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Comment by Dr. Krishna Kumari Challa on April 5, 2022 at 9:34am

Large-Scale Study Confirms Hybrid Immunity Best Protects Against COVID

People with the "hybrid immunity" of having been both fully vaccinated and previously infected with COVID-19 have the strongest protection against the virus, two new studies said  recently.

After two years of a pandemic that has seen nearly 500 million people infected and billions vaccinated, the studies highlighted the importance of getting jabbed for those who have natural immunity after recovering from the disease.

One of the two studies published in The Lancet Infectious Diseases medical journal analyzed the health data of more than 200,000 people in 2020 and 2021 in hard-hit Brazil, which has the world's second-largest COVID death toll.

It found that for people who have already had COVID, Pfizer and AstraZeneca's vaccines offered 90 percent effectiveness against hospitalization and death, China's CoronaVac had 81 percent and Johnson & Johnson's one-shot jab had 58 percent.

All four of these vaccines have proven to provide significant extra protection for those with a previous COVID-19 infection.

Hybrid immunity due to exposure to natural infection and vaccination is likely to be the norm globally and might provide long-term protection even against emerging variants.

Source:News agencies

https://www.sciencealert.com/huge-study-confirms-hybrid-immunity-gi...

Comment by Dr. Krishna Kumari Challa on April 4, 2022 at 9:13am

RNA switches 'on' and 'off'

Similar to a light switch, RNA switches (called riboswitches) determine which genes turn "on" and "off." Although this may seem like a simple process, the inner workings of these switches have confounded biologists for decades.Now researchers led by Northwestern University and the University at Albany discovered one part of RNA smoothly invades and displaces another part of the same RNA, enabling the structure to rapidly and dramatically change shape. Called "strand displacement," this mechanism appears to switch genetic expression from "on" to "off."

Using a simulation they launched last year, the researchers made this discovery by watching a slow-motion simulation of a riboswitch up close and in action. Affectionately called R2D2 (short for "reconstructing RNA dynamics from data"), the new simulation models RNA in three dimensions as it binds to a compound, communicates along its length and folds to turn a gene "on" or "off."

The findings could have potential implications for engineering new RNA-based diagnostics and for designing successful drugs to target RNA to treat illness and disease.
Luyi Cheng et al, Cotranscriptional RNA strand exchange underlies the gene regulation mechanism in a purine-sensing transcriptional riboswitch, Nucleic Acids Research (2022). DOI: 10.1093/nar/gkac102

Angela M Yu et al, Computationally reconstructing cotranscriptional RNA folding from experimental data reveals rearrangement of non-native folding intermediates, Molecular Cell (2021). DOI: 10.1016/j.molcel.2020.12.017

https://phys.org/news/2022-03-unprecedented-videos-rna.html?utm_sou...

Comment by Dr. Krishna Kumari Challa on April 4, 2022 at 9:10am

First audio recorded on Mars reveals two speeds of sound

The first audio recordings on Mars reveal a quiet planet with occasional gusts of wind where two different speeds of sound would have a strange delayed effect on hearing.

After NASA's Perseverance rover landed on Mars in February last year, its two microphones started recording, allowing scientists to hear what it is like on the Red Planet for the first time.

In a study published in the Nature journal on Friday, the scientists gave their first analysis of the five hours of sound picked up by Perseverance's microphones.

The audio revealed previously unknown turbulence on Mars.

 S. Maurice et al, In situ recording of Mars soundscape, Nature (2022). DOI: 10.1038/s41586-022-04679-0

https://phys.org/news/2022-04-audio-mars-reveals.html?utm_source=nw...

Comment by Dr. Krishna Kumari Challa on April 4, 2022 at 7:02am

Spiders Don't Have Ears, But They Can Boost Their 'Hearing' Through Giant Webs

Spider webs are essential for capturing food – but they might also be used as giant hearing aids for the arachnids that spin them, according to new research. 

