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Comment by Dr. Krishna Kumari Challa on October 9, 2020 at 5:06am

New method can pinpoint cracks in metal long before they cause catastrophes

Fatigue failure plagues all metals and mitigating it is of great importance.

It is the leading cause of cracks in metallic components of aircraft.

That is why it is common practice in the airline industry to adhere to regular—and expensive—replacement schedules for many parts. But the life of those parts could be more accurately determined by better understanding the origins of crack initiation.

Whether it is the pounding of vehicles on bridges or shifts in air pressure on airplanes, such continuous change called "cyclic loading" gradually induces slips in the internal molecular structure of the most durable metals until cracks occur that could have been anticipated long before their perilous appearance.

With the lack of understanding of the mechanisms that lead to crack initiation, it has been difficult to predict with any reasonable accuracy the remaining life of a cyclically loaded material. The component could actually be fine and never fail but they throw it away anyway solely on the bases of statistical arguments. That's a huge waste of money.

Most current tests to understand the origins of crack initiation have focused on the moments just prior to or after cracking to assess what happened in the makeup of the metal. And many of those tests use far larger samples that preclude tracking the initiation of damage, which is a sub-micrometer scale feature. The new method narrows the lens as small as feasible and begins when metals are first exposed to loads that lead to localized damage that could become cracks.

 "The heterogeneity of persistent slip band nucleation and evolution in metals at the micrometer scale" Science (2020). science.sciencemag.org/cgi/doi … 1126/science.abb2690

https://phys.org/news/2020-10-method-metal-catastrophes.html?utm_so...

Comment by Dr. Krishna Kumari Challa on October 8, 2020 at 7:59am

Study Points to Novel Role for Microglia in Down Syndrome

Overactive immune cells identified in a mouse model and in postmortem human brain tissue may offer a potential therapeutic target for cognitive delays associated with the condition, researchers report.

Overactivation of the brain’s immune cells, called microglia, may play a role in cognitive impairments associated with Down syndrome.

Researchers in Italy identified elevated numbers of the cells in an inflammation-promoting state in the brains of mice with a murine version of the syndrome as well as in postmortem brain tissue from people with the condition. The team additionally showed that drugs that reduce the number of activated microglia in juvenile mice could boost the animals’ performance on cognitive tests.

https://www.cell.com/neuron/fulltext/S0896-6273(20)30710-8

https://www.the-scientist.com/news-opinion/study-points-to-novel-ro...

Comment by Dr. Krishna Kumari Challa on October 8, 2020 at 7:36am

Neurobiology of conversation: Brain activity depends on who you're talking to

Our brains respond differently when talking to a person from a different socioeconomic group than during a conversation with someone of a similar background, a novel new imaging study shows.

While neuroscientists have used brain imaging scans to track in great detail neural responses of individuals to a host of factors such as stress, fear, addiction, and even love and lust, new research shows what happens in the brains of two individuals engaged in a simple social interaction.

The study reveals the distinct neurobiology of a conversation between two people of different backgrounds.

When a  professor talks to a homeless person, his or her frontal lobe activates a different neural network than if they were chatting with another colleague. Our brain has apparently designed a frontal lobe system that helps us deal with our diversity.

The researchers found that in both subjects the activity in the left dorsolateral prefrontal cortex, which is involved in control of cognitive processes, was much higher when they talked with someone from a different socioeconomic background than with someone of similar status.

There is a neurobiology of socialness, and neurobiology allows us to modulate our response to diversity.  We want to be inclusive, we want equity, and theoretically, neuroscience can say something about how we can achieve that.

https://news.yale.edu/2020/10/05/neurobiology-conversation-brain-ac...

https://researchnews.cc/news/2902/Neurobiology-of-conversation--Bra...

Comment by Dr. Krishna Kumari Challa on October 8, 2020 at 7:30am

https://www.sciencealert.com/a-bacterial-clone-is-behind-a-concerni...

A Historical Epidemic Has Been Making a Scary Comeback Due to a Bacterial 'Clone'

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Brain Cells Turned to Glass Found in a Victim of The Vesuvius Eruption

Preserved brain cells have been found in the remains of a young man who died in the eruption of Mount Vesuvius in 79 CE. 

The brain cells' structure is still visible in a black, glassy material found in the man's skull. The new discovery of this structure, described on October 2 in the journal PLOS One, adds to the accumulating evidence that this glassy material is indeed part of the man's brain.

The transformation to glass occurred as a result of extreme heating and rapid cooling. 

The results of the study show that the vitrification process occurred at Herculaneum, unique of its kind, has frozen the neuronal structures of this victim, preserving them intact until today

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0...

https://www.sciencealert.com/brain-cells-turned-to-glass-have-been-...

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2,500 y/o mummy in "perfect condition" revealed after discovery of 59 sarcophagi

https://www.youtube.com/watch?v=7sd0BomMDDk&feature=emb_logo

Comment by Dr. Krishna Kumari Challa on October 8, 2020 at 7:16am

New research: nitrous oxide emissions 300 times more powerful than CO₂ are jeopardising Earth’s future

Nitrous oxide from agriculture and other sources is accumulating in the atmosphere so quickly it puts Earth on track for a dangerous 3℃ warming this century,  new research has found.

This colossal amount of nitrogen makes crops and pastures grow more abundantly. But it also releases nitrous oxide (N₂O), a greenhouse gas.

