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Comment by Dr. Krishna Kumari Challa on January 24, 2025 at 9:18am

Mane attraction: Molecular 'switch' may control long scalp hair

Treating hair loss may be as simple as developing therapies to flip a molecular "switch," according to a new study by researchers .

The researchers reviewed the biological and social evolution of human scalp hair. Based on their analysis, they proposed a novel theory that points to a molecular basis underlying the ability to grow long scalp hair. In short, human ancestors may have always had the ability to grow long scalp hair, but the trait remained dormant until certain environmental and biological conditions—like walking upright on two legs—turned on the molecular program.

The team published their findings, which they said could serve as the basis for future experimental work, in the British Journal of Dermatology.

Humans grow extremely long scalp hair.

Likewise, attributes of scalp hair—its length, shape, color and loss of hair—play an essential role in social communication. They signify our ancestry, age, health, sexual maturity and social status, to name but a few. And yet, despite the importance of having long scalp hair, we know very little about how this feature of human skin came about and how it is regulated.

Previous research had shown that tightly curled hair, in particular, served as an effective shield against the sun, reducing the need for excessive sweating that can cause dangerous dehydration. 

Building on this work, the researchers proposed that long scalp hair initially evolved to protect early human ancestors in equatorial Africa from the intense heat and solar radiation of their environment, and then it came to have meaning in many other spheres of life, such as signaling age, health, maturity and social status.

Long, tightly curled hair was a crucial adaptation that allowed our ancestors to thrive in hot, open environments. Understanding when long scalp hair evolved will help to better appreciate when it acquired its essential non-biological purposes.

While long hair is rare among mammals, it is not entirely unique to humans. Animals like male lions, orangutans and even now-extinct wooly mammoths also grew remarkably long hair, albeit for different reasons, according to the researchers.

What these examples tell us is that the molecular blueprint for growing very long hair has always existed, albeit often in a 'silenced' state. When human ancestors evolved their ability to grow extremely long scalp hair, it was likely accomplished by just a few genetic tweaks that reactivated a dormant program rather than via the evolution of an entirely new molecular mechanism.

The findings have broader implications for medical research, particularly in addressing hair loss, a condition that impacts millions worldwide. Understanding how human scalp hair follicles normally grow very long hair will naturally result in novel molecular targets for more efficacious therapies for hair loss.

This knowledge could lead to treatments that help restore hair growth and alleviate the emotional distress that often accompanies hair loss.

Lo-Yu Chang et al, Evolution of long scalp hair in humans, British Journal of Dermatology (2025). DOI: 10.1093/bjd/ljae456

Comment by Dr. Krishna Kumari Challa on January 24, 2025 at 9:06am

In addition to fieldwork, laboratory experiments revealed that methanotrophic microbes are remarkably adaptable. They thrive in a range of environmental conditions, including shifts in temperature, salinity, and methane levels.
As ecosystems change, methane-eating microbes adapt. When one group struggles, another takes over, keeping nature's methane filter running even in a warming world.

Tim de Groot. Environmental controls on microbial methane oxidation in the coasta... ( PhD Dissertation)

Part 2

Comment by Dr. Krishna Kumari Challa on January 24, 2025 at 9:05am

An underestimated source of methane found in shallow coastal waters

Shallow coastal waters are hotspots for methane emissions, releasing significant amounts of this potent greenhouse gas into the atmosphere and contributing to global warming. New research highlights how tides, seasons, and ocean currents strongly influence methane emissions and how tiny microorganisms, called methanotrophs, help reduce their impact.

While human-made sources of methane are well-studied, natural sources like coastal waters remain less understood. These shallow, dynamic ecosystems are rich in methane, and because the water is not very deep, methane-eating microbes (methanotrophs) have little time to break it down before it escapes into the atmosphere.

The study investigated three regions: the Doggerbank seep area in the North Sea, the Dutch Wadden Sea, and coastal waters near Svalbard in the Arctic. Findings revealed that methane emissions are highly influenced by natural factors like tides and seasonal changes, which also affect the activity of methane-eating microbes.

