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Comment by Dr. Krishna Kumari Challa on September 28, 2024 at 9:49am

**Which men may be more likely to commit sexual assault: women take note of this**
Research by Psychologists sheds light on which men might choose to ignore a lack of consent and why. Their research explores how men make decisions in high-risk sexual situations, which could potentially offer insights into prevention.
They found that adherence to cultural myths about what constitutes rape was the strongest predictor of assaultive behaviour, even controlling for other personality factors. We may, therefore, be able to curtail some assaults by dispelling these myths through education.

However, underlying beliefs or the particulars of a situation form only part of the picture. The risk for sexual assault is even more strongly linked to who a man actually is in terms of personality—a factor that may be less amenable to change.
The researchers focused on "emerging adults," a category that ranges from the late teens to the mid-to-late 20s. Individuals in this age range are more likely to find themselves in higher-risk sexual situations, such as hookups, rather than long-term, exclusive sexual relationships. It's also a time when individuals are still developing beliefs and behaviors related to sex, making them more amenable to intervention.
Part 1

Comment by Dr. Krishna Kumari Challa on September 28, 2024 at 9:14am

Multiple surgeries could contribute to cognitive decline in older people

Multiple surgeries could lead to cognitive decline, a study has found, using data from the United Kingdom's Biobank to analyze half a million patients aged 40 to 69 and followed over 20 years of brain scans, cognitive tests and medical records.

Many families have stories of how repeated surgeries and hospitalizations worsened the reaction time and memory of elderly relatives. Now, a University of Sydney led study has revealed multiple surgeries have a small effect on memory, reaction time, task-switching and problem-solving for older patients with each additional surgery.

The study also found brain MRIs of people who had surgeries also showed physical differences in areas of the brain responsible for memory.

People who had surgeries were also found to have a smaller hippocampus, the area of the brain responsible for memory and learning. They also had more evidence of brain damage associated with blocked blood vessels, compared to those who did not undergo repeated surgeries.

"The results suggest that the cognitive decline per surgery may seem small, but those changes and losses in neurodegeneration really start to add up after multiple surgeries," say the researchers. They found that surgeries are safe on average but also that the burden of multiple surgeries on the brain health of older patients should not be underestimated.

This is a reminder to medical professionals to consider all treatment options and be cautious in recommending major surgery for older and more vulnerable patients. If surgery is the best or only treatment option, patients should be reassured that the cognitive harm from each surgery is small on average. Nonetheless, careful attention in perioperative care is required to prioritize brain health and recovery."

Jennifer Taylor et al, Association between surgical admissions, cognition, and neurodegeneration in older people: a population-based study from the UK Biobank, The Lancet Healthy Longevity (2024). DOI: 10.1016/j.lanhl.2024.07.006

Comment by Dr. Krishna Kumari Challa on September 28, 2024 at 8:32am

Fruit juice offers a fresh take on kombucha

Kombucha is a fizzy, tangy drink made by fermenting tea. But brewers are now fermenting other plant-based drinks to explore nutritional properties and flavors. Researchers in ACS Agricultural Science & Technology compared the biochemistry and flavor of kombucha with brews made from apple and passion fruit juices. They found that the apple beverage contained high levels of bioactive compounds called flavonoids and ranked highly among taste testers, signaling its promise as a kombucha alternative. 

To make kombucha, brewers ferment sweetened tea with a spongy disk of microbes known as a SCOBY, or symbiotic culture of bacteria and yeast. The resulting beverage contains beneficial bacteria from the fermentation process and bioactive compounds from the tea, including flavonoids, phenolics and anthocyanins that may have antioxidant and anti-inflammatory properties. Few studies have investigated whether liquids other than tea could be brewed as kombucha-like beverages with boosted antioxidant levels or unique flavors. So, Socorro Vanesca, Frota Gaban and coworkers fermented antioxidant-rich apple and passion fruit juices with a SCOBY to find out.

After fermenting apple juice, passion fruit juice, and tea in separate jars for 10 days at room temperature, the researchers measured the levels of several bioactive compounds in each brew and found that:

• The apple beverage had the highest level of flavonoids, followed by kombucha and the passion fruit drink.
• The kombucha and apple beverages had comparable levels of phenolic compounds that were higher than those of the passion fruit beverage.
• All three brews had similar amounts of anthocyanin, a red-colored antioxidant.

Because fermented apple juice has more flavonoids and a pleasant taste compared with the other beverages, the researchers say it could be a successful alternative to kombucha made from tea.

https://www.acs.org/pressroom/presspacs/2024/september/fruit-juice-...

