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Comment by Dr. Krishna Kumari Challa 1 hour ago

Fever chills explained: How brain signals push warmth-seeking to fight infection

When running a fever during infection, we often feel chills, which prompt us to take action to warm ourselves, such as turning on a heater or adding layers of clothing. Increased body temperature helps inhibit pathogen growth and boosts immune cell activity.

A recent rat study by researchers identified the neural mechanism underlying chills, a cold sensation that supports the body's response to infection. The findings were published in The Journal of Physiology.

When mammals are infected, their immune system produces a pyrogenic mediator, prostaglandin E₂ (PGE₂), in the brain's vascular cells. PGE₂ acts on the preoptic area, the brain's thermoregulatory center, and triggers autonomic fever responses, such as shivering, increased heat production in brown adipose tissue, and constriction of skin blood vessels.

PGE₂ is known to trigger not only autonomic fever responses but also behavioral fever responses including warming behaviors with chills.

The team hypothesized that PGE₂ acts on the lateral parabrachial nucleus (LPB) in the brain, which relays sensory signals, to trigger chills and warmth-seeking behaviors during infection. This was based on their 2023 study showing that LPB neurons transmit skin-temperature sensations to the forebrain and influence body temperature regulation. To test this hypothesis, the team conducted experiments on rats.

The researchers found that the rats' axons primarily target the central nucleus of the amygdala, which regulates emotions such as discomfort and fear, with minimal projections to the preoptic area.

The team also found that the pathway from EP3-expressing neurons to the amygdala is activated in cold environments and transmits cold sensations.

These findings suggest that during infection, PGE₂ boosts cold signals from the LPB to the central nucleus of the amygdala via EP3 receptors, triggering chills and promoting warmth-seeking behaviour.

This study demonstrates that PGE₂ increases body temperature by acting on two brain regions: the preoptic area, which drives autonomous thermogenic responses, and the lateral parabrachial nucleus (LPB), which mediates behavioural responses.

The pyrogenic mediator prostaglandin E2 elicits warmth seeking via EP3 receptor-expressing parabrachial neurons: a potential mechanism of chills, The Journal of Physiology (2026). DOI: 10.1113/JP289466

Comment by Dr. Krishna Kumari Challa 1 hour ago

Boxfish

Comment by Dr. Krishna Kumari Challa 2 hours ago

Old galaxies in a young universe?
Analysis of 31 high-redshift galaxies observed with JWST indicates average stellar ages of about 600 million years, close to the universe's age at that epoch (~700 Myr), with some cases, such as JADES-1050323, appearing older than the universe at their redshift. These findings challenge the standard Lambda-CDM model and suggest a need for further investigation.

The standard cosmological model (present-day version of "Big Bang," called Lambda-CDM) gives an age of the universe close to 13.8 billion years and much younger when we explore the universe at high-redshift. The redshift of galaxies is produced by the expansion of the universe, which causes emitted wavelengths to lengthen and move toward the red end of the electromagnetic spectrum.

The further away a galaxy is, the more rapidly it is moving with respect to us, and so the greater is its redshift; and, given that the speed of light is finite, the more we travel to the past. Hence, measuring the age of very high redshift galaxies would be a way to test the cosmological model. Galaxies cannot be older than the age of the universe in which they are; it would be absurd, like a son older than his mother.\

In work carried out  by researchers at the Canary Islands Astrophysics Institute (IAC; Spain), we analyzed 31 galaxies with average redshift 7.3 (when the universe was 700 Myr old, according to the standard model) observed with the most powerful available telescope available: the James Webb Space Telescope (JWST).

The findings are published in the journal Monthly Notices of the Royal Astronomical Society.

As a result, they found that they are on average ~600 Myr old, according to the comparison with theoretical models based on previous knowledge of nearby galaxies. Our models include all of the known possibilities: old and young stellar populations, thermally-pulsating AGB stars, emission lines associated with HII regions, black holes in active galactic nuclei (AGN), interstellar dust extinction, and intergalactic extinction from neutral hydrogen.

