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Comment by Dr. Krishna Kumari Challa on January 3, 2025 at 10:20am

How does a hula hoop master gravity? Mathematicians prove that body shape matters

Hula hooping is so commonplace that we may overlook some interesting questions it raises: "What keeps a hula hoop up against gravity?" and "Are some body types better for hula hooping than others?" A team of mathematicians explored and answered these questions with findings that also point to new ways to better harness energy and improve robotic positioners.

The results are the first to explain the physics and mathematics of hula hooping.

A paper based on the results appears in the Proceedings of the National Academy of Sciences.

The researchers tested different shapes and motions in a series of experiments on robotic hula hoopers using 3D-printed bodies of different shapes (e.g., cylinders, cones, hourglass shapes) to represent human forms at one-tenth the size.

These shapes were driven to gyrate by a motor, replicating the motions we take when hula hooping. Hoops approximately 6 inches in diameter were launched on these bodies, with high-speed video capturing the movements.

The results showed that the exact form of the gyration motion or the cross-section shape of the body (circle versus ellipse) wasn't a factor in hula hooping.

In all cases, good twirling motions of the hoop around the body could be set up without any special effort.

However, keeping a hoop elevated against gravity for a significant period of time was more difficult, requiring a special "body type"—one with a sloping surface as "hips" to provide the proper angle for pushing up the hoop and a curvy form as a "waist" to hold the hoop in place.

The  results explain why some people are natural hoopers and others seem to have to work extra hard.

The paper's authors conducted mathematical modeling of these dynamics to derive formulas that explained the results—calculations that could be used for other purposes.

 The math and physics involved are very subtle, and the knowledge gained could be useful in inspiring engineering innovations, harvesting energy from vibrations, and improving robotic positioners and movers used in industrial processing and manufacturing.

Xintong Zhu et al, Geometrically modulated contact forces enable hula hoop levitation, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2411588121

Comment by Dr. Krishna Kumari Challa on January 1, 2025 at 8:35am

Needle-Free Shock Syringes for painless medical treatments

Medical practitioners have been using needles to inject medicines into human bodies for decades. But no one likes getting pricked, be it children or adults. In some cases, the fear is so strong, especially in children, that many miss out on vaccinations and other medical treatments. For patients who have diabetes, the stress is even greater as they may require frequent insulin injections. 

As a relief to patients, a team of researchers led by Prof. Viren Menezes from the Department of Aerospace Engineering at the Indian Institute of Technology Bombay (IIT Bombay) has now worked a way around to deliver drugs without needles by developing a shock syringe. In their study published in the Journal of Biomedical Materials & Devices, the IIT Bombay researchers compared the effectiveness of drug delivery by a shock syringe versus a regular needle on laboratory rats. 

Unlike syringes with needles, the shock syringe doesn’t rely on piercing the skin with a sharp tip. Instead, it uses high-energy pressure waves (shock waves) that can travel faster than the speed of sound to pierce the skin. These waves, when generated, compress the surrounding medium (such as air or liquid) through which they travel. A similar effect happens during a sonic boom; when an aircraft flies faster than the speed of sound, it creates shock waves that push and disturb the air.

The shock syringe, developed earlier in 2021 in Prof. Menezes’ lab, is slightly longer than a regular ballpoint pen. The device has a micro shock tube consisting of three sections: the driver, driven, and drug holder, which work together to create the shockwave-driven microjet for drug delivery. Pressurised nitrogen gas is applied to the shock syringe (driver section of micro shock tube part) filled with liquid drugs to create a microjet of the drug. The microjet travels at a speed nearly twice as fast as a commercial aeroplane at takeoff. This jet stream of liquid drug passes through the nozzle of the syringe before penetrating the skin. The entire process of delivering drugs using a shock syringe is rapid and gentle; most patients wouldn’t feel a thing.

To minimise tissue damage and ensure consistent and precise drug delivery, the pressure in the shock syringe is continuously monitored. Additionally, the researchers have optimised the nozzle design to have an opening of just 125 μm (roughly the width of a human hair).

The development of a shock syringe promises more than pain-free injections. It could make immunization drives quicker and more efficient for both children and adults. It could prevent the occurrence of bloodborne diseases caused by needle-stick injuries due to mishandling or improper disposal.

https://link.springer.com/article/10.1007/s44174-024-00239-4

Comment by Dr. Krishna Kumari Challa on January 1, 2025 at 7:13am

Animal studies have shown its potential as an endocrine disruptor, affecting pregnancy in mice and puberty in rats. A study published back in 2022 found a significant link between increased DEHP metabolites in the urine samples of 5303 US adults and an increase in mortality rate. This recent study calculates 164,000 deaths worldwide could be related to DEHP exposure, with an estimated US$398 billion in equivalent economic losses.

