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Comment by Dr. Krishna Kumari Challa 10 hours ago

A tick bite can cause a deadly meat allergy

Tick bites can introduce the alpha-gal sugar molecule into the bloodstream, leading some individuals to develop IgE antibodies and become sensitized to mammalian meat allergy. Subsequent consumption of red meat or products containing alpha-gal can trigger allergic reactions, including potentially fatal anaphylaxis. Most cases occur in older adults, with incidence rising mainly due to increased awareness and testing.
There is no cure for mammalian meat allergy. So preventing tick bites is best:

wear long-sleeved shirts and long pants when walking or working in areas where there are ticks
tuck pants into long socks
wear a wide-brimmed hat
wear light-colored clothing
use insect repellent, particularly ones containing DEET.

https://theconversation.com/how-can-a-tick-bite-cause-a-deadly-meat...

Comment by Dr. Krishna Kumari Challa 10 hours ago

Study finds more parents saying 'no' to vitamin K at birth, putting babies' brains at risk

Increasing numbers of parents are refusing vitamin K shots for their newborns, putting infants at greater risk of avoidable brain injuries, according to a preliminary systematic review released February 26, 2026.

A vitamin K injection is a supplement that provides babies with an essential vitamin that is naturally low in newborns. It is not a vaccine. Vitamin K is needed to help blood clot. Getting a vitamin K shot right after birth can prevent a rare but serious condition called vitamin K deficiency bleeding. This condition can cause an intracerebral hemorrhage, a type of stroke, when a blood vessel bursts in the brain, which can lead to death or lifelong brain problems.
Refusal of vitamin K injections at birth is increasing in several regions, raising the risk of vitamin K deficiency bleeding in newborns, which can cause brain hemorrhage, death, or long-term neurological disability. Infants without the injection are 81 times more likely to develop this condition. Refusal is also linked to declining other newborn health interventions.

Researchers found that among case series reports of babies who had vitamin K deficiency bleeding, approximately 14% of the babies died, about 40% had long-term neurological disabilities such as cognitive impairment, seizures or motor deficits, and about 63% of babies had brain bleeds.

They also found that parents who refused vitamin K for their babies were more likely to skip other recommended health protections.

Parental concerns included pain, preservatives and belief in inaccurate information.

Source: A preliminary systematic review released February 26, 2026, that will be presented at the American Academy of Neurology's 78th Annual Meeting taking place April 18–22, 2026, in Chicago and online.

Comment by Dr. Krishna Kumari Challa 10 hours ago

Frequently distracted? Your brain rhythms may be to blame
Attention naturally shifts rhythmically about 7–10 times per second, creating alternating periods of heightened and reduced focus. These cycles, once advantageous for environmental monitoring, now increase susceptibility to distractions from digital stimuli. EEG data show that during low-focus phases, individuals are more easily distracted, suggesting implications for understanding conditions like ADHD.

Zach V. Redding et al, Frequency-specific attentional mechanisms phasically modulate the influence of distractors on task performance, PLOS Biology (2026). DOI: 10.1371/journal.pbio.3003664

Comment by Dr. Krishna Kumari Challa 10 hours ago

Ancient mosquitoes developed a taste for early hominins, research reveals

The preference of some mosquitoes in the Anopheles leucosphyrus (Leucosphyrus) group—including those that transmit malaria—for feeding on humans may have evolved in response to the arrival of early hominins in Southeast Asia around 1.8 million years ago.
A preference for feeding on humans is uncommon among the 3,500 known mosquito species, yet this feeding preference is the main factor influencing the potential of mosquitoes to spread disease-causing pathogens.
Mosquitoes in the Anopheles leucosphyrus group developed a preference for feeding on humans between 2.9 and 1.6 million years ago in Sundaland, coinciding with the arrival of Homo erectus. This shift from feeding on non-human primates likely required genetic changes in odour detection and provides independent evidence for early hominin presence in Southeast Asia.

Researchers estimate that the preference for feeding on humans evolved once within Leucosphyrus between 2.9 and 1.6 million years ago in a region known as Sundaland, which includes the Malay Peninsula, Borneo, Sumatra, and Java. Prior to this, ancestors of the group fed on non-human primates.

