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Comment by Dr. Krishna Kumari Challa on August 1, 2024 at 10:03am

Study uncovers unique brain plasticity in people born blind

A study by neuroscientists reveals that the part of the brain that receives and processes visual information in sighted people develops a unique connectivity pattern in people born blind. They say this pattern in the primary visual cortex is unique to each person—akin to a fingerprint.

The findings, described July 30, 2024, in PNAS, have profound implications for understanding brain development and could help launch personalized rehabilitation and sight restoration strategies.

For decades, scientists have known that the visual cortex in people born blind responds to a myriad of stimuli, including touch, smell, sound localization, memory recall and response to language. However, the lack of a common thread linking the tasks that activate primary areas in the visual cortex has perplexed researchers.

The new study offers a compelling explanation: differences in how each individual's brain organizes itself.

We don't see this level of variation in the visual cortex connectivity among individuals who can see—the connectivity of the visual cortex is usually fairly consistent, say the researchers.

The connectivity pattern in people born blind is more different across people, like an individual fingerprint, and is stable over time—so much so that the individual person can be identified from the connectivity pattern.

Lénia Amaral et al, Longitudinal stability of individual brain plasticity patterns in blindness, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2320251121

Comment by Dr. Krishna Kumari Challa on August 1, 2024 at 9:58am

Engineered microbes found to repel mosquitoes

Genetically-engineered human skin bacteria can make mice less attractive to mosquitoes for 11 days. Mosquitoes transmit a host of deadly diseases, including malaria, West Nile, dengue, yellow fever, and Zika. Female mosquitoes on the hunt for a blood meal tune into scents released by skin microbes that live on their targets.

Researchers engineered versions of the common human  skin commensals Staphylococcus epidermidis and Corynebacterium amycolatum to produce much less of a form of lactic acid known to attract mosquitoes. The work is published in the journal PNAS Nexus.

The authors tested the microbes alone and found the engineered version of S. epidermidis attracted about half as many Aedes aegypti and Anopheles gambiae mosquitoes and about 22% fewer Culex quinquefasciatus as the wildtype versions of the microbes.

The authors also tried the engineered microbes on mice. Painting the mice with wildtype S. epidermidis attracted mosquitos. However, painting the mice with engineered S. epidermidis reduced mosquito attraction by up to 64.4%, compared with wildtype, starting three days after the microbe was applied.

The effect lasted for 11 days. Trials with engineered C. amycolatum had similar results. In addition, a smaller proportion of mosquitoes that landed on mice painted with engineered microbes bit the mice. According to the authors, the results suggest the feasibility of creating a living and long-lasting engineered microbiome-based mosquito repellent.

 Feng Liu et al, Engineered skin microbiome reduces mosquito attraction to mice, PNAS Nexus (2024). DOI: 10.1093/pnasnexus/pgae267

Comment by Dr. Krishna Kumari Challa on August 1, 2024 at 9:46am

Why men and women feel touch differently

Why women generally seem to have a more acute sense of touch than men?

 Women are better than men at touch discrimination—although not because they have smaller fingers, but because in general they have softer fingers. 

But demonstrating the "why" behind the gender difference, first published in November 2023 in the Journal of Physiology, continues to be a cited topic of interest. The insight could be useful as engineers develop softer sensor materials for wearable technology, improve prosthetics with a sense of touch, or design better interfaces for surgical robots.

The experimental design combined novel 3D imaging and biomechanical observations of skin and how it deforms when pressed, statistical analysis and machine learning, and experiments to test how the participants used touch to perceive objects.
They found that softer skin resulted in greater rates of change in surface contact with objects, which correlated with a greater ability to distinguish small changes in the objects' stiffness.

"The mechanism seems to be that attributes of surface contact control the recruitment of sensory nerve fibers in the skin".

For those who'd like to improve their touch perception, the researchers said, apply hyaluronic acid, an effective skin moisturizer and softener.

Bingxu Li et al, An individual's skin stiffness predicts their tactile discrimination of compliance, The Journal of Physiology (2023). DOI: 10.1113/JP285271

Comment by Dr. Krishna Kumari Challa on August 1, 2024 at 9:42am

Who needs males? Female sharks make babies alone

 Researchers have noted the first case of "virgin birth", or reproduction without fertilization, in an endangered shark species, a scientific journal reported this week.

The findings published in Scientific Reports concern the first case of the phenomenon in the common smooth-hound shark, Mustelus mustelus, a species threatened by illegal fishing that inhabits the Mediterranean and other warm waters.

Researchers found that two female M. mustelus sharks under observation in captivity had exhibited parthenogenesis—in which a female can reproduce asexually without the need of sperm to fertilize the egg—each year since 2020.

The two 18-year-old sharks have been at the Cala Gonone Aquarium in Sardinia since 2010.

