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Comment by Dr. Krishna Kumari Challa on June 14, 2021 at 7:42am

Russel's Tea pot and the thought experiment

A quick explanation of Russell's Teapot, a thought experiment demonstrating that the burden of proof rests on the claimant.

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Comment by Dr. Krishna Kumari Challa on June 12, 2021 at 9:47am

South African worker honeybees reproduce by making near-perfect clones of themselves

A team of researchers  has found that workers in a species of honeybee found in South Africa reproduce by making near-perfect clones of themselves.

Prior research has found that some creatures reproduce through parthenogenesis, in which individuals reproduce without mating. This form of reproduction has the advantage of not wasting time and energy on mating and the gene pool remains undiluted. The downside, of course, is loss of genetic diversity, which helps species survive in changing conditions. Prior research has also shown that for most species, parthenogenesis is a less-than-perfect way to produce offspring. This is because some tiny bit of genetic material is generally mixed wrong—these mistakes, known as recombinations, can lead to birth defects or non-productive eggs. In this new effort, the researchers have found a kind of honeybee that has developed a way to avoid recombinations.

The researchers found that South African Cape honeybee queens reproduce sexually, but the workers reproduce asexually.

They then conducted a small experiment—they affixed tape to the reproductive organs of a queen, preventing males from mating with her, and then allowed both her and the worker bees in the same hive to reproduce asexually. They then tested the degree of recombination in both. They found that offspring of the queen had approximately 100 times as much recombination as the worker bees. Even more impressive, the offspring of the worker bees were found to be nearly identical clones of their parent. More testing showed that one line of worker bees in the hive had been cloning themselves for approximately 30 years—a clear sign that workers in the hive were not suffering from birth defects or an inability to produce viable offspring. It also showed that they have evolved a means for preventing recombination when they reproduce. The researchers note that despite their unique abilities, the bees are still in line with evolutionary theory—they are simply doing what works best for their continued existence.

 Benjamin P. Oldroyd et al, Adaptive, caste-specific changes to recombination rates in a thelytokous honeybee population, Proceedings of the Royal Society B: Biological Sciences (2021). DOI: 10.1098/rspb.2021.0729

https://phys.org/news/2021-06-south-african-worker-honeybees-near-p...

Comment by Dr. Krishna Kumari Challa on June 12, 2021 at 9:35am

New discovery shows human cells can write RNA sequences into DNA

Cells contain machinery that duplicates DNA into a new set that goes into a newly formed cell. That same class of machines, called polymerases, also build RNA messages, which are like notes copied from the central DNA repository of recipes, so they can be read more efficiently into proteins. But polymerases were thought to only work in one direction DNA into DNA or RNA. This prevents RNA messages from being rewritten back into the master recipe book of genomic DNA. Now, researchers provide the first evidence that RNA segments can be written back into DNA, which potentially challenges the central dogma in biology and could have wide implications affecting many fields of biology.

Polθ reverse transcribes RNA and promotes RNA-templated DNA repair, Science Advances (2021). DOI: 10.1126/sciadv.abf1771

https://phys.org/news/2021-06-discovery-human-cells-rna-sequences.h...

Comment by Dr. Krishna Kumari Challa on June 12, 2021 at 6:41am

Comment by Dr. Krishna Kumari Challa on June 11, 2021 at 11:52am

Bodies May Treat Fast Food Like a Dangerous Infection

The immune system can respond to a fast food diet in much the same way it does to a bacterial infection, according to a 2018 study on mice, raising new questions about just how damaging regular trips to burger and pizza chains could be to our health.

Mice fed the equivalent of a "Western diet" high in saturated fats, sugar, and salt for a month, with nothing in the way of fresh fruit, vegetables, or fibre, were shown to increase the number of immune cells in their blood, just as they would if they'd been hit by a microbial infection.

What's more, this aggressive state of alarm that fast food triggers could stick around for the long term, said the international team of researchers – that's based on recent research into the way our immune systems can remember aspects of past battles they've fought.

Those white blood cells pointed the scientists towards certain genes that were activated by the mouse diets, genes containing progenitor cells – the types of cells responsible for raising up an immune cell army.

