Comment

Comment by Dr. Krishna Kumari Challa on January 31, 2021 at 12:15pm

Major discovery helps explain coral bleaching

Corals, like all animals, must eat to live. The problem is that most corals grow in tropical waters that are poor in nutrients, sort of like ocean deserts; it’s this lack of nutrients that makes the water around coral reefs so crystal clear. Because food is not readily available, corals have developed a remarkable feeding mechanism that involves a symbiotic relationship with single-celled algae. These algae grow inside the corals, using the coral tissue as shelter and absorbing the CO2 that the corals produce. In exchange, the algae provide corals with nutrients they produce through photosynthesis. These algae contain a variety of pigments, which give the coral reefs the colors they’re known for.

Over the past 35 years, tropical oceans have experienced multiple major heat waves. Scientists have observed that during these episodes, the algae – stressed by the warmer temperatures – release compounds that are toxic to the coral, prompting the coral to expel the algae from their tissue. That means the corals lose their color and their primary food source, and then begin to starve. This is the process of coral bleaching. And it has been occurring more and more frequently, threatening the survival of many reefs, including Australia’s Great Barrier Reef. Bleached corals do not necessarily die; their symbiotic algae population can be reestablished if the conditions around a reef return to normal. But if the heat persists, or is aggravated by other factors like pollution, the coral becomes too weak to survive.

In a paper published in the prestigious PNAS on 26 January, an international team of scientists  reveals a major discovery related to how the symbiotic relationship ends between the coral and algae.  Theyshowed for the first time that the coral starts to suffer from hunger long before the algae are expelled. The algae apparently stop providing sufficient nutrients while they are still inside the coral tissue.

Scientists already knew that ocean warming is the main factor causing the symbiotic relationship to break down. But what the team now discovered was that the coral is already in a stressed state and lacking nutrients even before the algae begin releasing toxic compounds. The roots of the problem are much deeper than the scientists thought, and they involve an early breakdown of the metabolic exchanges in these fascinating organisms.

Based on these findings, researchers can determine which environmental conditions other than temperature (such as water quality) stress the corals in a reef, and use this information to predict whether the reef will bleach.

"Heat stress destabilizes symbiotic nutrient cycling in corals". Nils Rädecker, Claudia Pogoreutz, Hagen M. Gegner, Anny Cardenas, Florian Roth, Jeremy Bougoure, Paul Guagliardo, Christian Wild, Mathieu Pernice, Jean-Baptiste Raina, Anders Meibom, Christian R. Voolstra. PNAS, 26 January 2021.

https://actu.epfl.ch/news/major-discovery-helps-explain-coral-bleac...

Comment by Dr. Krishna Kumari Challa on January 31, 2021 at 12:06pm

Scientists jump-start two people's brains after coma

In 2016, a team of researchers reported that a 25-year-old man recovering from a coma had made remarkable progress following a treatment to jump-start his brain using ultrasound.

Now they report that two more patients with severe brain injuries — both had been in what scientists call a long-term “minimally conscious state” — have made impressive progress thanks to the same technique. The results are published online in the journal Brain Stimulation.

The paper notes that, of three people who received the treatment, one — a 58-year-old man who had been in a car accident five-and-a-half years prior to treatment and was minimally conscious — did not benefit. However, the other two did.

One is a 56-year-old man who had suffered a stroke and had been in a minimally conscious state, unable to communicate, for more than 14 months. After the first of two treatments, he demonstrated, for the first time, the ability to consistently respond to two distinct commands — the ability to drop or grasp a ball, and the ability to look toward separate photographs of two of his relatives when their names were mentioned.

He also could nod or shake his head to indicate “yes” or “no” when asked questions such as “Is X your name?” and “Is Y your wife’s name?” In the days following the second treatment, he also demonstrated, for the first time since the stroke, the ability to use a pen on paper and to raise a bottle to his mouth, as well as to communicate and answer questions.

These behaviors are diagnostic markers of emergence from a disorder of consciousness.

The other patient who improved is a 50-year-old woman who had been in even less of a conscious state for more than two-and-a-half years following cardiac arrest. In the days after the first treatment, she was able, for the first time in years, according to her family, to recognize a pencil, a comb and other objects.

Both patients showed the ability to understand speech. What is remarkable is that both exhibited meaningful responses within just a few days of the intervention.