Remarkably, this finding reveals that parthenogenesis can occur annually in these sharks, alternating between two females, and conclusively excludes long-term sperm storage as a cause.

Cycling parthenogenesis, in which progeny can be born either from fertilized eggs or asexually with unfertilized eggs, occurs in over 15,000 species, yet is not fully understood.

Parthenogenesis,  is more common in invertebrates than vertebrates. Reptiles and some sharks, rays and skates are able to "modify their adaptive strategy according to the surrounding circumstances".

Although the mechanisms driving parthenogenesis remain unclear, it is suggested that male population reduction could be a pivotal factor.

Giuseppe Esposito et al, First report of recurrent parthenogenesis as an adaptive reproductive strategy in the endangered common smooth-hound shark Mustelus mustelus, Scientific Reports (2024). DOI: 10.1038/s41598-024-67804-1

Comment by Dr. Krishna Kumari Challa on August 1, 2024 at 9:38am

Comment by Dr. Krishna Kumari Challa on August 1, 2024 at 9:06am

AI predicts male infertility risk with blood test, no semen needed

According to a World Health Organization (WHO) study (2017), about half of all infertility is due to men. Semen analysis is considered essential for diagnosis of male infertility, but is not readily available at medical institutions other than those specializing in infertility treatment, and there is a high threshold for receiving it.

In a new study, researchers developed an AI model that can predict the risk of male infertility without the need for semen analysis by only measuring hormone levels in a blood test. AI creation software that requires no programming was used for the model, and the study was reported in Scientific Reports.

The AI prediction model was based on data from 3,662 patients and had an accuracy rate of approximately 74%. In particular, it was 100% correct in predicting non-obstructive azoospermia, the most severe form of male infertility.

The current study collected clinical data from 3,662 men who underwent semen and hormone testing for male infertility between 2011 and 2020. Semen volume, sperm concentration, and sperm motility were measured in the semen tests, and LH, FSH, PRL, testosterone, and E2 were measured in the hormone tests. T/E2 was also added. Total motile sperm count (semen volume X sperm concentration X sperm motility rate) was calculated from the semen test results.

Based on the reference values for semen testing in the WHO laboratory manual for the examination and processing of human semen, 6th edition (2021), a total motile sperm count of 9.408 X 10⁶ (1.4 mL X 16 X 10⁶/mL X 42%) was defined as the lower limit of normal, assigning a value of "0" if the total motility sperm count for an individual patient was above 9.408 X 10⁶ and a value of "1" when it was below. The accuracy of the AI model was approximately 74%.

A New Model for Determining Risk of Male Infertility from Serum Hormone Levels, without Semen Analysis, Scientific Reports (2024).

Next, the AI model was validated using data from 2021 and 2022 for which both semen and hormone tests were available. Using the data of 188 patients in 2021, the accuracy was about 58%, while accuracy using the data for 166 patients in 2022 was about 68%. However, non-obstructive azoospermia could be predicted with a 100% accuracy rate in both 2021 and 2022.

Comment by Dr. Krishna Kumari Challa on August 1, 2024 at 9:01am

Incidence of heart attacks and strokes was lower after COVID-19 vaccination, finds study of 46 million adults

A new study, published recently in Nature Communications and involving nearly the whole adult population of England, has found that the incidence of heart attacks and strokes was lower after COVID-19 vaccination than before or without vaccination.

Researchers analyzed de-identified health records from 46 million adults in England between 8 December 2020 and 23 January 2022. Data scientists compared the incidence of cardiovascular diseases after vaccination with the incidence before or without vaccination, during the first two years of the vaccination program.

The study showed that the incidence of arterial thromboses, such as heart attacks and strokes, was up to 10% lower in the 13 to 24 weeks after the first dose of a COVID-19 vaccine. Following a second dose, the incidence was up to 27% lower after receiving the AstraZeneca vaccine and up to 20% lower after the Pfizer/Biotech vaccine. The incidence of common venous thrombotic events—mainly pulmonary embolism and lower limb deep venous thrombosis—followed a similar pattern.

This research further supports the large body of evidence on the effectiveness of the COVID-19 vaccination program, which has been shown to provide protection against severe COVID-19 and saved millions of lives worldwide. It did not identify new adverse cardiovascular conditions associated with COVID-19 vaccination and offers further reassurance that the benefits of vaccination outweigh the risks.

The incidence of cardiovascular disease is higher after COVID-19, especially in severe cases. This may explain why the incidence of heart attacks and strokes is lower in vaccinated people compared with unvaccinated people.

Cohort study of cardiovascular safety of different COVID-19 vaccination doses among 46 million adults in England, Nature Communications (2024). DOI: 10.1038/s41467-024-49634-x

Comment by Dr. Krishna Kumari Challa on August 1, 2024 at 8:54am

43% of cocoa products exceed lead safety levels, study finds

When our friends, relatives and colleagues come from the US they bring lots of chocolates  and we consume them very fondly. But this new information is alarming ....

