes with a heavy environmental cost as they end up as significant contributors to plastic pollution. Their commonly multi-layered design, using different materials, makes them hard to recycle.
Consumer goods giants Unilever, Nestlé and Procter & Gamble are among the biggest contributors to plastic sachet pollution in developing countries in Asia, despite promises to reduce plastic packaging, according to a multi-country environmental audit report.
It said some corporations were trying to deal with the waste problem by burning sachets as fuel, creating further pollution.
Environmental groups in Asia have long been demanding firms to phase out their sachet packaging as the resulting waste is deluging the region's landfills and waters.
Consumers, can you please help by avoiding these small plastic sachet based products?
When massive stars die, as we understand the Universe, they don't go quietly. As their fuel runs out, they become unstable, wracked by explosions before finally ending their lives in a spectacular supernova.
But some massive stars, scientists have found, have simply vanished, leaving no trace in the night sky. Stars clearly seen in older surveys are inexplicably absent from newer ones. A star isn't exactly a set of keys – you can't just lose it down the back of the couch. So where the heck do these stars go?
A new study has given us the most compelling explanation yet. Some massive stars, suggest an international team led by astrophysicist Alejandro Vigna-Gómez of the Niels Bohr Institute in Denmark and the Max Planck Institute for Astrophysics in Germany, can die, not with a bang, after all, but a whimper.
Their evidence? A binary system named VFTS 243 in the Large Magellanic Cloud, consisting of a black hole and a companion star. This system shows no signs of a supernova explosion that, according to the models, ought to have accompanied the formation of the black hole.
Were one to stand gazing up at a visible star going through a total collapse, it might, just at the right time, be like watching a star suddenly extinguish and disappear from the heavens.
The collapse is so complete that no explosion occurs, nothing escapes and one wouldn't see any bright supernova in the night sky. Astronomers have actually observed the sudden disappearance of brightly shining stars in recent times. Scientists cannot be sure of a connection, but the results they have obtained from analyzing VFTS 243 has brought them much closer to a credible explanation.
Dr. Krishna Kumari Challa
Bid to end deadly cooking methods which stoke global warming
Fifty countries are meeting in France today to discuss the lack of access to clean cooking methods worldwide which causes millions of deaths every year and fuels global warming.
Some 2.3 billion people across 128 countries breathe in harmful smoke when they cook on basic stoves or over open fires, according to an International Energy Agency (IEA)-African Development Bank (ADB) report that sounded the alarm last year.
It said 3.7 million people a year die prematurely from harmful cooking practices, with children and women most at risk.
The IEA said the "unprecedented" Paris gathering aims to be "a moment of changing the direction". The problem "touches on gender, it touches on forestry, it touches on climate change, it touches on energy, it touches on health.
A third of the world cooks with fuels which produce harmful fumes when burned, including wood, charcoal, coal, animal dung and agricultural waste.
They pollute indoor and outdoor air with fine particles that penetrate the lungs and cause multiple respiratory and cardiovascular problems, including cancer and strokes.
These cooking practices are the third highest cause of premature deaths in the world and the second highest in Africa. In young children , they are a major cause of pneumonia, experts say.
They also prevent women and children from accessing education or earning a wage, as they spend hours looking for fuel.
Part 1
May 14
Dr. Krishna Kumari Challa
Greenhouse gas emissions from using basic stoves and deforestation from collecting wood also contribute hugely to global warming.
Switching to clean cooking methods, such as LPG or electric cooking, would save 1.5 billion tonnes of CO2 a year by 2030—roughly the amount emitted by ships and planes last year, according to the IEA.
IEA also recommends strong national leadership as well as grassroots efforts to change social norms.
Source: AFP and other news agencies
May 14
Dr. Krishna Kumari Challa
This New Plastic Disappears When You Don't Need It Anymore
The plastic that eats itself
Our reliance on plastic has become a huge problem, which is why researchers are excited about a new type of material – one that comes with built-in biodegrading capabilities, due to the bacterial spores living inside it. The new self-digesting plastic combines thermoplastic polyurethane (TPU) and Bacillus subtilis bacteria, which had to be engineered to survive the high temperatures involved in plastic production. By repeatedly exposing the spores to increasing levels of heat, the team of researchers behind this new work found that the bacteria could eventually cope with the temperatures of 135 degrees Celsius (275 degrees Fahrenheit) required to mix the bacterial spores and TPU together. Past efforts to find ways to degrade plastics, fast, have often sourced bacterial enzymes and fungi from soils and compost heaps where those microbes are naturally abundant. But this new material needs only the bacterial spores inside it, reawakened with some nutrients and moisture, to start breaking down.
https://www.nature.com/articles/s41467-024-47132-8
May 14
Dr. Krishna Kumari Challa
A minimal cognitive architecture reproduces control of human decision-making processes
Neuroscientists and psychologists have been trying to pinpoint the processes behind human decision-making for decades. While their efforts led to numerous interesting insights, the intricacies of complex decision-making remain poorly understood.
Researchers at the Paris Brain Institute carried out a study aimed at better understanding how the human brain allocates its resources when making decisions. Their paper, published in Communications Psychology, introduces an architecture that operates the online metacognitive control of decisions (oMCD), a theoretical construct describing why and how the brain choses to stop of continue deliberating.
Past studies have found that humans do not always invest their maximum mental efforts when making decisions. This can lead to various widely documented errors and cognitive biases (i.e., recurring deviations from rational thinking).
So when making a decision, what determines the amount of mental effort we invest in decisions?
Previous behavioral research suggested that, for certain kinds of decisions (so-called 'evidence-based' decisions), this may be done by balancing decision confidence (which tends to increase with mental effort) with the cost of mental effort. This then triggered the question: can this work for all kinds of decisions?
To address this question, researchers should first demonstrate that a confidence-based control policy eventually yields mental effort investments resembling those of optimal control policies that are specific to different kinds of decisions. This was one of the primary objectives of this work.
Part 1
May 15
Dr. Krishna Kumari Challa
Researchers approached this problem in many different ways.
In the context of this study, the researchers effectively provided two lines of evidence. The first one is theoretical in essence. Specifically, we rely on so-called Markov Decision Processes (MDPs) to demonstrate that confidence-based control policies are quasi-optimal for a broad class of decisions."
After having identified the non-trivial quantitative properties of confidence-based control policies, the researchers set out to determine whether these properties can be found in empirical data gathered in experiments where humans completed decision-making tasks. The properties they specifically sought for included three-way interactions between the values of different options, decision times and the reported confidence in a decision.
In brief, they identified a minimal cognitive architecture for quasi-optimal decision control (in terms of how much effort is invested). Importantly, this architecture may generalize over most, if not all, kinds of decision types. This implies that a single brain system may operate decision control, irrespective of the type of decision.
Juliette Bénon et al, The online metacognitive control of decisions, Communications Psychology (2024). DOI: 10.1038/s44271-024-00071-y.
Part 2
May 15
Dr. Krishna Kumari Challa
Why subsequent bouts of dengue are worse than a first-time infection
A massive upsurge in dengue cases marked by multiple outbreaks is occurring worldwide and raising new questions about who is at elevated risk of severe forms of the mosquito-transmitted disease.
Incidence of the infection has increased by orders of magnitude throughout the so-called dengue belt, which encompasses Central and South America, Sub-Saharan Africa, Southeast Asia and swaths of the South Pacific, home to densely populated islands. Dengue, without question, is the most widespread and rapidly increasing vector-borne disease in the world, according to the World Health Organization.
The story is similar in other dengue-affected areas of the world where lapses in vector control have conspired with global climate change to create an explosion of bloodthirsty mosquitoes, swarms of them moving into regions once considered dengue-free. Only female mosquitoes feed on blood, they're in constant need of the nutrients in it to nurture their eggs.
Now, more than two decades of dengue surveillance is answering a slew of questions at a time when the world needs guidance most.
Findings from the research have revealed how various subgroups—what virologists call subtypes—of the dengue virus influence future risk of severe infection. It has been known for years that those who become infected in subsequent outbreaks, after a usually mild bout with a first-time infection, are at significant risk of severe disease in later dengue exposures. New research finally has analyzed more than 15,000 cases to discern why that is so.
Writing in Science Translational Medicine, a global team of scientists has explained how the four dengue viral subtypes—DENV-1, 2, 3, and 4—influence the risk of repeated severe infections. The findings provide a new framework for disease monitoring and lay the foundation for vaccination strategies as the new dengue immunizations emerge.
Part 1
May 15
Dr. Krishna Kumari Challa
The team also underscored how dengue, a pernicious tropical malady, can be understood within the context of other common viral diseases that circle the globe.
The ability of viruses, such as SARS-CoV- 2 and influenza, to continuously change their genetic structure in response to the selective pressure of population immunity complicates control efforts.
