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Comment by Dr. Krishna Kumari Challa on July 2, 2021 at 6:47am

Scientists discover a new class of memory cells in the brain

Scientists have long searched in vain for a class of brain cells that could explain the visceral flash of recognition that we feel when we see a very familiar face, like that of our grandmothers. But the proposed "grandmother neuron"—a single cell at the crossroads of sensory perception and memory, capable of prioritizing an important face over the rabble—remained elusive.

Now, new research reveals a class of neurons in the brain's temporal pole region that links face perception to long-term memory. It's not quite the apocryphal grandmother neuron—rather than a single cell, it's a population of cells that collectively remembers grandma's face. The findings, published in Science, are the first to explain how our brains inculcate the faces of those we hold dear.

"A fast link between face perception and memory in the temporal pole" Science (2021). science.sciencemag.org/lookup/ … 1126/science.abi6671

https://medicalxpress.com/news/2021-07-scientists-class-memory-cell...

Comment by Dr. Krishna Kumari Challa on July 2, 2021 at 6:43am

Physicists observationally confirm Hawking's black hole theorem for the first time

There are certain rules that even the most extreme objects in the universe must obey. A central law for black holes predicts that the area of their event horizons—the boundary beyond which nothing can ever escape—should never shrink. This law is Hawking's area theorem, named after physicist Stephen Hawking, who derived the theorem in 1971.

Fifty years later, physicists at MIT and elsewhere have now confirmed Hawking's area theorem for the first time, using observations of gravitational waves. Their results appear yesterday (2nd July,2021) in Physical Review Letters.

In the study, the researchers take a closer look at GW150914, the first gravitational wave signal detected by the Laser Interferometer Gravitational-wave Observatory (LIGO), in 2015. The signal was a product of two inspiraling black holes that generated a new black hole, along with a huge amount of energy that rippled across space-time as gravitational waves.

If Hawking's area theorem holds, then the horizon area of the new black hole should not be smaller than the total horizon area of its parent black holes. In the new study, the physicists reanalyzed the signal from GW150914 before and after the cosmic collision and found that indeed, the total event horizon area did not decrease after the merger—a result that they report with 95 percent confidence.

Their findings mark the first direct observational confirmation of Hawking's area theorem, which has been proven mathematically but never observed in nature until now. The team plans to test future gravitational-wave signals to see if they might further confirm Hawking's theorem or be a sign of new, law-bending physics.

Testing the black-hole area law with GW150914, Physical Review Letters (2021). journals.aps.org/prl/accepted/ … 4336d883136eb53c122b

https://phys.org/news/2021-07-physicists-observationally-hawking-bl...

Comment by Dr. Krishna Kumari Challa on July 2, 2021 at 6:39am

Lowering Blood Pressure in 5 Minutes

Comment by Dr. Krishna Kumari Challa on July 1, 2021 at 12:06pm

Solving a murder case with physics

In 2009, famed music producer Phil Spector was found guilty of the murder of actress Lana Clarkson, who was found dead from a single gunshot to her mouth at close range in Spector's California mansion.

During the trial, the attorney argued that Spector couldn't have been the shooter because his white dinner jacket only had a handful blood droplets on it. If he shot Clarkson, the jacket would be covered with blood.

After watching a film about the trial, UIC Distinguished Professor Alexander Yarin was intrigued by the scientific questions it raised. Yarin and his colleagues from Iowa State University—Assistant Professor James Michael and Associate Professor Daniel Attinger— started researching blood spatter, and their recent papers show how Spector could be the shooter and remain relatively free of blood droplets.

The researchers discovered that the gases released from a gun's muzzle brakes escape in a series of turbulent vortex rings, which causes a phenomenon called "blood back spatter"—the blood that travels back toward the shooter—to reverse direction away from the shooter.

At shortrange shooting, the muzzle gasses interfere with the blood back spatter and deflect droplets. Researchers did simulations  and found that there are scenarios where droplets can be turned around completely and land behind the victim. Experiments confirmed that prediction.