 Soraya Ferreira da Silva et al, Physicochemical Properties, Antioxidant Activity, and Sensory Profiles of Kombucha and Kombucha-Like Beverages Prepared Using Passion Fruit (Passiflora edulis) and Apple (Malus pumila), ACS Agricultural Science & Technology (2024). DOI: 10.1021/acsagscitech.4c00372

Comment by Dr. Krishna Kumari Challa on September 28, 2024 at 8:07am

As LLMs grow bigger, they're more likely to give wrong answers than admit ignorance

A team of AI researchers  has found that as popular LLMs (Large Language Models) grow larger and more sophisticated, they become less likely to admit to a user that they do not know an answer.

In their study  published in the journal Nature, the group tested the latest version of three of the most popular AI chatbots regarding their responses, accuracy, and how good users are at spotting wrong answers.

As LLMs have become mainstream, users have become accustomed to using them for writing papers, poems or songs and solving math problems and other tasks, and the issue of accuracy has become a bigger issue. In this new study, the researchers wondered if the most popular LLMs are getting more accurate with each new update and what they do when they are wrong.

To test the accuracy of three of the most popular LLMs, BLOOM, LLaMA and GPT, the group prompted them with thousands of questions and compared the answers they received with the responses of earlier versions to the same questions.

They also varied the themes, including math, science, anagrams and geography, and the ability of the LLMs to generate text or perform actions such as ordering a list. For all the questions, they first assigned a degree of difficulty.

They found that with each new iteration of a chatbot, accuracy improved in general. They also found that as the questions grew more difficult, accuracy decreased, as expected. But they also found that as the LLMs grew larger and more sophisticated, they tended to be less open about their own ability to answer a question correctly.

In earlier versions, most of the LLMs would respond by telling users they could not find the answers or needed more information. In the newer versions, the LLMs were more likely to guess, leading to more answers in general, both correct and incorrect. They also found that all the LLMs occasionally produced incorrect responses even to easy questions, suggesting that they are still not reliable.

The research team then asked volunteers to rate the answers from the first part of the study as being either correct or incorrect and found that most had difficulty spotting incorrect answers.

Lexin Zhou et al, Larger and more instructable language models become less reliable, Nature (2024). DOI: 10.1038/s41586-024-07930-y

Comment by Dr. Krishna Kumari Challa on September 28, 2024 at 8:03am

Study finds estrogens play a hidden role in cancers, inhibiting a key immune cell

Estrogens are known to drive tumor growth in breast cancer cells that carry its receptors, but a new study by Duke Cancer Institute researchers unexpectedly finds that estrogens play a role in fueling the growth of breast cancers without the receptors, as well as numerous other cancers.

Appearing Sept. 27 in the journal Science Advances, the researchers describe how estrogens not only decrease the ability of the immune system to attack tumors, but also reduce the effectiveness of immunotherapies that are used to treat many cancers, notably triple-negative breast cancers. Triple-negative breast cancers are an aggressive form of disease that are negative for estrogen, progesterone, and the HER2 receptor proteins

Informed by retrospective analysis of patient data and experiments in mice, the researchers found that anti-estrogen drugs reversed the effects of estrogens, restoring potency to immunotherapies.

The researchers  focused on a type of white blood cell called eosinophils, which are typically activated during allergic reactions and inflammatory diseases.

Eosinophils have recently been identified as important in tumors, and a phenomenon called tumor associated tissue eosinophilia, or TATE, is associated with better outcomes among patients with multiple types of cancer, including colon, esophageal, gastric, oral, melanoma and liver cancers.

In their studies, the Duke team described how estrogens decrease the number of eosinophils and TATE in mice. The hormone contributes to increased tumor growth in estrogen receptor-negative breast cancer tumors and in melanoma tumors, which do not rely on estrogen receptors for tumor growth.

Conversely, anti-estrogen therapies inhibited estrogen receptor signaling and enhanced the efficacy of immunotherapies, slowing tumor growth.

Sandeep Artham et al, Estrogen signaling suppresses tumor associated tissue eosinophilia to promote breast tumor growth., Science Advances (2024). DOI: 10.1126/sciadv.adp2442. www.science.org/doi/10.1126/sciadv.adp2442

Comment by Dr. Krishna Kumari Challa on September 28, 2024 at 7:54am

Changes in risk factors may be contributing to growing number of babies born prematurely

Preterm births have increased by more than 10% over the past decade, with racial and socioeconomic disparities persisting over time, according to a new study analyzing more than five million births.