In the case of dengue virus, an arbovirus that infects more than 100 million people each year, the situation is even more complex. Individuals with high dengue virus antibody titers are protected from infection and developing severe disease.
However, individuals with sub-neutralizing antibody titers have been shown to have the highest risk of severe disease, through multiple hypothesized mechanisms including antibody-dependent enhancement.
A dengue infection can be tricky. Some patients who have weathered an infection but get infected in a subsequent outbreak can have more severe symptoms the second time around. Yet, most research on repeat dengue infections has regarded each of the serotypes as no different from the other. An assessment of each serotype's genetic differences was needed to provide a clearer picture of potential risks.
To develop that clearer picture, researchers studied each serotype in more than 15,000 patients' infections as a way to peel away much of the mystery surrounding why first-time dengue illnesses are traditionally milder than subsequent ones.
Part 2
May 15
Dr. Krishna Kumari Challa
To determine how each of the viral serotypes affects the risk of severe disease, the researchers analyzed viral genetic data. The team also studied cases of patients hospitalized for dengue to determine which viral subtype caused their infections. Researchers gathered data from 21 years of dengue surveillance, ranging from 1994 to 2014, in a children's hospital in Bangkok, encompassing 15,281 individual cases. This allowed them to find repeat cases and each viral subtype in all infections.
Based on the pediatric patients' hospital records, researchers discovered a link between hospitalization and the order in which patients became infected with different dengue-virus serotypes. They were also able to determine which combinations of viral subtypes pointed to mild or severe forms of dengue. For instance, people who became infected with serotypes that were very similar, such as DENV-3 and DENV-4, or very different serotypes as in the case of DENV-1 and DENV-4, tended to have a lower risk of severe disease during the second infection.
Patients who were infected with serotypes that were only moderately different had a higher risk of severe symptoms in subsequent infections. The highest risk group in this category involved patients who had an initial infection with DENV-2 followed by a subsequent infection triggered by DENV-1.
The new research adds clarity to a disease risk that may seem paradoxical to the lay public. For example, most people infected with dengue virus for the first time develop extremely mild signs of the disease or none at all. But for those who do get sick, soaring fever, headache, body aches, nausea and rash are the primary symptoms, and they intensify in severe manifestations of the infection.
For more than a century a severe bout with dengue has been known as breakbone fever because of the intensity of the pain and accompanying muscle spasms.
The virus is carried in the tropics and subtropics by Aedes aegypti and Aedes albopictus mosquitoes, which are endemic in the dengue belt. But while the belt, which runs through latitudes 35-degrees North and 35-degrees South, has traditionally been home to dengue-carrying mosquitoes, the arthropods have been extending their range northward as global climate change intensifies, scientists say.
These findings suggest that immune imprinting helps determine dengue disease risk and provides a pathway to monitor the changing risk profile of populations and to quantifying risk profiles of candidate vaccines.
Lin Wang et al, Antigenic distance between primary and secondary dengue infections correlates with disease risk, Science Translational Medicine (2024). DOI: 10.1126/scitranslmed.adk3259
Part 3
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May 15
Dr. Krishna Kumari Challa
Artificial intelligence tool detects sex-related differences in brain structure
Artificial intelligence (AI) computer programs that process MRI results show differences in how the brains of men and women are organized at a cellular level, a new study shows. These variations were spotted in white matter, tissue primarily located in the human brain's innermost layer, which fosters communication between regions.
The work appears in Scientific Reports.
Men and women are known to experience multiple sclerosis, autism spectrum disorder, migraines, and other brain issues at different rates and with varying symptoms. A detailed understanding of how biological sex impacts the brain is therefore viewed as a way to improve diagnostic tools and treatments. However, while brain size, shape, and weight have been explored, researchers have only a partial picture of the brain's layout at the cellular level.
The new study used an AI technique called machine learning to analyze thousands of MRI brain scans from 471 men and 560 women. Results revealed that the computer programs could accurately distinguish between biological male and female brains by spotting patterns in structure and complexity that were invisible to the human eye.
The findings were validated by three different AI models designed to identify biological sex using their relative strengths in either zeroing in on small portions of white matter or analyzing relationships across larger regions of the brain.
These findings provide a clearer picture of how a living, human brain is structured, which may in turn offer new insight into how many psychiatric and neurological disorders develop and why they can present differently in men and women.
For the research, researchers started by feeding AI programs existing data examples of brain scans from healthy men and women and also telling the machine programs the biological sex of each brain scan. Since these models were designed to use complex statistical and mathematical methods to get "smarter" over time as they accumulated more data, they eventually "learned" to distinguish biological sex on their own. Importantly, the programs were restricted from using overall brain size and shape to make their determinations.
According to the results, all of the models correctly identified the sex of subject scans between 92% and 98% of the time. Several features in particular helped the machines make their determinations, including how easily and in what direction water could move through brain tissue.
These results highlight the importance of diversity when studying diseases that arise in the human brain.
Part 1
May 15
Dr. Krishna Kumari Challa
If, as has been historically the case, men are used as a standard model for various disorders, researchers may miss out on critical insight.
While the AI tools could report differences in brain-cell organization, they could not reveal which sex was more likely to have which features.
According to the researchers, the team next plans to explore the development of sex-related brain structure differences over time to better understand environmental, hormonal, and social factors that could play a role in these changes.
Deep Learning with Diffusion MRI as in vivo Microscope Reveals Sex-related Differences in Human White Matter Microstructure, Scientific Reports (2024).
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Part 2
May 15
Dr. Krishna Kumari Challa
Analysis suggests people with more copies of ribosomal DNA have higher risks of developing disease
Ribosomal DNA (rDNA) is present in hundreds of copies in the genome, but has not previously been part of genetic analyses. A new study of 500,000 individuals indicates that people who have more copies of rDNA are more likely to develop inflammation and diseases during their lifetimes.
Standard genetic analysis techniques have not studied areas of the human genome that are repetitive, such as ribosomal DNA (rDNA), a fundamental part of the molecular mechanism which makes proteins in cells.
A new study has discovered that genetic disposition to disease can be found in these previously understudied areas of the genome.
The results, published in Cell Genomics, suggest that wider genome analysis could bring opportunities for preventative diagnostics, novel therapeutics, and greater insight into the mechanism of different human diseases.
In this study, samples from 500,000 individuals in the UK Biobank project were analyzed. Researchers used new whole genome sequencing (WGS) techniques to identify differences in numbers of copies of rDNA in each sample, and compared them with other health metrics and medical records.
The researchers found that the number of copies of rDNA in an individual showed strong statistical association with well-established markers of systemic inflammation—such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII). These statistically significant associations were seen in the genomes of individuals of different ethnicities, suggesting a common indicator for risks of future disease.
Part 1
May 15
Dr. Krishna Kumari Challa
rDNA copy number was also linked with an individual's kidney function within the sample of individuals of European ancestry. A similar effect was seen in samples from other ancestries, but further research using larger sample sizes will be needed to confirm this connection.
This research highlights the importance of analyzing the whole genome to better understand the factors impacting on our health. This study is also an example of how having access to large biobanks allows us to make unexpected discoveries, and provides new avenues for harnessing the power of genetics to understand human diseases.
Geneticists have long struggled to fully explain the genetic basis of many common complex traits and diseases. This work suggests that at least part of this missing heritability resides in difficult to sequence regions of the genome such as those encoding ribosomal copy number variation.
Ribosomal DNA Copy Number Variation Associates with Hematological Profiles and Renal Function in the UK Biobank, Cell Genomics (2024). DOI: 10.1016/j.xgen.2024.100562. www.cell.com/cell-genomics/ful … 2666-979X(24)00128-9
Part 2
May 15
Dr. Krishna Kumari Challa
Scientists develop sticky pesticide to combat pest insects
Researchers have engineered a biological barrier that protects plants from diseases and pests. It concerns a sticky substance that is sprayed on leaves, to which pests stick.
The researchers hope that this insect glue will help to reduce the use of toxic chemical pesticides. They published their findings in the Proceedings of the National Academy of Sciences.
In the search for alternatives, scientists turned to nature for inspiration. The carnivorous sundew plant has so-called glandular hairs that secrete a sticky substance to catch insects. The researchers wanted to mimic this to protect the plants and crops in a natural way.
The researchers succeeded in their endeavor.
They transformed vegetable rice oil into a yellow, sticky substance by blowing air over it and grinding it into small particles using a laboratory blender. This results in beads of about one millimeter in diameter that are as sticky as duct tape. The size matches one of the common pest insect: thrips. By catching these insects, plants stay healthier and are less likely to become infected with fungi that the thrips carry with them.
