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Comment by Dr. Krishna Kumari Challa on July 14, 2022 at 9:27am

Sun Exposure Triggers Hunger in Men but Not Women, Study Suggests

Ultraviolet radiation leads to secretion of an appetite-boosting hormone in male mice, but experts say it’s not yet clear whether the mechanism applies to humans.

it turns out the sun perhaps influences how much some of us eat. A team of researchers at Tel Aviv University describe a new mechanism in a paper published recently (July 11) in Nature Metabolism in which sun exposure appears to stimulate hunger—though only in males.  

The researchers analyzed data from Israel’s three-year National Health and Nutritional Survey (MABAT), which included 3,000 participants between the ages of 25 to 65. By looking at season, food intake, and self-reported sex, they found that men increased their consumption by 17 percent during the warmer months of March through September relative to the rest of the year, while women’s caloric consumption remained the same.  

One possible explanation for that finding is that there are sex-based differences in how sun exposure affects appetite. To confirm this, the scientists asked a group of 13 men and 14 women between the ages of 18 to 55 to spend 25 minutes in the sun. Participants were then asked questions about their appetites; men reported feeling hungrier, while women experienced no significant differences in their hunger levels before and after sun exposure.  

The researchers collected participants’ blood samples before and after the exposure and found that circulating levels of ghrelin, a hormone that stimulates appetite, were elevated in men after they spent time in the sun.  

Previous research has shown that elevation in ghrelin levels of male mice is driven by a gene called p53, which is responsible for DNA repair. According to Levy, other research groups have found that when male mice are exposed to UVB radiation, changes in the expression of p53 trigger the release of ghrelin from fat tissue in the skin. This hormone circulates in the bloodstream and signals hunger to the hypothalamus, a region of the brain that controls feeding.  

So the question is, why not in females then? Because women have estrogen. And Estrogen inhibits p53 activity and prevents the gene from activating.  

From an evolutionary perspective, researchers speculate that there may be evolutionary benefits to increasing food intake in sun-kissed males, such as potentially increasing sperm production.  

However,  the study does not show convincingly that prolonged sun exposure increases circulating ghrelin levels in humans through the same mechanism as it does in mice. Moreover, Prior studies have shown that women are also more sensitive to environmental cues for food consumption than men.

https://www.the-scientist.com/news-opinion/sun-exposure-triggers-hu...

Comment by Dr. Krishna Kumari Challa on July 14, 2022 at 7:54am

Turning white blood cells into medicinal microrobots with light

Medicinal microrobots could help physicians better treat and prevent diseases. But most of these devices are made with synthetic materials that trigger immune responses in vivo. Now, for the first time, researchers reporting in ACS Central Science have used lasers to precisely control neutrophils—a type of white blood cell—as a natural, biocompatible microrobot in living fish. The "neutrobots" performed multiple tasks, showing they could someday deliver drugs to precise locations in the body.

Microrobots currently in development for medical applications would require injections or the consumption of capsules to get them inside an animal or person. But researchers have found that these microscopic objects often trigger immune reactions in small animals, resulting in the removal of microrobots from the body before they can perform their jobs. Using cells already present in the body, such as neutrophils, could be a less invasive alternative for drug delivery that wouldn't set off the immune system. These white blood cells already naturally pick up nanoparticles and dead red blood cells and can migrate through blood vessels into adjacent tissues, so they are good candidates for becoming microrobots.

Previously, researchers have guided neutrophils with lasers in lab dishes, moving them around as "neutrobots." However, information on whether this approach will work in living animals was lacking. So the

researchers manipulated and maneuvered neutrophils in zebrafish tails, using focused laser beams as remote optical tweezers. The light-driven microrobot could be moved up to a velocity of 1.3 µm/s, which is three times faster than a neutrophil naturally moves. In their experiments, the researchers used the optical tweezers to precisely and actively control the functions that neutrophils conduct as part of the immune system. For instance, a neutrobot was moved through a blood vessel wall into the surrounding tissue. Another one picked up and transported a plastic nanoparticle, showing its potential for carrying medicine. And when a neutrobot was pushed toward red blood cell debris, it engulfed the pieces. Surprisingly, at the same time, a different neutrophil, which wasn't controlled by a laser, tried to naturally remove the cellular debris.

Because they successfully controlled neutrobots in vivo, the researchers say this study advances the possibilities for targeted drug delivery and precise treatment of diseases.

Optically Manipulated Neutrophils as Native Microcrafts In Vivo, ACS Central Science (2022). DOI: 10.1021/acscentsci.2c00468

Comment by Dr. Krishna Kumari Challa on July 14, 2022 at 7:33am

Researchers find the missing photonic link to enable an all-silicon quantum internet

Researchers have made a crucial breakthrough in the development of quantum technology.

