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Comment by Dr. Krishna Kumari Challa on December 26, 2020 at 9:22am

Putting The History Of Earth Into Perspective

Comment by Dr. Krishna Kumari Challa on December 26, 2020 at 9:04am

Breaking bad: How shattered chromosomes make cancer cells drug-resi...

Researchers recently described how a phenomenon known as chromothripsis breaks up chromosomes, which then reassemble in ways that ultimately promote cancer cell growth. Chromothripsis is a catastrophic mutational event in a cells history that involves massive rearrangement of its genome, as opposed to a gradual acquisition of rearrangements and mutations over time. Genomic rearrangement is a key characteristic of many cancers, allowing mutated cells to grow or grow faster, unaffected by anti-cancer  therepies.

These rearrangements can occur in a single step. During chromothripsis, a chromosome in a cell is shattered into many pieces, hundreds in some cases, followed by reassembly in a shuffled order. Some pieces get lost while others persist as extra-chromosomal DNA (ecDNA). Some of these ecDNA elements promote cancer cell growth and form minute-sized chromosomes called ‘double minutes.

Research found that up to half of all cancer cells in many types of cancers contain ecDNA carrying cancer-promoting genes. The scientists also identified how chromothripsis drives ecDNA formation after gene amplification inside a chromosome.

Chromothripsis converts intra-chromosomal amplifications (internal) into extra-chromosomal (external) amplifications and that amplified ecDNA can then reintegrate into chromosomal locations in response to DNA damage from chemotherapy or radiotherapy. The new work highlights the role of chromothripsis at all critical stages in the life cycle of amplified DNA in cancer cells, explaining how cancer cells can become more aggressive or drug-resistant.

https://health.ucsd.edu/news/releases/Pages/breaking-bad-how-shatte...

https://researchnews.cc/news/4292/Breaking-bad--How-shattered-chrom...

Comment by Dr. Krishna Kumari Challa on December 26, 2020 at 8:58am

https://actu.epfl.ch/news/when-light-and-atoms-share-a-common-vibe/

When light and atoms share a common vibe- explained below

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When light and atoms share a common vibe

1. A laser generates a very short pulse of light 2. A fraction of this pulse is sent to a nonlinear device to change its color 3. The two laser pulses overlap on the same path again, creating a “write & read” pair of pulses. 4. Each pair is split into a short and a long path, 5. yielding an “early” and a “late” time slot, overlapping once again 6. Inside the diamond, during the “early” time slot, one photon from the “write” pulse may generate a vibration, while one photon from the “read” pulse converts the vibration back into light. 7. The same sequence may also happen during the “late” slot. But in this experiment, the scientists made sure that only one vibration is excited in total (in both early and late time slots). 8. By overlapping the photons in time again it becomes impossible to discriminate the early vs. late moment of the vibration. The vibration is now in a quantum superposition of early and late time. 9. In the detection apparatus, “write” and “read” photons are separated according to their different colors, and analyzed with single-photon counters to reveal their entanglement. Full article: https://actu.epfl.ch/news/when-light-...

Comment by Dr. Krishna Kumari Challa on December 26, 2020 at 8:56am

When light and atoms share a common vibe

An especially counter-intuitive feature of quantum mechanics is that a single event can exist in a state of superposition – happening both here and there, or both today and tomorrow.

Such superpositions are hard to create, as they are destroyed if any kind of information about the place and time of the event leaks into the surrounding – and even if nobody actually records this information. But when superpositions do occur, they lead to observations that are very different from that of classical physics, questioning down to our very understanding of space and time.

Scientists demonstrated a state of vibration that exists simultaneously at two different times, and evidence this quantum superposition by measuring the strongest class of quantum correlations between light beams that interact with the vibration.

The researchers used a very short laser-pulse to trigger a specific pattern of vibration inside a diamond crystal. Each pair of neighboring atoms oscillated like two masses linked by a spring, and this oscillation was synchronous across the entire illuminated region. To conserve energy during this process, a light of a new color is emitted, shifted toward the red of the spectrum.

This classical picture, however, is inconsistent with the experiments. Instead, both light and vibration should be described as particles, or quanta: light energy is quantized into discrete photons while vibrational energy is quantized into discrete phonons (named after the ancient Greek “photo = light” and “phono = sound”).

The process described above should therefore be seen as the fission of an incoming photon from the laser into a pair of photon and phonon – akin to nuclear fission of an atom into two smaller pieces.