There were other independent works that also pointed out  strong anomalies with JWST galaxies, including the existence of old galaxies (e.g., Steinhardt et al. 2024, ApJ, 967, 172; Wang et al. 2024, ApJL, 969, L13; Martínez-García 2025, MNRAS, 541, 1988). If this result is correct, we would have to think about how it is possible that these massive and luminous galaxies were formed and started to produce stars in a short time. It is a challenge.

The fact that some of these galaxies might be older than the universe within some significant confidence level is even more challenging.

M López-Corredoira et al, Improved measurements of the age of JWST galaxies at z = 6 − 10, Monthly Notices of the Royal Astronomical Society (2026). DOI: 10.1093/mnras/stag089

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Comment by Dr. Krishna Kumari Challa 2 hours ago

Obesity linked to one in 10 infection deaths globally

Just over one in 10 deaths from a wide range of infectious diseases can be attributed to obesity worldwide, finds a major new study. People with obesity face a 70% higher risk of hospitalization or death from an infection than those of a healthy weight, according to the findings published in The Lancet.

Obesity can increase the risk posed by many different infectious diseases, from flu and COVID-19 to stomach bugs and urinary tract infections, and the researchers found that the higher the BMI, the greater the risk.

While this study did not investigate the causes of the association, the researchers say that previous studies have suggested that obesity contributes to a general impairment of immune, including immune dysregulation, chronic systemic inflammation, and metabolic disturbances.

Obesity weakens the body's defenses against infections, resulting in more serious diseases. People may not get infected more easily, but recovery from infection is clearly harder.

The researchers found evidence that losing weight can reduce the risk of severe infections, as people with obesity who lost weight had a roughly 20% lower risk of severe infections than those who remained obese.

Adult obesity and risk of severe infections: a multicohort study with global burden estimates, The Lancet (2026). DOI: 10.1016/S0140-6736(25)02474-2

Comment by Dr. Krishna Kumari Challa 2 hours ago

Female scientists wait longer to have papers published in life and biomedical sciences

If you are a woman working in biomedical and life sciences, you may have longer to wait for your academic paper to appear in print than a comparable paper authored by a man. According to research published in the journal PLOS Biology, female-authored biomedical and life science articles spend around 7.4% to 14.6% longer under review than male-authored articles.

Despite increasing calls for equality and inclusion, there is still a gender gap in academia. Women are underrepresented in senior academic positions, and whether through anecdotal evidence or studies, the data show that female researchers face more obstacles than their male colleagues, including in academic peer review.

The study found significant delays for female researchers. These ranged from 7.4% for papers with a female first author to 10% for all-female teams and 14.6% when both the first and corresponding authors were women. These delays occur across different countries and nearly every branch within biomedical and life sciences.

This is unequivocal evidence that female-authored articles tend to spend longer under review than male-authored articles. Even though, for each manuscript, time under review is only 7–15 days longer for females—than for male-authored articles, accumulated over a woman's career, these delays can be very substantial.

These delays can have knock-on effects on a scientist's career, including fewer opportunities for promotion and difficulty obtaining research funding. By documenting these problems, the researchers hope their study will help the community devise mitigation strategies.

David Alvarez-Ponce et al, Biomedical and life science articles by female researchers spend longer under review, PLOS Biology (2026). DOI: 10.1371/journal.pbio.3003574

Comment by Dr. Krishna Kumari Challa 2 hours ago

Current flows without heat loss in newly engineered fractional quantum material

A team of researchers has unveiled a device that can conduct electricity along its fractionally charged edges without losing energy to heat. Described in Nature Physics, the work marks the first demonstration of a "dissipationless fractional Chern insulator," a long-sought state of matter with promising implications for future quantum technologies.

A device based on twisted molybdenum ditelluride bilayers demonstrates dissipationless edge conduction with fractionally quantized Hall resistance at zero magnetic field, realizing a fractional Chern insulator. Improved crystal quality and fabrication eliminate energy loss, while the thermal activation gap shows an unusual dependence on magnetic field, indicating complex low-energy excitations.