Their research, published in Nature today, describes their observations of more than 150,000 silicon "T center" photon-spin qubits, an important milestone that unlocks immediate opportunities to construct massively scalable quantum computers and the quantum internet that will connect them.

Quantum computing has enormous potential to provide computing power well beyond the capabilities of today's supercomputers, which could enable advances in many other fields, including chemistry, materials science, medicine and cybersecurity.

In order to make this a reality, it is necessary to produce both stable, long-lived qubits that provide processing power, as well as the communication technology that enables these qubits to link together at scale.

Past research has indicated that silicon can produce some of the most stable and long-lived qubits in the industry. Now this new research   provides proof of principle that T centers, a specific luminescent defect in silicon, can provide a "photonic link" between qubits. 

This work is the first measurement of single T centers in isolation, and actually, the first measurement of any single spin in silicon to be performed with only optical measurements.

Stephanie Simmons, Optical observation of single spins in silicon, Nature (2022). DOI: 10.1038/s41586-022-04821-y. www.nature.com/articles/s41586-022-04821-y

Comment by Dr. Krishna Kumari Challa on July 14, 2022 at 7:10am

A glove that mimics the arm of an octopus

Comment by Dr. Krishna Kumari Challa on July 13, 2022 at 10:10am

Crew aboard private yacht confirm sighting of bioluminescent 'milky sea'

An atmospheric scientist has gained confirmation of his discovery of a bioluminescent "milky sea" event through testimony of a crew aboard a private yacht. In his paper published in Proceedings of the National Academy of Sciences, the scientist describes how he discovered the event while studying satellite images and then gained confirmation from a crew aboard a yacht that happened to be sailing through the area.

Prior incidents have suggested that large bioluminescent events sometimes occur in parts of the ocean, but such events are rare and there is little photographic evidence of them. One of the more notorious was Charles Darwin and crew sailing over such an event just below the tip of South America. Ocean scientists think they are created by millions of tiny bioluminescent creatures all glowing together. Only one test has been confirmed, a research vessel sailing through such an event collected water samples and found them filled with glowing bacteria.

Researchers now pored over old sailor logs looking for descriptions of bioluminescent events and found a lot of them, most describing them as traveling through a milky sea. They noted that the events were seen most commonly in the Indian Ocean and the waters around Java.

https://www.youtube.com/watch?v=sFkaGM8rDGw&t=9s

A  private yacht, had sailed in the area and had documented what they saw. They described the sea as glowing at night, from below the surface, with a description of it appearing as if sailing on snow. 

Steven D. Miller, Boat encounter with the 2019 Java bioluminescent milky sea: Views from on-deck confirm satellite detection, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2207612119

Comment by Dr. Krishna Kumari Challa on July 13, 2022 at 10:02am

How stressed-out plants produce their own aspirin

Plants protect themselves from environmental hazards like insects, drought and heat by producing salicylic acid, also known as aspirin. A new understanding of this process may help plants survive increasing stress caused by climate change.

Scientists recently published a seminal paper in the journal Science Advances reporting how plants regulate the production of salicylic acid.

The researchers studied a model plant called Arabidopsis, but they hope to apply their understanding of stress responses in the cells of this plant to many other kinds of plants, including those grown for food. They'd like to be able to use the gained knowledge to improve crop resistance. That will be crucial for the food supply in our increasingly hot, bright world.

Environmental stresses result in the formation of reactive oxygen species or ROS in all living organisms. High levels of ROS in plants are lethal. 

As with many substances, the poison is in the amount. At low levels, ROS have an important function in plant cells. At non-lethal levels, ROS are like an emergency call to action, enabling the production of protective hormones such as salicylic acid. 

The research team discovered that heat, unabated sunshine, or drought cause the sugar-making apparatus in plant cells to generate an initial alarm molecule known as MEcPP.

Going forward, the researchers want to learn more about MEcPP, which is also produced in organisms such as bacteria and malaria parasites. Accumulation of MEcPP in plants triggers the production of salicylic acid, which in turn begins a chain of protective actions in the cells.

It's like plants use a painkiller for aches and pains, just like we do. The acid protects plants' chloroplasts, which are the site of photosynthesis, a process of using light to convert water and carbon dioxide into sugars for energy.

Because salicylic acid helps plants withstand stresses becoming more prevalent with climate change, being able to increase plants' ability to produce it represents a step forward in challenging the impacts of climate change on everyday life. 

 Jin-Zheng Wang et al, Reciprocity between a retrograde signal and a putative metalloprotease reconfigures plastidial metabolic and structural states, Science Advances (2022). DOI: 10.1126/sciadv.abo0724

Comment by Dr. Krishna Kumari Challa on July 12, 2022 at 1:25pm

Wearable Muscles

Comment by Dr. Krishna Kumari Challa on July 12, 2022 at 1:18pm

What happens to your brain during a migraine 

Comment by Dr. Krishna Kumari Challa on July 11, 2022 at 8:21am

Mathematical calculations show that quantum communication across interstellar space should be possible

A team of physicists  has used mathematical calculations to show that quantum communications across interstellar space should be possible. In their paper published in the journal Physical Review D, the group describes their calculations and also the possibility of extraterrestrial beings attempting to communicate with us using such signaling.