The scientists used a technique called low-intensity focused ultrasound, which uses sonic stimulation to excite the neurons in the thalamus, an egg-shaped structure that serves as the brain’s central hub for processing. After a coma, thalamus function is typically weakened. Doctors use a device about the size of a saucer creates a small sphere of acoustic energy they can aim at different brain regions to excite brain tissue. The researchers placed the device by the side of each patient’s head and activated it 10 times for 30 seconds each in a 10-minute period. Each patient underwent two sessions, one week apart.

The treatment appears to be well tolerated; the researchers saw no changes to the patients’ blood pressure, heart rate or blood oxygen levels, and no other adverse events.

While the scientists are excited by the results, they emphasize that the technique is still experimental and likely will not be available to the public for at least a few years. 

https://www.brainstimjrnl.com/article/S1935-861X(21)00009-7/fulltext

https://newsroom.ucla.edu/releases/ucla-scientists-jump-start-brain...

https://researchnews.cc/news/4841/Scientists-jump-start-two-people-...

Comment by Dr. Krishna Kumari Challa on January 30, 2021 at 9:26am

India's vaccine production capacity is best asset world has today, says UN chief

Calling for India to play a major role in global vaccination campaign, United Nations Secretary-General Antonio Guterres recently termed the vaccine production capacity of India as the "best asset" that the world has today.

India has gifted over 55 lakh doses of coronavirus vaccine to neighbouring countries. India plans to gift vaccines doses to Oman, CARICOM countries, Nicaragua, Pacific Island states.

New Delhi plans to supply 1 crore or 10 million vaccine doses to Africa and 10 lakh to United Nations health workers under GAVI's (Global Alliance for Vaccines and Immunisation) COVAX facility.

There is interest in many countries to access vaccine from India. India leads in democratisation of vaccines supplying to poor and developing countries unlike developed  countries.

From 20th January 2021 onward, India has gifted over 55 lakh doses of coronavirus vaccines to our neighbouring countries and in the extended neighbourhood--1.5 lakh to Bhutan, 1 lakh to Maldives, Mauritius and Bahrain, 10 lakhs to Nepal, 20 lakhs to Bangladesh, 15 lakhs to Myanmar, 50,000 to Seychelles, 5 lakh to Sri Lanka. In the coming days, it plans to gift further quantity to Oman that is of 1 lakh doses, 5 lakh doses to CARICOM countries. 2 lakh to Nicaragua, 2 lakh doses to the Pacific island state.

It also plans to commercially export coronavirus vaccine to Saudi Arabia, South Africa, Canada, Mongolia and other countries.

https://health.economictimes.indiatimes.com/news/industry/indias-va...

Comment by Dr. Krishna Kumari Challa on January 30, 2021 at 9:15am

Genes that dance to the circadian rhythm

Scientists  have made breakthrough discoveries on the circadian clock and how it affects gene expression. Some of the findings suggest a biological underpinning for different behaviors in people, such as morning people, nappers, evening people, night owls etc.

The study of circadian rhythms has grown into its own field: chronobiology. And given that a person's circadian rhythm seems to dictate when certain drugs must be taken in order to maximize their effects, a new branch of medicine has also emerged recently: chronopharmacology.

 Now scientists have carried out an extensive study using Drosophila to study how different genes in various tissues of the animal are regulated so that they "know" when to turn on and off during the course of a day, i.e. in function of the circadian clock.

The study revealed three major points about the circadian rhythm.

First, the scientists detected more than 1700 genes whose expression cycles under the control of the circadian clock, with only fourteen of those genes being the same across all tissues in the fruit fly.

"At least two of these fourteen were so far uncharacterized and significantly impact several locomotor activity rhythms parameters.

Second, that each individual may have its own circadian rhythm, which may explain the large range of human behaviors, such as morning people, nappers, evening people, night owls etc.

The physiological clock in about a third of Drosophila lines significantly deviates from the "natural" time by more than three hours. And most of the lines showed a circadian expression variation only in one or two tissues.

There seems to be an abundant, natural circadian asynchrony in molecular circadian rhythms between various tissues, which has to our knowledge not been observed before and which may have all kinds of physiological consequences in metabolic patterns, digestive fluctuations etc.

Finally, that a small genetic mutation can disrupt an individual's "photoentrainment," which refers to the aligning of the circadian rhythm to the pattern of light and dark in its environment.