Spiders don't have ears, but they can 'hear' vibrations through their legs. When prey or predators are on the move, having those vibrations boosted through the web could be invaluable, the new study suggests, with webs spun that are sometimes 10,000 times the size of the actual creatures.

The researchers used a collection of orb-weaver spiders, known for making large webs, for their experiments, getting them to produce webs inside rectangular frames in the lab that could then be put through a series of tests.

They find that the wispy, wheel-shaped orb web acts as a hyperacute acoustic antenna to capture the sound-induced air particle movements.

A laser vibrometer was used to measure the response of spider web silk to music in an anechoic chamber, a room designed to minimize sound wave reflections. The measurements showed that the webs moved in almost perfect unison with the sound, potentially capturing the audio as it hits.

Sounds of different frequencies and from different directions were tested with the webs, which then got related responses from the spiders – they typically turned, crouched, or flattened out in response. In the case of the directional audio, the spiders oriented themselves towards the location the sound was coming from.

Further experiments with miniature speakers placed close to the edge of the web showed sounds traveling further through the webs than through the air, and some of the spiders responded to the vibrations even when the sound hadn't reached the spiders through the air. 

We know that spiders are able to hunt in packs, for example, via web vibrations passed through the sensory organs on the tarsal claws at the tip of spider legs. In this case, they're obviously responding to something when the sound waves hit, but further research will be required to figure out how the spiders are processing this information.

https://www.pnas.org/doi/10.1073/pnas.2122789119

https://www.sciencealert.com/study-shows-how-spiders-can-use-their-...

Comment by Dr. Krishna Kumari Challa on April 3, 2022 at 11:06am

Creature that blows fire like a dragon?

There are no fire-breathing dragons, but there is the bombardier beetle, which ejects a hot, fiery mixture from its butt when threatened. The spray is produced by the reaction between two chemicals; hydroquinone and hydrogen peroxide, which are stored in separate abdominal compartments before coming together with a bang.

The resulting heat brings the mixture to almost 100°C and produces gas which drives the expulsion. This means that if a bombardier beetle gets eaten by a toad, it can literally fart its way out of trouble. It lets rip inside the amphibian’s belly until the predator vomits it up.

https://www.sciencefocus.com/nature/can-any-creature-blow-fire-like...

Comment by Dr. Krishna Kumari Challa on April 2, 2022 at 8:35am

In this new study, researchers from the Wellcome Sanger Institute and the Josep Carreras Leukemia Research Institute generated single-cell data to investigate epigenetic factors involved in CVID. Samples were taken from a pair of identical twins, only one of whom suffered from CVID, as well as a wider group of CVID patients and healthy individuals.

Analysis of the identical twin participants found that not only did the sibling with CVID have fewer B cells, but that B cell defects resulted in epigenetic problems with DNA methylation, chromatin accessibility and transcriptional defects in memory B cells themselves. In addition, researchers found massive defects in the cell-to-cell communication required for the immune system to function normally.

Single-Cell Atlas of Common Variable Immunodeficiency reveals germinal center-associated epigenetic dysregulation in B cell responses, Nature Communications (2022). DOI: 10.1038/s41467-022-29450-x

https://medicalxpress.com/news/2022-04-immunodeficiency-affects-ide...

Part 2

Comment by Dr. Krishna Kumari Challa on April 2, 2022 at 8:34am

Study sheds light on why immunodeficiency affects only one identical twin

Scientists have long queried the causes of immune disorders in only one of two identical twins with identical genes. New research  has found the answer lies in both alterations in immune cell-cell communication and the epigenome, the host of biological processes that regulate how our genes function.

The study, published today in Nature Communications, is the first cell atlas to categorize common variable immunodeficiency (CVID) at the single-cell resolution. Researchers found that 'communication problems' resulting from defects in B cells and other immune cell types impaired immune response, highlighting a number of pathways that are promising targets for epigenetic treatments. In addition, they also identified major defects in the epigenome.