In addition, the researchers noted that a shooter could stand in a certain position or at a specific angle and all backward blood spatter would be turned around, keeping the shooter clean.

Gen Li et al, Blood backspatter interaction with propellant gases, Physics of Fluids (2021). DOI: 10.1063/5.0045214

https://phys.org/news/2021-06-case-physics.html?utm_source=nwletter...

Comment by Dr. Krishna Kumari Challa on June 30, 2021 at 3:50pm

COVID-19 Makes Lasting Changes to Blood Cells
Why does long COVID last for so long, leaving long-haulers with symptoms that persist for months after initial infection?

New evidence suggests the enduring imprint of COVID-19 could be due to the virus making significant alterations to people's blood – yielding lasting changes to blood cells that are still evident several months after infection is diagnosed.

While the pathology is not yet fully understood, hyper-inflammatory response and coagulation disorders leading to congestions of microvessels are considered to be key drivers of the still increasing death toll.

The results showed that red blood cells (erythrocytes) in COVID-19 patients varied more in size than those from healthy people, and showed signs of stiffness in their physical structure, exhibiting less deformability, which could affect their ability to deliver oxygen through the body.

"The physical properties of erythrocytes are crucial for microcirculatory flow and as such, these changes could impair circulation and promote hypoxemia.

The effect could persist in COVID-19 patients long after the infection is not active anymore; we found that in recovered patients phenotype alterations were not as prominent, but still present. In contrast, the researchers discovered that a form of white blood cells (leukocytes) called lymphocytes showed decreased stiffness in COVID-19 patients, while other white blood cells, known as monocytes, were significantly larger than in cells from the control group.

Meanwhile, neutrophils – another type of white blood cell – showed numerous changes in COVID-19 patients, seen in higher volume, with greater deformation.

the observed changes could arise due to cytoskeletal alterations of immune cells. Mechanical properties of cells can be directly related to the cytoskeleton, an important supportive structure which also determines cellular function."

https://www.cell.com/biophysj/pdf/S0006-3495(21)00454-9.pdf

https://www.sciencealert.com/covid-19-is-making-lingering-changes-t...

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Comment by Dr. Krishna Kumari Challa on June 30, 2021 at 11:24am

Delhi: New virus, Cytomegalovirus, found in Covid patients

As the world prepares itself against the new and emerging Delta Plus strain of the coronavirus, India has reported a new type of virus in people who have already suffered COVID-19.

Delhi’s Ganga Ram Hospital has reported five cases of Cytomegalovirus (CMV) in Covid patients, the hospital reported in a written statement

Comment by Dr. Krishna Kumari Challa on June 30, 2021 at 11:18am

Scientists discover new type of quasiparticle

Russian scientists have experimentally proved the existence of a new type of quasiparticle - previously unknown excitations of coupled pairs of photons in qubit chains. This discovery could be a step towards disorder-robust quantum metamaterials. The study was published in Physical Review B.

Superconducting qubits are a leading qubit modality today that is currently being pursued by industry and academia for quantum computing applications. However, the performance of quantum computers is largely affected by decoherence that contributes to a qubits extremely short lifespan and causes computational errors. Another major challenge is low controllability of large qubit arrays.

Metamaterial quantum simulators provide an alternative approach to quantum computing, as they do not require a large amount of control electronics. The idea behind this approach is to create artificial matter out of qubits, the physics of which will obey the same equations as for some real matter. Conversely, you can program the simulator in such a way as to embody matter with properties that have not yet been discovered in nature.

Arrays of superconducting qubits are generally described by the Bose-Hubbard model. An interesting feature of the Bose-Hubbard model is the emergence of bound boson pairs (doublons) caused by the strong quantum nonlinearity. The topological physics of doublons has been extensively explored in a series of recent theoretical works. However, the experimental investigation of topological properties of bound photon pairs is still lacking.

the scientists were able to demonstrate for the first time that a new type of quasiparticles - doublon topological excitations - can arise in qubit chains.

https://www.eurekalert.org/pub_releases/2021-06/nuos-sdn062921.php

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Comment by Dr. Krishna Kumari Challa on June 30, 2021 at 9:46am

Researchers discover unique 'spider web' mechanism that traps, kills viruses

Immunologists  have discovered a previously unknown mechanism which acts like a spider web, trapping and killing pathogens such as influenza or SARS-CoV-2, the virus responsible for COVID-19.