The study, published in the journal JAMA Network Open, also found that some factors that increase the risk for preterm birth—such as diabetes, sexually transmitted infections, and mental health conditions—became much more common over the past decade, while other factors that protect against preterm birth declined.

These  findings not only show that preterm births are on the rise, but provide clues as to why this may be the case.

Babies born preterm or prematurely—before the 37th week of pregnancy—are more likely to experience a range of short and longer-term problems, including a higher risk for illness, intellectual and emotional difficulty, and death.

Certain factors are known to increase the risk of preterm birth, including mothers having high BP, diabetes, stress because of social and economical conditions, an infection,  smoking, previously having a preterm birth, having fewer than three prenatal care visits, and even housing insecurity. 

Rates of preterm birth grew across nearly all groups, but varied by racial/ethnic and socioeconomic group.  And researchers noted that the causal  rates of preexisting diabetes, sexually transmitted infections, and mental health conditions more than doubled during the decade studied.

The researchers note that their findings underscore the need to improve pregnancy care and promote treatments that address risk factors associated with preterm birth—which are often underutilized during pregnancy.

 Laura Jelliffe-Pawlowski et al, Risk and Protective Factors for Preterm Birth Among Racial, Ethnic, and Socioeconomic Groups in California, JAMA Network Open (2024). DOI: 10.1001/jamanetworkopen.2024.35887. jamanetwork.com/journals/jaman … tworkopen.2024.35887

Comment by Dr. Krishna Kumari Challa on September 27, 2024 at 10:59am

We found a new shape, say mathematicians

A geometric building block with rounded corners.

Mathematicians have declared a new class of shape – but it’s not like your typical circle, triangle or square. So what is it? The ‘shape’ is one seen throughout nature, which the scientists have named the ‘soft cell’. 

The shape can take different forms, so long as it has rounded edges and fits together in a tessellated grid – known as ‘tiling’ in maths.

In 2D, tessellating fully rounded shapes isn't possible, unless there are ‘cusps’ – the sharp points between curves (like the top of a teardrop). An example of this in 2D is the cross section of an onion.

But the researchers behind the new study have discovered it is possible to tesselate a fully rounded shape in 3D – such as the chambers of a nautilus shell (the spiralling mollusc with orange stripes). These chambers look angular in 2D, but the researchers were amazed to see that, when modelled in 3D, there were no edges at all.

While these shapes have been known for centuries, no-one has formalised the notion of soft cells until now.

The Hungarian team behind the newer paper, published in the journal PNAS Nexus, considered what happens if you give this tile, known as an ‘einstein’, rounded corners. Using algorithms to convert geometric shapes into soft cells, they discovered that in 3D, soft cells can fill all the gaps without having any corners at all.

The team then tried to work out the maximum ‘softness’ a shape can have, and realised that the softest shapes are not compact and simple but actually flare out at the sides like wings (like the shape of a horse saddle).

In nature, the researchers think, corners are points of structural weakness. Bending around corners may also cost energy and build tension at edges, so natural shapes tend to avoid them.

 The discovery could inspire architecture: already, since finishing writing the paper, the researchers have collaborated with architects at the California College of Arts in San Francisco, USA, to design buildings comprised of soft cells.

https://academic.oup.com/pnasnexus/article/3/9/pgae311/7754698?logi...

Comment by Dr. Krishna Kumari Challa on September 27, 2024 at 9:46am

In the new study, mice (which have many genetic and physiological similarities to humans) developed a rodent form of psoriasis after being exposed to high levels of skin-produced hepcidin.

This over-abundance of the hormone caused the animals' skin cells to retain far more iron than was required. In turn, this excess iron triggered both a hyperproliferation of skin cells and an abnormally high concentration of inflammation-inducing neutrophils (a type of immune system cell) in the topmost layer of skin.

These two outcomes—an overproduction of skin cells and an abundance of neutrophils—are main features of human psoriasis.

Psoriasis runs in families, though experts believe "environmental" factors such as weight, infections and smoking are also triggers.

Currently there is no cure for psoriasis, though treatments that include topical creams, light therapy and oral drugs can help keep symptoms under control for patients with some forms of the condition. Recent treatments have focused on targeting the immune pathways that contribute to the development of psoriasis.

