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Comment by Dr. Krishna Kumari Challa on October 24, 2024 at 9:51am

To test the obstetrical dilemma hypothesis, the research team first compared the available space in the birth canal of chimpanzees and humans, using the average distance between the fetal head and the pelvic bones while accounting for soft tissue contributions.

Using a three-dimensional virtual simulation of the birth process, they were able to show that the space in the chimpanzee pelvis is actually just as tight as it is in humans. Interestingly, after a detailed shape analysis, they also found that female chimpanzees have a more spacious pelvis than males, especially the smaller females, providing evidence of adaptations to deal with these space limitations.

The researchers also show that the great apes appear to trend towards humans in how neurologically immature, or how secondarily altricial their infants are compared to monkeys—again surprisingly similar to humans, although to a lesser magnitude.
Based on these intriguing parallels, the researchers propose a new hypothesis that the obstetrical dilemma developed gradually and became increasingly exacerbated over the course of evolution. This contradicts the previous theory that our long and difficult births emerged abruptly with the enlargement of the brain in Homo erectus.
The increase in body size in the ancestors of the great apes made their pelvis stiffer, which limited the ability of their ligaments to stretch during birth. In early hominins, the upright gait also led to a twisted bony birth canal, which required complex movements of the fetal head. This mechanism, rather than the narrowness of the birth canal, is likely the main cause of the difficult birth process in humans, the researchers argue.
The study shows that the remarkably complex human birth process is the result of gradual compromises during hominoid evolution. The difficult birth and the neurological immaturity of our newborns, with the long learning phase that follows, are a prerequisite for the evolution of our intelligence. At the same time, we humans are only at one extreme—we are not unique among primates, say the researchers.

Nicole M. Webb et al, Gradual exacerbation of obstetric constraints during hominoid evolution implied by re-evaluation of cephalopelvic fit in chimpanzees, Nature Ecology & Evolution (2024). DOI: 10.1038/s41559-024-02558-7

Part 2

Comment by Dr. Krishna Kumari Challa on October 24, 2024 at 9:48am

Study shows birth is a tight squeeze for chimpanzees, too

According to a new study, chimpanzees, like humans, must contend with a confined bony birth canal when giving birth. In humans, the problem is exacerbated by our unique form of upright walking, since this led to a twisting of the bony birth canal, while the fetal head grew larger. The obstetrical dilemma therefore evolved gradually over the course of primate evolution rather than suddenly in humans as originally argued.

The birth process in chimpanzees and other great apes is generally considered to be easy. This is usually attributed to a relatively large pelvis and the small head of their newborn. In contrast, human childbirth is both more complex and riskier when compared to other mammals.

According to the original obstetrical dilemma hypothesis, our birth difficulty stems from a conflict that arose during human evolution between adaptations in the pelvis for upright walking and an increase in our infants' brain size.

On the one hand, the pelvis shortened to improve balance while moving bipedally, while the baby's larger head still had to fit through the birth canal. As a solution to this dilemma, the shape of the pelvic bones differs between the sexes (with females having larger dimensions despite smaller body sizes), and human babies are born more neurologically immature than other primates, so that brain growth is delayed to the postnatal period.

An international team of researchers simulated birth in chimpanzees and humans and quantified the space between the bony birth canal and the fetal head. The work is published in the journal Nature Ecology & Evolution.

The study shows that narrow birth canals in relation to the infant head size are not unique to humans. Accordingly, the obstetrical dilemma hypothesis, which had previously been explained solely by the development of bipedalism and the size of the human brain, did not suddenly appear during the development of modern humans, but rather developed gradually over the course of primate evolution—and then intensified in humans, thus explaining the high rates of birth complications observed today.

Part 1

Comment by Dr. Krishna Kumari Challa on October 24, 2024 at 8:29am

Comment by Dr. Krishna Kumari Challa on October 24, 2024 at 7:57am

People with no sense of smell found to have abnormal breathing patterns

A team of neuroscientists  has found that people who have lost the ability to smell have slightly different breathing patterns than those with a normal sense of smell. 

Anosmia is the inability to smell. Unfortunately, the condition was found to be a common symptom for people with COVID-19. The condition has been studied for hundreds of years and has a variety of causes, from depression to drug use, and negatively impacts quality of life. In this new effort, the research team has found yet another feature of the condition.

The researchers sought to address anecdotal accounts of people who could not smell and began "breathing funny" after contracting COVID-19. To find out if such accounts were true and to quantify the differences, the research team recruited 52 volunteers, 21 of whom were suffering from anosmia.

Each of the volunteers was fitted with a device that monitors breathing and each wore it for 24 hours. The research team found that those volunteers with anosmia did have slightly different than normal breathing patterns.

People without the condition, they note, have small inhalation peaks, which prior research suggests coincides with a suspected change in smell. People without the ability to smell had no such peaks.

The research team also found that they could identify with 83% accuracy which members of the group had anosmia simply by evaluating the breathing patterns. They suggest more research is required to determine if changes inbreathing patterns have later impacts, such as an increase in risk of developing depression.

