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Comment by Dr. Krishna Kumari Challa on July 7, 2022 at 10:07am

Scientists discover how first quasars in universe formed

The mystery of how the first quasars in the universe formed—something that has baffled scientists for nearly 20 years—has now been solved by a team of astrophysicists whose findings are published in Nature.

The existence of more than 200 quasars powered by supermassive balckholes less than a billion years after the Big Bang had remained one of the outstanding problems in astrophysics because it was never fully understood how they formed so early.

 Daniel Whalen, Turbulent cold flows gave birth to the first quasars, Nature (2022). DOI: 10.1038/s41586-022-04813-y. www.nature.com/articles/s41586-022-04813-y

Daniel Whalen et al, Revealing the origin of the first supermassive black holes, Nature (2022). DOI: 10.1038/d41586-022-01560-y , www.nature.com/articles/d41586-022-01560-y

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Comment by Dr. Krishna Kumari Challa on July 7, 2022 at 10:02am

Mathematical calculations show that quantum communication across interstellar space should be possible

A team of physicists  has used mathematical calculations to show that quantum communications across interstellar space should be possible. In their paper published in the journal Physical Review D, the group describes their calculations and also the possibility of extraterrestrial beings attempting to communicate with us using such signaling.

Over the past several years, scientists have been investigating the possibility of using quantum communications as a highly secure form of message transmission. Prior research has shown that it would be nearly impossible to intercept such messages without detection. In this new effort, the researchers wondered if similar types of communications might be possible across interstellar space. To find out, they used math that describes that movement of X-rays across a medium, such as those that travel between the stars. More specifically, they looked to see if their calculations could show the degree of decoherence that might occur during such a journey.

With quantum communications, engineers are faced with quantum particles that lose some or all of their unique characteristics as they interact with obstructions in their path—they have been found to be quite delicate, in fact. Such events are known as decoherence, and engineers working to build quantum networks have been devising ways to overcome the problem. Prior research has shown that the space between the stars is pretty clean. But is it clean enough for quantum communications? The math shows that it is. Space is so clean, in fact, that X-ray photons could travel hundreds of thousands of light years without becoming subject to decoherence—and that includes gravitational interference from astrophysical bodies. They noted in their work that optical and microwave bands would work equally well.

The researchers noted that because quantum communication is possible across the galaxy, if other intelligent beings exist in the Milky Way, they could already be trying to communicate with us using such technology and we could begin looking for them. They also suggest that quantum teleportation across interstellar space should be possible.

Arjun Berera et al, Viability of quantum communication across interstellar distances, Physical Review D (2022). DOI: 10.1103/PhysRevD.105.123033

Comment by Dr. Krishna Kumari Challa on July 7, 2022 at 9:59am

Physicists see electron whirlpools for the first time

Though they are discrete particles, water molecules flow collectively as liquids, producing streams, waves, whirlpools, and other classic fluid phenomena.

Not so with electricity. While an electric current is also a construct of distinct particles—in this case, electrons—the particles are so small that any collective behavior among them is drowned out by larger influences as electrons pass through ordinary metals. But, in certain materials and under specific conditions, such effects fade away, and electrons can directly influence each other. In these instances, electrons can flow collectively like a fluid.

Now, physicists  have observed electrons flowing in vortices, or whirlpools—a hallmark of fluid flow that theorists predicted electrons should exhibit, but that has never been seen until now.

It's a clear signature  where electrons behave as a fluid, not as individual particles.

The observations, reported in the journal Nature, could inform the design of more efficient electronics.

When electrons go in a fluid state, [energy] dissipation drops, and that's of interest in trying to design low-power electronics. This new observation is another step in that direction.

Eli Zeldov, Direct observation of vortices in an electron fluid, Nature (2022). DOI: 10.1038/s41586-022-04794-y. www.nature.com/articles/s41586-022-04794-y

Comment by Dr. Krishna Kumari Challa on July 6, 2022 at 9:16am

Scientists unravel the key to colon cancer relapse after chemotherapy

Approximately 1 in 25 people will develop colon cancer during their lifetime and nearly 2 million cases new cases are diagnosed worldwide each year. Chemotherapy is commonly used to treat colon cancer. While this treatment is initially effective in most cases, many patients relapse after treatment.

This study reveals that some tumor cells remain in a latent state and, after chemotherapy, they are reactivated, thus causing relapse. Their study is published in Nature Cancer.

In short, scientists have discovered that tumor stem cells with Mex3a protein activity remain in a state of latency that confers resistance to chemotherapy. Due to the action of the drugs used in this treatment, these cells adopt a state similar to the embryonic one, and sometime after chemotherapy, when the environment is more favorable, they are reactivated to regenerate the tumor in all its complexity. These persistent cells are responsible for cancer relapse after treatment.

https://www.nature.com/articles/s43018-022-00402-0

Comment by Dr. Krishna Kumari Challa on July 6, 2022 at 9:05am

Defining the Anthropocene: Radioactive traces in ocean materials mark the start of the modern age

For the first time, researchers can offer a strong quantitative definition for the start of what is known as the Anthropocene, thanks to traces of radioactive material in marine sediments and corals. The Anthropocene period is considered important by researchers in many fields as it effectively marks a milestone for humanity's impact on Earth's environment and ecosystem.

Researchers combined records of nuclear fallout from atomic tests present in ocean sediments and coral skeletons. These records show a clear change in the ocean environment before, during and after a period of worldwide atomic testing, which the researchers have defined as marking the beginning of the Anthropocene.