So far, the researchers mainly focused on this type of pest, but the insect glue may also work against other pests, such as the Suzuki fruit fly that currently threatens cherry cultivation. At the same time, the drops are small enough that beneficial insects, such as pollinators, do not get stuck.
Unlike chemical pesticides, insects are unlikely to develop resistance against this adhesive, the researchers think.
Insects have already evolved so that they avoid adhesion, for example through hairs on their body and a bumpy surface. Increasing their body size remains one of the few escape methods from this sticky trap. That is not nearly as easy as developing tolerance to a chemical substance. If it happens at all, it takes many generations and only happens if the insect glue is used on a large scale.
After application, the sticky substance remains on the leaves for three months and cannot be washed off by rain. That is long enough to control pests until harvest. By spraying the insect glue on crops before the fruits develop, farmers minimize the chance of the pesticide getting onto the food. However, contact with food cannot be ruled out.
The advantage of this pesticide over chemical pesticides is that you can see the small, yellow drops. You can wash it off with water and dish soap. If you do ingest some of it, it is probably not harmful. As it is derived from vegetable oil.
But scientists still need to investigate how (un)healthy it is exactly.
Ralph van Zwieten et al, Mimicking natural deterrent strategies in plants using adhesive spheres, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2321565121
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May 15
Dr. Krishna Kumari Challa
Scientists discover blood proteins that may give cancer warning seven years before diagnosis
Two studies have discovered proteins in the blood that could warn people of cancer more than seven years before it is diagnosed.
Scientists identified 618 proteins linked to 19 different types of cancer, including 107 proteins in a group of people who blood was collected at least seven years before diagnosis. The team has discovered that these proteins could be involved at the very earliest stages of cancer, where it could be prevented.
They think that some of these proteins could be used to detect cancer much earlier than is currently possible. In the future, this could help treat the disease at a much earlier stage or prevent it altogether.
The papers, titled "Identifying proteomic risk factors for cancer using prospective and exome analyses of 1,463 circulating proteins and risk of 19 cancers in the UK Biobank" and "Identifying therapeutic targets for cancer among 2,074 circulating proteins and risk of nine cancers," are published in Nature Communications.
In these studies, the team used a powerful technique called proteomics. Proteomics allows scientists to analyze a large set of proteins in tissue samples at a single point in time, to see how they interact with each other and find any important differences in proteins between different tissue samples.
In the first study, scientists analyzed blood samples from UK Biobank that had been taken from more than 44,000 people, including over 4,900 people who subsequently had a cancer diagnosis.
Using proteomics, the team analyzed a set of 1,463 proteins from a single sample of blood from each person. They compared the proteins of people who did and did not go on to be diagnosed with cancer to look for important differences between them and find out which ones were linked to cancer risk. The scientists also identified 182 proteins that differed in the blood three years before a cancer diagnosis took place.
In the second study, the scientists looked at genetic data from over 300,000 cancer cases to do a deep dive into which blood proteins were involved in cancer development and could be targeted by new treatments.
The scientists found 40 proteins in the blood that influenced someone's risk of getting 9 different types of cancer. While altering these proteins may increase or decrease the chances of someone developing cancer, the scientists also found that in some cases this may lead to unintended side effects.
However, the team stressed that they will need to do further research to find out the exact role these proteins play in cancer development, which of the proteins are the most reliable ones to test for, which tests could be developed to detect the proteins in the clinic, and which drugs could target these proteins.
Part 1
May 16
Dr. Krishna Kumari Challa
Identifying proteomic risk factors for cancer using prospective and exome analyses of 1,463 circulating proteins and risk of 19 cancers in the UK Biobank, Nature Communications (2024). www.nature.com/articles/s41467-024-48017-6
Karl Smith-Byrne et al, Identifying therapeutic targets for cancer among 2074 circulating proteins and risk of nine cancers, Nature Communications (2024). DOI: 10.1038/s41467-024-46834-3
Part 2
May 16
Dr. Krishna Kumari Challa
Scientists generate heat over 1,000°C with solar power instead of fossil fuel
Instead of burning fossil fuels to smelt steel and cook cement, researchers in Switzerland want to use heat from the sun. The proof-of-concept study, published May 15 in the journal Device, uses synthetic quartz to trap solar energy at temperatures over 1,000°C (1,832°F), demonstrating the method's potential role in providing clean energy for carbon-intensive industries.
Glass, steel, cement, and ceramics are at the very heart of modern civilization, essential for building everything from car engines to skyscrapers. However, manufacturing these materials demands temperatures over 1,000°C and relies heavily on burning fossil fuels for heat. These industries account for about 25% of global energy consumption.
Researchers have explored a clean-energy alternative using solar receivers, which concentrate and build heat with thousands of sun-tracking mirrors. However, this technology has difficulties transferring solar energy efficiently above 1,000°C.
To boost the efficiency of solar receivers, the researchers turned to semitransparent materials such as quartz, which can trap sunlight—a phenomenon called the thermal-trap effect. The team crafted a thermal-trapping device by attaching a synthetic quartz rod to an opaque silicon disk as an energy absorber.
When they exposed the device to an energy flux equivalent to the light coming from 136 suns, the absorber plate reached 1,050°C (1,922°F), whereas the other end of the quartz rod remained at 600°C (1,112°F).
Using a heat transfer model, the team also simulated the quartz's thermal-trapping efficiency under different conditions. The model showed that thermal trapping achieves the target temperature at lower concentrations with the same performance, or at higher thermal efficiency for equal concentration.
Solar thermal trapping at 1000 ºC and above, Device (2024). DOI: 10.1016/j.device.2024.100399. www.cell.com/device/fulltext/S2666-9986(24)00235-7
May 16
Dr. Krishna Kumari Challa
Gut bacteria enhance cancer immunotherapy in mouse study
Roughly one in five cancer patients benefit from immunotherapy—a treatment that harnesses the immune system to fight cancer. Such an approach to beating cancer has seen significant success in lung cancer and melanoma, among others. Optimistic about its potential, researchers are exploring strategies to improve immunotherapy for cancers that don't respond well to the treatment, with the hope of benefiting more patients.
Cancer immunotherapy employs the body's immune cells to target and destroy tumors. One such treatment uses immune checkpoint inhibitor drugs to unleash the immune system by releasing the natural brakes that keep immune T cells quiet, a feature that prevents the body from harming itself. But some tumors fight back to suppress the attacking immune cells, damping the effectiveness of such inhibitors.
Now, researchers have found, in mice, that a strain of gut bacteria—Ruminococcus gnavus—can enhance the effects of cancer immunotherapy. The study, which appears May 17 in Science Immunology, suggests a new strategy of using gut microbes to help unlock immunotherapy's untapped cancer-fighting potential.
R. gnavus has been found in gut microbiota of cancer patients who respond well to immunotherapy. In clinical trials, fecal transplants from such individuals have helped some unresponsive patients reap immunotherapy's benefits.
Blanda Di Luccia et al, TREM2 deficiency reprograms intestinal macrophages and microbiota to enhance anti-PD-1 tumor immunotherapy, Science Immunology (2024). DOI: 10.1126/sciimmunol.adi5374. www.science.org/doi/10.1126/sciimmunol.adi5374
May 18
Dr. Krishna Kumari Challa
New technique to freeze brain tissue without harm
A team of medical researchers has developed a technique to freeze and thaw brain tissue without causing damage.
In their study, published in the journal Cell Reports Methods, the group tested bathing brain organoid tissue in candidate chemicals before freezing them using liquid nitrogen.
Prior research has shown that no matter how quickly brain matter is frozen, the freezing and thawing process always causes tissue damage. This has made it more difficult for researchers to study brain matter because research must be conducted immediately after obtaining a tissue sample. In this new effort, the team found a way around this problem by soaking the tissue in a special solution before freezing.
The work involved dipping or soaking brain organoids (brain tissue grown from stem cells) in candidate compounds and then freezing and thawing them to see how they fared. After many attempts, they found one combination of solutions that worked best—a mix of ethylene glycol, methylcellulose DMSO and Y27632. They named the solution mix MEDY.
The research team then tested MEDY under a variety of conditions to see how well it prevented damage from freezing. The conditions involved changing variables, such as the age of the organoids prior to freezing and how long they were soaked in a MEDY solution. They then allowed the organoids to resume growing after they were thawed for up to 150 days.
The researchers found little difference between organoids that had been frozen and those that had not—even those that had been frozen for as long as 18 months.
As a final test, the research team used their technique on a sample of brain tissue obtained from a live human patient and found that it worked just as well.
The research team suggests that their technique should allow researchers to store brain tissue samples on a scale large enough to allow for new types of brain and nervous system research.
