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Comment by Dr. Krishna Kumari Challa on June 29, 2024 at 8:25am

The earliest known eyed needles appeared approximately 40,000 years ago in Siberia. One of the most iconic of Paleolithic artifacts from the Stone Age, eyed needles are more difficult to make when compared to bone awls, which sufficed for creating fitted clothing. Bone awls are tools made of animal bones that are sharpened to a point. Eyed needles are modified bone awls, with a perforated hole (eye) to facilitate the sewing of sinew or thread.
As evidence suggests bone awls were already being used to create tailored clothes, the innovation of eyed needles may reflect the production of more complex, layered clothing, as well as the adornment of clothes by attaching beads and other small decorative items onto garments.
We know that clothing up until the last glacial cycle was only used on an ad hoc basis. The classic tools that we associate with that are hide scrapers or stone scrapers, and we find them appearing and going away during the different phases of the last ice ages.
Clothing became an item of decoration because traditional body decoration methods, like body painting with ocher or deliberate scarification, weren't possible during the latter part of the last ice age in colder parts of Eurasia, as people were needing to wear clothes all the time to survive.

That's why the appearance of eyed needles is particularly important because it signals the use of clothing as decoration.
Eyed needles would have been especially useful for the very fine sewing that was required to decorate clothing."

Clothing therefore evolved to serve not only a practical necessity for protection and comfort against external elements, but also a social, aesthetic function for individual and cultural identity.

The regular wearing of clothing allowed larger and more complex societies to form, as people could relocate to colder climates while also cooperating with their tribe or community based on shared clothing styles and symbols. The skills associated with the production of clothing contributed to a more sustainable lifestyle and enhanced the long-term survival and prosperity of human communities.
Covering the human body regardless of climate is a social practice that has endured.

Ian Gilligan, Palaeolithic eyed needles and the evolution of dress, Science Advances (2024). DOI: 10.1126/sciadv.adp2887. www.science.org/doi/10.1126/sciadv.adp2887

Part 2

Comment by Dr. Krishna Kumari Challa on June 29, 2024 at 8:22am

The beginnings of fashion: Paleolithic eyed needles and the evolution of dress

A team of researchers led by an archaeologist  are the first to suggest that eyed needles were a new technological innovation used to adorn clothing for social and cultural purposes, marking the major shift from clothes as protection to clothes as an expression of identity.

Eyed needle tools are an important development in prehistory because they document a transition in the function of clothing from utilitarian to social purposes.

From stone tools that prepared animal skins for humans to use as thermal insulation, to the advent of bone awls and eyed needles to create fitted and adorned garments, why did we start to dress to express ourselves and to impress others?

Dr. Gilligan and his co-authors reinterpret the evidence of recent discoveries in the development of clothing in their new Science Advances paper, "Paleolithic eyed needles and the evolution of dress."

Why do we wear clothes? We assume that it's part of being human, but once you look at different cultures, you realize that people existed and functioned perfectly adequately in society without clothes. What intrigued the researchers 's the transition of clothing from being a physical necessity in certain environments, to a social necessity in all environments.

Part 1

Comment by Dr. Krishna Kumari Challa on June 29, 2024 at 7:06am

Most kids get antibiotics for pink eye, study shows. Experts say they're usually not needed

Doctors are prescribing antibiotics to most kids and teens who have pink eye, despite guidelines that discourage their use, researchers reported this week.

More than two-thirds of  children and teens who saw a doctor for pink eye left with a prescription for antibiotic eye drops, their research found. The American Academy of Ophthalmology recommends that doctors do not routinely give out antibiotics for what's also called conjunctivitis, which usually clears up on its own.

Antibiotics don't work at all on viruses—the most common cause of pink eye. And even mild eye infections from bacteria will resolve on their own in most cases, the medical group says.

Pink eye is highly contagious and causes red, swollen and sometimes itchy eyes. Often, a chilled, wet towel and artificial tears are enough to ease symptoms.

But antibiotics shouldn't be overused if they aren't going to help. Moreover, the misuse can lead to resistance. 

There are more supportive measures you can take to make your child or you feel comfortable without resorting to antibiotic eye drops.

Daniel J. Shapiro et al, Antibiotic Treatment and Health Care Use in Children and Adolescents With Conjunctivitis, JAMA Ophthalmology (2024). DOI: 10.1001/jamaophthalmol.2024.2211

Comment by Dr. Krishna Kumari Challa on June 29, 2024 at 6:56am

Kids given 'digital pacifiers' to calm tantrums fail to learn how to regulate emotions, study finds

Tantrums are part of growing up. How these outbursts of anger or frustration are managed, however, can impact children's emotional development.

An international team of researchers has investigated how giving children digital devices acting as "digital pacifiers" to avoid or manage tantrums impacts children's later anger management skills. They found that children who were routinely given digital devices when they threw a tantrum had more difficulties regulating their emotions. The researchers also stressed the importance of letting children experience negative emotions and the crucial role parents play in the process.

