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Comment by Dr. Krishna Kumari Challa on September 8, 2021 at 12:07pm

 Fridge-free COVID-19 vaccines  grown in plants and bacteria

Nanoengineers have developed COVID-19 vaccine candidates that can take the heat. Their key ingredients? Viruses from plants or bacteria.

The new fridge-free COVID-19 vaccines are still in the early stage of development. In mice, the vaccine candidates triggered high production of neutralizing antibodies against SARS-CoV-2, the virus that causes COVID-19. If they prove to be safe and effective in people, the vaccines could be a big game changer for global distribution efforts, including those in rural areas or resource-poor communities.

What's exciting about this vaccine technology is that is thermally stable, so it could easily reach places where setting up ultra-low temperature freezers, or having trucks drive around with these freezers, is not going to be possible.

The researchers created two COVID-19 vaccine candidates. One is made from a plant virus, called cowpea mosaic virus. The other is made from a bacterial virus, or bacteriophage, called Q beta.

Both vaccines were made using similar recipes. The researchers used cowpea plants and E. coli bacteria to grow millions of copies of the plant virus and bacteriophage, respectively, in the form of ball-shaped nanoparticles. The researchers harvested these nanoparticles and then attached a small piece of the SARS-CoV-2 spike protein to the surface. The finished products look like an infectious virus so the immune system can recognize them, but they are not infectious in animals and humans. The small piece of the spike protein attached to the surface is what stimulates the body to generate an immune response against the coronavirus.

The researchers note several advantages of using plant viruses and bacteriophages to make their vaccines. For one, they can be easy and inexpensive to produce at large scales.

Another big advantage is that the plant virus and bacteriophage nanoparticles are extremely stable at high temperatures. As a result, the vaccines can be stored and shipped without needing to be kept cold. 

Trivalent subunit vaccine candidates for COVID-19 and their delivery devices, Journal of the American Chemical Society (2021). DOI: 10.1021/jacs.1c06600

https://phys.org/news/2021-09-fridge-free-covid-vaccines-grown-bact...

Comment by Dr. Krishna Kumari Challa on September 8, 2021 at 11:30am

Cavendish Gravity Experiment

A qualitative demonstration of universal gravitation using a torsion balance.

The Cavendish Experiment Explained

Comment by Dr. Krishna Kumari Challa on September 7, 2021 at 8:52am

Sport science: How do swimmers control their front crawl swimming velocity?

A research team  has reviewed the hydrodynamics literature related to swimming. They identified certain biomechanical aspects, including the relationship between velocity and drag forces, that are not completely understood. This work may help direct future research that could improve the performance of competitive swimmers.

The recent Tokyo Olympics provided impressive feats of speed in the pool, with elite athletes setting many new Olympic and World records. What viewers might not realize, however, is the complexity of the science underlying the sometimes split-second difference between winning a gold medal and going home empty-handed. Biomechanics, the study of motion of the body, and hydrodynamics, the area of physics dealing with fluid flows, contain many questions that remain poorly understood—and swimming fits right at the intersection of these topics. For swimmers who participate in races, even a tiny advance in knowledge can led to a competitive edge.

Now, a team of researchers  has drawn together research on front crawl swimming biomechanics, focusing on propulsive and resistive forces at different swimming velocities, to form a more complete picture of the relationships between the critical variables. New knowledge of swimming energetics and fluid mechanics has improved our understanding of factors that determine swimming performance.

One of the most important relationships to understand is how resistive forces, like drag when moving through the water, depend on the speed of the swimmer. The researchers looked at recent studies that indicated the resistive force increases in proportion to the cube of the velocity. To compensate, swimmers may try to increase their stroke frequency. However, this has limitations. Researchers inferred from experimental and simulation studies that there is a maximum frequency beyond which swimmers cannot further increase swimming velocity due to a change in the angle of attack of the hand that reduces its propulsive force. The different balance of forces at different swimming speeds also means that optimal technique may differ between long-distance and short-distance swimming.

The team also identified conflicting evidence over the effectiveness of kicking for increasing the speed of high-velocity front crawl. This indicates an opportunity to further optimize competitive swimming technique if future research can further unpack the relevant hydrodynamic factors.

The researchers found that certain simplified models of swimming often break down when trying to model more realistic conditions. For example, swimmers are not simply 'pushing' or 'pulling' the water to increase their velocity, as some textbooks frame it. This is because the increase in the negative pressure acting on the dorsal side of the hand is crucial for increasing propulsion. Therefore, teaching the proper technique is important, even for phases considered to be non-propulsive.

Hideki Takagi et al, How do swimmers control their front crawl swimming velocity? Current knowledge and gaps from hydrodynamic perspectives, Sports Biomechanics (2021). DOI: 10.1080/14763141.2021.1959946

https://phys.org/news/2021-09-swimmers-front-velocity.html?utm_sour...