Over the past several years, scientists have been investigating the possibility of using quantum communications as a highly secure form of message transmission. Prior research has shown that it would be nearly impossible to intercept such messages without detection. In this new effort, the researchers wondered if similar types of communications might be possible across interstellar space. To find out, they used math that describes that movement of X-rays across a medium, such as those that travel between the stars. More specifically, they looked to see if their calculations could show the degree of decoherence that might occur during such a journey.

With quantum communications, engineers are faced with quantum particles that lose some or all of their unique characteristics as they interact with obstructions in their path—they have been found to be quite delicate, in fact. Such events are known as decoherence, and engineers working to build quantum networks have been devising ways to overcome the problem. Prior research has shown that the space between the stars is pretty clean. But is it clean enough for quantum communications? The math shows that it is. Space is so clean, in fact, that X-ray photons could travel hundreds of thousands of light years without becoming subject to decoherence—and that includes gravitational interference from astrophysical bodies. They noted in their work that optical and microwave bands would work equally well.

The researchers noted that because quantum communication is possible across the galaxy, if other intelligent beings exist in the Milky Way, they could already be trying to communicate with us using such technology and we could begin looking for them. They also suggest that quantum teleportation across interstellar space should be possible.

Arjun Berera et al, Viability of quantum communication across interstellar distances, Physical Review D (2022). DOI: 10.1103/PhysRevD.105.123033

Comment by Dr. Krishna Kumari Challa on July 10, 2022 at 10:44am

Scientists hijack bacteria to ease drug manufacturing

Many of the medicines we take are made with ingredients extracted from plants (think, for example, morphine, the narcotic painkiller that comes from poppies, or galantamine, a drug treatment for dementia that comes from daffodils). Extracting drugs from these plants is complicated and resource-intensive, requiring water and acreage to grow the crops. Supply chains are easily disrupted. And crops can be damaged by floods, fires and drought. Deriving similar therapeutic components using synthetic chemistry brings problems, too, since the process depends on petroleum and petroleum-based products linked to waste and expense.

Enter the humble bacteria, a cheap, efficient and sustainable alternative. The genetic code of bacteria can be easily manipulated to become factories for drug production. In a process called biosynthesis, the bacteria’s biological systems are harnessed to produce specific molecules as part of the natural cellular process. And bacteria can replicate at high speed. All they need to do the job is sugar.

For more affordable, sustainable drug options than we have today, the medication we take to treat high blood pressure, pain or memory loss may one day come from engineered bacteria, cultured in a vat like yogurt. And thanks to a new bacterial tool developed by scientists , the process of improving drug manufacturing in bacterial cells may be coming sooner than we thought.

For decades, researchers have been eyeing ways to make drug manufacturing more affordable and sustainable than pharmaceutical makers’ current processes, many of which depend on either plant crops or petroleum. Using bacteria has been suggested as a good organic alternative, but detecting and optimizing the production of therapeutic molecules is difficult and time-consuming, requiring months at a stretch. In a new paper out this week in Nature Chemical Biology, researchers introduce a biosensor system, derived from E. coli bacteria, that can be adapted to detect all kinds of therapeutic compounds accurately and in mere hours.

Unfortunately, manufacturers have not had a way to quickly analyze different strains of engineered bacteria to identify the ones capable of producing quantities of a desired drug at commercial volumes — until now. Accurately analyzing the thousands of engineered strains on the way to a good producer can take weeks or months with current technology, but only a day with the new biosensors.

The biosensors developed now quickly and accurately determine the amount of a given molecule that a strain of bacteria is producing. The researchers developed the biosensors for several types of common drugs, such as cough suppressants and vasodilators, which are used to treat muscle spasms. Molecular images of the biosensors taken by X-ray crystallographers now show exactly how they tightly grab onto their partner drug. When the drug is detected by the biosensor, it glows. Additionally, the team engineered their own bacteria to produce a compound found in several FDA-approved drugs and used the biosensors to analyze product output, in essence showing how industry might adopt biosensors to quickly optimize chemical manufacturing.

This technique allows them to be developed faster and more efficiently. In turn, that opens the door to more medicines being produced using biosynthesis.

Simon d’Oelsnitz, Wantae Kim, Nathaniel T. Burkholder, Kamyab Javanmardi, Ross Thyer, Yan Zhang, Hal S. Alper, Andrew D. Ellington. Using fungible biosensors to evolve improved alkaloid biosyntheses. Nature Chemical Biology, 2022; DOI: 10.1038/s41589-022-01072-w

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