Common variable immunodeficiency (CVID) encompasses a range of immune disorders caused by a reduced ability to produce protective antibodies, which leaves the individual vulnerable to persistent or repeated infection. These individuals usually have low levels of immunoglobulin, more commonly known as antibodies, due to problems with the B cells that create them.

Though identical twins share the same genome, most will be born with a small number of genetic and epigenetic differences and the number of variations will increase over their lifetime. But where one twin experiences a health problem that their sibling does not, in most cases genetic differences alone cannot explain why this has occurred.

Around 20 percent of CVID cases can be attributed to a defect in a gene associated with the condition. But with four in five cases remaining largely unexplained, scientists have predicted that other factors must be involved. This was confirmed by a recent study, which linked CVID to DNA methylation, an epigenetic process that turns the level of a particular gene up or down.

Part1

Comment by Dr. Krishna Kumari Challa on April 1, 2022 at 9:59am

Researchers identify compound with potent antiseizure effects

Comment by Dr. Krishna Kumari Challa on April 1, 2022 at 9:50am

Air pollution dims India's solar energy potential

Prospects for India achieving the target of generating 100 gigawatts of solar power in 2022 have waned because of high levels of atmospheric pollution.

Atmospheric pollution reduces solar power generation in two main ways: by absorbing and scattering the sun's rays and by soiling solar panels.

A study carried out by IIT Delhi and published March in Environmental Research Letters, calculates that between 2001 and 2018 India lost 29 percent of its solar energy potential as a result of atmospheric pollution—equivalent to an annual loss of US$835 million. As of March this year, India had only reached the halfway mark of 50 gigawatts of installed solar capacity, according to the research group, Mercom India.

Put simply, aerosols, which include fine particulate matter, dust, mist and fumes suspended in the air, significantly reduce incoming solar radiation in what we call the 'atmospheric attenuation effect. This needs to be factored in when undertaking large solar energy projects.

Such projects are also failing to account for the "soiling effect" of aerosols depositing on solar panels, blocking solar radiation from reaching the photovoltaic cells. Since air pollution over South Asia has been on the rise, both effects need to be addressed and mitigation steps taken to maximize benefits from solar power installations.

In heavily polluted regions particulate matter can cause a drop in photovoltaic solar power generation by more than 50 percent, most of it caused the soiling of panels, according to a previous study. Aerosols in the atmosphere also work against solar power generation by increasing cloudiness and interfering with rainfall which could wash out particles.

Acid rain can also corrode solar power equipment and support structures, adding to maintenance costs.

Sushovan Ghosh et al, Cleaner air would enhance India's annual solar energy production by 6-28 TWh, Environmental Research Letters (2022). DOI: 10.1088/1748-9326/ac5d9a

Xiaoyuan Li et al, Global reduction of solar power generation efficiency due to aerosols and panel soiling, Nature Sustainability (2020). DOI: 10.1038/s41893-020-0553-2

https://phys.org/news/2022-03-air-pollution-dims-india-solar.html?u...

Comment by Dr. Krishna Kumari Challa on March 31, 2022 at 10:26am

Metformin Prescriptions Linked to Sons’ Birth Defects

A new cohort study finds that boys whose fathers took the type 2 diabetes drug metformin three months before their conception were more likely to have a birth defect.

Men who took the type 2 diabetes drug metformin three months before conceiving their children seem to have an increased risk of having sons with birth defects, new research finds.

The study, a retroactive analysis of Denmark’s federal registry of healthcare data that was published Tuesday (March 29) in Annals of Internal Medicine, found a significantly increased risk of genital birth defects among boys whose fathers had filled a prescription for metformin—commonly branded as Glucophage, Riomet, and Glumetza—about three months prior to conception, roughly the duration of time it takes for sperm to mature. A correlation between birth defects and paternal metformin prescriptions was not seen in girls, according to the study.

https://www.acpjournals.org/doi/10.7326/M21-4389

https://www.the-scientist.com/news-opinion/metformin-prescriptions-...

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