"Extensive tissue-specific expression variation and novel regulators underlying circadian behavior" Science Advances, advances.sciencemag.org/lookup … .1126/sciadv.abc3781

https://phys.org/news/2021-01-genes-circadian-rhythm.html?utm_sourc...

Comment by Dr. Krishna Kumari Challa on January 30, 2021 at 9:07am

New technology to detect bitter almonds in real time

Who hasn't at some point been chewing on an almond and tasted an unpleasant and unexpected aftertaste that has nothing to do with the taste we are used to from one of the most consumed nuts in the world? The culprit has a name: amygdalin, a diglucoside that, when in contact with enzymes present in saliva, breaks down into glucose, benzaldehyde (the cause of the bitter taste) and hydrogen cyanide.

To reduce this unpleasant ''surprise," researchers have developed a method that can predict levels of the abovementioned amygdalin present in the nuts analyzed both with and without shells, as well as correctly classify sweet almonds and bitter ones on an industrial scale, something that has only been done with shelled nuts, individual kernels or ground nuts to date.

The new system uses portable equipment based on near infrared spectroscopy (NIRS) technology, which can analyze large amounts of a product in situ in real time, without having to go into a lab. This technological application is "of great interest to the farming sector.

This technology is especially useful in the early detection of possible fraud and in food authentication.

Miguel Vega-Castellote et al, Exploring the potential of NIRS technology for the in situ prediction of amygdalin content and classification by bitterness of in-shell and shelled intact almonds, Journal of Food Engineering (2020). DOI: 10.1016/j.jfoodeng.2020.110406

https://phys.org/news/2021-01-technology-bitter-almonds-real.html?u...

Comment by Dr. Krishna Kumari Challa on January 30, 2021 at 9:02am

Accurate drug dosages with proton traps

Researchers have developed a proton trap that makes organic electronic ion pumps more precise when delivering drugs. The new technique may reduce drug side effects, and in the long term, ion pumps may help patients with symptoms of neurological diseases for which effective treatments are not available. The results have been published in Science Advances.

Currently available drug delivery methods—mainly tablets and injections—place the drug in locations where it is not required. This can lead to side effects that harm the patient.

Researchers are trying to control this. Recent discovery in this regard is a proton trap that makes the amount delivered even more precise.

"An electronic proton-trapping ion pump for selective drug delivery" Science Advances, advances.sciencemag.org/lookup … .1126/sciadv.abd8738

https://phys.org/news/2021-01-accurate-drug-dosages-proton.html?utm...

Comment by Dr. Krishna Kumari Challa on January 30, 2021 at 8:51am

Dewdrops on a spiderweb reveal the physics behind cell structures

As any cook knows, some liquids mix well with each other, but others do not. For example, when a tablespoon of vinegar is poured into water, a brief stir suffices to thoroughly combine the two liquids. However, a tablespoon of oil poured into water will coalesce into droplets that no amount of stirring can dissolve. The physics that governs the mixing of liquids is not limited to mixing bowls; it also affects the behavior of things inside cells. It's been known for several years that some proteins behave like liquids, and that some liquid-like proteins don't mix together. However, very little is known about how these liquid-like proteins behave on cellular surfaces.

--

How vitamins, steroids and potential antivirals might affect SARS-C...

Evidence is emerging that vitamin D—and possibly vitamins K and A—might help combat COVID-19. A new study from the University of Bristol published in the journal of the German Chemical Society Angewandte Chemie has shown how they—and other antiviral drugs—might work. The research indicates that these dietary supplements and compounds could bind to the viral spike protein and so might reduce SARS-CoV-2 infectivity. In contrast, cholesterol may increase infectivity, which could explain why having high cholesterol is considered a risk factor for serious disease.

--

It's elemental: Ultra-trace detector tests gold purity

Unless radon gas is discovered in a home inspection, most people remain blissfully unaware that rocks like granite, metal ores, and some soils contain naturally occurring sources of radiation. In most cases, low levels of radiation are not a health concern. But some scientists and engineers are concerned about even trace levels of radiation, which can wreak havoc on sensitive equipment. The semiconductor industry, for instance, spends billions each year to source and "scrub" ultra-trace levels of radioactive materials from microchips, transistors and sensitive sensors.

--

How lipids distribute proteins within cells

Researchers have observed how lipids distribute proteins within cells, a discovery that could open the door to understanding the causes of protein transport related diseases, such as cancer or neurodegenerative diseases.