Weiwei Xue et al, Effective cryopreservation of human brain tissue and neural organoids, Cell Reports Methods (2024). DOI: 10.1016/j.crmeth.2024.100777
May 18
Dr. Krishna Kumari Challa
Microplastics may slow the rate at which carbon is pulled from the sea surface to the depths
Plastics in the ocean do more harm than suffocate turtles, fish and other marine life.
A new study shows that microplastics may reduce the ability of the ocean to help offset the climate crisis by slowing down the rate at which carbon is taken from the sea surface to the depths.
For millennia, the ocean has been part of a carbon sink process in which dead phytoplankton clump together and fall into the deep ocean in showers of what look like "marine snow". The resulting carbon sequestration is a marine version of how trees and plants on terrestrial Earth take carbon from the atmosphere and store it in soil.
But new research shows that microplastics in the ocean are slowing the process down by making the "marine snow" more buoyant. Plastics want to float. If phytoplanktons grow on microplastics in biofilms, instead of as free living organisms, that changes the buoyancy of the phytoplankton when they die.
Basically, the plastics are slowing down the sinking rate of the marine snow, which is potentially reducing the efficiency with which the ocean can remove carbon dioxide from the atmosphere.
So microplastics could be a threat to global scale processes, such as the carbon cycle that is so important for all life.
Kai Ziervogel et al, Microbial interactions with microplastics: Insights into the plastic carbon cycle in the ocean, Marine Chemistry (2024). DOI: 10.1016/j.marchem.2024.104395
May 18
Dr. Krishna Kumari Challa
A high-fat diet promotes cancer progression by inducing gut microbiota–mediated leucine production
Researchers have found a link between diet, a type of gut bacterium and breast cancer. The study, published on 6 May in the Proceedings of the National Academy of Science, found that a high-fat diet increased the number of Desulfovibrio bacteria in the guts of mice, suppressing their immune systems and accelerating tumour growth.
Researchers say the finding could spark new ideas for therapies for breast cancer, the most common malignancy affecting women worldwide.
Mice that are fed a high-fat diet often serve as a proxy for human obesity in animal studies. The team found that mice consuming a high-fat diet had more Desulfovibrio bacteria and had elevated levels of a type of cell that suppresses the immune system, myeloid-derived suppressor cells (MDSCs), which originate in the bone marrow. This suggested to the researchers that higher numbers of Desulfovibrio bacteria and a suppressed immune system were linked;
High-fat-diet mice also had higher levels of the amino acid leucine circulating in their blood than did mice fed a normal diet. Knowing that leucine can be made by some kinds of gut bacteria, the team treated the mice with antibiotics that killed Desulfovibrio. This caused both MDSC and leucine levels to return to normal.
Armed with this information, the researchers went back to the blood samples that they had taken from the people with breast cancer. As anticipated, those with a BMI of more than 24 had higher levels of leucine, more immunosuppressive MDSCs and survived fewer years post-treatment than those with a lower BMI.
In other words, Desulfovibrio bacteria, benefiting from a high-fat diet, made excess leucine. This caused a spike in the numbers of MDSCs, which suppress the immune system and allow tumours to grow.
https://www.nature.com/articles/d41586-024-01443-4?utm_source=Live+...
https://www.pnas.org/doi/10.1073/pnas.2306776121?utm_source=Live+Au...
May 18
Dr. Krishna Kumari Challa
Why digging soil is not good?
Digging disrupts natural processes that keep soil healthy and productive. Minimising cultivation is desirable when trying to grow plants in ways that have the least environmental impact.
Digging the soil bulldozes a number of structures underground. Drainage channels created by worms are destroyed, important fungal networks are broken and carbon that’s been locked in the soil is released into the atmosphere.
Digging also brings weed seeds closer to the surface, causing them to sprout more readily.
Benefits don’t necessarily include better crops, although some gardeners have reported higher yields.
Charles Dowding, a champion of no-dig gardening, compared side-by-side beds over eight years. One was dug, the other wasn’t. He reported 100kg of additional produce from the no-dig bed.
So how does a no-dig garden grow? Instead of cultivating the soil, no-dig gardeners cover their beds with a layer of mulch or well-rotted organic matter, either from their own compost bins or the garden centre.
If the ground is weedy, simply cover it with a few sheets of cardboard.
Then add another layer of compost on top (this is sometimes known as lasagne gardening).
The weeds will be smothered and plants root into the soil below, which will be enriched by the activity of worms carrying the compost into the underlying soil.
Source:
https://www.sciencefocus.com/science/no-dig-gardening?utm_campaign=...
May 19
Dr. Krishna Kumari Challa
Discovery may explain why Egyptian pyramids were built along long-lost Ahramat branch of the Nile
Some 31 pyramids in Egypt, including the Giza pyramid complex, may originally have been built along a 64-km-long branch of the river Nile which has long since been buried beneath farmland and desert. The findings, reported in a paper in Communications Earth & Environment, could explain why these pyramids are concentrated in what is now a narrow, inhospitable desert strip.
The Egyptian pyramid fields between Giza and Lisht, built over a nearly 1,000-year period starting approximately 4,700 years ago, now sit on the edge of the inhospitable Western Desert, part of the Sahara. Sedimentary evidence suggests that the Nile used to have a much higher discharge, with the river splitting into several branches in places. Researchers have previously speculated that one of these branches may have flown by the pyramid fields, but this has not been confirmed.
Eman Ghoneim and colleagues studied satellite imagery to find the possible location of a former river branch running along the foothills of the Western Desert Plateau, very near to the pyramid fields. They then used geophysical surveys and sediment cores to confirm the presence of river sediments and former channels beneath the modern land surface, indicating the presence of a former branch, which they propose naming "Ahramat" (meaning pyramids in Arabic).
The authors suggest that an increased build-up of windblown sand, linked to a major drought which began approximately 4,200 years ago, could be one of the reasons for the branch's migration east and eventual silting up.
The discovery may explain why these pyramid fields were concentrated along this particular strip of desert near the ancient Egyptian capital of Memphis, as they would have been easily accessible via the river branch at the time they were built. Additionally, the authors found that many of the pyramids had causeways that ended at the proposed riverbanks of the Ahramat branch, which they suggest is evidence the river was used for transporting construction materials.
The findings reiterate the importance of the Nile as a highway and cultural artery for ancient Egyptians, and also highlight how human society has historically been affected by environmental change, according to the authors.
Future research to find more extinct Nile branches could help prioritize archaeological excavations along their banks and protect Egyptian cultural heritage, they add.
Eman Ghoneim, The Egyptian pyramid chain was built along the now abandoned Ahramat Nile Branch, Communications Earth & Environment (2024). DOI: 10.1038/s43247-024-01379-7. www.nature.com/articles/s43247-024-01379-7
May 20
Dr. Krishna Kumari Challa
Quantum Breakthrough Could Charge Batteries in a Snap
Batteries based on the wave-like nature of charged particles could revolutionize energy storage, potentially cramming in more power at a faster rate than conventional electrochemical cells could ever hope to manage. A new protocol developed by a team of physicists from National Cheng Kung University could transform the basic principles of a fast-charging quantum battery into a practical system, demonstrating ways the superposition of a battery may be used to store energy quickly and efficiently.Fundamental to quantum physics is the principle that all bits of matter have a wave-like identity that spreads out through space and time.
As counterintuitive as it is to our experience of reality, these waves represent the properties of an object – whether it's an electron, a molecule, a cat, or a whole planet – as a spectrum of possibility referred to as its superposition.
In recent years, researchers have pondered whether one or more objects in a superposition have something in common with the chaotic zip and bounce of heated material in an engine. Tapping into this quantum phenomenon could even provide new ways to transfer and hold energy.
It's a nice idea in concept, but transforming the theory behind quantum heat engines into a working device requires identifying suitable processes that don't waste a whole lot of energy.
The researchers experimentally evaluated two approaches to using the superposition of a particle to charge a hypothetical quantum battery to determine whether its fuzzy state is indeed transferring energy.
In place of an actual battery, the team simply used a trapped ion in a superposition state known as a qubit, which can gain energy as it passes through a reflective space that constrains the kinds of waves passing through.
Sending the ion through a device that split its wave into two beams, the team compared the battery's ability to store energy as separated waves passed through multiple entry points into a single cavity, and then into multiple cavities.
Not only did they find the ion's superposition really can allow for efficient charging, they found the 'many doorways, one room' approach induced an interference effect that could theoretically lead to what they call a "perfect charging phenomenon", which allows a complete conversion of stored energy to work from the quantum battery at any point in the charging process.
Part 1
May 20
Dr. Krishna Kumari Challa
They also demonstrated the process as scalable, with the interference effect persisting even when sending more than one qubit through the cavity.