In the Wadden Sea, methane levels and emissions were higher during warmer seasons when microbial activity was stronger. However, even in colder seasons, methane concentrations remained high, with windy conditions contributing to significant atmospheric releases. Tidal currents transported methane into neighboring waters, where it could still escape into the atmosphere, highlighting the broader impact of coastal methane dynamics.
At the Doggerbank seep area, falling tides triggered bursts of methane release while also stimulating microbial activity in deeper waters. However, during cooler autumn months, when water mixed, microbial activity decreased, leading to more methane escaping into the atmosphere compared to summer.

In the Arctic near Svalbard, methane concentrations were highest near the seafloor, where diverse and abundant microbial communities were present. Ocean currents played a key role in spreading methane and microbes, limiting their ability to fully break down the gas before it reached the atmosphere.
Part 1

Comment by Dr. Krishna Kumari Challa on January 24, 2025 at 8:45am

Smart fabric can heat up by 30°C after 10 minutes of sun exposure

A new type of cloth developed by researchers at the University of Waterloo can heat up when exposed to the sun thanks to innovative nanoparticles embedded in the fabric's fibers. This advance represents an innovative and environmentally friendly option for staying warm in the winter.

Wearable heated clothing typically relies on metals or ceramic heating elements to heat up and an external power source, which could pose safety risks for users.

This new cloth incorporates conductive polymer nanoparticles that can heat up to 30°C when exposed to sunlight. The design requires no external power and can also change color to visually monitor temperature fluctuations. The study was recently published in Advanced Composites and Hybrid Materials.

The magic behind the temperature-sensitive color change lies in the combination of nanoparticles embedded in the polymer fibers. The nanoparticles are activated by sunlight, enabling the fabric to absorb heat and convert it into warmth.

The fiber is created using a scalable wet-spinning process, combining polyaniline and polydopamine nano particles to enhance light absorption and improve photothermal conversion. Thermoplastic polyurethane serves as the spinning matrix, while thermochromic dyes enable the reversible color-changing feature. The resultant fiber can be woven into fabric for wearable applications.

In addition to its temperature-changing capability, the Waterloo researchers' new fabric can stretch out by as much as five times its original shape and withstand as much as two-dozen washings while still maintaining its function and appearance. Its reversible color-changing ability provides a built-in temperature monitoring feature to ensure the wearer's safety and convenience.

The fabric's potential applications include aiding in cold rescue situations and solar-powered pet clothing to help keep them comfortable when outside during the winter.

 Fangqing Ge et al, Color tunable photo-thermochromic elastic fiber for flexible wearable heater, Advanced Composites and Hybrid Materials (2024). DOI: 10.1007/s42114-024-00994-4

Comment by Dr. Krishna Kumari Challa on January 24, 2025 at 8:33am

Uncovering the role of Y chromosome genes in male fertility in mice

Researchers at the Crick have uncovered which genes on the Y chromosome regulate the development of sperm and impact fertility in male mice. This research could help us understand why some men don't produce enough sperm and are infertile.

Males typically have one copy of the Y chromosome and one copy of the X chromosome, whereas females typically have two X chromosomes. Scientists know that the Y chromosome is essential for male fertility, but which genes are the most important and how they work is less clear till now.

In research published in Science, a research team at the Crick resolved this question by generating 13 different mouse models, each with different Y genes removed, and investigated their fertility.

The researchers studied the ability of these adult mice to reproduce, including looking at the number of offspring, number of sperm produced and the appearance and motility of the sperm.

They found that several Y genes were critical for reproduction. If these genes were removed, the mice couldn't produce young, due to absence or reduced number of sperm, failure to produce a reservoir of sperm stem cells or abnormal sperm shape or movement.

Interestingly, some other genes had no impact when removed individually, but did lead to the production of abnormal sperm when removed together.

This was the case for a group of three genes which model a region of the chromosome called AZFa in humans. AZFa deletions are a common cause of the most severe cases of male infertility, but it has been hard to tell which genes in the region are responsible.