Lior Gorodisky et al, Humans without a sense of smell breathe differently, Nature Communications (2024). DOI: 10.1038/s41467-024-52650-6

Comment by Dr. Krishna Kumari Challa on October 24, 2024 at 7:53am

Physicists observed a "black hole triple" for the first time: sheds new light on blackhole formation

The new system holds a central black hole in the act of consuming a small star that's spiraling in very close to the black hole, every 6.5 days—a configuration similar to most binary systems. But surprisingly, a second star appears to also be circling the black hole, though at a much greater distance. The physicists estimate this far-off companion is orbiting the black hole every 70,000 years.

That the black hole seems to have a gravitational hold on an object so far away is raising questions about the origins of the black hole itself. Black holes are thought to form from the violent explosion of a dying star—a process known as a supernova, by which a star releases a huge amount of energy and light in a final burst before collapsing into an invisible black hole.

The team's discovery, however, suggests that if the newly-observed black hole resulted from a typical supernova, the energy it would have released before it collapsed would have kicked away any loosely bound objects in its outskirts. The second, outer star, then, shouldn't still be hanging around.

Instead, the team suspects the black hole formed through a more gentle process of "direct collapse," in which a star simply caves in on itself, forming a black hole without a last dramatic flash. Such a gentle origin would hardly disturb any loosely bound, faraway objects.

Because the new triple system includes a very far-off star, this suggests the system's black hole was born through a gentler, direct collapse. And while astronomers have observed more violent supernovae for centuries, the team says the new triple system could be the first evidence of a black hole that formed from this more gentle process.

 Kevin Burdge, The black hole low-mass X-ray binary V404 Cygni is part of a wide triple, Nature (2024). DOI: 10.1038/s41586-024-08120-6. www.nature.com/articles/s41586-024-08120-6

Comment by Dr. Krishna Kumari Challa on October 23, 2024 at 11:55am

In a chaotic and emotionally charged response to the situation, surgeons declined to continue the procedure .

"It was very chaotic. Everyone was just very upset."

That's everybody's worst nightmare, right? Being alive during surgery and knowing that someone is going to cut you open and take your body parts out?

Deep concerns have been raised about the potential for errors such as these. 

But these are rare cases. You don't have to worry.

Please donate your organs and those of your loved ones without any hesitation. 

Source: https://www.npr.org/sections/shots-health-news/2024/10/16/nx-s1-511...

Part 2

Comment by Dr. Krishna Kumari Challa on October 23, 2024 at 11:55am

Man Declared Brain Dead Wakes Up as Organs About to Be Removed

This story brought back traumatic memories to me.
I decided to donate my mother's corneas when the doctors treating her declared her brain dead. But my sister was very scared. "What if she isn't actually dead?", she asked me, "What if she gets up again from her deep sleep? She won't have eyes to see!"

Despite my sister's fear, I went ahead and signed the papers. The doctors removed her corneas and transplanted them to two blind people and I was told the surgery was successful.. After her cremation,   I told my sister her fears were exaggerated. 

Are they, really? 

A case of a Kentucky man waking up as his organs were about to be harvested for donation has called into question the protocols used by  hospitals and organ donation networks to qualify death.

Whistleblower Nyckoletta Martin outlined the horrifying case in a letter addressing the US House of Representatives Energy and Commerce Committee's September hearing on the nation's organ procurement and transplantation system. 

While employed as an organ preservationist for Kentucky Organ Donor Affiliates (KODA), Martin had allegedly reviewed case notes on the October 2021 surgical procedure.

 According to a report by the US public broadcasting organization National Public Radio (NPR), those case notes indicated the donor had shown signs of life following a clinical test to evaluate the heart's fitness for transplant purposes. The donor had woken up during his procedure that morning for a cardiac catheterization. And he was thrashing around on the table.

 The patient at the center of the incident is 36-year-old Anthony Thomas 'TJ' Hoover II, who had been rushed to Baptist Health Hospital in Richmond, Kentucky, following a drug overdose. Declared brain dead in the wake of a cardiac arrest, TJ was removed from life support and prepared for organ donation in accordance with his wishes. TJ's sister Donna Rhorer was by her brother's side following his passing. Along with other family members, Rhorer recalled seeing TJ's eyes open and looking about on the way to the theater, to be told by staff this was a common reflex. It was only later when TJ displayed more exaggerated movements on the operating table and "was crying visibly" that medical staff in the room became alarmed.

Part 1

Comment by Dr. Krishna Kumari Challa on October 23, 2024 at 9:54am

Psychopaths could be suffering from alexithymia or emotional blindness, study finds

Psychopathic people have great difficulty or are even unable to show empathy and regulate their emotions. According to a new study this could be because these people suffer from alexithymia, also known as emotional blindness. The work is published in the journal PLOS ONE.

The term alexithymia is an amalgam of the Greek prefix a- (without) and the words lexis (reading) and thymos (emotion). It refers to the inability of a person to recognize and describe their own emotions. People with alexithymia tend to perceive their feelings as purely physical sensations. For example, emotional tension is registered as mere physical discomfort or pain.