The researchers have found that neutrophils, the most abundant white blood cells in the human body, explode when they bind to such pathogens coated in antibodies and release DNA outside of the cell, creating a sticky tangle which acts as a trap.

The findings, published online in the Proceedings of the National Academy of Science, are significant because little is understood about how antibodies neutralize viruses in the respiratory tract.

The discovery has implications for vaccine design and delivery, including aerosol and nasal spray technologies that could help the body head off infections before they have a chance to take hold.

Researchers caution that while the body's spider-web mechanism has the potential to be hugely beneficial, it can cause harm too, including inflammation and further illness when the web formation is uncontrollable.

Hannah D. Stacey et al, IgA potentiates NETosis in response to viral infection, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2101497118

https://medicalxpress.com/news/2021-06-unique-spider-web-mechanism-...

Comment by Dr. Krishna Kumari Challa on June 29, 2021 at 1:54pm

Broken Heart Syndrome Linked to the Brain

A chronically stressed amygdala can prime the heart to overreact to acute stress events, a new study shows.

Takotsubo syndrome, also known as broken heart syndrome, is a rare, reversible condition with symptoms mimicking a mild heart attack. A disease that disproportionately affects women, TTS is triggered by stressful events such as bankruptcy, the death of a loved one, or divorce, and results in a weakening of the heart’s left ventricle such that it becomes temporarily misshapen.

Previous work has shown that TTS patients have elevated activity in their amygdala, a brain region involved in stress response. What has never been clear, however, is whether this activity in the brain happens as a result of the syndrome or whether it began many years before.

Higher amygdala activity was associated with an increased risk for TTS, and among those with the condition, patients with higher ratios had developed TTS roughly two years earlier following the imaging than those with lower ratios. “We can now show that this syndrome happens as a result of chronic stress over years that makes you vulnerable to developing the syndrome more easily and sooner than [less stressed] people.

This study confirms our suspicion that there’s a relationship between amygdala activity and future risk of Takotsubo.

A. Radfar et al., “Stress-associated neurobiological activity associates with the risk for and timing of subsequent Takotsubo syndrome,” Eur Heart J, ehab029, 2021

https://www.the-scientist.com/the-literature/broken-heart-syndrome-...

Comment by Dr. Krishna Kumari Challa on June 29, 2021 at 12:22pm

Study explores how the perception of internal bodily signals influences the concept of self

In contrast with other animal species on Earth, over the course of their life, humans can develop a fairly clear idea of who they are as individuals and what sets them apart from others. This abstract concept of self is known to be fragmented and fuzzy in individuals with certain psychiatric disorders, including schizophrenia, borderline personality disorder and dissociative identity disorder.

Researchers recently authored a review paper examining experimental evidence suggesting that the birth, maintenance and loss of this abstract concept of self is deeply tied to what is known as interoception. This refers to an individual's sense of his/her internal physiological signals.

A couple of years ago, researchers discovered a new bodily illusion. This 'embreathment' illusion, as they called it, suggests that your concept of yourself (i.e., who you think you are) is partly shaped by feelings that come from your viscera, particularly from the heart and the lungs.

They realized that the concept of self has several dimensions, ranging from mundane and material to social and spiritual. They thus decided to investigate the illusion more in depth and try to better understand what it suggested about people's concept of self.

The inside of me: interoceptive constraints on the concept of self in neuroscience and clinical psychology. Psychological Research(2021). DOI: 10.1007/s00426-021-01477-7.

The "embreathment" illusion highlights the role of breathing in corporeal awareness. Journal of Neurophysiology(2020). DOI: 10.1152/jn.00617.2019.

Gut markers of bodily self-consciousness. bioRxiv. DOI: 10.1101/2021.03.05.434072.

https://medicalxpress.com/news/2021-06-explores-perception-internal...

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