Children learn much about self-regulation—that is, affective, mental, and behavioral responses to certain situations—during their first few years of life. Some of these behaviors are about children's ability to choose a deliberate response over an automatic one. This is known as effortful control, which is learned from the environment, first and foremost through children's relationship with their parents.

In recent years, giving children digital devices like smart phones or tablets to control their responses to emotions, especially if they're negative, has become common. Children are fascinated by digital content, so this is an easy way to stop tantrums and it is very effective in the short term.

But researchers found  that when parents used digital emotion regulation more often, children showed poorer anger and frustration management skills. Children who were given devices more often as they experienced negative emotions also showed less effortful control at the follow-up assessment.

Tantrums cannot be cured by digital devices. And the researchers recommend new training and counseling methods  for parents. 

Cure for tantrums? Longitudinal associations between parental digital emotion regulation and children's self-regulatory skills, Frontiers in Child and Adolescent Psychiatry (2024). DOI: 10.3389/frcha.2024.1276154

Comment by Dr. Krishna Kumari Challa on June 28, 2024 at 10:38am

A typical CT scanner scans the human body using X-rays, and reconstructs its spatial internal structure section by section. In biology, a similar function has recently been performed by the holotomographic microscope. Here, cells are also swept by a beam of radiation, though not high-energy radiation, but electromagnetic radiation. Its energy is chosen so that the photons do not disturb cell metabolism.

The result of the scan is a set of holographic cross-sections containing information about the distribution of refractive index changes. Since light refracts differently on the cytoplasm and differently on the cell membrane or nucleus, it is possible to reconstruct a three-dimensional image of both the cell itself and its interior.

Unlike other high-resolution microscopy techniques, holotomography does not require the preparation of samples or the introduction of any foreign substances into the cells. The interactions of gold nanoparticles with cancer cells could therefore be observed directly in the incubator, where the latter were cultured, in an undisturbed environment--what's more, with nanometric resolution--from all sides simultaneously and practically in real time.

The unique features of holotomography allowed the physicists to determine the causes of the unexpected behavior of cancer cells in the presence of gold nanoparticles. A series of experiments was conducted on three cell lines: two glioma and one colon. Among others, it was observed that although the small, spherical nanoparticles easily penetrated the cancer cells, the cells regenerated and even started to divide again, despite the initial stress.

In the case of colon cancer cells, the gold nano particles were quickly pushed out of them. The situation was different for the large star-shaped nanoparticles. Their sharp tips perforated the cell membranes, most likely resulting in increasing oxidative stress inside the cells. When these cells could no longer cope with repairing the increasing damage, the mechanism of apoptosis, or programmed death, was triggered.

Researchers used the data from the  experiments to build a theoretical model of the process of nanoparticle deposition inside the cells under study. The final result is a differential equation into which suitably processed parameters can be substituted—for the time being only describing the shape and size of nanoparticles—to quickly determine how the uptake of the analyzed particles by cancer cells will proceed over a given period of time and how they kill the cancer cells.

Joanna Depciuch et al, Modeling Absorption Dynamics of Differently Shaped Gold Glioblastoma and Colon Cells Based on Refractive Index Distribution in Holotomographic Imaging, Small (2024). DOI: 10.1002/smll.202400778

Part 2

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Comment by Dr. Krishna Kumari Challa on June 28, 2024 at 10:34am

What type of Gold nanoparticles kill cancer

Gold particles of the size of billionths of a meter are lethal to cancer cells. This fact has been known for a long time, as has a simple correlation: The smaller the nanoparticles used to fight the cancer cells, the faster they die. However, a more interesting, more complex picture of these interactions is emerging from the latest research  using a novel microscopic technique.

Smaller kills faster—this is what was previously thought about gold nanoparticles used to fight cancer cells. Scientists thought that small nanoparticles would simply find it easier to penetrate the interior of a cancer cell, where their presence would lead to metabolic disturbances and ultimately cell death.

The reality, however, turns out to be more complex, as demonstrated by research carried out by scientists.

Nanoparticles can be produced using a variety of methods, yielding particles of different sizes and shapes. Shortly after starting their own experiments with gold nanoparticles, researchers  noticed that biology does not follow the popular rule that their toxicity is greater the smaller they are.

Spherical nanoparticles of 10 nanometers in size  turned out to be practically harmless to the glioma cell line studied. However, high mortality was observed in cells exposed to nanoparticles as large as 200 nanometers, but with a star-shaped structure.

Elucidation of the stated contradiction became possible thanks to the use of the first holotomographic microscope.

Part 1

Comment by Dr. Krishna Kumari Challa on June 28, 2024 at 9:38am

This theory fits with a pattern of strategies mammals have adopted in an evolutionary bid to limit the spread of potentially harmful elements. Notably, in humans, mitochondrial DNA is exclusively passed down from the mother. This mechanism serves as a natural filter, maintaining genetic integrity by suppressing the proliferation of detrimental mutations. Additionally, the prevalence of monogamous relationships among certain species has been suggested as an adaptive response aimed at minimizing the transmission of sexually transmitted infections (STIs).

