Comment

Comment by Dr. Krishna Kumari Challa on February 25, 2025 at 9:37am

Humanoid robots can swiftly get up after they fall with new learning framework

Humanoid robots, which have a body structure that mirrors that of humans, could rapidly and effectively tackle a wide range of tasks in real-world settings. These robots and their underlying control algorithms have improved considerably in recent years. Many of them can now move faster, emulating various human-like movements.

As these robots are designed to walk or run similarly to humans, thus balancing on two legs, they can sometimes collide with objects or trip on uneven terrain, falling to the ground. Yet, in contrast with humans, who can easily pick themselves up when they fall, humanoid robots can sometimes get stuck on the ground, requiring the support of human agents to get back on their feet.

Researchers recently developed a new machine learning frame work that could allow humanoid robots to automatically get back up and recover after falling to the ground. This framework, presented in a paper on the arXiv preprint server, could make these robots more autonomous, potentially contributing to their future large-scale deployment.

Learning Getting-Up Policies for Real-World Humanoid Robots

Xialin He et al, Learning Getting-Up Policies for Real-World Humanoid Robots, arXiv (2025). DOI: 10.48550/arxiv.2502.12152

Comment by Dr. Krishna Kumari Challa on February 25, 2025 at 9:10am

For chronic radicular spine pain, moderate certainty evidence indicates that epidural injection of local anesthetic and steroids and radiofrequency of the dorsal root ganglion are unlikely to result in pain relief. Low certainty evidence suggests epidural injections of local anesthetic or steroids may also yield minimal pain relief.

In physical functioning, moderate certainty evidence shows joint-targeted injections and epidural injections with local anesthetic or steroids probably provide little to no improvement.

Low certainty evidence suggests certain procedures may slightly increase the risk of non-serious adverse events, including joint radiofrequency ablation.

When looking at the substantial cost, inconvenience, and false hope of these common procedures compared to data that suggests they are ineffective, it is unclear why they have persisted. If the study results are valid, another issue suggested is a major communication disconnect regarding procedures and patient outcomes in health care.

Xiaoqin Wang et al, Common interventional procedures for chronic non-cancer spine pain: a systematic review and network meta-analysis of randomised trials, BMJ (2025). DOI: 10.1136/bmj-2024-079971

Jane C Ballantyne, Spinal interventions for chronic back pain, BMJ (2025). DOI: 10.1136/bmj.r179

Part 2

Comment by Dr. Krishna Kumari Challa on February 25, 2025 at 9:10am

Common procedures for chronic spine pain found to offer little to no relief

Researchers found that commonly performed interventional procedures for chronic non-cancer spine pain may provide little to no pain relief when compared with sham procedures.

Chronic spine pain, defined as persistent pain along or referred from the spine lasting three months or longer, presents a global health challenge with significant socioeconomic implications.

While interventional procedures such as epidural steroid injections, nerve blocks, and radiofrequency nerve ablation are frequently used, clinical guidelines have offered conflicting recommendations regarding their effectiveness.

In the study, "Common interventional procedures for chronic non-cancer spine pain: a  systematic review and network meta-analysis of randomized trials," published in The BMJ, researchers conducted a comprehensive search of Medline, Embase, CINAHL, CENTRAL, and Web of Science, for spine pain procedural outcome efficacy.

Eighty-one trials with 7,977 patients were included in meta-analyses out of 132 eligible studies. Patients with chronic axial or radicular spine pain were randomized to receive common interventional procedures or comparators, including sham procedures and usual care. Frequentist network meta-analyses were performed, and the GRADE approach was used to assess the certainty of evidence.

For chronic axial spine pain, moderate certainty evidence showed that epidural injection of local anesthetic, epidural injection of local anesthetic and steroids, and joint-targeted steroid injection, result in little to no difference in pain relief compared with sham procedures.
Low certainty evidence suggests minimal pain relief differences for intramuscular and joint-targeted injections of local anesthetic, with or without steroids. Intramuscular injection of local anesthetic with steroids signaled that it may actually increase pain.
Part 1

Comment by Dr. Krishna Kumari Challa on February 22, 2025 at 12:01pm

Breathing and vision may be linked

Researchers  have discovered a fundamental mechanism that affects the size of the pupil, namely our breathing. The study, published in the Journal of Physiology, shows that the pupil is smallest during inhalation and largest during exhalation—something that could affect our vision.

