Comment

Comment by Dr. Krishna Kumari Challa on August 29, 2024 at 8:37am

Looking to animals that have existed for millions of years allows us to start to catalog changes that have happened over evolution. What makes Neotropical leaf-nosed bats so unique to study is that this group is comprised of many different species with very diverse diets, making it feasible to find answers about how diet evolves. The hope is that we can extend this understanding to other mammals, including humans, where there may be ways to learn how to better protect our own health.
To uncover how bats diversified their diets, the research team traveled to the jungles of Central America, South America, and the Caribbean to conduct fieldwork over several years. These catch-and-release expeditions were focused on performing glucose tolerance tests—measuring the concentration of sugar in blood—on nearly 200 wild-caught bats across 29 species after a single feeding of one of three types of sugars associated with diets of insects, fruits, or nectar.
They observed various ways sugar is assimilated—absorbed, stored and used in the body—and how this process has become specialized due to different diets.
The mechanism for maintaining blood sugar levels within a narrow, healthy range is called glucose homeostasis, which is typically regulated by the hormone insulin and is what goes awry in diabetes. Different species of leaf-nosed bats reveal a spectrum of adaptations to glucose homeostasis, ranging from changes in intestinal anatomy to genetic alterations for proteins that transport sugar from blood to cells.
Fruit bats have honed their insulin signaling pathway to lower blood sugar. On the other extreme, nectar bats can tolerate high blood glucose levels, similar to what is observed in people with unregulated diabetes. They have evolved a different mechanism, and it does not seem to depend on insulin.
Although precisely how nectar bats are managing glucose is still under investigation, the researchers found potential clues for alternative metabolic strategies for glucose regulation. Bats with sugar-rich diets were observed to have longer portions of their intestines and to have intestinal cells with greater surface areas for absorbing nutrients from food, compared to bats with other diets. In addition, nectar bats, separate from fruit bats, have a continual expression of a gene responsible for sugar transport, a trait also observed in a species of hummingbird.
Part 2

Comment by Dr. Krishna Kumari Challa on August 29, 2024 at 8:32am

Some bats are surviving and thriving with blood sugar levels that would be lethal for other mammals

Humans must regulate blood sugar concentrations to stay healthy and to fuel our cells. Too little or too much can cause serious health complications, and high blood sugar is a hallmark of the metabolic condition, diabetes. New research  may enable potential solutions to metabolic disease by turning to evolution and to bats.

Published in Nature Ecology and Evolution, the study reports the highest naturally occurring blood sugar concentrations in mammals ever observed, a finding that suggests bats have evolved strategies to survive, and even thrive, with this extreme trait.

This new study  reports blood sugar levels that are the highest we have ever seen in nature—what would be lethal, coma-inducing levels for mammals, but not for bats.

Thirty million years ago, the Neotropical leaf-nosed bat survived solely on insects. Since then, these bats have diversified into many different species by changing what they eat. From insects, different lineages now specialize in diets including fruits, nectar, meat, and everything in between—even just blood.

The new study reports the highest naturally occurring blood sugar concentrations in mammals ever observed, a finding that suggests bats have evolved strategies to survive, and even thrive, with this extreme trait. Credit: Stowers Institute for Medical Research

Part 1

Comment by Dr. Krishna Kumari Challa on August 28, 2024 at 9:52am

How mindset could affect the body's response to vaccination

In a recent study, researchers found that beliefs and assumptions people have about COVID-19 vaccines seemed to influence their vaccination experience—including side effects and, in some cases, immune response.

While most people can appreciate that vaccination is an amazing achievement, their enthusiasm might falter when it comes time to schedule and receive their own. And new research suggests that might influence how the vaccine affects them.

Researchers studied the effects of different types of positive and negative mindsets regarding the COVID-19 vaccine.

Their work, published in the journal Brain, Behavior & Immunity—Health, suggests that a positive mindset is associated with more positive outcomes, such as less stress and side effects, better mood, and possibly even better immune response.

*Details of the findings include: All positive vaccine-related mindsets predict lower anxiety on the day of the appointment, and lower stress and sadness—and more happiness—in the days around vaccination.

*A positive mindset about the efficacy of the vaccine and how the body will respond to vaccination were linked to fewer negative physical side effects.

*The vaccine mindset that side effects indicate "the vaccine is working" was associated with better immune response—specifically, higher antibodies six months later.