The results suggest that many Y genes play a role in fertility and can compensate for each other if one gene is lost. This also means that some cases of infertility likely result from multiple genes being deleted at the same time.

As well as regulating sperm generation, some Y genes are also active in other organs, like the heart and the brain, where they may be very important. Also, as they age, some men can lose their Y chromosomes in blood due to errors in cell division. 

This loss is associated with conditions like Alzheimer's disease or cancer, so the lab is now aiming to understand what happens in other organs in the mice with Y gene deletions.

Infertility is a big problem, with one in six couples struggling to conceive. In a significant proportion of cases,genetic factors, particularly those involving the Y chromosome, are the cause.

Now that scientists have shed light on the Y genes, it will be important to start sequencing the Y chromosome in more individuals, to potentially uncover unexplained causes of male infertility. With more research, we may be able to one day replace missing genes in the cells that make sperm to help couples have children through IVF.

Jeremie Subrini et al, Systematic identification of Y-chromosome gene functions in mouse spermatogenesis, Science (2025). DOI: 10.1126/science.ads6495. www.science.org/doi/10.1126/science.ads6495

Comment by Dr. Krishna Kumari Challa on January 23, 2025 at 11:43am

Insulin-producing cells avoid immune attack

Gene-edited insulin-producing beta cells have survived for a month after being injected into a man with type 1 di.... These tweaked cells have a protein called CD47 on their surface, which tells the immune system not to destroy them. Only a small number of cells were injected into the man’s arm, but they have produced insulin and avoided his immune system’s crosshairs so far, suggesting that they could become an effective treatment for diabetes.

https://ir.sana.com/news-releases/news-release-details/sana-biotech...

https://www.newscientist.com/article/2463508-gene-edited-cells-that...

Comment by Dr. Krishna Kumari Challa on January 23, 2025 at 9:38am

Silver nanoparticles in packaging can contaminate dry foods, testing shows

A team of research scientists has found evidence of silver nanoparticles embedded in packaging used as an antimicrobial agent seeping into the dry food it is meant to protect. In their paper published in the journal ACS Food Science & Technology, the group describes how they created their own packaging with embedded silver nanoparticles and tested it with various foods, and what they learned by doing so.

Silver has been a known antimicrobial agent for centuries, but it has only recently been made into nanoparticle-sized grains for use in food packaging. Prior research has shown that when such packaging is used for liquid or gelatinous foods or beverages, the nanoparticles can easily seep into and permeate the food. It is still not known if such particles can cause harm to people who consume them—testing is still ongoing, which is why they are banned in many countries. In this new effort, the research team wanted to know if such particles also find their way into dry foods.

To find out, the team created samples of silver nanoparticles and embedded them in polyethylene film wraps, which could hold various types of food items. They tested wheat flour, slices of cheese, ground rice and spinach leaves. They then stored the packages in ways normal to consumers' homes.

The team then brought the packages into their lab for testing with mass spectrometry. In so doing, they found that the nanoparticles had made their way to all the foods, though to varying degrees. They found, for example, that there was far more contamination of the cheese than there was with the spinach leaves. They noted that the more surface contact between the food and the packaging, the more contamination. They also noted that most of the contamination was confined to the surface of the food, which meant that most of it could be easily rinsed away.

 Laxmi Adhikari et al, Silver Migrates to Solid Foods and Abiotic Surfaces from Model Plastic Packaging Containing Silver Nanoparticles, ACS Food Science & Technology (2025). DOI: 10.1021/acsfoodscitech.4c00813

Comment by Dr. Krishna Kumari Challa on January 23, 2025 at 8:51am

Fighting experience plays key role in brain chemical's control of male aggression

Like humans, mice will compete over territory and mates, and show increased confidence in their fighting skills the more they win. At first, a brain chemical called dopamine is essential for young males to master this behavior. But as they gain experience, the chemical grows less important in promoting aggression, a new study shows.

Dopamine has been linked to male aggression for decades. How past experiences might influence this relationship, however, had until now been unclear.