That genetic breadcrumb trail matters, because it's these progenitor cells that have previously been found to have a kind of memory in dealing with biological attack.

In other words, once the body has started to react to a fast food diet, returning to a healthy eating regime may not be enough to completely undo the changes, and that's got some implications for our overall health.

Indeed, when the mice went back to their regular cereal diet after a month, the inflammation disappeared – but the genetic reprogramming that kept the mice more sensitive to a future attack stuck around.

https://www.cell.com/cell/fulltext/S0092-8674(17)31493-9

https://www.sciencealert.com/bodies-may-treat-a-western-diet-like-a...

https://www.sciencealert.com/bodies-may-treat-a-western-diet-like-a...

Comment by Dr. Krishna Kumari Challa on June 11, 2021 at 10:51am

The mere sight of illness may kick-start a canary’s immune system

Simply seeing another bird get sick is enough to trigger an immune response in healthy birds

For canaries, just seeing their feathered friends get sick may be enough to preemptively rev up their immune systems.

Healthy birds housed within view of fellow fowl infected with a common pathogen mounted an immune response, despite not being infected themselves, researchers report online June 9 in Biology Letters. 

It’s fascinating that some sort of visual cue could alter immune function.

one experiment in humans found that a mere photo of a sick person increases the activity of inflammation-stimulating chemicals called cytokines. But no one had ever looked to see whether being within eyeshot of an actually sick individual could compel the immune system to preemptive action.

In the experiments researchers conducted,  as healthy birds witnessed neighbors becoming visibly sick, their immune systems stirred. A measure of the birds’ ability to burst foreign cells, called CH50 complement activity, rose in conjunction with how sick the infected birds appeared. White blood cell counts were also significantly different in birds exposed to sick individuals, rather than healthy ones. Cytokine levels did not differ between the two groups.

Blood tests showed that no healthy birds caught MG during the experiment, suggesting that some sort of external cue altered immune function. That cue was likely visual.

A.C. Love et al. Perception of infection: disease-related social cues influence immu.... Biology Letters. Published online June 9, 2021. doi: 10.1098/rsbl.2021.0125.

https://www.sciencenews.org/article/canary-immune-system-sight-illn...

Comment by Dr. Krishna Kumari Challa on June 11, 2021 at 9:29am

Physicists dream big with an idea for a particle collider on the moon

A lunar particle accelerator could reach 1,000 times the energy of Earth’s largest collider

A very high energy hadron collider on the Moon

A particle collider encircling the moon could reach an energy of 14 quadrillion electron volts, physicists report June 6 at arXiv.org. That’s about 1,000 times the energy of the world’s biggest particle accelerator, the Large Hadron Collider, or LHC, at CERN near Geneva.

Such a fantastical machine would probably be buried under the moon’s surface to avoid wild temperature swings, the researchers say, and could be powered by a ring of solar panels around the moon.

https://arxiv.org/abs/2106.02048

https://www.sciencenews.org/article/moon-particle-collider-accelera...

Comment by Dr. Krishna Kumari Challa on June 11, 2021 at 9:14am

The digestive system of cows influences human's vitamin B12 intake

What a cow eats determines how much vitamin B12 you get from milk!

Milk is the main source of vitamin B12 consumption for many people around the world. A glass of cow’s milk contains about 46% of the daily-recommended dietary intake of vitamin B12 for adults. But what factors influence the concentration of B12 in a glass of milk? Turns out, what cows eat and how they digest it can impact human’s B12 intake.

Many plants that grow on our planet cannot be used directly by humans as food. But cows have the ability to convert these plants into proteins and vitamins humans can consume through milk. Vitamin B12 comes from animal products, produced by microorganisms in the digestive tract of cows, sheep, and goats. Cow’s milk is an excellent natural source of B12, because of the abundance of bacteria in their digestive tract capable of producing the vitamin.

Specifically, cows have a digestive system that is uniquely different from our own. Instead of a single compartment to the stomach they have four. Of the four compartments, the rumen is the largest and the main digestive center filled with billions of microorganisms that are able to break down grass and other vegetation that animals with one stomach, including humans, cannot digest.