But it is not the only shortcoming of classical physics. In quantum mechanics, particles can exist in a superposition state, like the famous Schrödinger cat being alive and dead at the same time.

Even more counterintuitive: two particles can become entangled, losing their individuality. The only information that can be collected about them concerns their common correlations. Because both particles are described by a common state (the wavefunction), these correlations are stronger than what is possible in classical physics. It can be demonstrated by performing appropriate measurements on the two particles. If the results violate a classical limit, one can be sure they were entangled.

In the new study, EPFL researchers managed to entangle the photon and the phonon (i.e., light and vibration) produced in the fission of an incoming laser photon inside the crystal. To do so, the scientists designed an experiment in which the photon-phonon pair could be created at two different instants. Classically, it would result in a situation where the pair is created at time t1 with 50% probability, or at a later time t2 with 50% probability.

But here comes the “trick” played by the researchers to generate an entangled state. By a precise arrangement of the experiment, they ensured that not even the faintest trace of the light-vibration pair creation time (t1 vs. t2) was left in the universe. In other words, they erased information about t1 and t2. Quantum mechanics then predicts that the phonon-photon pair becomes entangled, and exists in a superposition of time t1andt2. This prediction was beautifully confirmed by the measurements, which yielded results incompatible with the classical probabilistic theory.

By showing entanglement between light and vibration in a crystal that one could hold in their finger during the experiment, the new study creates a bridge between our daily experience and the fascinating realm of quantum mechanics.

https://researchnews.cc/news/4299/When-light-and-atoms-share-a-comm...

Comment by Dr. Krishna Kumari Challa on December 26, 2020 at 8:24am

Different people will show different views on the best science breakthroughs of the year. We present some of them here.

One such view: The biggest and most important scientific breakthroughs of 2020

https://au.news.yahoo.com/most-important-scientific-breakthroughs-o...

Comment by Dr. Krishna Kumari Challa on December 26, 2020 at 7:40am

The Year's Biggest Breakthroughs in Physics

Comment by Dr. Krishna Kumari Challa on December 26, 2020 at 7:30am

The Year's Biggest Breakthroughs in Biology

Comment by Dr. Krishna Kumari Challa on December 25, 2020 at 10:09am

How could stars help us detect life on other planets?

Comment by Dr. Krishna Kumari Challa on December 25, 2020 at 9:45am

There’s no magic way to boost your energy. But ‘perineum sunning’ isn’t the answer

Perineum sunning is said to have roots in an ancient Taoist practice, where the perineum, or “Hui Yin”, is regarded as a gateway where energy enters and exits the body.

It’s probably also related to the idea that the sun has healing powers. Many years ago sun exposure was recommended after childbirth, and sunlamps were used in labour wards to ostensibly aid healing. But there was no evidence for this.

Some of the appeal of the trend might also lie in the fact many pale-skinned people like to be tanned.

That said, tanning is not the motivation behind the perineum sunning wellness trend. People who do it say it gives their body an intense dose of vitamin D, and therefore a significant energy boost.

It can also supposedly increase creativity, improve sleep, and even promote a healthy libido, among other reported benefits.

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Read more: Your vagina cleans itself: why vagina cleaning fads are unnecessary...

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But there’s no evidence to support any of these supposed benefits. Although there have been no scientific studies on perineum sunning to date. 

However, we can’t dismiss the placebo effect. For example, if someone thinks sunning their perineum will improve their libido, it probably will.

The main risk of perineum sunning is sunburn. Sun-exposed skin adapts to exposure to ultraviolet (UV) light by forming melanin, the natural protective pigment in skin that reduces the risk of sunburn. So when you get UV light on a part of your skin that’s not accustomed to sun exposure, you’re much more likely to get burnt.

If you do get sunburnt in this sensitive area, it’s likely to be very sore. You won’t be able to have sex for about a week, and it might sting to urinate.

And of course, UV is a known carcinogen, which is why nowadays we discourage any kind of tanning. Sunburn can increase your risk of skin cancer, and chronic UV exposure can raise skin cancer risk even without causing sunburn.

https://theconversation.com/theres-no-magic-way-to-boost-your-energ...

Comment by Dr. Krishna Kumari Challa on December 25, 2020 at 9:41am

Study on health effects and citizen resistance during the lockdown

https://medicalxpress.com/news/2020-12-publish-health-effects-citiz...

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