In experiments in rodents, a team led by researchers at NYU Langone Health boosted activity in dopamine-releasing cells in a part of the brain called the ventral tegmental area. The findings revealed that in inexperienced male fighters, this led the animals to attack for twice as long as they would have fought naturally. When the cells were blocked, the novice mice would not fight at all.

By contrast, this pattern did not hold true in males that had extensive fighting experience. Whether or not dopamine-releasing cells were boosted or blocked, the duration of the attack did not change. Notably, though, the more clashes a mouse won, the more fights it would start in the future.

These findings show that while aggression is an innate behaviour, dopamine—and fighting experience—is essential for its maturation during adulthood.

A report on the findings was published online Jan. 22 in the journal Nature.

Dayu Lin, Experience-dependent dopamine modulation of male aggression, Nature (2025). DOI: 10.1038/s41586-024-08459-w. www.nature.com/articles/s41586-024-08459-w

Comment by Dr. Krishna Kumari Challa on January 23, 2025 at 8:47am

The survey collected sociodemographic data, self-reported social media usage, and measures of irritability. Participants completed the Brief Irritability Test (BITe), which consists of five statements evaluating irritability symptoms over the previous two weeks. Scores range from 5 to 30, with higher scores indicating higher levels of irritability. The analysis also included depression and anxiety metrics to account for overlapping psychological symptoms.

Social media use was categorized based on frequency: never, less than once per week, once per week, several times per week, once per day, several times per day, or most of the day. Platforms analyzed included Facebook, Instagram, TikTok, and Twitter/X. Frequency of active posting, political engagement, and political affiliation were also examined to identify potential confounding factors.

Participants had a mean age of 46 years, with 58.5% identifying as women, 40.4% as men, and 1.1% as nonbinary. Among respondents, 78.2% reported daily use of at least one social media platform. Frequent social media use correlated with higher irritability scores, even after adjusting for anxiety and depression.

For example, participants using social media most of the day scored 3.37 points higher on the BITe in unadjusted models. After adjusting for anxiety and depression, the increase remained significant at 1.55 points.

Platform-specific analyses revealed a dose-response relationship between posting frequency and irritability. Posting multiple times per day was associated with the highest irritability levels across all platforms, with TikTok users showing the largest increase (1.94 points; 95% CI, 1.57-2.32 points).

Political engagement variables, such as frequent political posting or consuming political news, were associated with increased irritability. Political engagement did not diminish the observed relationship between social media use and irritability, though following political news "not very closely" was associated with a slight decrease.

High social media engagement levels, particularly frequent posting, were associated with greater irritability in US adults. While the study could not establish direct causation, findings suggest a potential feedback loop relationship, where irritability may both influence a desire to engage and increase irritation from social media use.

 Roy H. Perlis et al, Irritability and Social Media Use in US Adults, JAMA Network Open (2025). DOI: 10.1001/jamanetworkopen.2024.52807

Part 2

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Comment by Dr. Krishna Kumari Challa on January 23, 2025 at 8:46am

Frequent social media use tied to higher levels of irritability

A survey led by researchers has analyzed the association between self-reported social media use and irritability among US adults. Frequent social media use, especially among active posters, was correlated with higher levels of irritability.

Existing studies on social media and mental health predominantly focus on depressive symptoms, with limited attention to other negative emotions such as irritability. Irritability, defined as a tendency toward anger and frustration, has been linked to functional impairments, poorer mental health outcomes, and suicidal behaviours.

While prior research has established connections between social media use and depressive symptoms, the extent to which social media engagement is associated with irritability or its influence on depression and anxiety has remained uncertain.

In the study, "Irritability and Social Media Use in US Adults," published in JAMA Network Open, the research team used data from two waves of the COVID States Project, a nationwide nonprobability web-based survey conducted between November 2, 2023, and January 8, 2024, which included questions about social media use and irritability.

Researchers evaluated the relationship between social media use and irritability by analyzing responses from 42,597 participants using multiple linear regression models.

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