Many people will be surprised by these findings, but they shouldn't be," said the authors. Our brains are connected to every physiological system in our bodies, and we know from decades of previous research on placebo effects and psychoneuroimmunology that our mindsets can influence physiological outcomes, including the immune system.

Darwin A. Guevarra et al, Examining the association of vaccine-related mindsets and post-vaccination antibody response, side effects, and affective outcomes, Brain, Behavior, & Immunity - Health (2024). DOI: 10.1016/j.bbih.2024.100818

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Comment by Dr. Krishna Kumari Challa on August 28, 2024 at 9:41am

Eastern equine encephalitis

Most people infected with eastern equine encephalitis don't develop symptoms, but some can come down with fever or swelling of the brain and about one third of people infected die.

 It is caused by a virus and is not very common around the world. The virus typically spreads in certain swamps.

West Nile virus

About 2 in 10 people infected with West Nile virus develop symptoms, which can include fever and swelling of the brain. About 1 in 10 people who develop severe symptoms die. 

Malaria

Malaria infected nearly 250 million people globally in 2022 and killed more than 600,000, mostly children. It is caused by a parasite carried by mosquitoes and mainly infects people in tropical regions, especially Africa. A vaccination campaign has been launched in recent months that health officials hope will help reduce cases and deaths.

Dengue

Also known as "break-bone fever" because it can be so painful, dengue is becoming more common. The World Health Organization says that about half the world's population is at risk of getting the disease, and there are 100 million to 400 million infections every year. Not everyone gets symptoms, which can include fever, severe headaches and pain in the muscles and joints.

Source: News agencies

Part 2

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Comment by Dr. Krishna Kumari Challa on August 28, 2024 at 9:36am

EEE, West Nile, malaria: Know the difference between these mosquito-borne diseases

The world's deadliest animal can be squashed flat with a quick slap: It's the mosquito.

The buzzing insects are more than annoying—they spread disease. When they bite and drink blood from a person or animal they can pick up viruses or germs too. If they can go on to bite someone or something else, they deposit the germ right under the skin.

The best way to avoid getting sick is of course to avoid getting bitten, which means taking steps like using repellent, wearing clothing with long sleeves and long pants and staying indoors when the mosquitoes are out. Local health departments also work to reduce mosquito numbers, including spraying neighborhoods with insecticide.

Here's a look at some common—and not so common—mosquito-borne diseases.

Part 1

Comment by Dr. Krishna Kumari Challa on August 28, 2024 at 9:29am

Menopause potentially linked to adverse cardiovascular health through blood fat profile changes

New research presented at the ESC Congress 2024 in London, UK (30 August—2 September) shows that women in the menopause transition period show changes in their blood cholesterol profiles which could have an adverse impact on their cardiovascular health.

There is an increase in 'bad' low-density type lipoprotein (LDL) particles and a decrease in 'good' high-density lipoprotein particles (HDL) that takes place during and after the menopause transition. Taken together, these changes suggest that menopause is associated with a transition to a higher-risk lipoprotein profile that could be more likely to cause cardiovascular disease, such as coronary artery disease.

Cardiovascular disease (CVD) is the biggest killer of women, despite the misconception that CVD is a "man's disease"—40% of all deaths in women are from CVD. While women develop cardiovascular disease (CVD) approximately ten years later than men, risk of CVD in women rises after menopause.

In the present study, the researchers found that found that menopause is associated with adverse changes in lipoprotein profiles, with the most pronounced changes found to be in increases in 'bad' LDL-particles and subfractions observed for peri-menopausal women. When looked at together, these changes could help explain the increase of cardiovascular disease in post-menopausal women and help determine if earlier interventions are warranted.

 esc365.escardio.org/ESC-Congress/sessions/11918

Comment by Dr. Krishna Kumari Challa on August 28, 2024 at 9:22am

Pregnancy after sterilization turns out to be surprisingly common

Tubal sterilization is thought to be a permanent form of birth control and is the most common method of contraception in several parts of the world. But a new study reports that tubal surgery fails often enough that some other forms of birth control are usually more effective.

The authors found that 3–5% of women in the  US who had their tubes tied later reported an unplanned pregnancy. This failure rate led the authors to suggest that patients who really want to avoid future pregnancy should instead use a contraceptive arm implant or intrauterine device (IUD).

The paper appears August 27 in NEJM Evidence.