Previous research has linked alexithymia to mental health issues such as depression and anxiety. However, research in clinical psychology shows that the ability to properly identify and understand one's own emotions is essential for the healthy functioning of other emotional abilities such as empathy and emotion regulation.

The result of the study: the "forensic sample" ( comprising people who committed crimes) was found to exhibit significantly higher levels of boldness, meanness, and disinhibition compared to the general population cohort. These characteristics are considered typical psychopathic traits.

This result corresponds to earlier studies and indicates that there is a higher proportion of people with psychopathic symptoms in groups of offenders from forensic clinics than in the general population.

What is new, however, is the scientific finding that individuals with strong psychopathic traits tend to have greater difficulty recognizing and describing their own emotions (i.e., to be suffering from alexithymia), which in turn contributes to a lack of empathy and poor emotion regulation. Conversely, this means that therapeutic measures to improve emotional awareness could be helpful for people with psychopathic personalities.

If these people manage to recognize and describe their own emotions, their empathy and ability to regulate their emotions may also improve. Ideally, this therapeutic approach could reduce the risk of recidivism in offenders.

Matthias Burghart et al, Understanding empathy deficits and emotion dysregulation in psychopathy: The mediating role of alexithymia, PLOS ONE (2024). DOI: 10.1371/journal.pone.0301085

Comment by Dr. Krishna Kumari Challa on October 23, 2024 at 9:30am

Worst agricultural practices: plastic mulch is contaminating agricultural fields

Using plastic sheets for weed control, even under current best management practices, pollutes soil with macro- and micro-plastics and negatively affects critical soil functions, according to a study. The United Nations considers soil plastic contamination an environmental health and food security threat.

Around the world, over 25 million acres of farmland is seasonally covered with opaque plastic films used as "mulch" to prevent weeds, retain moisture, and warm soil—a practice known as "plasticulture." Most studies have assessed plastic mulch soil contamination impacts using lab-based models or in experimental plots.

Researchers surveyed fields after plastic mulch had been carefully removed for the season—a "best practice" to reduce plastic contamination in fields. However, all the fields surveyed had plastic contamination and the authors found up to 25 kg of macroplastic debris per hectare, covering up to 3.4% of field surface area. Microplastics were also found in all fields and microplastic concentrations positively correlated with macroplastic concentrations.

Key soil heath traits were negatively correlated with macroplastic accumulation even at relatively low contamination levels. 

Thus, current "best practices" are causing subtle but deleterious effects to soil.

Because the use of plastic film mulch is rapidly expanding globally, the authors suggest exploring a non-plastic, biodegradable alternative to limit the threat to soil function and agricultural productivity caused by unabated plastic accumulation.

Agricultural plastic pollution reduces soil function even under best management practices, PNAS Nexus (2024). DOI: 10.1093/pnasnexus/pgae433. academic.oup.com/pnasnexus/art … 3/10/pgae433/7828925

Comment by Dr. Krishna Kumari Challa on October 23, 2024 at 9:25am

Discovery of new bacterial toxins could be key to fighting infections

Researchers have discovered a new group of bacterial toxins that can kill harmful bacteria and fungi, opening the door to potential new treatments for infections. These toxins, found in over 100,000 microbial genomes, can destroy the cells of bacteria and fungi without harming other organisms.

The study, published in Nature Microbiology, has uncovered how some bacteria use these toxins to compete with other microbes, and the findings could lead to new ways to fight infections, especially as antibiotic resistance becomes a growing concern.

These toxins, which are encoded in the genomes of certain bacteria, exhibit potent antibacterial and antifungal properties, offering exciting new possibilities for clinical and biotechnological applications.

Microbial competition is a natural phenomenon, and bacteria have evolved sophisticated methods, including toxins, to eliminate competitors. The most famous examples of natural compounds used in competition in nature are antibiotics produced by bacteria and fungi.

These toxins, which are encoded in the genomes of certain bacteria, exhibit potent antibacterial and antifungal properties, offering exciting new possibilities for clinical and biotechnological applications. Microbial competition is a natural phenomenon, and bacteria have evolved sophisticated methods, including toxins, to eliminate competitors. The most famous examples of natural compounds used in competition in nature are antibiotics produced by bacteria and fungi.

The research team successfully validated nine newly-discovered toxins, each representing a large evolutionary conserved family, demonstrating their ability to cause cell death in both Escherichia coli and Saccharomyces cerevisiae when expressed in these model organisms. Of particular note, five antitoxin genes--also known as immunity genes--were identified, which protect the bacteria producing the toxins from self-destruction.

It is interesting to note that the toxins exhibit powerful antifungal activity against a range of pathogenic fungi, while leaving certain invertebrate species and macrophages unaffected. 

Systematic Discovery of Antibacterial and Antifungal Bacterial Toxins, Nature Microbiology (2024). DOI: 10.1038/s41564-024-01820-9

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