Like the aperture in a camera, the pupil controls how much light reaches the eye. It is therefore fundamental to our vision and how we perceive our surroundings. Three mechanisms that can change the size of the pupil have been known for over a century: the amount of light, focus distance and cognitive factors such as emotion or mental effort.

Now, scientists have discovered a fourth: breathing. The pupil is smallest around inhalation onset and largest during exhalation.

This mechanism is unique in that it is cyclical, ever-present and requires no external stimulus

Martin Schaefer et al, The pupillary respiratory‐phase response: pupil size is smallest around inhalation onset and largest during exhalation, The Journal of Physiology (2025). DOI: 10.1113/JP287205

Comment by Dr. Krishna Kumari Challa on February 22, 2025 at 11:35am

To show how this works, the researchers placed genetically identical Escherichia coli bacteria—which exhibit different swimming behaviors—in both liquid and porous environments and then observed their collective migration.

In the liquid environment, which the researchers compared to a straight highway, bacteria that swam straight for longer took the lead while those that turned frequently lagged behind. Over time, the population of these bacteria became enriched with these smooth swimmers.

On the other hand, in porous environments with more obstructions, the tendency to turn frequently proved advantageous for escaping dead ends. In these environments, the bacteria that turned more often emerged as the leaders while populations of smooth swimmers gradually thinned.
Crucially, the enrichment of specific swimming behaviors could not be explained by mutations or gene expression. The researchers found no evidence of an increase or decrease in the expression of genes regulating the swimming behaviors of these bacteria during migration.

Since there were no changes in gene expression or mutations, the populations didn't commit to one environment or another—migration alone was enough to temporarily enrich the population with well-adapted individuals.

Non-genetic adaptation via collective migration not only permits a rapid response to new environments, but also enables cell populations to respond to many biological challenges simultaneously.
While gene regulation typically allows for a quick reaction by modifying one or two traits at a time, the mechanism now discovered facilitates a rapid response by simultaneously altering many traits.
Beyond enabling populations to adapt to changes in the environment within two to three generations of cell division, this mechanism can also modulate chemoreceptor abundances depending on what attractants the bacteria are chasing, highlighting its potential flexibility, the researchers found.
This process is likely applicable to many cell types, both prokaryotic and eukaryotic, that break down environmental factors and generate their own gradient to chase, say the researchers.
These findings demonstrate that when collective behaviors create selection pressures, cell populations can reversibly adapt multiple traits with a level of speed and flexibility that is difficult to achieve via classical mechanisms.

Lam Vo et al, Nongenetic adaptation by collective migration, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2423774122

Part 2

Comment by Dr. Krishna Kumari Challa on February 22, 2025 at 11:32am

How do cells respond to changes? New study finds it's not all in the genes

Cells are constantly on the move, whether in a developing embryo or metastatic cancer. But how do cells adapt to the new environments they encounter? Earlier scientists thought that cells adapt to changes and stressors in their environment through genetic mutations or by altering gene expression.

But a new  study shows that migrating bacterial cells can also respond to changes in their surroundings, quickly and collectively, without any genetic alterations. Specifically, the researchers found that cell populations can adapt "non-genetically" to new environments just by growing and leaving behind slower cells.

This new discovery, which is described in the journal Proceedings of the National Academy of Sciences, has implications across biology, from advancing our understanding of evolution to informing new therapeutic strategies for diseases like cancer.

Given the prevalence of collective migration in microbes, cancers, and embryonic development, non-genetic adaptation through collective migration may be a universal mechanism for populations to navigate diverse environments. 

Past research has shown that bacterial cells can acquire genetic mutations that confer resistance in response to antibiotics. Similarly, cancer cells can develop resistance to chemotherapy through genetic changes. Yet such adaptations typically require tens of generations before the mutated cells become predominant. (In some bacterial cells , cell division or generation happens about every hour).

The new adaptive mechanism enables migrating cell populations to respond to environmental changes in just two or three generations and without relying on gene regulation or mutation.  

Part 1

Comment by Dr. Krishna Kumari Challa on February 21, 2025 at 12:29pm

The potential health effects of plastic pollution are only just beginning to emerge, but the mounting evidence is not exactly inspiring hope.

In a study published last year, scientists discovered that when people put hot, disposable plastic cutlery in their mouths, it reduces their diversity of intestinal microbiota.