A new study  found a disquieting percentage of cocoa products in the U.S. contain heavy metals that exceed guidelines, including higher concentrations in organic products.

The study, "A Multi-Year Heavy Metal Analysis of 72 Dark Chocolate and Cocoa Pr... was published on July 31, 2024 in Frontiers in Nutrition.

Researchers analyzed 72 consumer cocoa products, including dark chocolate, every other year over an eight year period for contamination with lead, cadmium, and arsenic, heavy metals that pose a significant health hazard in sufficient amounts.

We all love chocolate but it's important to indulge with moderation, as with other foods that contain heavy metals, including large fish like tuna and unwashed brown rice. While it's not practical to avoid heavy metals in your food entirely, you must be cautious of what you are eating and how much.

The researchers used a threshold of maximum allowable dose levels to assess the extent of heavy metal contamination in an array of chocolate products, found on grocery store shelves.

Key findings:

43% of the products studied exceeded the maximum allowable dose level for lead. 35% of the products studied exceeded the maximum allowable dose level for cadmium.

None of the products exceeded the maximum allowable dose level for arsenic. Surprisingly, organic labeled products showed higher levels of both lead and cadmium compared to non-organic products.

For the average consumer, consuming a single serving of these cocoa products may not pose significant health risks based on the median concentrations found. However, consuming multiple servings or combining consumption with other sources of heavy metals could lead to exposures that exceed the maximum allowable dose level.

Foods with high lead levels may include animal foods that can bioaccumulate heavy metals (shellfish, organ meats) and foods or herbal supplements grown in contaminated soil and/or imported from countries with less regulation.  For cadmium, the main concerns are the same with the addition of some seaweeds.

Consumers should be aware of potential cumulative exposure risks, particularly with cocoa products labeled organic, as they may have higher heavy metal concentrations. A serving size of dark chocolate is typically one ounce and has been generally suggested to have health benefits including cardiovascular health, cognitive performance, and chronic inflammation.

 Study Finds Many Cocoa Products Contaminated by Heavy Metals, Frontiers in Nutrition (2024). DOI: 10.3389/fnut.2024.1366231 , www.frontiersin.org/journals/n … 024.1366231/abstract

Comment by Dr. Krishna Kumari Challa on July 31, 2024 at 12:47pm

Scientists 'Mind Controlled' Mice Remotely 

At the mere flick of a magnetic field, mice engineered with nanoparticle-activated 'switches' inside their brains were driven to feed, socialize, and act like clucky new mothers in an experiment designed to test an innovative research tool.

While 'mind control' animal experiments are far from new, they have generally relied on cumbersome electrodes tethering the subject to an external system, which not only requires invasive surgery but also sets limits on how freely the test subject can move about.
In what is claimed to be a breakthrough in neurology, researchershave developed a method for targeting pathways in the brain using a combination of genetics, nanoparticles, and magnetic fields.

They call the technology Nano-MIND, an acronym for Magnetogenetic Interface for NeuroDynamics. And while mind-control is a coarse but relatively accurate way of describing it, the system in its current form is intended to provide researchers with a means of remotely activating neural circuits for a range of research applications.

This is the world's first technology to freely control specific brain regions using magnetic fields. Magnetic stimulation is an emerging field of research in neurology, where washing the brain with pulses of electromagnetism broadly massages whole regions into subtly changing their behavior. 

To target specific circuits, the researchers took a leaf out of another field of research called optogenetics, which genetically engineers mechanisms into cells that can be readily activated by a light source. In this case, the team integrated ion channels into targeted populations of brain cells in mice. Instead of delivering light through a localized fiber, as in optogenetics, the ion channels could be switched on magnetically with a twist of a tiny actuator. All that's required is a surrounding field that's strong enough to pull at the nanoparticle.

similar nanotechnology may even treat poor mental health in humans or play a significant role in therapies for debilitating neurological conditions, thereby returning complete control of a person's mind back to the individual.

https://www.nature.com/articles/s41565-024-01694-2

Comment by Dr. Krishna Kumari Challa on July 31, 2024 at 11:55am

Study finds working from home stifles innovation

Remote and hybrid working may be great for employees' work-life balance, but it may be stifling innovation, according to new research.

The study found that staff who worked in a hybrid model were less likely to come up with innovative ideas than colleagues who always worked in the office. And staff working from home tended to produce lower quality innovative ideas than those who always worked in the office. 

Innovation in the workplace can occur through random, spontaneous 'watercooler' conversations between employees. However, these 'productive accidents' are less likely to occur when employees work from home. This  research work has found that innovation is suffering as a result.

Michael Gibbs et al, Employee innovation during office work, work from home and hybrid work, Scientific Reports (2024). DOI: 10.1038/s41598-024-67122-6

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