By carrying out the process on the IBM Quantum Platform and IonQ's quantum hardware, the team demonstrated a proof-of-concept for their protocol, showing a similar system could have the potential to be an energy-effective way of rapidly charging and extracting power from a quantum system.
Though a qubit can simulate the fundamental physics, new methods will be needed to turn the protocol into something more practical and battery-like, meaning it will be a while before you'll be recharging your electric moped in an eyeblink.
Still, the experiment shows there's nothing in the laws of physics that says we can't exploit the quantum landscape for long-life, rapid-charging energy storage.
https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearc...
Part 2
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May 20
Dr. Krishna Kumari Challa
What is the Blood Brain Barrier?
May 20
Dr. Krishna Kumari Challa
Composition of gut microbiota could influence decision-making
The way we make decisions in a social context can be explained by psychological, social, and political factors. But what if other forces were at work? Scientists show that changes in gut microbiota can influence our sensitivity to fairness and how we treat others. Their findings are published in the journal PNAS Nexus.
The intestinal microbiota—i.e., all the bacteria, viruses and fungi that inhabit our digestive tract—plays a pivotal role in our bodies, well beyond digestive function. Recent research underscores its impact on cognition, stress, anxiety, depressive symptoms, and behaviour; mice raised in a sterile environment, for example, have difficulty interacting with other individuals.
While these findings are promising, most of this research is carried out on animals and cannot be extrapolated to humans. Nor does it allow us to understand what neuronal, immune, or hormonal mechanisms are at work in this fascinating dialogue between brain and intestine: researchers observe a link between the composition of the microbiota and social skills but do not know precisely how one controls the other.
The available data suggests that the intestinal ecosystem communicates with the central nervous system via various pathways, including the vagus nerve. It might also use biochemical signals that trigger the release of neurotransmitters, such as dopamine and serotonin, which are essential for proper brain function.
To determine whether the composition of the human gut microbiota could influence decision-making in a social setting, researchers used behavioural tests—including the famous "ultimatum game" in which one player is given a sum of money he must split (fairly or unfairly) with a second player, who is free to decline the offer if s/he deems it insufficient. In that case, neither player receives any money.
Refusing the sum of money is equivalent to what we call "altruistic punishment," i.e., the impulse to punish others when a situation is perceived as unfair: for the second player, restoring equality (no one receives any money) sometimes feels more important than obtaining a reward. The ultimatum game is then used as an experimental way of measuring sensitivity to fairness.
To fully exploit this effect, the researchers recruited 101 participants. For seven weeks, 51 took dietary supplements containing probiotics (beneficial bacteria) and prebiotics (nutrients that promote the colonization of bacteria in the gut), while 50 others received a placebo. They all participated in an ultimatum game during two sessions at the beginning and end of the supplementation period.
Part 1
May 21
Dr. Krishna Kumari Challa
The study's results indicate that the group that received the supplements was much more inclined to reject unequal offers at the end of the seven weeks, even when the money split was slightly unbalanced. Conversely, the placebo group behaved similarly during the first and second test sessions.
Moreover, the behavioral change in the supplemented group was accompanied by biological changes: the participants who, at the start of the study, had the greatest imbalance between the two types of bacteria that dominate the gut flora (Firmicutes and Bacteroidetes) experienced the most significant change in the composition of their gut microbiota with the intake of supplements. In addition, they also showed the greatest sensitivity to fairness during the tests.
The researchers also observed a sharp drop in their levels of tyrosine, a dopamine precursor, after the seven-week intervention. For the first time, a causal mechanism is emerging: the composition of the gut microbiota could influence social behavior through the precursors of dopamine, a neurotransmitter involved in brain reward mechanisms.
"It's too early to say that gut bacteria can make us less rational and more receptive to social considerations," conclude the researchers.
However, these new results clarify which biological pathways we must look at. The prospect of modulating the gut microbiota through diet to positively influence decision-making is fascinating. We need to explore this avenue very carefully.
Marie Falkenstein et al, Impact of the gut microbiome composition on social decision-making, PNAS Nexus (2024). DOI: 10.1093/pnasnexus/pgae166
Part 2
May 21
Dr. Krishna Kumari Challa
Rusting Rivers: The Alarming Impact of Permafrost Thaw on Arctic Rivers
In this video, researchers reveal the startling discovery of over 75 streams and rivers in Alaska's Brooks Range turning orange due to metals released in permafrost thaw. Researchers delve into the consequences of this phenomenon, its impact on aquatic ecosystems and local communities, and the ongoing research efforts to understand and mitigate these changes.
May 21
Dr. Krishna Kumari Challa
Now Cancer drug pollution is a cause for concern!
As incidence of cancer increases globally, the use of cancer drugs is also growing at a rate of approximately 10 percent per year in developed countries.
Pharmaceuticals significantly contribute to the improvement of human health; however, their environmental impacts have also become a major concern.
Cancer drugs in our ecosystems
Among the many molecules used to treat cancers are cytostatics.
As defined by the United States' National Institutes of Health (NIH), a cystostatic is "a substance that slows or stops the growth of cells, including cancer cells, without killing them."
When a cancer patient takes these drugs, the chemicals in them, including cytostatics, are eventually evacuated through the patients' solid and liquid waste.
A patients' waste ends up in the hospital or domestic wastewater system, where the chemicals in it are not entirely eliminated by end of pipe wastewater treatment plants. These chemicals can then find their way into aquatic ecosystems, and even our drinking water supply, at varying concentrations.
Cytostatic drugs are now classified as contaminants of emerging concern (CECs) due to their hazardous environmental impact.
The message is clear: this problem is only going to get worse as more people use cancer drugs.
The continuous release of pharmaceuticals into aquatic ecosystems (even at low levels) can reduce surface water quality, endanger biodiversity and disrupt ecosystem functioning.
They have a toxic impact on aquatic flora and fauna, especially the fish.
https://www.sciencedirect.com/science/article/abs/pii/S004896972205...
May 21
Dr. Krishna Kumari Challa
Scientists Confirm Microplastics Now Detected in Human Testicles
We can now add testicles to the list of places where microplastics have managed to spread – alongside human placentas, ancient rocks, clogged arteries, blue whales, baby poop, the wilderness of Antarctica, near the peak of Mount Everest, and the bottom of the ocean.
Research led by the University of New Mexico looked at testicular tissue taken from both dogs and humans, finding microplastics in every sample, with an abundance almost three times higher in humans than in dogs.
The team found an average 122.63 micrograms of microplastics per gram of tissue in canines, and 329.44 micrograms per gram in people.
Besides giving us another sobering reminder of how plastic pollution is penetrating every part of our bodies, the study raises some concerning questions in regards to how these microscopic fragments might impact male fertility.
https://academic.oup.com/toxsci/advance-article-abstract/doi/10.109...
May 21
Dr. Krishna Kumari Challa
Male and female mice exhibit different empathic behaviors to others' pain
Social interactions are multi-faceted experiences that entail understanding the emotional states of others and responding appropriately. Neuroscientists and psychologists have been studying social interactions for decades, in the hope of understanding their neural and behavioral underpinnings.
A team of researchers recently carried out a study exploring how male and female mice respond to the pain of other mice. Their findings, published in Neuron, suggest that there are both neurobiological and behavioural differences between the two sexes, specifically in relation to their empathic responses.
Recognizing the affective states of social counterparts and responding appropriately fosters successful social interactions.
The primary objective of the recent study was to delve deeper into how male and female mammals respond to another animal in pain, both in terms of their behavior and brain activity. To do this, they carried out a series of experiments on mice, where two mice were placed in lateral chambers, while an observing mouse was placed in the central section of a common cage.
One of the mice in the lateral chamber was given an injection that caused abdominal pain, while the other two were not administered anything. The researchers monitored the behavior of the mouse in the central part of the cage, who could explore the environment freely and thus whether to interact with the other mice and in what ways.
Initially, both male and female mice moved in their surroundings, displaying similar exploratory behaviors. Yet after a while, particularly towards the end of each experimental trial, the team found that male mice exhibited more grooming behaviors, while female mice demonstrated a social preference for the mouse that was in pain, as they spent more time in its proximity and sniffing it.
"We show that male and female mice emit distinct olfactory cues after experiencing distress," the researchers wrote. "These cues activate distinct neural circuits in the piriform cortex (PiC) and evoke sexually dimorphic empathic behaviours on observers.
Specifically, the PiC → PrL pathway is activated in female observers, inducing a social preference for the distressed counterpart. Conversely, the PiC → MeA pathway is activated in male observers, evoking excessive self-grooming behaviors."
This distinct neural pathway that the researchers found to be activated in male observers originated from non-overlapping PiC neuron populations with different gene expression signatures. Notably, these gene expression signatures are regulated by transcription factors and sex hormones.
