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Comment by Dr. Krishna Kumari Challa yesterday

Scientists’ brains shrank a bit after an extended stay in Antarctica. The effects of isolation and a monotonous environment may be to blame

Socially isolated and faced with a persistently white polar landscape, a long-term crew of an Antarctic research station saw a portion of their brains shrink during their stay, a small study finds.

“It’s very exciting to see the white desert at the beginning,” says physiologist Alexander Stahn, who began the research while at Charité-Universitätsmedizin Berlin. “But then it’s always the same.”

The crew of eight scientists and researchers and a cook lived and worked at the German research station Neumayer III for 14 months. Although joined by other scientists during the summer, the crew alone endured the long darkness of the polar winter, when temperatures can plummet as low as –50° Celsius and evacuation is impossible. That social isolation and monotonous environment is the closest thing on Earth to what a space explorer on a long mission may experience, says Stahn, who is interested in researching what effect such travel would have on the brain.

Animal studies have revealed that similar conditions can harm the hippocampus, a brain area crucial for memory and navigation . For example, rats are better at learning when the animals are housed with companions or in an enriched environment than when alone or in a bare cage, Stahn says. But whether this is true for a person’s brain is unknown.

Stahn, now at the Perelman School of Medicine at the University of Pennsylvania, and his colleagues used magnetic resonance imaging to capture views of the team members’ brains before their polar stay and after their return. On average, an area of the hippocampus in the crew’s brains shrank by 7 percent over the course of the expedition, compared with healthy people matched for age and gender who didn’t stay at the station, the researchers report online December 4 in the New England Journal of Medicine.

But there are good reasons to believe that this change is reversible, Stahn says. While the hippocampus is highly vulnerable to stressors like isolation, he says, it is also very responsive to stimulation that comes from a life filled with social interactions and a variety of landscapes to explore.

A.C. Stahn et al. Brain changes in response to long Antarctic expeditions. New England Journal of Medicine. Published online December 4, 2019. doi:10.1056/NEJMc1904905.

Comment by Dr. Krishna Kumari Challa yesterday

Biomimicry - the process of mimicing nature for our benefit. Plants serve as the inspiration for new energy technologies — and more efficient agriculture. So scientists are now looking to hack photosynthesis for a greener planet.

Photosynthesis comes as naturally to plants as breathing does to people. This process converts the simple ingredients of carbon dioxide, water and sunlight into energy. Photosynthesis allows plants to grow. In turn, we rely on photosynthesis as the foundation for our life on Earth.  

When sunlight touches the leaves of a plant it does more. It powers a chemical reaction that converts one type of energy into another. Those plant leaves contain plenty of water. That water is made of oxygen atoms bonded to hydrogen atoms. The sun’s energy can excite electrons inside the water molecule enough that the bonds split.

This triggers a reaction “that takes the oxygen away from the water. And that becomes the oxygen in the air that we all breathe. Meanwhile, Hydrogen from the water gets smushed together with the carbon dioxide [in air], and that makes sugar. People and all other animals use this sugar — glucose — as an energy source from food. Plants become the food that our bodies can convert into energy. Essentially, photosynthesis is the reason we can exist.

Artificial photosynthesis: 

Scientists have already begun copying, or mimicking, photosynthesis. Their artificial processes also use light to split oxygen and hydrogen — for energy. The dream is to eventually replace fossil fuels. If people could make energy from sun, air and water — as plants do — it would cut down on planet-warming releases of carbon dioxide. It also could create a huge new source of renewable energy.

Many researchers look to solar fuels — fuels made from sunlight — as “green” replacements for today’s carbon-based fossil fuels. These include oil, gas and coal.

Scientists around the world are experimenting with devices — think of them as artificial leaves.

Comment by Dr. Krishna Kumari Challa on Tuesday

We heard the consequences of AGW ( human-caused change of global warming). Like wildfires, hurricanes and floods that forced thousands of people to evacuate, damage property, and erase tangible reminders of our past.

Like more ubiquitous, but less publicized, are the millions of people who are exposed to heat waves, long-term droughts, rising sea levels, and eroding coastlines, forcing them to move elsewhere or spend large sums of money building communities that are habitable.