This overlaps with the earliest proposed date for the arrival of the hominin species Homo erectus in the region around 1.8 million years ago and predates the arrival of modern humans between 76,000 and 63,000 years ago. It also predates previously published estimates of the evolution of a preference for feeding on humans among the mosquito lineage that gave rise to the major African malaria carriers Anopheles gambiae and Anopheles coluzzii.

Upasana Shyamsunder Singh, Early hominin arrival in Southeast Asia triggered the evolution of major human malaria vectors, Scientific Reports (2026). DOI: 10.1038/s41598-026-35456-y. www.nature.com/articles/s41598-026-35456-y

Comment by Dr. Krishna Kumari Challa 10 hours ago

Middle-aged men are most vulnerable to faster aging due to 'forever chemicals,' study finds

"Forever chemicals" in common parlance—are a class of thousands of synthetic chemicals often used in non-stick coatings, water-resistant fabrics, fire-fighting foams, food packages, cleaning products, and plastics. They contain exceptionally strong molecular bonds, which makes them hard to break down.

PFAS pollution is increasingly detectable in water, soil, and tissues of organisms, and some have been implicated in human cancers, obesity, infertility, and hormonal imbalances.

PFAS have wide-ranging toxic effects. Now, researchers have found that two non-legacy PFAS, namely perfluorononanoic acid (PFNA) and perfluorooctanesulfonamide (PFOSA), appear to speed up biological aging in middle-aged men, but not women. These results suggest that newer PFAS are not necessarily risk-free and should be considered for stricter regulation.

But why would the effects of PFNA and PFOSA be strongest in middle-aged men?

Midlife is a sensitive biological window where the body becomes more susceptible to age-related stressors, which may explain why this group responds more strongly to chemical exposure, say the researchers.

 Men may be at higher risk because the aging markers we analyzed are heavily influenced by lifestyle factors such as smoking, which can compound the damaging effects of these pollutants.

 To reduce risk, individuals can try to limit their consumption of packaged foods and avoid microwaving fast-food containers.

Ya-Qian Xu, et al. Emerging PFAS Contaminants PFNA and PFSA Amplify Epigenetic Aging: Sex-and Age-Stratified Risks in an Aging Population, Frontiers in Aging (2026). DOI: 10.3389/fragi.2025.1722675

Comment by Dr. Krishna Kumari Challa 11 hours ago

Wildfire smoke linked to rise in violent assaults

A new study spanning 11 years of data has revealed a clear link between wildfire smoke pollution and an increase in violent assaults.

These findings represent the first direct causal evidence that short-term exposure to wildfire-driven air pollution can increase interpersonal violence in an urban environment. The work is published in Environmental Research Letters .

The authors of the study, warns that air-quality deterioration may be driving social as well as health consequences.

The researchers  analyzed daily air pollution levels and police-reported assaults from 2013 to 2023, found that:
Wildfire smoke increased daily PM2.5 levels by an average of 7 μg/m³.
On smoke-affected days, assaults rose by approximately 3.6%.
Each additional 1 μg/m³ of PM2.5 was linked to a 0.5% increase in daily assaults.

Although the study did not test individual biological changes due to wildfire smoke pollution, the pattern of results points to short-lived physiological and psychological responses to fine particulate pollution—such as discomfort, inflammation or stress reactions—as likely contributors to the rise in assaults.

Importantly, the researchers ruled out other factors that might drive increased violence. For instance, traffic collisions and police response times remained stable on smoke-affected days, ruling out explanations related to inattention or reduced police capacity.

Domestic violence call volumes also did not increase, suggesting that the effect is concentrated in outdoor settings where exposure to wildfire smoke is highest and incidents of low severity police use of force did rise on smoke days, mirroring the uptick in interpersonal assaults and further supporting an exposure-driven behavioural response.

What really stands out in the study is that the burden of wildfire smoke won't be shared equally. Outdoor workers, people without access to clean indoor air, and those experiencing homelessness are likely to feel the effects most intensely, and that's something we can't ignore.