Comment by Dr. Krishna Kumari Challa on September 6, 2021 at 9:21am

Robo Pill

Comment by Dr. Krishna Kumari Challa on September 5, 2021 at 11:44am

Why words become harder to remember as we get older

As we get older, we find it increasingly difficult to have the right words ready at the right moment, even though our vocabulary actually grows continuously over the course of our lives. Until now, it was unclear why this is. Researchers  have now found out: It is the networks in the brain that change their communication over time. This makes them more inefficient.

The researchers investigated these connections with the help of two groups - younger study participants between the ages of 20 and 35 and older ones between the ages of 60 and 70. Both groups were asked to name words in the MRI scanner that belong to certain categories, including animals, metals or vehicles.

It became clear that both age groups were good at finding words. However, the younger ones were somewhat faster. The reason for this could be the different brain activities. For one thing, not only were the language areas themselves more active in the younger ones. They also showed a more intensive exchange within two decisive networks: the network for semantic memory, in which factual knowledge is stored, and the executive network, which is responsible for general functions such as attention and memory.

The reverse was true for older people. Here, executive areas showed stronger activity, indicating that the task was more difficult for these individuals overall. In addition, the exchange within the crucial networks was less effective than in the younger people. The older group was most likely to benefit from inter-network exchange, but this is associated with losses. Communication within neuronal networks is more efficient and thus faster than between them.

 Why these activity patterns shift with age has not yet been fully explained. One theory, says Martin, is that as people age, they rely more on the linguistic knowledge they have, so exchanges between networks come into focus, while younger people rely more on their fast working memory and cognitive control processes. On the structural level, the loss of grey matter in the brain could also play a role, which is compensated for by the exchange between networks.

“Age-Dependent Contribution of Domain-General Networks to Semantic C...” by Sandra Martin et al. Cerebral Cortex

https://researchnews.cc/news/8725/Why-words-become-harder-to-rememb...

Comment by Dr. Krishna Kumari Challa on September 4, 2021 at 2:05pm

Biomedical Innovations from Women Less Likely to be Adopted: Study

An analysis of scientists’ networks finds discrepancies in the diffusion of novel ideas through communities.

A study published Monday (August 30) by the National Bureau of Economic Research finds that new ideas in biomedical research are less likely to spread when they are generated by women and minorities than when generated by men.

The authors of the study, which was not peer-reviewed, used a computational technique called natural language processing to scan titles and abstracts in MEDLINE for novel one, two, or three-word phrases originating in biomedical research papers published between 1980 and 2008. The researchers ranked these phrases by the total number of mentions they received in the year when they first appeared and analyzed the top 0.1 percent of phrases for each year to assess whether each represented an actual new idea or scientific innovation.

Ideas generated by teams of mostly male innovators were mentioned just over one percent more frequently in subsequent titles and abstracts than ideas generated by mostly female teams over a period of five years after they were first published.

Biomedical Innovations from Women Less Likely to be Adopted: Study

An analysis of scientists' networks finds discrepancies in the diffusion of novel ideas through communities.

https://www.the-scientist.com/news-opinion/biomedical-innovations-f...

Comment by Dr. Krishna Kumari Challa on September 4, 2021 at 1:28pm

“Mystery Fever” Claims the Lives of Dozens of Indian Children

So far, more than 50 people have died of a febrile illness, though the cause isn’t clear.

In addition to the ongoing COVID-19 pandemic and an uptick of malaria cases across the country, an unknown disease has killed more than 50 people in the state of Uttar Pradesh, India in the last week; most were children. All of the patients tested negative for COVID-19, and India Today reports it is likely that scrub typhus is to blame, though other possibilities, such as dengue, have not been ruled out.

 The Hindustan Times reports, and monsoon season has brought a greater number of mosquito-borne illnesses. Now, many regions in the state are reporting illness and death due to a mystery fever.

Water-logging, and lack of sanitation and hygiene are the reasons behind the disease spread. The patients, especially children, in hospitals are dying very quickly.

According to multiple news outlets, the hundreds of people hospitalized by the illness have experienced fever, headaches, joint pain, nausea, rashes, and dehydration. A drop in platelet count has also been observed in many fatal cases. Though many of these symptoms can occur in severe dengue cases, The Hindustan Times and others report that the likely culprit is a bacterial disease called scrub typhus.

Scrub typhus can occur after a person is bitten by chiggers infected with Orientia tsutsugamushi bacteria. According to the BBC, these mites live on plants that flourish after the monsoon rains, and they can hitchhike into people’s homes on firewood. The symptoms of O. tsutsugamushi infection largely overlap with what has been seen in the patients.

