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Comment by Dr. Krishna Kumari Challa on March 25, 2024 at 9:26am

New research shows unintended harms of organic farming

Although organic agricultural practices generally improve environmental conditions such as soil and water quality, the trade-offs aren't very well understood.

Organic farming is often touted as a more sustainable solution for food production, leveraging natural forms of pest control to promote eco-friendly cultivation.

But a new study published in Science on Thursday finds that expanding organic cropland can lead to increased pesticide use in surrounding non-organic fields, offsetting some environmental benefits.

These harmful "spillover effects" can be mitigated if organic farms are clustered together and geographically separated from conventional farms, the researchers found.

Organic fields could harbour more beneficial species that prey on insects, such birds, spiders and predatory beetles and fewer pests. Or, the lack of chemical pesticides and genetically modified seeds could mean they harbour more pests.

The researchers found that surrounding organic agriculture leads to an increase in pesticide use on conventional fields, but also leads to a larger decrease on nearby organic fields, with the effect manifesting primarily in insecticides, which specifically target insects. The level of pesticides in conventional fields decreased the further away they were from organic fields.

But the situation could be completely remedied if organic fields were grouped together, the researchers found. Spatially clustering organic fields and spatially separating organic and conventional fields could reduce the environmental footprint of both organic and conventional cropland, the team concluded.

 Farmers' decisions about pesticide are influenced by the presence of nearby organic fields—but it's not fully clear why.

The value of the crops, their susceptibility to pests, and farmers' personal risk tolerances likely all play roles.

Which mobile pests are involved, where they originate in the landscape, or how and why they move across the landscape are poorly understood, according to the researchers  calling for more research in this area.

Ashley E. Larsen et al, Spillover effects of organic agriculture on pesticide use on nearby fields, Science (2024). DOI: 10.1126/science.adf2572

Erik Lichtenberg, Collateral impacts of organic farming, Science (2024). DOI: 10.1126/science.ado4083

Comment by Dr. Krishna Kumari Challa on March 24, 2024 at 10:56am

The World's First 'Unconventional' Superconductor was Found in Nature

Few materials have the uncanny talent of carrying a current with virtually no resistance in what is known as superconductivity. The smallest handful of those can be found in nature. Scientists have discovered that one material with a formula found in nature is capable of superconducting at low temperatures without using the typical quantum trickery, making it the first unconventional superconductor of its kind. Superconductors are fascinating and also hugely useful, because they conduct electricity without energy loss. This is typically thanks to their electrons sharing identity in what are known as Cooper pairs, allowing them to slip through a jumble of atoms with relative ease. Cooper pairs in unconventional superconductors link up in ways that weren't described in early models on superconductivity, ways that also mean they appear at higher temperatures. Through a series of detailed lab tests, an international team of researchers found that the mineral miassite – already known to be a superconductor – can show the properties of an unconventional superconductor. That miassite occurs in nature as well as being something scientists can synthesize in the lab makes it even more unusual. However, it's worth pointing out that it's unlikely any pieces of miassite found in nature would ever have the purity required to function as an unconventional superconductor. you think that this is something which is produced deliberately during a focused search, and it cannot possibly exist in nature. But it turns out it does. Three different tests were used to establish the unconventional superconductivity of miassite, including the London penetration depth test, which measures the reaction of the material to a weak magnetic field. Another test involved creating defects in the material, which can affect the temperature at which it becomes a superconductor. Unconventional superconductors are much more sensitive to the disorder caused by these defects than conventional superconducting materials. The discovery was made as part of efforts to find new, novel materials to advance fields such as quantum science.

https://www.nature.com/articles/s43246-024-00456-w

Comment by Dr. Krishna Kumari Challa on March 23, 2024 at 10:53am

Accumulation of 'junk proteins' identified as one cause of aging and possible source of ALS

Amyotrophic lateral sclerosis (ALS) is a degenerative disease. The neurons responsible for movement begin to die and muscle control is progressively lost, leading to a fatal outcome. The causes of ALS are currently unknown, and there is no effective treatment.

In a paper published in Molecular Cell, researchers provide the first evidence that a possible cause of the hereditary type of ALS—familial ALS—is the accumulation in motor neurons of "junk proteins," proteins with no function that wrongly accumulate and prevent the cell from functioning properly.

Specifically, these non-functional proteins that accumulate are ribosomal proteins, which normally form ribosomes, molecular factories in charge of protein production.