Each of these responses represent a challenge to our mental health. For instance, people exposed to life-threatening extreme weather events are more likely to experience post-traumatic stress disorder, depression and anxiety.

People exposed to prolonged heat waves are more likely to make poor decisions that place them at risk for death or severe injury. People exposed to long-term drought are more likely to experience depression, interpersonal violence and thoughts of suicide. People exposed to sea level rise and coastal erosion are more likely to experience anxiety and interpersonal conflict with others in their community.

These mental health challenges are perhaps the most overlooked consequences of climate change and need a thorough understanding to deal with them.

Increasing temperatures and heatwaves, the spread of emerging infectious illnesses, and the widespread concerns about food security in drought-plagued regions of the world all threaten our physical health.

Environmental changes that threaten our livelihoods, access to food, and habitability of our communities lead to widespread unemployment and poverty, civil conflict, and dislocation.

Comment by Dr. Krishna Kumari Challa on November 24, 2019 at 9:10am

Chinese scientists programme stem cells to ‘fight and destroy’ cancer

• Team from Guangzhou Institutes of Biomedicine and Health says technique was successful in treatment of mice
• Technique represents another step forward in field of immune therapy, researchers say

Chinese scientists claim to have made a major step towards a breakthrough in cancer treatment by programming stem cells to “seek and destroy” the disease.

Professor Wang Jinyong and a team from the Guangzhou Institutes of Biomedicine and Health, under the Chinese Academy of Sciences, say that the technique was successfully used to treat mice with cancer of the thymus, an organ central to the body’s immune system.

According to a paper published last week in the peer-reviewed scientific journal Cell Research, the team used stem cells to create infant immune cells that would later develop into T cells, which are produced in the thymus and play a central role in the body’s immune response.

After a period of time, the tumours disappeared. And because the new T cells had memory, the mice were immune from this type of cancer for life, the report said.

In a statement on the academy’s website, the team said the method could lead to a breakthrough in cancer treatment.

Comment by Dr. Krishna Kumari Challa on November 24, 2019 at 8:57am

Infectious bacteria communicate to avoid antibiotics

A bacterial infection is not just an unpleasant experience - it can also be a major health problem. Some bacteria develop resistance to otherwise effective treatment with antibiotics. Therefore, researchers are trying to develop new types of antibiotics that can fight the bacteria, and at the same time trying to make the current treatment with antibiotics more effective.

Researchers are now getting closer to this goal with a type of bacteria called Pseudomonas aeruginosa, which is notorious for infecting patients with the lung disease cystic fibrosis. In a new study, researchers found that the bacteria send out warning signals to their conspecifics when attacked by antibiotics or the viruses called bacteriophages which kill bacteria.

'We can see in the laboratory that the bacteria simply swim around the 'dangerous area' with antibiotics or bacteriophages. When they receive the warning signal from their conspecifics, you can see in the microscope that they are moving in a neat circle around. It is a smart survival mechanism for the bacteria. If it turns out that the bacteria use the same evasive manoeuvre when infecting humans, it may help explain why some bacterial infections cannot be effectively treated with antibiotics', says researcher Nina Molin Høyland-Kroghsbo, Assistant Professor at the Department of Veterinary and Animal Sciences and part of the research talent programme UCPH-Forward.

One United Organism

In the study, which is a collaboration between the University of Copenhagen and the University of California Irvine, researchers have studied the growth and distribution of bacteria in petri dishes. Here, they have created environments that resemble the surface of the mucous membranes where an infection can occur - as is the case with the lungs of a person with cystic fibrosis.

In this environment, researchers can see both how bacteria usually behave and how they behave when they are affected by antibiotics and bacteriophages.

Comment by Dr. Krishna Kumari Challa on November 6, 2019 at 9:09am

World scientists’ warning of a climate emergency

A new report by 11,258 scientists in 153 countries from a broad range of disciplines warns that the planet “clearly and unequivocally faces a climate emergency,” and provides six broad policy goals that must be met to address it.