Overall, their observations suggest that male and female mice are biologically inclined to respond differently to other mice in pain. While females are more likely to get closer to a peer who is in pain, males tend to respond to another's pain with excessive self-grooming.
The results of this study could soon be explored further and validated in additional experiments. In the future, they could pave the way for the discovery of new neural processes underpinning sex-specific social behaviours.
Shunchang Fang et al, Sexually dimorphic control of affective state processing and empathic behaviors, Neuron (2024). DOI: 10.1016/j.neuron.2024.02.001
May 22
Dr. Krishna Kumari Challa
Body lice may be bigger plague spreaders than previously thought
A new laboratory study suggests that human body lice are more efficient at transmitting Yersinia pestis, the bacterium that causes plague, than previously thought, supporting the possibility that they may have contributed to past pandemics.
Y. pestis has been the culprit behind numerous pandemics, including the Black Death of the Middle Ages that killed millions of people in Europe. It naturally cycles between rodents and fleas, and fleas sometimes infect humans through bites; thus, fleas and rats are thought to be the primary drivers of plague pandemics.
Body lice—which feed on human blood—can also carry Y. pestis, but are widely considered to be too inefficient at spreading it to contribute substantially to outbreaks. However, the few studies that have addressed lice transmission efficiency have disagreed considerably.
To help clarify the potential role of body lice in plague transmission, Bland and colleagues conducted a series of laboratory experiments in which body lice fed on blood samples containing Y. pestis. These experiments involved the use of membrane feeders, which simulate warm human skin, enabling scientists to study transmission potential in a laboratory setting.
They found that the body lice became infected with Y. pestis and were capable of routinely transmitting it after feeding on blood containing levels of the pathogen similar to those found in actual human plague cases.
They also found that Y. pestis can infect a pair of salivary glands found in body lice known as the Pawlowsky glands, and lice with infected Pawlowsky glands transmitted the pathogen more consistently than lice whose infection was limited to their digestive tract. It is thought that Pawlowsky glands secrete lubricant onto the lice's mouthparts, leading the researchers to hypothesize that, in infected lice, such secretions may contaminate mouthparts with Y. pestis, which may then spread to humans when bitten. These findings suggest that body lice may be more efficient spreaders of Y. pestis than previously thought, and they could have played a role in past plague outbreaks.
Bland DM, Long D, Rosenke R, Hinnebusch BJ (2024) Yersinia pestis can infect the Pawlowsky glands of human body lice and be transmitted by louse bite. PLoS Biology (2024). DOI: 10.1371/journal.pbio.3002625
May 22
Dr. Krishna Kumari Challa
Nightmares could be an early warning sign of an autoimmune disease flare-up – new study
Nightmares coming before autoimmune diseases have been found in other neurological diseases. Descriptions of flare-related nightmares in our study often involved being attacked, trapped, crushed or falling. Many were very distressing. One person described them as: “Horrific, like murders, like skin coming off people, horrific.” Another important finding was that these nightmares often came before a disease flare-up, particularly in people who then had hallucinations as part of their disease pattern. This was more likely in people with lupus than the other rheumatological diseases such as inflammatory arthritis. This wasn’t unexpected as lupus is known to affect the brain in some cases. Of the patients also reporting hallucinations, 61% of lupus patients and 34% with other autoimmune rheumatological diseases reported increasing disrupted sleep (mostly nightmares) just before their hallucinations.
https://theconversation.com/nightmares-could-be-an-early-warning-si...
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May 22
Dr. Krishna Kumari Challa
Newborns whose mother spoke in a mix of languages during pregnancy are more sensitive to a range of sound pitches
It's well established that babies in the womb hear and learn about speech, at least in the third trimester. For example, newborns have been shown to already prefer the voice of their mother, recognize a story that had been repeatedly told to them while in the womb, and tell apart their mother's native language.
What wasn't known until now was how developing fetuses learn about speech when their mother speaks to them in a mix of languages. Yet this is common: there are 3.3 billion bilingual people (43% of the population) worldwide, and in many countries, bilingualism or multilingualism is the norm.
Researchers showed that exposure to monolingual or a bilingual speech has different effects at birth on 'neural encoding' of voice pitch and vowel sounds: that is, how information about these aspects of speech has been initially learned by the fetus.
At birth, newborns from bilingual mothers appear more sensitive to a wider range of acoustic variation of speech, whereas newborns from monolingual mothers seem to be more selectively tuned to the single language they have been immersed in.
Exposure to bilingual or monolingual maternal speech during pregnancy affects the neurophysiological encoding of speech sounds in neonates differently, Frontiers in Human Neuroscience (2024). DOI: 10.3389/fnhum.2024.1379660
May 23
Dr. Krishna Kumari Challa
Exposure to endocrine-disrupting chemicals in utero associated with higher odds of metabolic syndrome in children
The term 'metabolic syndrome' (MetS) encompasses a group of factors, such as abdominal obesity, hypertension and insulin resistance, that together increase the risk of cardiovascular disease and type 2 diabetes.
A new study suggests that prenatal exposure to a combination of endocrine disrupting chemicals (EDCs) is associated with poorer metabolic health in childhood, which in turn may contribute to an increased risk of metabolic syndrome in adulthood.
EDCs are chemical substances that are so named because of their ability to interfere with the functioning of our hormonal system, growth, energy balance and metabolism and whose exposure, given their ubiquity in our environment, is difficult to escape.
Previous studies have already shown a link between individual exposure to some of these compounds during the prenatal phase and some of the factors that make up the metabolic syndrome, particularly obesity and blood pressure.
The study involved 1,134 mothers and their children from six European countries (Spain, France, Greece, Lithuania, Norway and the United Kingdom), all volunteers from the HELIX (Human Early Life Exposome) cohort. Prenatal exposure to a total of 45 endocrine disruptors was analyzed through blood and urine samples collected from the mothers during pregnancy or from the umbilical cord after birth.
Later, when the children were between 6 and 11 years old, they were followed up, including a clinical examination, interview and collection of biological samples. This yielded data on waist circumference, blood pressure, cholesterol, triglycerides and insulin levels, which were aggregated to obtain a risk index for metabolic syndrome.
Statistical analysis showed that mixtures of metals, perfluoroalkylated and polyfluoroalkylated substances (PFAS), organochlorine pesticides and flame retardants (or PBDEs) were associated with a higher risk of metabolic syndrome. In the case of metals, the association observed was mainly due to the effect of mercury, the main source of which is the intake of large fish.
PFASs are one of the most widely used families of chemical compounds, being used in pesticides, paints, non-stick pans or fast food packaging, among many other common uses. Because of their persistence, they are also known as the "forever chemicals." Also very persistent are organochlorine pesticides, which were already banned in Europe in the 1970s, but to which we are still widely exposed due to their permanence in the environment.
Researchers also observed that associations were stronger in girls for mixtures of PFASs and polychlorinated biphenyls (PCBs), while boys were more susceptible to exposure to parabens. Since endocrine disruptors interfere with sex steroid hormones, these differences fall within what would be expected.
These results suggest that exposure to widespread mixtures of endocrine disruptors during pregnancy may be associated with adverse metabolic health in both boys and girls. This association may contribute to the current increase in the prevalence of lifetime metabolic syndrome, which currently affects a quarter of the adult population, with upward trends evident even among young people
Prenatal Exposure to Chemical Mixtures and Metabolic Syndrome Risk in Children, JAMA Network Open (2024). DOI: 10.1001/jamanetworkopen.2024.12040
May 24
Dr. Krishna Kumari Challa
Why the brain can robustly recognize images, even without colour
Even though the human visual system has sophisticated machinery for processing colour, the brain has no problem recognizing objects in black-and-white images. A new study offers a possible explanation for how the brain comes to be so adept at identifying both colour and colour-degraded images.
Using experimental data and computational modeling, the researchers found evidence suggesting the roots of this ability may lie in development. The work has been published in Science
Early in life, when newborns receive strongly limited colour information, the brain is forced to learn to distinguish objects based on their luminance, or intensity of light they emit, rather than their colour. Later in life, when the retina and cortex are better equipped to process colours, the brain incorporates colour information as well but also maintains its previously acquired ability to recognize images without critical reliance on colour cues.
The findings also help to explain why children who are born blind but have their vision restored later in life, through the removal of congenital cataracts, have much more difficulty identifying objects presented in black and white. Those children, who receive rich colour input as soon as their sight is restored, may develop an overreliance on colour that makes them much less resilient to changes or removal of colour information.
Researchers have observed that limitations in early sensory input can also benefit other aspects of vision, as well as the auditory system.
In 2022, they used computational models to show that early exposure to only low-frequency sounds, similar to those that babies hear in the womb, improves performance on auditory tasks that require analyzing sounds over a longer period of time, such as recognizing emotions.