Heonjoon Park et al, Observation of dissipationless fractional Chern insulator, Nature Physics (2026). DOI: 10.1038/s41567-025-03167-2

Comment by Dr. Krishna Kumari Challa 2 hours ago

Early-life indoor mold linked to reduced childhood lung function, long-term study finds

Mold is a silent threat, often going unnoticed as it quietly harms health. What's concerning is that exposure to mold during early childhood leaves its mark way into adolescence. In a study published in Environmental Research: Health, a team  tapped into data from the Avon Longitudinal Study of Parents and Children —a well-known birth cohort study also known as Children of the 90s—to explore how early-life exposure to indoor mold may affect lung function, its development over time, and the risk of doctor-diagnosed asthma.

The researchers analyzed medical data from nearly 14,000 children, whose health and development were followed closely from birth through to approximately 24 years of age, using information collected from clinic visits and questionnaires.

The data indicated that serious exposure to indoor mold at age 5 was associated with a nearly 6% reduction in lung function by age 15. There was also a strong association with asthma, with children exposed to serious mold by age 5 being 1.85 times more likely to have been diagnosed with asthma by age 8 compared to those with no mold exposure. This link, however, weakened as the child approached adulthood.

Joshua Khan et al, Early-life exposure to indoor mould and associations with lung function, lung function trajectories and asthma, Environmental Research: Health (2026). DOI: 10.1088/2752-5309/ae3eda

Comment by Dr. Krishna Kumari Challa yesterday

Infusing asphalt with plastic could help roads last longer and resist cracking under heat
Incorporating 8–10% recycled plastic into asphalt enhances road durability, flexibility, and heat resistance, reducing cracking and maintenance needs. This approach diverts plastic waste from landfills, lowers demand for petroleum-based materials, and shows minimal microplastic release. Challenges include sourcing clean plastic and ensuring safe processing, but early results indicate environmental and economic benefits.

"Reuse of Recycled Plastic for Plastic Road Design" by Tahsina Islam

Comment by Dr. Krishna Kumari Challa yesterday

Structural differences found in brains of people with panic disorder

Panic disorder (PD) is a mental health disorder characterized by recurring panic attacks, episodes of intense fear and anxiety accompanied by physical sensations and physiological responses such as a racing heart, shortness of breath, dizziness, blurred vision and other symptoms. Estimates suggest that approximately 2–3% of people worldwide experience PD at some point during their lives.

Better understanding the neural underpinnings and features of PD could have important implications for its future treatment.

Researchers of many institutes worldwide recently carried out a new study shedding new light on the neuroanatomical signatures of PD, via the analysis of a large pool of brain scans collected from people diagnosed with the disorder and others with no known psychiatric diagnoses. Their paper, published in Molecular Psychiatry, identifies marked differences in the brains of individuals with PD, such as a slightly thinner cortex and frontal, temporal and parietal brain regions that are smaller than those of people with no known mental health disorders.

The team's analyses allowed them to pin-point various marked differences between the brains of people with PD and others with no known psychiatric or mental health disorders. The researchers found that people with PD had a slightly thinner cortex and that some parts of their brain had a smaller surface area or a reduced volume.

They identified subtle but consistent reductions in cortical thickness and surface area in frontal, temporal, and parietal regions, along with smaller subcortical volumes within the thalamus and caudate volumes, among individuals with PD.

Among other things, these regions govern how emotionally salient information is perceived, processed, modulated, and responded to. The analyses also showed that some differences are age-dependent and that early-onset PD (before age 21) is linked to larger lateral ventricles.

Overall, the findings of this recent study appear to confirm existing models of PD that suggest that the disorder is linked to disruptions in brain regions associated with the processing and regulation of emotions. 

Laura K. M. Han et al, Structural brain differences associated with panic disorder: an ENIGMA-Anxiety Working Group mega-analysis of 4924 individuals worldwide, Molecular Psychiatry (2026). DOI: 10.1038/s41380-025-03376-4.

Comment by Dr. Krishna Kumari Challa on Saturday

The secrets under our skin
Mysterious undulating microstructures in our skin, called rete ridges, could help explain how the organ can regenerate and why it is that humans don’t have fur. The ridges act “like velcro to keep the top layer of your skin attached firmly to the bottom layer of your skin”, biologist Ryan Driskell, who co-authored a new study on the ridges, tells Nature. Driskell and his colleagues scoured the animal kingdom to find the skin that most resembled humans’ and found clues as to how these ridges form.

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