Most patients with hereditary ALS share mutations in a gene called C9ORF72. This mutation results in the production of toxic proteins—or peptides—rich in the amino acid arginine. In a previous work,  the same researchers took the first steps to understand why these peptides are toxic. The reason is that these toxins stick to DNA and RNA "as if they were tar," affecting virtually all reactions in the cell that use these nucleic acids.

Thus, this study provides a new hypothesis for understanding the origin of ALS, by suggesting that it has a similar origin to another group of rare diseases known as ribosomopathies, also associated with an excess of non-functional ribosomal proteins (in the case of ALS, this problem is restricted to motor neurons).

The new study also opens a new front in a different area, aging research. The authors propose a new causal factor in the aging process, which until now would have been overlooked: nucleolar stress, a mechanism by which organelles called nucleoli react to various damages in the cell.

In this new work, scientists report a new model that explains how nucleolar stress induces toxicity in animal cells, and they provide direct evidence that it accelerates aging in mammals. This is the first experimental evidence that generating nucleolar stress accelerates aging.

Nucleolar stress caused by arginine-rich peptides triggers a ribosomopathy and accelerates aging in mice, Molecular Cell (2024). DOI: 10.1016/j.molcel.2024.02.031. www.cell.com/molecular-cell/fu … 1097-2765(24)00173-4

Comment by Dr. Krishna Kumari Challa on March 23, 2024 at 10:31am

Prosopometamorphopsia: a condition where people see  'demonic' face distortions

Imagine if every time you saw a face, it appeared distorted. Well, for those who have a very rare condition known as prosopometamorphopsia (PMO), which causes facial features to appear distorted, that is reality.

Prosopometamorphopsia explains, "Prosopo comes from the Greek word for face 'prosopon' while 'metamorphopsia' refers to perceptual distortions.  Specific symptoms vary from case to case and can affect the shape, size, color, and position of facial features. The duration of PMO also varies; it "can last for days, weeks, or even years.

A new Dartmouth study published in the "Clinical Pictures" section of The Lancet reports on a unique case of a patient with PMO. The research is the first to provide accurate and photorealistic visualizations of the facial distortions experienced by an individual with PMO.

The patient, a 58-year-old male with PMO, sees faces without any distortions when they are viewed on a screen and on paper, but he sees distorted faces that appear "demonic" when viewed in-person. Most PMO cases however, see distortions in all contexts, so his case is especially rare and presented a unique opportunity to accurately depict his distortions.

Scientists have heard from multiple people with PMO that they have been diagnosed by psychiatrists as having schizophrenia and put on anti-psychotics, when their condition is a problem with the visual system,  according to the researchers.

And it's not uncommon for people who have PMO to not tell others about their problem with face perception because they fear others will think the distortions are a sign of a psychiatric disorder.

"It's a problem that people often don't understand."

Through their paper, the researchers hope to increase public awareness of what PMO is.

Visualising facial distortions in prosopometamorphopsia, The Lancet (2024). www.thelancet.com/journals/lan … (24)00136-3/fulltext

Comment by Dr. Krishna Kumari Challa on March 23, 2024 at 10:23am

Messenger RNAs with multiple 'tails' could lead to more effective therapeutics: researchers

Messenger RNA (mRNA) made its big leap into the public limelight during the pandemic, thanks to its cornerstone role in several COVID-19 vaccines. But mRNAs, which are genetic sequences that instruct the body to produce proteins, are also being developed as a new class of drugs. For mRNAs to have broad therapeutic uses, however, the molecules will need to last longer in the body than those that make up the COVID vaccines.

Researchers have engineered a new mRNA structure by adding multiple "tails" to the molecules that boosted mRNA activity levels in cells by five to 20 times. They  also showed that their multi-tailed mRNAs lasted two- to three-times longer in animals compared to unmodified mRNA, and when incorporated into a CRISPR gene-editing system, resulted in more efficient gene editing in mice.

The new mRNAs, reported in Nature Biotechnology, could potentially be used to treat diseases that require long-lasting treatments that edit genes or replace faulty proteins.

Scientists have shown that non-natural structures can function so much better than naturally occurring ones. This research has given them a lot of confidence in their ability to modify mRNA molecules chemically and topologically.

Branched chemically modified poly(A) tails enhance the translation capacity of mRNA, Nature Biotechnology (2024). DOI: 10.1038/s41587-024-02174-7

Comment by Dr. Krishna Kumari Challa on March 23, 2024 at 10:12am

The dissimilar smells of babies and teenagers

A team of aroma chemists has uncovered the reasons for the dissimilar smells between babies and teenagers. The study is published in the journal Communications Chemistry.