 Yusuke Yokoyama et al, Plutonium isotopes in the North Western Pacific sediments coupled with radiocarbon in corals recording precise timing of the Anthropocene, Scientific Reports (2022). DOI: 10.1038/s41598-022-14179-w

Comment by Dr. Krishna Kumari Challa on July 6, 2022 at 8:44am

LHCb discovers three new exotic particles: the pentaquark and the first-ever pair of tetraquarks

The international LHCb collaboration at the Large Hadron Collider (LHC) has observed three never-before-seen particles: a new kind of pentaquark and the first-ever pair of tetraquarks, which includes a new type of tetraquark. The findings, presented recently at a CERN seminar, add three new exotic members to the growing list of new hadrons found at the LHC. They will help physicists better understand how quarks bind together into these composite particles.

Quarks are elementary particles and come in six flavors: up, down, charm, strange, top and bottom. They usually combine together in groups of twos and threes to form hadrons such as the protons and neutrons that make up atomic nuclei. More rarely, however, they can also combine into four-quark and five-quark particles, or "tetraquarks" and "pentaquarks." These exotic hadrons were predicted by theorists at the same time as conventional hadrons, about six decades ago, but only relatively recently, in the past 20 years, have they been observed by LHCb and other experiments.

Most of the exotic hadrons discovered in the past two decades are tetraquarks or pentaquarks containing a charm quark and a charm antiquark, with the remaining two or three quarks being an up, down or strange quark or their antiquarks. But in the past two years, LHCb has discovered different kinds of exotic hadrons. Two years ago, the collaboration discovered a tetraquark made up of two charm quarks and two charm antiquarks, and two "open-charm" tetraquarks consisting of a charm antiquark, an up quark, a down quark and a strange antiquark. And last year it found the first-ever instance of a "double open-charm" tetraquark with two charm quarks and an up and a down antiquark. Open charm means that the particle contains a charm quark without an equivalent antiquark.

The discoveries announced now by the LHCb collaboration include new kinds of exotic hadrons. The first kind, observed in an analysis of "decays" of negatively charged B mesons, is a pentaquark made up of a charm quark and a charm antiquark and an up, a down and a strange quark. It is the first pentaquark found to contain a strange quark. The finding has a whopping statistical significance of 15 standard deviations, far beyond the 5 standard deviations that are required to claim the observation of a particle in particle physics.

The second kind is a doubly electrically charged tetraquark. It is an open-charm tetraquark composed of a charm quark, a strange antiquark, and an up quark and a down  antiquark, and it was spotted together with its neutral counterpart in a joint analysis of decays of positively charged and neutral B mesons. The new tetraquarks, observed with a statistical significance of 6.5 (doubly charged particle) and 8 (neutral particle) standard deviations, represent the first time a pair of tetraquarks has been observed.

https://lhcb-outreach.web.cern.ch/2022/07/05/observation-of-a-stran...

Comment by Dr. Krishna Kumari Challa on July 6, 2022 at 7:58am

8,000 kilometers per second: Star with the shortest orbital period around black hole discovered

Researchers have discovered the fastest known star, which travels around a black hole in record time. The star, S4716, orbits Sagittarius A*, the black hole in the center of our Milky Way, in four years and reaches a speed of around 8,000 kilometers per second. S4716 comes as close as 100 AU (astronomical unit) to the black hole—a small distance by astronomical standards. One AU corresponds to 149,597,870 kilometers. The study has been published in The Astrophysical Journal.

Florian Peißker et al, Observation of S4716—a Star with a 4 yr Orbit around Sgr A*, The Astrophysical Journal (2022). DOI: 10.3847/1538-4357/ac752f

Comment by Dr. Krishna Kumari Challa on July 5, 2022 at 12:37pm

Study explores coevolution of mammals and their lice

According to a new study, the first louse to take up residence on a mammalian host likely started out as a parasite of birds. That host-jumping event tens of millions of years ago began the long association between mammals and lice, setting the stage for their coevolution and offering more opportunities for the lice to spread to other mammals.

Reported in the journal Nature Ecology and Evolution, the study compared the genomes and family trees of lice and their mammalian hosts. The effort revealed that the two trees share a lot of parallel branches and twigs. Those branching points—where one group of mammals began diverging into new forms—often were echoed in the genomes of the lice that parasitized those mammals, the researchers reported.

In this paper, researchers used data from genome sequencing to show that a major newly recognized group of mammalian lice, including lice of humans, originated on the common ancestor of Afrotheria, a group of mammals primarily of African distribution that includes elephants, hyraxes and elephant shrews, among others. These lice then went on to colonize other major groups of mammals through the process of host switching.

Lice fall into two groups based on their eating habits. Chewing lice munch on skin or secretions, while sucking lice pierce the skin to consume the blood of their hosts. Both types feed on mammals, but sucking lice are exclusive to mammals.

Recent genomic studies revealed that sucking lice are closely related to two groups of chewing lice that also feed on mammals, and "each of the major groups within this newly identified lineage occurs on at least one member of Afrotheria.

Kevin Johnson, Phylogenomics reveals the origin of mammal lice out of Afrotheria, Nature Ecology & Evolution (2022). DOI: 10.1038/s41559-022-01803-1. www.nature.com/articles/s41559-022-01803-1

Comment by Dr. Krishna Kumari Challa on July 2, 2022 at 12:24pm

100 Fun Facts collected from Google's "i'm feeling curious" feature

Comment by Dr. Krishna Kumari Challa on July 2, 2022 at 12:18pm

Blood pressure e-tattoo promises continuous monitoring

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