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Comment by Dr. Krishna Kumari Challa on October 13, 2023 at 10:18am

Study finds we can respond to verbal stimuli while sleeping

Sleep is not a state in which we are completely isolated from our environment: while we sleep, we are capable of hearing and understanding words. These observations, the result of close collaboration between various research teams call into question the very definition of sleep and the clinical criteria that make it possible to distinguish between its different stages.

Sleep is generally defined as a period during which the body and mind are at rest—as if disconnected from the world. However, a new study shows that the frontier between wakefulness and sleep  is much more porous than it seems.

The researchers have shown that ordinary sleepers can pick up verbal information transmitted by a human voice and respond to it by contracting their facial muscles. This astonishing ability occurs intermittently during almost all stages of sleep—like windows of connection with the outside world were temporarily opened on this occasion. These new findings suggest that it may be possible to develop standardized communication protocols with sleeping individuals to understand better how mental activity changes during sleep. On the horizon: a new tool to access the cognitive processes that underlie both normal and pathological sleep.

Part 1

Comment by Dr. Krishna Kumari Challa on October 13, 2023 at 10:10am

Simulations of 'backwards time travel' can improve scientific experiments

Physicists have shown that simulating models of hypothetical time travel can solve experimental problems that appear impossible to solve using standard physics.

If gamblers, investors and quantum experimentalists could bend the arrow of time, their advantage would be significantly higher, leading to significantly better outcomes. Researchers at the University of Cambridge have shown that by manipulating entanglement—a feature of quantum theory that causes particles to be intrinsically linked—they can simulate what could happen if one could travel backwards in time. So that gamblers, investors and quantum experimentalists could, in some cases, retroactively change their past actions and improve their outcomes in the present. Whether particles can travel backwards in time is a controversial topic among physicists, even though scientists have previously simulated models of how such spacetime loops could behave if they did exist. By connecting their new theory to quantum metrology, which uses quantum theory to make highly sensitive measurements, the Cambridge team has shown that entanglement can solve problems that otherwise seem impossible.

 David R. M. Arvidsson-Shukur et al, Nonclassical Advantage in Metrology Established via Quantum Simulations of Hypothetical Closed Timelike Curves, Physical Review Letters (2023). DOI: 10.1103/PhysRevLett.131.150202

Comment by Dr. Krishna Kumari Challa on October 12, 2023 at 10:35am

Gene editing makes chickens flu-resistant

The same lab that cloned Dolly the sheep has used gene editing to create chickens resistant to avian flu

The proof of concept still needs to be refined to achieve full protection and address the challenges of practical application

Bird-flu-resistant chickens have been created using CRISPR gene editing. When exposed to the flu virus, nine out of ten of the animals remained uninfected and didn’t pass the virus to other birds. Researchers modified a gene encoding a chicken protein that the virus needs to replicate. But this prompted the virus to start replicating using other proteins in the same family, which the researchers think could be addressed with more edits. “We must be careful not to facilitate adaptations of the virus that make it more dangerous than it [already] is,” says virologist and study co-author Wendy Barclay.

https://english.elpais.com/science-tech/2023-10-10/the-same-lab-tha...

https://www.nature.com/articles/s41467-023-41476-3.epdf?sharing_tok...

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Comment by Dr. Krishna Kumari Challa on October 12, 2023 at 9:55am

Why this type of dispersal not seen among other insects? 

The eggs of most insect species are typically fertilized just before being laid, relying on sperm stored within the female insects after copulation. However, in some stick insect species, females are parthenogenic, that is, they can produce viable eggs without fertilization. It is only because of this quirk in their nature that viable stick insect babies can hatch from the eggs.

Suetsugu Kenji et al, Phylogeographical evidence for historical long-distance dispersal in the flightless stick insect Ramulus mikado, Proceedings of the Royal Society B: Biological Sciences (2023). DOI: 10.1098/rspb.2023.1708. royalsocietypublishing.org/doi … .1098/rspb.2023.1708

Part 2

Comment by Dr. Krishna Kumari Challa on October 12, 2023 at 9:54am

Birds disperse eaten insects' eggs

Relationship patterns among flightless stick insects suggest that birds disperse the eggs after eating gravid females. Now this is shown to be true in a new study.