PBDEs are a class of brominated flame retardants controversially behind advice to throw out your black plastic spatula. Common in materials that are exposed to high levels of heat, they're also present in electronics, car parts, aircraft, and certain textiles.

They can enter your body by inhalation, dermal absorption, or via your food – a seemingly unlikely route, but they've turned up in utensils, food packaging, and children's toys made from recycled black plastic.
A correlation between PBDE exposure and measures of intelligence suggests almost 12 million collective IQ points may have been lost due to maternal PBDE exposure.
The cumulative impact, it seems, is damning. BPA and DEHP may be eliminated from the body relatively quickly over a course of days, but the continuous stream of plastics in our lives means we have little relief from their exposure. The 'stickiness' of PBDE in our bodies is less clear, and depends on the specific chemical makeup.
All of the study's estimates lean heavily on the data from existing observational studies, making causation difficult to confirm. Some unrelated factor might increase people's exposure to the chemicals as well as their health problems – a diet high in fast food, for instance, would increase a person's exposure to plastics and is also known to increase the risk of cardiovascular disease.

https://www.pnas.org/doi/epub/10.1073/pnas.2412714121

Part 2

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Comment by Dr. Krishna Kumari Challa on January 1, 2025 at 7:11am

Common Plastic Additives May Have Affected The Health of Millions

Exposure to a trio of chemicals found in many everyday household and industrial items may have contributed to millions of cases of heart disease, stroke, and deaths over the years according to estimations of the health and economic impacts of common plastic additives.

An international team of researchers pooled findings from over 1,700 existing studies from 38 different countries investigating links between people's exposure to the chemicals and certain health impacts.

The researchers argue the results are concerning enough to warrant global action, but critics say we still need conclusive proof that these chemicals are the true cause.

The suspects in question – BPA (bisphenol A), DEHP (di(2-ethylhexyl) phthalate) and PBDEs (polybrominated diphenyl ethers) – have been previously associated with serious health issues.

The safety of BPA has been questioned for a while: widespread in our food packaging, especially in the form of the epoxy that lines some food and drink cans and bottles, exposure to this compound has been linked to higher rates of ischemic heart disease and stroke.

This latest study found 5.4 million cases of ischemic heart disease and 346,000 cases of stroke in 2015 could be associated with BPA exposure. That suggests BPA exposure could be associated with 431,000 deaths. An estimate on the total economic impact suggests the resulting loss in health could have cost nations an equivalent of US$1 trillion in purchasing power.

DEHP is present in the flexible plastics of garden hoses, shower curtains, medical tubing, and synthetic leathers.

Part 1

Comment by Dr. Krishna Kumari Challa on December 31, 2024 at 10:37am

Although the researchers suspected estrogen would have an effect on drinking, they were surprised by its mechanism of action. This steroid hormone typically regulates behaviours by binding to receptors that then travel to the nucleus, where they alter the activity of specific genes—a process that could take hours.

However, researchers now realized that something else must be happening when estrogen infused directly into the BNST excited the neurons and triggered binge drinking within minutes.

So, the researchers tested estrogen that had been doctored so it could not enter cells and bind to nuclear receptors—a feat of chemical engineering performed by Dr. Jacob Geri, assistant professor of pharmacology at Weill Cornell Medicine. They determined that when estrogen promotes binging, the hormone is binding to receptors on the neurons' surface, where it directly modulates cell-cell communication.
This is the first time that anybody has shown that during a normal estrous cycle, endogenous estrogen made by the ovaries can use such a rapid mechanism to control behaviour.
The team identified the estrogen receptor that mediates this effect and determined that it is expressed in the excited BNST neurons and in neurons from other brain regions that excite them. The researchers are now investigating the signaling mechanisms for this effect, and they will also examine whether the same system regulates drinking in males.

 Lia J. Zallar et al, Rapid nongenomic estrogen signaling controls alcohol drinking behavior in mice, Nature Communications (2024). DOI: 10.1038/s41467-024-54737-6

Part 3

Comment by Dr. Krishna Kumari Challa on December 31, 2024 at 10:22am

In a 2021 study, researchers showed that a specific subpopulation of neurons in a brain region called the bed nucleus of the stria terminalis (BNST) were more excitable in female mice than in males. This enhanced activity correlated with their binge-drinking behaviour.

But what makes this neural circuit more excitable in females? Estrogen has such powerful effects on so many behaviors, particularly in females. So, it makes sense that it would also modulate drinking.

To assess estrogen's potential involvement, the researchers began by monitoring the hormone levels throughout the estrous cycle of female mice. Then, they served up the alcohol. They found that when a female has a high level of circulating estrogen, she drinks much more than on days when her estrogen is low.