Prior research and anecdotal evidence have shown that babies have a pleasant smell, often described as sweet. Teenagers, on the other hand, especially males, have often been described as smelling less pleasant. In this new effort, the research team sought to find out what causes the difference.

The researchers recruited the parents of 18 children aged up to 3 years old to wash the youngsters with a fragrance-free gel and to take swap samples of the armpits of their pajamas prior to sleep. They did the same with 18 teenagers between the ages of 14 and 18. All the cotton pads were then collected and analyzed in a lab setting.

The research team used mass spectrometry to identify the chemical compounds in the pads, and used gas chromatography along with a human sniffer to assess the odorousness of the smells associated with each chemical compound.
The researchers found that most of the chemicals responsible for body odor were similar between the two groups of volunteers. But there were a few that made the difference. Teenage sweat, for example, had high levels of many kinds of carboxylic acids, which the assessors described as "earthy, musty or cheesy."
They also found two steroids in the teen sweat not present in the baby sweat, one of which resulted in "musk or urine-like" emanations—the other, the assessors suggested, smelled more like "musk and sandalwood." Without such chemicals, the sweat of babies smelled much sweeter.
The researchers suggest that study of the chemical compounds in teen sweat could prove fruitful for makers of odor-control products. They also suggest that more work could done to better understand the impact of such odors on parents.

Diana Owsienko et al, Body odor samples from infants and post-pubertal children differ in their volatile profiles, Communications Chemistry (2024). DOI: 10.1038/s42004-024-01131-4

Comment by Dr. Krishna Kumari Challa on March 23, 2024 at 9:58am

The study focused on Sphingopyxis alaskensis, a common bacterium in waters off Alaska. While many studies use the bacterium Escherichia coli as a model organism, this single-celled organism is much smaller, lives in cold environments, and can survive with few nutrients. All these things make it a better candidate for potential life on the icy moons of Saturn or Jupiter.

They are extremely small, so they are in theory capable of fitting into ice grains that are emitted from an ocean world like Enceladus or Europa.

Results show that the instruments can detect this bacterium, or portions of it, in a single ice grain. Different molecules end up in different ice grains. The new research shows that analyzing single ice grains, where biomaterial may be concentrated, is more successful than averaging across a larger sample containing billions of individual grains.

A recent study led by the same researchers showed evidence of phosphate on Enceladus. This planetary body now appears to contain energy, water, phosphate, other salts and carbon-based organic material, making it increasingly likely to support lifeforms similar to those found on Earth.

The authors hypothesize that if bacterial cells are encased in a lipid membrane, like those on Earth, then they would also form a skin on the ocean's surface. On Earth, ocean scum is a key part of sea spray that contributes to the smell of the ocean. On an icy moon where the ocean is connected to the surface (e.g., through cracks in the ice shell), the vacuum of outer space would cause this subsurface ocean to boil. Gas bubbles rise through the ocean and burst at the surface, where cellular material gets incorporated into ice grains within the plume.

In the paper published by the researchers,  they described a plausible scenario for how bacterial cells can, in theory, be incorporated into icy material that is formed from liquid water on Enceladus or Europa and then gets emitted into space.

The SUrface Dust Analyzer onboard Europa Clipper will be higher-powered than instruments on past missions. This and future instruments also will for the first time be able to detect ions with negative charges, making them better suited to detecting fatty acids and lipids.

Fabian Klenner, How to Identify Cell Material in a Single Ice Grain Emitted from Enceladus or Europa, Science Advances (2024). DOI: 10.1126/sciadv.adl0849. www.science.org/doi/10.1126/sciadv.adl0849

Part 2

Comment by Dr. Krishna Kumari Challa on March 23, 2024 at 9:54am

Signs of life detectable in single ice grain emitted from extraterrestrial moons, experimental setup shows

The ice-encrusted oceans of some of the moons orbiting Saturn and Jupiter are leading candidates in the search for extraterrestrial life. A new lab-based study  shows that individual ice grains ejected from these planetary bodies may contain enough material for instruments headed there in the fall to detect signs of life, if such life exists.

For the first time scientists have shown that even a tiny fraction of cellular material could be identified by a mass spectrometer onboard a spacecraft. These results give researchers more confidence that using upcoming instruments, they will be able to detect lifeforms similar to those on Earth, which we increasingly believe could be present on ocean-bearing moons. 

Researchers used an experimental setup that sends a thin beam of liquid water into a vacuum, where it disintegrates into droplets. They then used a laser beam to excite the droplets and mass spectral analysis to mimic what instruments on the space probe will detect.

Newly published results show that instruments slated to go on future missions, like the SUrface Dust Analyzer onboard Europa Clipper, can detect cellular material in one out of hundreds of thousands of ice grains. 