Marin Vogelsang et al, Impact of early visual experience on later usage of color cues, Science (2024). DOI: 10.1126/science.adk9587. www.science.org/doi/10.1126/science.adk9587
May 24
Dr. Krishna Kumari Challa
Nanoparticle vaccines: A potential leap forward in veterinary medicine
Classical vaccines often rely on traditional technologies, such as live attenuated or inactivated pathogens, which carry inherent risks including reduced immunogenicity under certain conditions and potential safety concerns. This has spurred the need for innovative approaches that can provide safer and more effective prophylactic solutions in veterinary medicine.
Self-assembled protein nanoparticles (SAPNs) emerge as a cutting-edge solution, harnessing the power of nanotechnology to revolutionize vaccine design and implementation.
In an article published on 10 May 2024 in Animal Diseases, researchers at Zhejiang University's Institute of Preventive Veterinary Medicine, delve into the development and application of SAPNs and virus-like nanoparticles (VLPs), offering a detailed discussion of their potential in veterinary medicine.
The article focuses on various types of SAPNs, including natural and synthetically designed nanoparticles. These nanoparticles are tailored to enhance the immune system's ability to recognize and respond to pathogens more effectively.
Key highlights include the use of animal virus-derived nanoparticles and bacteriophage-derived nanoparticles, which have shown the potential to elicit strong cellular and humoral responses. The nanoparticles' ability to mimic pathogen structures enables them to trigger a more substantial immune reaction, potentially leading to long-lasting immunity.
Researchers have documented successes in using these nanoparticles to protect against diseases like foot-and-mouth disease and swine fever, showcasing their broad applicability and effectiveness.
Veterinary nanoparticle vaccines have broad implications, with the potential to extend the benefits beyond veterinary applications into human health. The enhanced safety and immunogenicity of these vaccines could lead to the development of advanced vaccines for human use.
Additionally, by reducing the environmental impact of livestock diseases, this technology may contribute to more sustainable agricultural practices globally.
Meiqi Sun et al, Toward innovative veterinary nanoparticle vaccines, Animal Diseases (2024). DOI: 10.1186/s44149-024-00119-w
May 24
Dr. Krishna Kumari Challa
How a world record 'squeeze' could offer comfort for dark matter hunters
Quantum engineers have developed a new amplifier that could help other scientists search for elusive dark matter particles.
Imagine throwing a ball. You'd expect science to be able to work out its exact speed and location at any given moment, right? Well, the theory of quantum mechanics says you can't actually know both with infinite precision at the same time.
It turns out that as you more precisely measure where the ball is, knowing its speed becomes less and less accurate.
This conundrum is commonly referred to as Heisenberg's uncertainty principle, named after the famous physicist Werner Heisenberg who first described it.
For the ball, this effect is imperceptible, but in the quantum world of small electrons and photons the measurement uncertainty suddenly becomes very significant.
That's the problem being addressed by a team of engineers who have developed an amplifying device that performs precise measurements of very weak microwave signals, and it does so through a process known as squeezing.
Squeezing involves reducing the certainty of one property of a signal in order to obtain ultra-precise measurements of another property.
The team of researchers have significantly increased the accuracy of measuring signals at microwave frequencies, like those emitted by your mobile phone, to the point of setting a new world record.
The precision of measuring any signal is fundamentally limited by noise. Noise is the fuzziness that creeps in and masks signals, which is something you may have experienced if you've ever ventured out of range when listening to AM or FM radio.
However, uncertainty in the quantum world means there is a limit as to how low noise can be made in a measurement.
Even in a vacuum, a space void of everything, the uncertainty principle tells us we must still have noise. We call this 'vacuum' noise. For many quantum experiments, vacuum noise is the dominant effect that prevents us from making more precise measurements.
The squeezer produced by the research team now can beat this quantum limit.
The device amplifies noise in one direction, so that noise in another direction is significantly reduced, or 'squeezed.' Think of the noise as a tennis ball, if we stretch it vertically, then it must reduce along the horizontal to maintain its volume. Researchers can then use the reduced part of the noise to do more precise measurements.
They showed that the squeezer is able to reduce noise to record low levels.
Squeezing is very difficult at microwave frequencies because the materials used tend to destroy the fragile squeezed noise quite easily.
What they've done is a lot of engineering in order to remove sources of loss, which means utilizing very high-quality superconducting materials to build the amplifier.
Part 1
May 24
Dr. Krishna Kumari Challa
And the team think that the new device could help speed up the search for notoriously elusive particles known as axions, which are so far only theoretical, but proposed by many as the secret ingredient of mysterious dark matter.
The squeezed noise itself could even be used in future quantum computers.
It turns out that squeezed vacuum noise is an ingredient to build a certain type of quantum computer. Excitingly, the level of squeezing they've achieved is not far off the amount needed to build such a system.
Arjen Vaartjes et al, Strong microwave squeezing above 1 Tesla and 1 Kelvin, Nature Communications (2024). DOI: 10.1038/s41467-024-48519-3
Part 2
May 24
Dr. Krishna Kumari Challa
Atomic-resolution imaging shows why ice is so slippery
A team of physicists has uncovered the reason behind the slipperiness of ice. In their study, published in the journal Nature, the group used atomic force microscopy to get a closer look at the surface of ice at different temperatures.
Prior research and day-to-day experiences have shown that ice is slippery, even when temperatures are well below the freezing point. Research has suggested this is because of a pre-melt coating that develops at the surface, which serves as a lubricant.
In this new study, the research team used an atomic force microscope fitted with a carbon monoxide atom on its tip to get a better look at the structure of normal ice and its pre-melt coating.
The researchers began by chilling ice inside the microscope chamber to -150°C and then using the microscope to look at its atomic structure. They could see that the internal ice (known as ice Ih), and the ice at the surface were different.
The ice Ih, as expected, was arranged in stacked hexagons. The ice on the surface, by contrast, was only partially hexagonal. The researchers also found defects in the ice at the border between the two types of ice that occurred as the different ice shapes met one another.
The researchers then raised the temperature in the chamber slightly, which resulted in more disorder as the differences in shape became more pronounced. The team then created a simulation showing how such disorder would impact the surface as a whole unit—it showed the disorder expanding all the way across the surface, giving the ice a liquid-like appearance that would be slippery if trod upon.
Jiani Hong et al, Imaging surface structure and premelting of ice Ih with atomic resolution, Nature (2024). DOI: 10.1038/s41586-024-07427-8
May 24
Dr. Krishna Kumari Challa
Bizarre bacteria scramble workflow of life
Bacteria have stunned biologists by reversing the usual flow of information. Typically genes written in DNA serve as the template for making RNA molecules, which are then translated into proteins. Some viruses are known to have an enzyme that reverses this flow by scribing RNA into DNA. Now scientists have found bacteria with a similar enzyme that can even make completely new genes — by reading RNA as a template. These genes create protective proteins when a bacterium is infected by a virus. It should change the way we look at the genome.
https://www.biorxiv.org/content/10.1101/2024.05.08.593200v1
Part 1
May 24
Dr. Krishna Kumari Challa
Strange bacteria defy textbooks by writing new genes
Genetic information usually travels down a one-way street: genes written in DNA serve as the template for making RNA molecules.... That tidy textbook story got a bit complicated in 1970 when scientists discovered that some viruses have enzymes called reverse transcriptases, which scribe RNA into DNA — the reverse of the usual traffic flow.
Now, scientists have discovered an even weirder twist. A bacterial version of reverse transcriptase reads RNA as a template to make completely new genes written in DNA. These genes are then transcribed back into RNA, which is translated into protective proteins when a bacterium is infected by a virus. By contrast, viral reverse transcriptases don’t make new genes; they merely transfer information from RNA to DNA.
This is a crazy molecular biology!
https://www.nature.com/articles/d41586-024-01477-8?utm_source=Live+...
Part 2
The discovery that reverse transcriptase — which has previously been known only for copying genetic material — can create completely new genes has left other researchers gobsmacked.
May 24
Dr. Krishna Kumari Challa
Micro-ballistics research has shown metals hardening as they are heated, under extreme strain rates.
May 24
Dr. Krishna Kumari Challa
How gut microbes drive tumour growth
Scientists have long known that obese people have poorer cancer survival rates. Now they have some idea why. A high-fat diet increases the number of Desulfovibrio bacteria in the gut of mice. These release leucine, an amino acid, which encourages the proliferation of a kind of cell that suppresses the immune system. With a suppressed immune system, tumour growth can increase. In breast cancer patients, poorer outcomes were seen for women with higher body-mass index, who also had higher levels of Desulfovibrio bacteria in their gut and leucine in their blood. It’s a provocative finding that will open up new avenues that we should be thinking about.
https://www.pnas.org/doi/10.1073/pnas.2306776121?utm_source=Live+Au...