Wildfire smoke increases assaults: evidence from Seattle, Environmental Research Letters (2026). DOI: 10.1088/1748-9326/ae436c

Comment by Dr. Krishna Kumari Challa 11 hours ago

To determine whether Neanderthal X chromosomes contain alleles from humans, the team identified modern human DNA preserved in three Neanderthals—Altai, Chagyrskaya, and Vindija—and compared this dataset against one of diverse African genomes, a control group who had historically never encountered a Neanderthal.
What the researchers found was a striking imbalance. While modern humans lack Neanderthal X chromosomes, Neanderthals had a 62% excess of modern human DNA on their X chromosomes compared to their other chromosomes.
This mirrorlike reversal was their answer. If the two species were biologically incompatible, modern human DNA should have been missing from Neanderthal X chromosomes as well. But because the team found an abundance of human DNA in Neanderthal X chromosomes, they were able to rule out reproductive incompatibility or toxic gene interactions as the barrier.

The remaining explanation, the team argues, lies in sex-biased interbreeding.
Because females carry two X chromosomes and males carry only one, mating direction matters. If Neanderthal males partnered more often with modern human females, fewer Neanderthal X chromosomes would enter the human gene pool, and more human X chromosomes would enter Neanderthal populations.
Mathematical models confirmed that this bias could reproduce the observed genetic patterns. Other possibilities, such as sex-biased migration, could theoretically produce similar results—but only through complex, shifting scenarios that varied across time and geography.

Mating preferences provided the simplest explanation.
With the "who" and "how" of these ancient trysts established, the team is now turning their attention to the "why," investigating whether similar genetic comparisons—specifically the ratio of diversity between X chromosomes and autosomes—can reveal the gender dynamics of Neanderthal society, such as whether females stayed with their birth families while males migrated to new groups.

By mapping these ancient interactions, the researchers hope to further illuminate the complex social lives of human's closest evolutionary cousins.

Alexander Platt et al, Interbreeding between Neanderthals and modern humans was strongly sex biased, Science (2026). DOI: 10.1126/science.aea6774. www.science.org/doi/10.1126/science.aea6774

Part 2

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Comment by Dr. Krishna Kumari Challa 11 hours ago

Neanderthal males, human females? How ancient attraction shaped the human genome

The human genome is a rich, complex record of migration, encounters, and inheritance written over thousands of millennia. Genomic research is revisiting a particularly intimate chapter, suggesting that ancient mating patterns between modern humans and Neanderthals shaped why Neanderthal DNA is largely missing from the human X chromosome.

Along our X chromosomes, we have these missing swaths of Neanderthal DNA scientists call 'Neanderthal deserts".

For years, researchers just assumed these deserts existed because certain Neanderthal genes were biologically 'toxic' to humans—as tends to be the case when species diverge—so they thought the genes may have caused health problems and were likely purged by natural selection.

Now,  this new research work has discovered a more social explanation.

In a paper published in Science, their analysis of Neanderthal and modern human genomes suggests that long-standing mating preferences—rather than genetic incompatibility—shaped which Neanderthal DNA sequences persisted in modern humans and which were gradually lost.

Their findings reveal the role social interactions in sculpting the human genome, challenging the idea that human evolution was driven solely by survival of the fittest.

Researchers found a pattern indicating a sex bias: gene flow occurred predominantly between Neanderthal males and anatomically modern human females.

Roughly 600,000 years ago, the ancestors of anatomically modern humans and their closest-related species, the Neanderthals, diverged, forming two distinct groups.

Our ancestors evolved in Africa, while the ancestors of Neanderthals evolved in and adapted to life in Eurasia. But that separation was far from permanent.

Over hundreds of millennia human populations migrated into Neanderthal territories and back again, and when these groups met, they mated, swapping segments of DNA.

Part 1

Comment by Dr. Krishna Kumari Challa 11 hours ago

Single-celled organism becomes multicellular via three different pathways

Some single-celled organisms are known to transition to multicellularity during their lifetimes, usually either by cloning themselves or when many similar cells come together to form a larger multicellular organism. A new study published in Nature suggests that a combination of the two routes may be more common than previously thought—even in organisms distantly related to animals.