According to the US Center for Disease Control and Prevention (CDC), there are no vaccinations for scrub typhus and it should be treated with the antibiotic doxycycline. The agency recommends covering exposed skin to prevent chigger bites.

https://www.the-scientist.com/news-opinion/mystery-fever-claims-the...

Comment by Dr. Krishna Kumari Challa on September 4, 2021 at 1:23pm

Hormones May Contribute to Asymmetrical Effects of Brain Injury

Researchers studying rats claim to have found a novel connection between damage on one side of the brain and problems with the posture or movement of limbs on the opposite side of the body.

Injury to one side of the brain can cause abnormalities in posture or movement on the opposite side of the body. These effects, which are sometimes seen in people who have suffered a stroke or head trauma, have typically been attributed to neural pathways that link the right side of the brain to spinal cord neurons controlling muscles on the left side of the body, and vice versa. 

But in a new study on rats that had their spinal cords severed, researchers claim to have discovered another, parallel pathway that triggers opposite-side effects following brain injury and might instead operate via hormones circulating in the blood.

If similar mechanisms operate in humans, it’s conceivable that drugs blocking receptors for particular hormones could help treat some of the physical effects of brain injury

https://elifesciences.org/articles/65247

https://www.the-scientist.com/news-opinion/hormones-may-contribute-...

Comment by Dr. Krishna Kumari Challa on September 4, 2021 at 12:57pm

Coronavirus epidemics first hit more than 21,000 years ago

Sarbecoviruses have crossed into humans twice in the last decade, leading to the deadly SARS-CoV-1 outbreak in 2002-04 and the current COVID-19 pandemic, caused by the SARS-CoV-2 virus. A new Oxford University study, published today, shows that the most recent common ancestor of these viruses existed more than 21,000 years ago, nearly 30 times older than previous estimates.

Despite having a very rapid rate of evolution over short timescales, to survive, viruses must remain highly adapted to their hosts—this imposes severe restrictions on their freedom to accumulate mutations without reducing their fitness. This causes the apparent rate of evolution of viruses to slow down over time. The new research, for the first time, successfully recreates the patterns of this observed rate decay in viruses.

The study also demonstrates that while existing evolutionary models have often failed to measure the divergence between virus species over periods—from a few hundred to a few thousands of years—the evolutionary framework developed in this study will enable the reliable estimation of virus divergence across vast timescales, potentially over the entire course of animal and plant evolution.

The new model enables us to not only reconstruct the evolutionary history of viruses related to SARS-CoV-2, but also a much wider range of RNA and DNA viruses during more remote periods in the past.

Mahan Ghafari et al, A mechanistic evolutionary model explains the time-dependent pattern of substitution rates in viruses, Current Biology (2021). DOI: 10.1016/j.cub.2021.08.020

https://phys.org/news/2021-09-coronavirus-epidemics-years.html?utm_...

Comment by Dr. Krishna Kumari Challa on September 4, 2021 at 12:52pm

Fish eyes grown in a petri dish from embryonic stem cells

A research team has demonstrated that complex retinal tissue can be cultured in a Petri dish from embryonic stem cells of bony fish. Until now, stem cells from mammals, including humans, have been used in organoid research. For the first time, researchers have demonstrated that stem cells from medaka and zebrafish can also form highly organized neural structures under controlled laboratory conditions. Among other things, the researchers expect to gain new insights into the basic mechanisms of retinal development.

Organoids are bits of tissue that are grown from stem cells and resemble actual organs. They are used in basic research to gain new information on cell organization and organ development, to investigate the origin of disease, and to develop and test new medications. The major advantage of fish organoids is that they are highly reproducible, unlike organoids from mammalian stem cells. They develop reliably and very quickly and enable a direct comparison with living embryos that in fish grow outside of the womb.

Researchers are  now able to manipulate the molecular and genetic mechanisms of retina  formation.

  Researchers used pluripotent stem cells  from medaka and zebrafish embryos. Such cells have not yet differentiated and can potentially develop into many different cell types. All the cells taken from a single embryo independently aggregated into one large retina within 24 hours. In a matter of a few days, it then formed layers of different cell types that are also found in the fish eye, including photoreceptor cells, bipolar cells, amacrine cells, and ganglion cells. The growth process proved to be incredibly efficient. Hundreds of small retina organoids could be generated within a day. The high throughput allowed the researchers to precisely isolate the conditions in which structures resembling a head with two eyes, including both brain and retina, are formed.

Lucie Zilova et al, Fish primary embryonic pluripotent cells assemble into retinal tissue mirroring in vivo early eye development, eLife (2021). DOI: 10.7554/eLife.66998

https://phys.org/news/2021-09-fish-eyes-grown-petri-dish.html?utm_s...

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