The study, called the “World scientists’ warning of a climate emergency,” marks the first time a large group of scientists has formally come out in favor of labeling climate change an “emergency,” which the study notes is caused by many human trends that are together increasing greenhouse gas emissions.

The report, published 5th Nov., 2019 in the journal Bioscience, was spearheaded by the ecologists Bill Ripple and Christopher Wolf of Oregon State University, along with William Moomaw, a Tufts University climate scientist, and researchers in Australia and South Africa.

The study clearly lays out the huge challenge of reducing emissions of greenhouse gases. The paper bases its conclusions on a set of easy-to-understand indicators that show the human influence on climate, such as 40 years of greenhouse gas emissions, economic trends, population growth rates, per capita meat production, and global tree cover loss, as well as consequences, such as global temperature trends and ocean heat content.

Comment by Dr. Krishna Kumari Challa on October 29, 2019 at 6:05am

New light on how bacteria evolves resistance to drugs

Bacterial Evolution: The road to resistance

The way that bacteria grow – either floating in liquid or attached to a surface – affects their ability to evolve antimicrobial resistance and our ability to treat infections.

https://elifesciences.org/articles/52092?utm_source=content_alert&a...

Comment by Dr. Krishna Kumari Challa on October 25, 2019 at 8:43am

Algae inside blood vessels could act as oxygen factories

An unconventional way to get O₂ to nerve cells might one day aid stroke patients

Using algae as local oxygen factories in the brain might one day lead to therapies for strokes or other damage from too little oxygen, researchers from Ludwig-Maximilians University Munich said October 21 at the annual meeting of the Society for Neuroscience.

The researchers injected either green algae (Chlamydomonas reinhardtii) or cyanobacteria (Synechocystis) into tadpoles’ blood vessels, creating an eerie greenish animal. Both algae species make oxygen in response to light shining through the tadpoles’ translucent bodies.

When the researchers depleted the oxygen in the liquid surrounding a disembodied tadpole head, eye nerves fell silent and stopped firing signals. But a few minutes after a flash of algae-activating light, the nerves started firing signals again, the researchers found.

This work does “motivate further exploration of unconventional approaches to advance the treatments for brain hypoxia, including stroke.”

https://www.abstractsonline.com/pp8/index.html#!/7883/presentation/...

Comment by Dr. Krishna Kumari Challa on September 23, 2019 at 8:39am

Comment by Dr. Krishna Kumari Challa on September 20, 2019 at 7:02am

Sticky mucus may thwart alcohol-based hand sanitizers’ ability to fight the flu.

Flu viruses encased in mucus drops from infected people’s spit can withstand the alcohol in hand sanitizers for more than two minutes, researchers report September 18 in mSphere. Researchers dotted volunteers’ fingers with either mucus or saline solution containing the flu virus, then measured how long it took to inactivate the virus in both wet and dry samples.

A five-microliter drop — about the size of a pinhead — of mucus-coated flu virus took more than half an hour to dry, almost twice as long as saline. Drying time was important because previous studies tested sanitizers’ killing ability on dry viruses, and didn’t account for mucus’s moistening power.

A hand sanitizer containing 31 percent alcohol inactivated flu viruses in saline solution within 20 seconds. And in already dried mucus, that process took just under eight seconds. But moist mucus shielded flu viruses from alcohol, keeping the viruses viable for up to 2 minutes and 39 seconds, Ryohei Hirose, an infectious disease researcher at the Kyoto Prefectural University of Medicine in Japan, and his colleagues found. That may be long enough for health care workers to unwittingly transfer virus-infected mucus from one person to another.

The team didn’t test whether rubbing the sanitizer over the skin causes the alcohol to penetrate the mucus and kill viruses faster, Hirose says. Rubbing might help, he acknowledged. But there’s already an easy way to kill flu viruses: Washing hands with plain water or with soap killed viruses within 30 seconds, even when the mucus was still wet.

R. Hirose et al. Situations leading to reduced effectiveness of current hand hygiene.... mSphere. Published online September 18, 2019. doi: 10.1128/mSphere.00474-19

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