Choanoflagellates are single-celled flagellate eukaryotes considered to be the closest living relatives of animals. They are bacterium-eating aquatic organisms with a flagellum (a long, hair-like appendage that helps them swim) and a collar of microvilli, primarily used for absorption, secretion, and sensory functions.

Choanoflagellates possess the ability to form multicellular bodies. Like animals, they were thought to be purely clonal, but this has not been previously tested across different types. The choanoflagellate Salpingoeca rosetta, for example, only exhibits clonal multicellularity. However, other close relatives of animals have been shown to form aggregative groups.

Although animal multicellularity is purely clonal, other close relatives of animals exhibit diverse forms of multicellularity, including aggregation in filastereans and cellularization of multinucleated cells or cleavage-like serial cell divisions in ichthyosporeans.

The researchers set out to determine whether choanoflagellates can ever form aggregate groups. They were surprised by what they found. Not only did the choanoflagellates form clonal groups and aggregate groups separately, but they also formed mixed clonal-aggregative groups under certain conditions. They also found that the purely aggregative sheets were morphologically, behaviourally, and functionally equivalent to clonally grown sheets.

Furthermore, the team showed that the push to aggregative multicellularity was an active process.

They found that as salinity rises, multicellular sheets tend to dissociate, and cells turn into tough, unicellular cysts. When the pools are rehydrated, these cysts "wake up" and reform sheets using both division and aggregation methods.

The team also found that cell density had an interesting effect on whether the cells chose clonal or aggregative routes to multicellularity.

Núria Ros-Rocher et al, Clonal-aggregative multicellularity tuned by salinity in a choanoflagellate, Nature (2026). DOI: 10.1038/s41586-026-10137-y

Comment by Dr. Krishna Kumari Challa yesterday

Women with severe burn injuries are more likely than men to develop blood poisoning

The skin forms a natural barrier that prevents bacteria entering the body. Severe burns stop this protective function from working properly, and germs can enter the blood more easily through the wounds. If the airways have suffered thermal or chemical injury through the inhalation of hot and toxic substances, they are also a gateway for infection.
Bacteria can multiply in the blood and spread throughout the body. In the worst case, this can cause blood poisoning—also known as sepsis—which can lead to multiple organ failure. This is a common cause of death in people with burn injuries. A new study has identified for the first time which patients are affected by such infections. The study was carried out before the disaster in Crans-Montana, but it can now help to better understand the physiological processes in critically ill burn patients.

The study focused on sex-specific differences. It analyzed data from 269 patients with severe burn injuries who were treated at the Center for Severe Burn Injuries at the University Hospital Zurich between 2017 and 2021. The insights, published in Burns, should help to prevent sepsis in patients with severe burn injuries or get it under control at an early stage.

Women with severe burn injuries are nearly twice as likely as men to develop bacteremia, which can progress to sepsis. This increased risk is not due to different bacterial species but may relate to altered immune or hormonal responses following burns. Understanding these mechanisms could improve prevention and management of sepsis in burn patients.
Women's immune systems often seem better able to cope with pathogens, and a number of studies have observed a stronger immune response.
In burn victims, however, it seems that this is not necessarily the case. The researchers are not yet able to answer the question of why the women with severe burn injuries in this cohort were much more likely to develop bacteremia.
One explanation that can be ruled out, however, is the presence of different pathogens, as predominantly the same bacteria were identified in the blood of male and female patients. These are species that colonize the skin and mucous membranes as part of the natural microbiome. They are usually harmless but can become dangerous if they enter the bloodstream in large quantities.
Sex hormones have an effect on human immune cells, which also fight infections. Female sex hormones such as estrogen are actually associated with a better response. But it is possible that burn injuries alter hormone metabolism, which then weakens the immune response, say the researchers.
While patients are usually given antibiotics early to fight the bacteria, the damaged barrier means that new infections keep occurring. Resistant bacteria can also quickly develop, for which very few effective antibiotics are available.

Nicole J.M. Schweizer et al, Impact of sex on the development of bacteremia in critically ill burn patients: A retrospective cohort study, Burns (2026). DOI: 10.1016/j.burns.2025.107845

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