This research has found that certain microorganisms in the rumen of cows are linked to vitamin B12 abundance. Diets higher in acid detergent fibre, such as grass, tended to encourage increased vitamin B12 concentrations in milk. Alternativity, diets higher in starch and energy concentration, based feed tended to result in lower vitamin B12 concentrations. When the pH in the rumen is lower there tends to be higher production of vitamin B12. However, we do not know at this time if vitamin B12 concentration is driving changes in the microbiome or if the microbiome is driving changes in the concentration of vitamin B12.

Animals 2021, 11(2), 532; https://doi.org/10.3390/ani11020532

https://www.mdpi.com/2076-2615/11/2/532

https://researchnews.cc/news/7168/The-digestive-system-of-cows-infl...

Comment by Dr. Krishna Kumari Challa on June 11, 2021 at 9:00am

Nepal's unique lightning signature involves up to four strikes per flash

While every lightning flash is unique in the way the discharge travels through the atmosphere, whether cloud-to-cloud, cloud-to-ground or the more esoteric sprites, halos, jets, and elves of the upper atmosphere. There are common features in these different types of lightning and for cloud-to-ground flashes, it has been assumed that there are two main types of flash known to meteorologists and atmospheric scientists—negative ground flashes and positive ground flashes.

The difference between the negative and positive flash is simply that the polarity of the discharge reaching the ground in the lightning flash. Most (90 percent) cloud-to-ground flashes are negative ground flashes. Just 10 percent are positive. The positive ground flash involves a single stroke.

A novel phenomenon has been found  in the sub-tropical, mountainous region of Nepal now.

Researchers have used a simple circuit and antenna system to measure the electrical signature of lightning flashes in the Himalayan region and found that positive ground flashes there are unique. Instead of involving a single strike, lightning here involves up to four strikes per flash, or discharge.

They explain that the lightning signature in this region is characterized by a relatively slow, negative electric field event preceded by a pronounced opposite-polarity pulse. The average duration of the main waveform was about 500 microseconds and the average duration of the preceding opposite-polarity pulses was approximately 40 microseconds. These figures are based on measurements of more than 5000 lightning flashes.

A likely explanation may lie in the fact that Nepal has regions that are a mere 60 metres above sea level and then within just 160 kilometres we can figuratively scale the giddy heights of Mount Everest, the peak at 8848 metres above sea level. Moreover across this altitude gradient and through the course of the seasons, Nepal can have a temperature ranging from a balmy 30 degrees Celsius down to –50 Celsius. All such characteristics are unique of themselves and so it is perhaps no surprise that the lightning seen in this region is unique too.

It is worth pointing out that lightening signatures not dissimilar to the unique flashes measured in Nepal have been seen occasionally in Sweden and Florida but not at anything like the frequency compared to other flashes seen in Nepal.

Pitri Bhakta Adhikari, Unique lightning signatures observed from sub-tropical, mountainous country, Nepal, International Journal of Hydrology Science and Technology (2021). DOI: 10.1504/IJHST.2021.115488

https://phys.org/news/2021-06-nepal-unique-lightning-signature-invo...

Comment by Dr. Krishna Kumari Challa on June 11, 2021 at 8:52am

Researchers have turned transparent calcite into artificial gold

In a breakthrough in metamaterials, for the first time in the world, researchers at Tel Aviv University have developed an innovative nanotechnology that transforms a transparent calcite nanoparticle into a sparkling gold-like particle. In other words, they turned the transparent particle into a particle that is visible despite its very small dimensions. According to the researchers the new material can serve as a platform for innovative cancer treatments.

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Injectable microspheres to repair failing hearts

Biodegradable microspheres can be used to deliver heart cells generated from stem cells to repair damaged hearts after a heart attack, according to new findings by UCL researchers. This type of cell therapy could one day cure debilitating heart failure, which affects an estimated 920,000 people in the UK and continues to rise as more people are surviving a heart attack than ever before.

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