Schwarz, E. B. et al. Pregnancy after Tubal Sterilization in the United States, 2002 to 2015, NEJM Evidence (2024). DOI: 10.1056/EVIDoa2400023. evidence.nejm.org/doi/10.1056/EVIDoa2400023

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

Bees are generally considered the most effective pollinators because Rutgers scientists identified that blueberry, coffee and apple crops were most frequently affected by pollinator limitations. They visit more flowers and carry more pollen than other insects.

Researchers found yield deficits for 25 unique crops and in 85% of the countries evaluated.

On the bright side, scientists think current yield deficits could be remediated with realistic increases in pollinator visitation across individual crop fields. The study revealed in some cases an adequate number of bees were already visiting some fields.

If field managers could improve consistency across high- and low-yield fields, much of the observed yield problems could be addressed.
The findings are significant because crop yields, which measure the amount of crops grown per unit area of land, are relevant to assessing the adequacy of the world's food supply relative to its population.

Katherine J. Turo et al, Insufficient pollinator visitation often limits yield in crop systems worldwide, Nature Ecology & Evolution (2024). DOI: 10.1038/s41559-024-02460-2

Part 2

Comment by Dr. Krishna Kumari Challa on August 28, 2024 at 9:12am

Lack of pollinators limits worldwide food production

A team of researchers  has analyzed crop yields of more than 1,500 fields on six continents, and found that production worldwide of important, nutritionally dense foods such as fruits, vegetables, nuts and legumes is being limited by a lack of pollinators.

The results, detailed in Nature Ecology & Evolution, showed that across diverse crops and locations, one-third to two-thirds of farms contain fields that aren't producing at the levels they should be due to a lack of pollinators. The phenomenon of a low crop yield because of insufficient visits by insects is known as 'pollinator limitation'.

The study is especially timely given recent concern about global declines in insect abundance.

The scientists reached their conclusions by conducting a statistical analysis of more than 200,000 "bee visitations" to crop flowers, contained within one of the most comprehensive databases on crop pollination in the world.

The open-source database incorporates three decades of field observations of bees and other pollinators visiting plants.

The recent  study doesn't apply to major food crops, such as rice and wheat, which don't require pollinators to reproduce. But pollination by bees and other animals is critical to the proliferation of what Scientists describe as "nutrient-dense and interesting foods that we like and are culturally relevant," such as fruits, vegetables, nuts, and legumes.

Pollination is the process of transferring pollen from the male part of a flower to the female part, which allows a plant to become fertilized and produce seeds, fruits and young plants. Pollen can be moved by wind, water or pollinators such as honeybees and wild bees and other insects and other animals, such as bats.

Pollinators support the reproduction of about 88% of the world's flowering plants and 76% of the leading global food crops, according to previous research by this group and also other scientists.

Part 1

Comment by Dr. Krishna Kumari Challa on August 28, 2024 at 8:59am

Anthropocene: Why it matters even without a formal geological definition

For the last seven decades, Earth has been operating in unprecedented ways, leading many researchers to argue that we have entered a new geological epoch known as the Anthropocene.

While it may not have been formally accepted onto the geological time scale, the Anthropocene is real and its effects have drastically and irrevocably changed the living conditions on our planet. It should therefore be treated as a de facto new epoch of Earth's history, say some experts.

That argument is at the crux of an article published in the journal Nature .

The article was also co-signed by more than 50 other researchers representing many different disciplines and institutes from around the world. It summarizes the evidence of massive physical, chemical and biological change on the planet, including the rapidly warming climate.

For many thousands of years, large human populations coexisted with relatively stable planetary conditions and left abundant traces of their existence and their environmental impacts.

But the planet is now sharply different, and the significance of these changes extends far beyond the Earth sciences to affect the social sciences, the humanities and arts—and to form a now-permanent context for the work of planners and decision-makers.

The authors emphasize that it makes sense to precisely delimit the beginning of the Anthropocene at 1952. That year not only marks the prominent upturn of artificial radionuclide fallout around the Earth from hydrogen bomb tests, they note, but closely coincides with many other changes, such as the appearance of plastics and many other novel compounds and the rapid growth of greenhouse gases, as well as widespread social, economic and political changes as the postwar world entered a period of unprecedented growth.

Wide acceptance of such a definition would make for more precise analysis of the many phenomena associated with the Anthropocene, and allow us to communicate clearly, say these experts.

The Anthropocene may have been rejected by the International Commission on Stratigraphy—for now. But it is all too alive in the real world, and we should recognize that.

Jan Zalasiewicz et al, The meaning of the Anthropocene: why it matters even without a formal geological definition, Nature (2024). DOI: 10.1038/d41586-024-02712-y

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