Comment by Dr. Krishna Kumari Challa on January 30, 2021 at 8:50am

By changing their shape, some bacteria can grow more resilient to antibiotics

New research demonstrates how certain types of bacteria can adapt to long-term exposure to antibiotics by changing their shape. The work was published in the journal Nature Physics.

Adaptation is a fundamental biological process driving organisms to change their traits and behaviour to better fit their environment. While antibiotics have long helped people prevent and cure bacterial infections, many species of bacteria have increasingly been able to adapt to resist antibiotic treatments.

When exposed to less than lethal doses of the antibiotic chloramphenicol over multiple generations, the researchers found that the bacteria dramatically changed their shape by becoming wider and more curved.

These shape changes enable bacteria to overcome the stress of antibiotics and resume fast growth. 

The researchers came to this conclusion by developing a theoretical model to show how these physical changes allow the bacteria to attain a higher curvature and lower surface-to-volume ratio, which would allow fewer antibiotic particles to pass through their cellular surfaces as they grow.

This insight is of great consequence to human health and will likely stimulate numerous further molecular studies into the role of cell shape on bacterial growth and antibiotic resistance.

Shiladitya Banerjee et al. Mechanical feedback promotes bacterial adaptation to antibiotics, Nature Physics (2021). DOI: 10.1038/s41567-020-01079-x

https://phys.org/news/2021-01-bacteria-resilient-antibiotics.html?u...

Comment by Dr. Krishna Kumari Challa on January 30, 2021 at 8:42am

'Organs-on-a-chip' system sheds light on how bacteria in the human digestive tract may influence neurological diseases

In many ways, our brain and our digestive tract are deeply connected. Feeling nervous may lead to physical pain in the stomach, while hunger signals from the gut make us feel irritable. Recent studies have even suggested that the bacteria living in our gut can influence some neurological diseases.

Modeling these complex interactions in animals such as mice is difficult to do, because their physiology is very different from humans'. To help researchers better understand the gut-brain axis, MIT researchers have developed an "organs-on-a-chip" system that replicates interactions between the brain, liver, and colon.

Using that system, the researchers were able to model the influence that microbes living in the gut have on both healthy brain tissue and tissue samples derived from patients with Parkinson's disease. They found that short-chain fatty acids, which are produced by microbes in the gut and are transported to the brain, can have very different effects on healthy and diseased brain cells.

"While short-chain fatty acids are largely beneficial to human health, it 's observed that under certain conditions they can further exacerbate certain brain pathologies, such as protein misfolding and neuronal death, related to Parkinson's disease.

The brain has many interactions with the digestive tract, which can occur via the enteric nervous system or through the circulation of immune cells, nutrients, and hormones between organs.

"Human hysiomimetic model integrating microphysiological systems of the gut, liver and brain for studies of neurodegenerative diseases" Science Advances (2021). advances.sciencemag.org/lookup … .1126/sciadv.abd1707

https://medicalxpress.com/news/2021-01-organs-on-a-chip-bacteria-hu...

Comment by Dr. Krishna Kumari Challa on January 30, 2021 at 8:37am

A potentially safer, more effective gene therapy vector for blood disorders

Researchers at Children's Hospital of Philadelphia (CHOP) have developed a gene therapy vector for blood disorders like sickle cell disease and beta-thalassemia that is potentially safer and more effective than those currently used in gene therapy trials for those conditions. The vector, an engineered vehicle for delivering functional copies of the hemoglobin gene to correct a genetic abnormality, leads to the production of more hemoglobin with a lower dose, minimizing the risk of toxic side effects.

Breda L, Ghiaccio V, Tanaka N, Jarocha D, Ikawa Y, Abdulmalik O, Dong A, Casu C, Raabe TD, Shan X, Danet-Desnoyers GA, Doto AM, Everett J, Bushman FD, Radaelli E, Assenmacher CA, Tarrant JC, Hoepp N, Guzikowski V, Smith-Whitley K, Kwiatkowski JL, and Rivella S. "Lentiviral vector ALS20 yields high hemoglobin levels with low genomic integrations for treatment of beta-globinopathies," Molecular Therapy, online January 29, 2021. DOI: 10.1016/j.ymthe.2020.12.036

https://medicalxpress.com/news/2021-01-potentially-safer-effective-...

• ‹ Previous
• 1
• …
• 710
• 711
• 712
• 713
• 714
• …
• 1110
• Next ›
• Page