 Most species of stick insects are flightless, yet they are distributed over wide distances and across geographical features that would impede the expansion of flightless animals. This has caused researchers to think that their eggs might be dispersed by birds feeding on gravid females, much in the same way as many plant species rely on birds eating their seeds together with fruits and dispersing them while the seeds pass through the digestive tracts of the birds unharmed.

Experimental studies with Ramulus mikado, a common stick insect in Japan, had suggested that this is possible, but since direct observation of such an event in nature is highly unlikely, it has been unclear whether this mechanism actually contributes to the distribution of the insect.

So researchers turned to the analysis of the relationship patterns of Ramulus mikado populations. They made use of the idea of genetic isolation by geographic distance. 

According to this idea, when individual dispersal distances are smaller, such as in flightless insects, the accumulation of genetic mutations eventually leads to a positive correlation between genetic differentiation among locations and the geographic distance that separates them. Thus, the genetic variation between different populations can be a proxy for the species' rate of dispersal.

The results, published in the journal Proceedings of the Royal Society B, paint a vivid picture. Among many genes where the differences correlated with the geographic distance, the team found a few examples of genes that were clearly closely related even though they were geographically separated by up to hundreds of kilometers and across geographic features that these animals usually cannot overcome.

Astonishingly, amidst a sea of limited active dispersal, they discovered identical genotypes jumping across vast distances, strongly indicating the past occurrence of passive long distance genetic dispersal.

In other words, a few of the flightless insects must have flown from place to place, and the only plausible way in which this could happen is that the eggs of the insects survive the passage through the digestive tract of birds that eat them.

And the insect eggs were seen in bird faeces. 

Part 1

Comment by Dr. Krishna Kumari Challa on October 12, 2023 at 9:40am

Among the findings:

• Glyphosate, a nonselective herbicide used in many crops, including corn and soy, and for vegetation control in residential settings, was detected in 98% of participants.
• 2,4D, a broadleaf herbicide used on lawns, aquatic sites, and agricultural crops, was detected in 66% of participants.
• Higher amounts of 2,4D in urine were associated with lower neurobehavioral performance in the domains of attention and inhibitory control, memory and learning, and language.
• Glyphosate concentration in urine was associated with lower scores in social perception only, while DEET metabolites were not associated with neurobehavioral performance.

Following the introduction of genetically modified, glyphosate-resistant "Roundup-ready" crops in 1996 and 2,4D resistant crops in 2014, there have been substantial increases in glyphosate and 2,4D use, making them the most widely used herbicides in the world, they wrote in a published paper.

Briana Chronister et al, Urinary glyphosate, 2,4-D and DEET biomarkers in relation to neurobehavioral performance in Ecuadorian adolescents in the ESPINA cohort, Environmental Health Perspectives (2023). DOI: 10.1289/EHP11383

Part 2

Comment by Dr. Krishna Kumari Challa on October 12, 2023 at 9:39am

Research finds commonly-used herbicide is harmful to adolescent brain function

Herbicides are the most used class of pesticides worldwide, with uses in agriculture, homes and industry. Exposures to two of the most popular herbicides were associated with worse brain function among adolescents, according to a study  by researchers.

 Researchers reported measuring metabolite concentrations of two commonly used herbicides—glyphosate and 2,4-dichlorophenoxyacetic acid (2,4D)—and the insect repellent DEET in urine samples collected in 2016 from 519 adolescents, aged 11 to 17, living in the agricultural county of Pedro Moncayo, Ecuador. Researchers also assessed neurobehavioral performance in five areas: attention and inhibitory control, memory and learning, language, visuospatial processing, and social perception.

Many chronic diseases and mental health disorders in adolescents and young adults have increased over the last two decades worldwide, and exposure to neurotoxic contaminants in the environment could explain a part of this increase, according to the researchers. 