Elise Abboud et al, Skin hepcidin initiates psoriasiform skin inflammation via Fe-driven hyperproliferation and neutrophil recruitment, Nature Communications (2024). DOI: 10.1038/s41467-024-50993-8

Part 2

Comment by Dr. Krishna Kumari Challa on September 27, 2024 at 9:45am

A faulty iron hormone in the skin may be the root cause of psoriasis

Scientists may have uncovered the root cause of psoriasis, a chronic and sometimes debilitating skin disease that affects 2–3% of the global population. The condition is characterized by red, scaly patches that impact the quality of a patient's life and can sometimes be life-threatening.

New research strongly suggests the hormone hepcidin may trigger the onset of the condition. This marks the first time hepcidin has been considered a potential causal factor. In mammals, hepcidin is responsible for regulating iron levels in the body.

The study is published in the journal Nature Communications.

The researchers hope their finding will lead to the development of new drugs able to block the action of the hormone.

Those most likely to benefit from such a treatment are patients with pustular psoriasis (PP)—a particularly severe and treatment-resistant form of the disease that can affect a patient's nails and joints as well as skin.

Psoriasis is a life-changing dermatological disease. Patients face a potentially disfiguring and lifelong affliction that profoundly affects their lives, causing them both physical discomfort and emotional distress. The condition can also lead to other serious health conditions.

A new treatment targeting iron hormone imbalance in the skin offers hope. This innovative approach could significantly enhance the quality of life for millions, restoring their confidence and well-being.

Iron is an essential trace metal, not just for transporting oxygen through the body's circulatory system but also for maintaining healthy skin. It's involved in many essential cellular functions, including wound healing, collagen production and immune function. However, iron overload in the skin can be harmful, amplifying the damaging effects of UV sunlight and causing hyperproliferative chronic diseases (where cells grow and multiply more than normal), including psoriasis.

Studies going back 50 years have reported high iron concentrations in the skin cells of psoriatic patients. However, the cause of this excess and its significance to the condition have remained unclear until now.

The new study is the first to name hepcidin as the likely link.

Hepcidin is responsible for controlling how much iron is absorbed from food and later released into the body. In healthy individuals, it's produced exclusively in the liver. However, the new study has found that in people with psoriasis, the hormone is also generated in the skin.

Part 1

Comment by Dr. Krishna Kumari Challa on September 27, 2024 at 9:36am

Scientists discover 'pause button' in human development

Researchers have discovered a potential "pause button" in the earliest stages of human development.

Whether humans can control the timing of their development has long been debated. The new study suggests that this "pause button" can be activated in human cells as well. The findings have significant implications for our understanding of early human life and may improve reproductive technologies.

In some mammals, the timing of the normally continuous embryonic development can be altered to improve the chances of survival for both the embryo and the mother. This mechanism to temporarily slow development, called embryonic diapause, often happens at the blastocyst stage, just before the embryo implants in the uterus.

During diapause, the embryo remains free-floating and pregnancy is extended. This dormant state can be maintained for weeks or months before development is resumed, when conditions are favorable. Although not all mammals use this reproductive strategy, the ability to pause development can be triggered experimentally. Whether human cells can respond to diapause triggers remained an open question.

Now a study has identified that the molecular mechanisms that control embryonic diapause also seem to be actionable in human cells.

In their research, the scientists did not carry out experiments on human embryos and instead used human stem cells and stem cell-based blastocyst models called blastoids. These blastoids are a scientific and ethical alternative to using embryos for research. The researchers discovered that modulation of a specific molecular cascade, the mTOR signaling pathway, in these stem cell models induces a dormant state remarkably akin to diapause.

When the researchers treated human stem cells and blastoids with an mTOR inhibitor they observed a developmental delay, which means that human cells can deploy the molecular machinery to elicit a diapause-like response.

This dormant state is characterized by reduced cell division, slower development and a decreased ability to attach to the uterine lining. Importantly, the capacity to enter this dormant stage seems to be restricted to a brief developmental period.

The developmental timing of blastoids can be stretched around the blastocyst stage, which is exactly the stage where diapause works in most mammals.  Moreover, this dormancy is reversible, and blastoids resume normal development when the mTOR pathway is reactivated.

The researchers  concluded that humans, like other mammals, might possess an inherent mechanism to temporarily slow down their development, even though this mechanism may not be used during pregnancy.

This potential may be a vestige of the evolutionary process that we no longer make use of," say the researchers. "Although we have lost the ability to naturally enter dormancy, these experiments suggest that we have nevertheless retained this inner ability and could eventually unleash it."

 mTOR activity paces human blastocyst stage developmental progression, Cell (2024). DOI: 10.1016/j.cell.2024.08.048. www.cell.com/cell/fulltext/S0092-8674(24)00977-2

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