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Biggest risk factors for disease spread A meta-analysis of five ways that humanity’s environmental footprint spreads disease — biodiversity loss, chemical pollution, climate change, invasive species and deforestation/urbanization — suggests that conserving biodiversity, controlling invasive species and lowering greenhouse-gas emissions would reduce disease spread the most. This evidence can be used in international policy to spur action on climate change and biodiversity loss due to their negative impacts on disease.
https://www.nature.com/articles/s41586-024-07380-6?utm_source=Live+...
May 24
Dr. Krishna Kumari Challa
Biologists observe recurring evolutionary changes, over time, in stick insects
A long-standing debate among evolutionary scientists goes something like this: Does evolution happen in a predictable pattern or does it depend on chance events and contingency? That is, if you could turn back the clock, as celebrated scientist Stephen Jay Gould (1941–2002) described in his famous metaphor, "Replaying the Tape of Life," would life on Earth evolve, once again, as something similar to what we know now, or would it look very, very different?
Now researchers report evidence of repeatable evolution in populations of stick insects in the paper "Evolution repeats itself in replicate long-term studies in the wild," in Science Advances.
The team examined three decades of data on the frequency of cryptic color-pattern morphs in the stick insect species Timema cristinae in ten naturally replicate populations in California. T. cristinae is polymorphic in regard to its body colour and pattern. Some insects are green, which allows the wingless, plant-feeding insect to blend in with California lilac (Ceanothus spinosus) shrubs. In contrast, green striped morphs disappear against chamise (Adenostoma fasciculatum) shrubs.
Hiding among the plants is one of T. christinae's key defenses as hungry birds, such as scrub jays, are insatiable predators of the stick insects.
Bird predation is a constant driver shaping the insects' organismal traits, including coloration and striped vs. non-striped.
Scientists observed predictable 'up-and-down' fluctuations in stripe frequency in all populations, representing repeatable evolutionary dynamics based on standing genetic variation.
A field experiment demonstrates these fluctuations involved negative frequency-dependent natural selection (NFDS), where cryptic colour patterns are more beneficial when rare rather than common. This is likely because birds develop a 'search image' for very abundant prey.
At short time scales, evolution involving existing variations can be quite predictable. You can count on certain drivers always being there, such as birds feeding on the insects.
But at longer time scales, evolutionary dynamics become less predictable.
The populations might experience a chance event, such as a severe drought or a flooding event, that disrupts the status quo and thus, the predictable outcomes.
On long time scales, a new mutation in the species could introduce a rare trait. That's about as close to truly random as you can get.
Rare things are easily lost by chance, so there's a strong probability a new mutation could disappear before it gains a stronghold.
Indeed, another species of Timema stick insect that also feeds on chamise either never had or quickly lost the mutations making the cryptic stripe trait. Thus, the evolution of stripe is not a repeatable outcome of evolution at this long scale.
Part 1
May 25
Dr. Krishna Kumari Challa
Replicated, long-term studies from natural populations, including research on the famous Darwin's finches, are rare.
Because most of this work is restricted to one or few populations, it is difficult to draw inferences on repeatability among multiple evolutionary independent populations.
Such studies are challenging to implement not only because they take concerted effort, but also because you can't rush time.
Patrik Nosil et al, Evolution repeats itself in replicate long-term studies in the wild, Science Advances (2024). DOI: 10.1126/sciadv.adl3149. www.science.org/doi/10.1126/sciadv.adl3149
Part 2
May 25
Dr. Krishna Kumari Challa
How air pollution affects the digestive system
Fine air particles, less than 2.5 micrometers in diameter (PM2.5), are a major air pollutant linked to various health problems. These particles can travel deep into the lungs and even enter the bloodstream when inhaled. Recent research suggests a major health concern: PM2.5 exposure can also damage the digestive system, including the liver, pancreas, and intestines.
The work is published in the journal eGastroenterology. This recent research has been focused on how PM2.5 exposure triggers stress responses within the digestive system's cells. These stress responses involve specialized subcellular structures within cells called organelles, such as the endoplasmic reticulum (ER), mitochondria, and lysosomes. When PM2.5 disrupts these organelles, it creates a chain reaction within the cells that can lead to inflammation and other harmful effects.
The liver, a major organ for detoxification and metabolism, is particularly susceptible to PM2.5 damage. Studies have shown that PM2.5 exposure can lead to a cascade of problems within the liver, including inflammation, stress responses, and damage to the organelles, and disrupted energy metabolism. These effects can contribute to the development of non-alcoholic fatty liver disease (NASH) and type 2 diabetes.
PM2.5 exposure does not stop at the liver. It can also harm the pancreas and intestines. Studies have linked PM2.5 to an increased risk of pancreatic impairment in people with diabetes, as well as damage to intestinal cells and an increase in their permeability. This increased permeability can lead to a variety of digestive issues.
Researchers are exploring whether dietary or pharmaceutical interventions can mitigate PM2.5 damage. Interestingly, some studies suggest that certain nutrients, like monounsaturated fatty acids and vitamins, may offer some protection against the harmful effects of PM2.5.
Part 1
May 25
Dr. Krishna Kumari Challa
Many plants and plant oils are high in monounsaturated fats but low in saturated fats. These include: oils from olives, peanuts, canola seeds, safflower seeds, and sunflower seeds, avocadoes, pumpkin seeds, sesame seeds, almonds, cashews, peanuts and peanut butter, pecans.
Air pollution is a complex issue with no easy solutions. While research continues mitigating PM2.5 exposure, the current understanding of its impact on the digestive system highlights the far-reaching consequences of air pollution on human health. It underscores the need for continued efforts to reduce air pollution levels and develop strategies to protect ourselves from its detrimental effects.
Kezhong Zhang, Environmental PM2.5-triggered stress responses in digestive diseases, eGastroenterology (2024). DOI: 10.1136/egastro-2024-100063
Part 2
May 25
Dr. Krishna Kumari Challa
Big brands are 'failing to curb plastic sachet use'
Small plastic sachets commonly used in low- and middle-income countries must be phased out and packaging reuse systems promoted, urge campaigners and waste pickers, as new analysis reveals major corporations have failed to curb their use.
Pocket-sized individual portions of goods ranging from shampoo to instant coffee have become popular in lower-income communities for their affordability.
An estimated 855 billion sachets are sold globally each year with Southeast Asia consuming nearly half of the total and this figure projected to rise to 1.3 trillion by 2027, according to environmental groups.
But the convenience of sachets comes with a heavy environmental cost as they end up as significant contributors to plastic pollution. Their commonly multi-layered design, using different materials, makes them hard to recycle.
Consumer goods giants Unilever, Nestlé and Procter & Gamble are among the biggest contributors to plastic sachet pollution in developing countries in Asia, despite promises to reduce plastic packaging, according to a multi-country environmental audit report.
It said some corporations were trying to deal with the waste problem by burning sachets as fuel, creating further pollution.
Environmental groups in Asia have long been demanding firms to phase out their sachet packaging as the resulting waste is deluging the region's landfills and waters.
Consumers, can you please help by avoiding these small plastic sachet based products?
Source: SciDev.Net
May 25
Dr. Krishna Kumari Challa
Why some huge stars have disappeared from the sky
When massive stars die, as we understand the Universe, they don't go quietly. As their fuel runs out, they become unstable, wracked by explosions before finally ending their lives in a spectacular supernova.
But some massive stars, scientists have found, have simply vanished, leaving no trace in the night sky. Stars clearly seen in older surveys are inexplicably absent from newer ones. A star isn't exactly a set of keys – you can't just lose it down the back of the couch. So where the heck do these stars go?
A new study has given us the most compelling explanation yet. Some massive stars, suggest an international team led by astrophysicist Alejandro Vigna-Gómez of the Niels Bohr Institute in Denmark and the Max Planck Institute for Astrophysics in Germany, can die, not with a bang, after all, but a whimper.
Their evidence? A binary system named VFTS 243 in the Large Magellanic Cloud, consisting of a black hole and a companion star. This system shows no signs of a supernova explosion that, according to the models, ought to have accompanied the formation of the black hole.
Were one to stand gazing up at a visible star going through a total collapse, it might, just at the right time, be like watching a star suddenly extinguish and disappear from the heavens.
The collapse is so complete that no explosion occurs, nothing escapes and one wouldn't see any bright supernova in the night sky. Astronomers have actually observed the sudden disappearance of brightly shining stars in recent times. Scientists cannot be sure of a connection, but the results they have obtained from analyzing VFTS 243 has brought them much closer to a credible explanation.
Part 1
May 25