That enhanced binging behaviour was reflected in heightened activity in those same neurons in the BNST. When a female takes her first sip from the bottle containing alcohol, those neurons go crazy. And if she's in a high-estrogen state, they go even crazier. That extra boost of neural activity means the mice hit the bottle even harder, particularly within the first 30 minutes after the alcohol was made available, a behavior researchers refer to as "front-loading."
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Comment by Dr. Krishna Kumari Challa on December 31, 2024 at 10:19am

Preclinical study finds surges in estrogen promote binge drinking in females

The hormone estrogen regulates binge drinking in females, causing them to "pregame," or consume large quantities of alcohol in the first 30 minutes after it's offered, according to a preclinical study led by scientists at Weill Cornell Medicine. The study establishes—for what is thought to be the first time—that circulating estrogen increases binge alcohol consumption in females and contributes to known sex differences in this behaviour.

The findings, published Dec. 30 in the journal Nature Communications, could lead to novel approaches for treating alcohol use disorder.

Comment by Dr. Krishna Kumari Challa on December 31, 2024 at 10:14am

Analysis of 160,000 films shows rise in 'murderous verbs' since 1970

The amount of murdering and killing in movies has increased overall over the past 50 years, according to a study that analyzed a massive database of film dialogue.

Researchers used machine learning to search a database of subtitles from more than 160,000 English-language movies produced from 1970 to 2000. They calculated the amount of dialogue from characters using variations of the words "murder" or "kill" in each of the films.

While the total use of these "murderous verbs" varied widely from year to year, there was a clear increasing trend over the five-decade period.

And not just in crime movies, where violence might be expected. Characters in noncrime movies are also talking more about killing and murdering today than they did 50 years ago.

It is still happening. Researchers found increases in violence cross all genres.

These findings suggest that references to killing and murder in movie dialogue not only occur far more frequently than in real life but are also increasing over time.

Movies are trying to compete for the audience's attention and research shows that violence is one of the elements that most effectively hooks audiences."

That means we need to promote "mindful consumption and media literacy to protect vulnerable populations, especially children," the researchers wrote in the study.

Why only in English movies, we find this trend in all Indian language movies too!

Trends of Violence in Movies During the Past Half Century, JAMA Pediatrics (2024). DOI: 10.1001/jamapediatrics.2024.5741

Comment by Dr. Krishna Kumari Challa on December 31, 2024 at 10:07am

what came first, the lesion or the microplastic," it is possible that MNPs contribute to inflammation, oxidative stress, and cellular damage, which can cause or worsen tissue lesions. But it is also possible that these lesions accumulate more MNPs in already damaged tissue areas. While the current findings do not provide a direct cause-and-effect relationship, they offer good targets for further study.
There are no conventional methods for removing microplastics from the environment or human tissues. While efforts are underway to discover methods of environmental mitigation, developing such strategies to handle diverse particle sizes and chemistries of the particles embedded in living tissues presents an immense and potentially unattainable challenge.

Yating Luo et al, Mapping micro(nano)plastics in various organ systems: Their emerging links to human diseases?, TrAC Trends in Analytical Chemistry (2024). DOI: 10.1016/j.trac.2024.118114

Part 2

Comment by Dr. Krishna Kumari Challa on December 31, 2024 at 10:07am

Microplastics found in multiple human organ tissues correlated with lesions

Researchers have recently performed a metadata investigation into the presence of microplastics in humans. They report a concerning relationship between micro and nanoplastic (MNP) concentrations in damaged tissues and links with multiple health conditions.

With the increased use in consumer products came elevated microscopic plastic pollution circulating in soil and waterways, eventually accumulating in the environment, food webs and human tissues.

In the study, "Mapping micro(nano)plastics in various organ systems: Their emerging links to human diseases?" published in TrAC Trends in Analytical Chemistry, investigators collected 61 available research articles for MNP detection in human tissues, plus 840 articles on MNP toxicological mechanisms.

Data came from spectroscopy, microscopy, and pyrolysis-gas chromatography/mass spectrometry investigations to identify polymer types in different tissues. Toxicological studies employed cell models and animal experiments to examine oxidative stress, inflammatory responses, and related signaling pathways.

The studies documented particles detected in skin, arteries, veins, thrombi, bone marrow, testes, semen, uterus, and placenta. MNPs were found in the digestive system, from saliva to feces, liver, and gallstones.

Within the respiratory system, MNPs were everywhere, including lung tissue, with microscopic fibers common in bronchoalveolar lavage fluid and sputum. Positive correlations emerged between particle abundance and specific disorders, such as inflammatory bowel disease, thrombosis, cervical cancer, and uterine fibroids.

Toxicological tests showed possible MNP-triggered oxidative stress, mitochondrial dysfunction, inflammatory responses, and apoptosis in various cell types, along with organ-level concerns like neurodegenerative disease onset when crossing the blood-brain barrier.

A critically important signal in the metadata discovered by the researchers was that measured levels of MNPs tended to be higher in tissues with lesions than in non-lesioned tissues. These included inflamed intestines, fibrotic lungs, or cancerous growths, suggesting a potential link between MNP buildup and local pathology.

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