Maternal transmission as a microbial symbiont sieve, and the absence of lactation in male mammals, Nature Communications (2024). DOI: 10.1038/s41467-024-49559-5

Part 2

Comment by Dr. Krishna Kumari Challa on June 28, 2024 at 9:37am

Why male mammals don't breast feed

New mathematical model sheds light on the absence of breastfeeding in male mammals

Being nursed by a single parent could be an evolutionary strategy to curb the spread of harmful microbes in mammals, according to a novel theory developed by mathematicians.

The rainforests of Malaysia are home to the only known case of a wild male mammal that produces milk. The Dayak fruit bat is a vanishingly rare case of male milk production, despite the fact that the potential for breastfeeding remains in place in most male mammals.

Male Dyak's fruit bats, Dyacopterus spadiceus, are able to feed their young milk from their own mammary glands. This species has one of the only known natural occurrences of paternal lactation.

In the 1970s, evolutionary theorists posited that the near absence of lactation in males, even though offspring could benefit from the extra nutrition provided, could be attributed to the uncertainty of paternity: As male mammals can't be sure they are the biological father, this reduces their evolutionary drive to invest heavily in offspring care, including breastfeeding.

Now, mathematicians from the University of York have suggested a complementary perspective. Their hypothesis, published in Nature Communications, suggests that the reason male mammals don't breastfeed might be driven by the rich community of microbes that lives in breast milk, which plays an important part in establishing the gut microbiome of the infant.

The theory demonstrates how the transmission of the milk microbiome from both parents would allow harmful microbes to spread through mammalian populations. Maternal-only lactation stops this, as restricting transmission of the milk microbiome to females in effect acts as a sieve, retaining just the microbes with beneficial effects.

When both parents are involved in feeding, the chance of a microbe being passed along and getting an initial foothold in a population is essentially doubled. So this new theory suggests selection against the transmission of harmful microbes through mammary milk could be an additional selection pressure against male lactation.

Breast milk is a living substance and it plays a key role in establishing the gut microbiome of mammals, which is a complex ecosystem of bacteria, viruses and fungi, along with their genetic material. This ecosystem plays a crucial role in health, including by helping to protect animals against disease, helping to digest food and in many other ways we are only just discovering.

While microbes are not inherently harmful or beneficial; it's their presence and abundance that dictate the overall health of this internal community. A 'wrong actor' at the early point of an animal's life could change the microbiome at a pivotal moment.

The mathematical model highlights the advantage of being fed by just one parent, but the researchers say it makes evolutionary sense for this to be the mother because there has already been an inevitable transmission of microbes during birth and perhaps also in the womb.

Part 1

Comment by Dr. Krishna Kumari Challa on June 27, 2024 at 11:38am

At summer temperatures, wetting with anything more than water vapor leads to unsustainable carbon losses for boreal oak lichen, which may explain why it prefers humid environments like bogs. Scientists already knew this species is vulnerable to heating and drying, now we can start to understand exactly how and why—all key insights into the threats from future climate change.
n simple cases of symbiosis, such as a clownfish and a sea anemone, the needs of the partner organisms may be well-balanced and complimentary. The research shows that symbiosis in lichens is more complex, and each organism may react differently when faced with changing weather conditions or environmental stress.

"Unexpectedly, the alga just does its own thing: once active, it doesn't seem to respond at all to the major changes that the fungus undergoes when we add liquid water. It shouldn't be a surprise that the different organisms that make up lichen symbioses respond to different cues, but it has often been far too easy to lose sight of that when working with such seemingly closely integrated symbioses."

Future research will focus on unpacking when the components of lichen symbiosis are and aren't coordinated. The team hopes to better understand what each organism does under different circumstances.

 Abigail R. Meyer et al, Symbionts out of sync: Decoupled physiological responses are widespread and ecologically important in lichen associations, Science Advances (2024). DOI: 10.1126/sciadv.ado2783

Part 2

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Comment by Dr. Krishna Kumari Challa on June 27, 2024 at 11:35am

Lichen partnerships challenged by changes in climate

Lichen, which people may think of as a single organism, is in fact a community of several species that depend on each other for survival. Lichen symbiosis includes at least one fungus and one alga, along with other fungi and bacteria in roles that are still being investigated by biologists.

The continued health of lichens is vital to the future of our Northern forests because they provide a critical winter food source for many animals. They are also valuable "sentinels" of air quality and environmental health. For these reasons, scientists are eager to understand how they may be affected by climate change.

New research published in Science Advances from the University of Minnesota investigated symbiosis in boreal oak lichen, a variety widespread on several tree species across Minnesota and the Northwoods.

Using multiple research methods, the team found:

• The partner organisms that make up lichen symbioses are not always in sync—one organism may have an extreme response to changes in moisture while its partner remains unaffected.
• These differences may drive one partner to "go it alone" under some conditions, disrupting the symbiosis—other research has observed this in corals.
• The team used gas exchange data to show asymmetries in carbon balance are widespread across evolutionarily disparate lichen groups.

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