Part 1

Comment by Dr. Krishna Kumari Challa on March 22, 2024 at 9:42am

DNA attached to nanoparticles found to contribute to lupus symptoms

Autoimmune diseases are mysterious. It wasn't until the 1950s that scientists realized that the immune system could harm the organs of its own body. Even today, the fundamental causes and inner workings of most autoimmune diseases remain poorly understood, limiting the treatment options for many of these conditions.

Over the past several years, however, research has found clues for how autoimmune diseases might arise. This research has shown that DNA attached to small particles within the bloodstream is a likely culprit involved in many autoimmune diseases, especially systemic lupus erythematosus, or just lupus for short, which primarily affects young women and can cause kidney damage.

However, due to the large variety in sizes of both particles and DNA in the blood, testing to what extent and under what circumstances these DNA-particle combinations play a role in disease has been extremely difficult.

Researchers at Duke University have now developed a way to systematically test how these DNA-bound particles interact with the immune system. By using tiny particles of specific sizes, attaching DNA strands of certain lengths and exposing the resulting complexes to immune cells in a lab dish, the researchers show a better fundamental understanding of these diseases may be possible.

The results were published in the Proceedings of the National Academy of Sciences.

This new approach identified the cellular pathway that causes the harmful response to these hybrid particles, and showed that DNA bound to the surfaces of nanoparticles is protected from being degraded by enzymes.

While DNA is usually locked away within a cell's nucleus, it often gets into the bloodstream when cells die or are attacked by viruses and bacteria. While most so-called "cell-free DNA" only lasts minutes before being broken down by the body, in some people and situations, it can persist for much longer. In recent work, high levels of cell-free DNA have been closely related to the severity of lupus symptoms, and many doctors are now testing ways to use it to monitor disease activity.

Cell-free DNA may escape elimination largely by forming complexes with other molecules or attaching itself to naturally occurring particles. Depending on the origin of the DNA, it can range in length from a few hundred base pairs to several thousand. And the particles it can attach to range from 100 to 1000 nanometers in diameter.

The first important observation the team made was that DNA attached to nanoparticles was protected from degrative enzymes and that larger nanoparticles provided more protection.

The researchers think the enzymes might not be able to access the DNA to destroy it because of the shape the DNA makes with the surface of the nanoparticle.

The results showed that the macrophages responded to all types of DNA-particle complexes by producing inflammatory signals for other cells to follow, a hallmark of many autoimmune diseases.

This approach gives researchers a way to drill down and pinpoint factors that they wouldn't be able to with a purely biological system.

 Faisal Anees et al, DNA corona on nanoparticles leads to an enhanced immunostimulatory effect with implications for autoimmune diseases, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2319634121

Comment by Dr. Krishna Kumari Challa on March 22, 2024 at 9:30am

How cells in plant leaves organize themselves to ensure optimal area for photosynthesis

Plant leaves need a large surface area to capture sunlight for photosynthesis. Researchers  have now discovered which genetic mechanisms control leaves' growth into a flat structure capable of efficiently capturing sunlight.

A kind of built-in GPS informs each cell about its relative position in the growing leaf. The order corresponds to a biological concept of self-organization.

When cells divide and multiply, the result is usually a clump of cells. So researchers wanted to know how, in the case of a leaf, cell division leads to a large flat area.

To this end, a team of mathematicians and experimental biologists worked together to track the processes using computer models, methods of molecular genetics, and imaging techniques on living organisms.

The basis of such pattern formation is polarity; that is, the ability to distinguish, in this case, between top and bottom. It is usually created by a concentration gradient of a substance, called morphogen, that is low on one side and higher on the other.

The team discovered that "small RNAs" play a decisive role in controlling the growing leaf. As mobile messengers, they are used for communication between the cells and help the cells to perceive their relative position to each other in the structure—like a GPS. In addition, the small RNAs transmit information that coordinates which genes need to be activated or inhibited on the top and bottom side to give the leaf the right shape and function.

This regulatory mechanism works autonomously in the growing leaf; there is no central control in the plant.

The small RNA molecules in the cells of the growing leaf set in motion a genetic process that enables the cells to perceive and interpret their environment. The genes' activities are coordinated among the cells in such a way that each leaf is divided in a sharply defined top and bottom part that form a perfectly flat canvas for photosynthesis.

Emanuele Scacchi et al, A diffusible small-RNA-based Turing system dynamically coordinates organ polarity, Nature Plants (2024). DOI: 10.1038/s41477-024-01634-x

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