The next time you order takeaway, you might want to think about the heat of the food and the material of the packaging it might come in.

https://www.sciencedirect.com/science/article/pii/S0147651324014593

Part 2

Comment by Dr. Krishna Kumari Challa on February 21, 2025 at 12:28pm

Your Takeaway Food Packaging Could Increase Your Risk of Heart Failure

Disposable plastic containers could be leaching dangerous chemicals into your takeaway food, potentially increasing your risk of cardiovascular disease.

In experiments on rats, researchers in China have found evidence that drinking water exposed to the various chemical additives that seep from heated plastic packaging causes changes to the body, that begin with altered gut bacteria.

Rodents that ingested this cocktail of plastic contaminants for just three months showed broken or misaligned fibers, inflammatory cell infiltration, and mitochondrial swelling in their heart tissue. They also showed bleeding between myocardial cells.

Whether or not the same occurs in the human body is unknown, but the findings suggest that heated plastic containers may not be a safe vehicle for food.

Researchers argue that it is essential to avoid using plastic containers for high-temperature food.

Their experiments on rats were prompted by a survey of 3,179 older adults in China. Those who reported higher exposure to plastic on a questionnaire were more likely to suffer congestive heart failure.

Heat causes plastic to break down more easily, but even bottled water, which is usually kept at room temperature or colder, seems to be swimming with microplastics.

Recently, studies have shown that microwaving plastic food containers can release microplastics and nanoplastics into the meal, even if the containers claim to be microwave-safe. As few as three minutes can release billions of tiny plastic particles.

How many of those plastic particles are absorbed into the body when ingested is unknown. It's also a mystery as to how long the fragments stick around for.

Some studies on clogged arteries in human patients have found tiny fragments of plastic accumulating in more than 50 percent of plaques. Within roughly 34 months of surgery, those with plastics in their arteries were 4.5 times more likely to have a heart attack, stroke, or death compared to those where no plastic was detected.

When the body is exposed to plastic contaminants, researchers suspect there's a chance the additives can reduce the activity of antioxidant enzymes and trigger the body's inflammatory reaction, leaving it exposed to cardiovascular damage.

Part 1

Comment by Dr. Krishna Kumari Challa on February 21, 2025 at 11:35am

It is crucial to carefully consider the subject's posture during [pulse wave velocity] measurements to accurately assess arterial stiffness," the researchers wrote in their paper.

 Marino Karaki et al, The validity of carotid-femoral pulse wave velocity in the seated posture as an index of central arterial stiffness, American Journal of Physiology-Regulatory, Integrative and Comparative Physiology (2024). DOI: 10.1152/ajpregu.00073.2024

Part 2

Comment by Dr. Krishna Kumari Challa on February 21, 2025 at 11:34am

Vital sign accuracy may depend on body position, research suggests

Body position can affect the accuracy of vital sign measurements that indicate arterial stiffness—a risk factor for heart disease—according to new research. Sitting down during certain tests may cause a spike in arterial stiffness readings that does not reflect a true increase.

The study is published in the American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 

Arterial stiffness is when the walls of the blood vessels are not as elastic or stretchy as they should be. The condition is often a part of aging and can also occur in people who have diabetes, high cholesterol or high blood pressure. People with stiffer arteries have an increased risk of heart attack, stroke and other forms of heart disease.

Medical professionals most commonly measure markers of arterial stiffness with patients lying on their back (supine position). However, sitting may be a more practical option for people with chronic back pain or other health concerns.

In this study, researchers explored whether measuring carotid-femoral pulse wave velocity—the time it takes for the pulse to travel from the carotid to the femoral artery—can be considered reliable when measured in a seated position. Carotid-femoral pulse wave velocity (cfPWV) is considered the "gold standard" for measuring arterial stiffness.

The research team assessed a small group of young, healthy volunteers in both supine and seated positions on the same day. The researchers measured heart rate and blood pressure as well as cfPWV and took measurements three times in each position. They also analyzed the difference in arterial stiffness markers after a change from one position to the other.

Blood pressure, arterial pressure and heart rate were generally higher when participants were sitting compared to lying down. The researchers found cfPWV to be much higher when seated as well. However, when looking at blood flow and blood pressure between the two postures and adjusting the calculations to account for changes in hydrostatic pressure (pressure created due to gravity), the readings were much more comparable.
In addition, these findings suggest the activation of the sympathetic nervous system that occurs while sitting is not strong enough to cause large increases in arterial stiffness.

This study may have important implications for diagnosis of arterial stiffness and, in turn, the risk of heart disease.

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