Part 1

Comment by Dr. Krishna Kumari Challa on October 12, 2023 at 9:32am

NASA asteroid sample contains life-critical water and carbon

A sample collected from the 4.5-billion-year-old asteroid Bennu contains abundant water and carbon, NASA revealed on Wednesday, offering more evidence for the theory that life on Earth was seeded from outer space

The discovery follows a seven-year-round-trip to the distant rock as part of the OSIRIS-REx mission, which dropped off its precious payload in the Utah desert last month for painstaking scientific analysis.

"This is the biggest carbon-rich asteroid sample ever returned to Earth," NASA administrator Bill Nelson said at a press event at the Johnson Space Center in Houston, where the first images of black dust and pebbles were revealed.

Carbon accounted for almost five percent of the sample's total weight, and was present in both organic and mineral form, while the water was locked inside the crystal structure of clay minerals, he said.

Scientists think the reason Earth has oceans, lakes and rivers is because it was hit with water-carrying asteroids 4 to 4.5 billion years ago, making it a habitable planet.

All life on Earth meanwhile is based on carbon, which forms bonds with other elements to produce proteins and enzymes as well as the building blocks of genetic code, DNA and RNA.

The findings were made through a preliminary analysis involving scanning electron microscopy, X-ray computed tomography and more.

Comment by Dr. Krishna Kumari Challa on October 12, 2023 at 9:23am

Bionic hand merges with user's nervous and skeletal systems, remaining functional after years of daily use

A woman's life took a dramatic turn when a farming accident claimed her right arm more than 20 years ago. Since then, she has endured excruciating phantom limb pain.

In addition to her intractable pain, she found that conventional prostheses were uncomfortable and unreliable, and thus of little help in daily life. All this changed when she received groundbreaking bionic technology that allowed her to wear a much more functional prosthesis comfortably all day. The higher integration between the bionics and her residual limb also relieved her pain. 

Mechanical attachment and reliable control are two of the biggest challenges in artificial limb replacement. People with limb loss often reject even the sophisticated prostheses commercially available due to these reasons, after experiencing painful and uncomfortable attachment with limited and unreliable controllability. A multidisciplinary group of engineers and surgeons solved these problems by developing a human–machine interface that allows the prosthesis to be comfortably attached to the user's skeleton via osseointegration, while also enabling electrical connection with the nervous system via electrodes implanted in nerves and muscles. This research is now published in the journal Science Robotics.

 Max Ortiz-Catalan et al, A highly integrated bionic hand with neural control and feedback for use in daily life, Science Robotics (2023). DOI: 10.1126/scirobotics.adf7360. www.science.org/doi/10.1126/scirobotics.adf7360

Comment by Dr. Krishna Kumari Challa on October 11, 2023 at 9:57am

Сoconut shells can make concrete more durable

Scientists have found that concrete's compressive strength can be increased by 4.1% and its flexural strength by 3.4% by adding a small amount of coconut shell (only 5%). The material's performance increased by 6.1% compared to clear concrete. This effect is due to the fact that the cement paste—the bridge between all solid concrete particles—penetrates into the pores of the shell, firmly binding it with other components.

These results show that large amounts of coconut shell can be recycled without harm to the environment while improving the quality of building materials.

Sergey A. Stel'makh et al, Alteration of Structure and Characteristics of Concrete with Coconut Shell as a Substitution of a Part of Coarse Aggregate, Materials (2023). DOI: 10.3390/ma16124422

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Animals find humans scarier than lions

Human voices evoke more fear among animals living in the South African savanna than do snarls from lions. Researchers set up speakers near 21 water holes, which played one of several sounds when triggered by animal movement. When they heard humans, giraffes, leopards, elephants and 16 other species were twice as li... as when they heard growling lions, barking dogs or guns. The researchers suggest that recordings of human voices could be used to keep animals away from areas where a lot of poaching happens.

https://www.cell.com/current-biology/fulltext/S0960-9822(23)01169-7?utm_source=Nature+Briefing&utm_campaign=00a3d0b50b-briefing-dy-20231010&utm_medium=email&utm_term=0_c9dfd39373-00a3d0b50b-44672165

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