The study found that N₂O emissions from natural sources, such as soils and oceans, have not changed much in recent decades. But emissions from human sources have increased rapidly.

Agriculture caused almost 70% of global N₂O emissions in the decade to 2016. The emissions are created through microbial processes in soils. The use of nitrogen in synthetic fertilisers and manure is a key driver of this process.

Other human sources of N₂O include the chemical industry, waste water and the burning of fossil fuels.

https://theconversation.com/new-research-nitrous-oxide-emissions-30...

Comment by Dr. Krishna Kumari Challa on October 8, 2020 at 6:44am

**Aerodynamicists reveal link between fish scales and aircraft drag

Reducing drag means faster aircraft speeds and less fuel consumption this is an important area of study for aerodynamicists

Through their biomimetic study, Professor Bruecker's team has discovered that the fish-scale array produces a zig-zag motion of fluid in overlapping regions of the surface of the fish, which in turn causes periodic velocity modulation and a streaky flow that can eliminate Tollmien-Schlichting wave induced transition to reduce skin friction drag by more than 25 percent.

An examination of oil flow visualization using computational fluid dynamics (CFD) on sea bass and common carp enabled the authors to come up with a working hypothesis:

"Computation Fluid Dynamics (CFD) was used to study the flow pattern over the surface and revealed a hitherto unknown effect of the scales as a mechanism to generate a regular pattern of parallel streamwise velocity streaks in the boundary layer. To prove their existence also on the real fish skin, oil flow visualization was done on sea bass and common carp, which indeed confirmed their presence in a regular manner along their real body, with the same arrangement relative to the scale array as observed along the biomimetic surface. These results let the authors hypothesize about a possible mechanism for transition delay, inspired by various previous fundamental transition studies, where streaky structures generated by cylindrical roughness elements or vortex generator arrays have shown a delay of transition."

Their surprising research outcome runs counter to the common belief that roughness promotes by-pass transition. Instead, the scales largely increase the stability of the base flow similar to an array of vortex generators.

A technical realization of such patterns on aerodynamic surfaces will pave the way towards the drastic reduction in fuel consumption and future zero-emission flight.

Muthukumar Muthuramalingam et al, Transition delay using biomimetic fish scale arrays, Scientific Reports (2020). DOI: 10.1038/s41598-020-71434-8

Muthukumar Muthuramalingam et al. Streak formation in flow over biomimetic fish scale arrays, The Journal of Experimental Biology (2019). DOI: 10.1242/jeb.205963

https://phys.org/news/2020-10-aerodynamicists-reveal-link-fish-scal...

Comment by Dr. Krishna Kumari Challa on October 8, 2020 at 6:36am

Aerodynamicists reveal link between fish scales and aircraft drag

Reducing drag means faster aircraft speeds and less fuel consumption this is an important area of study for aerodynamicists

Through their biomimetic study, Professor Bruecker's team has discovered that the fish-scale array produces a zig-zag motion of fluid in overlapping regions of the surface of the fish, which in turn causes periodic velocity modulation and a streaky flow that can eliminate Tollmien-Schlichting wave induced transition to reduce skin friction drag by more than 25 percent.

An examination of oil flow visualization using computational fluid dynamics (CFD) on sea bass and common carp enabled the authors to come up with a working hypothesis:

"Computation Fluid Dynamics (CFD) was used to study the flow pattern over the surface and revealed a hitherto unknown effect of the scales as a mechanism to generate a regular pattern of parallel streamwise velocity streaks in the boundary layer. To prove their existence also on the real fish skin, oil flow visualization was done on sea bass and common carp, which indeed confirmed their presence in a regular manner along their real body, with the same arrangement relative to the scale array as observed along the biomimetic surface. These results let the authors hypothesize about a possible mechanism for transition delay, inspired by various previous fundamental transition studies, where streaky structures generated by cylindrical roughness elements or vortex generator arrays have shown a delay of transition."

Their surprising research outcome runs counter to the common belief that roughness promotes by-pass transition. Instead, the scales largely increase the stability of the base flow similar to an array of vortex generators.

A technical realization of such patterns on aerodynamic surfaces will pave the way towards the drastic reduction in fuel consumption and future zero-emission flight.

Muthukumar Muthuramalingam et al, Transition delay using biomimetic fish scale arrays, Scientific Reports (2020). DOI: 10.1038/s41598-020-71434-8

Muthukumar Muthuramalingam et al. Streak formation in flow over biomimetic fish scale arrays, The Journal of Experimental Biology (2019). DOI: 10.1242/jeb.205963

https://phys.org/news/2020-10-aerodynamicists-reveal-link-fish-scal...

Comment by Dr. Krishna Kumari Challa on October 8, 2020 at 6:27am

Extremely rare Higgs boson decay process spotted

The Higgs boson reached overnight fame in 2012 when it was finally discovered in a jumble of other particles generated at CERN's Large Hadron Collider (LHC) in Geneva, Switzerland. The discovery was monumental because the Higgs boson, which had only been theorized about previously, has the special property of endowing other elementary particles with mass. It is also exceedingly rare and difficult to identify in the debris of colliding particles.

Caltech physicists played a major role in the Higgs boson discovery, a result that earned theoretical physicist Peter Higgs a share of the 2013 Nobel Prize in Physics, and now they continue to make significant findings about rare Higgs boson processes.

This summer, for the first time, particle physicists using data collected by the experiment known as the Compact Muon Solenoid (CMS) at the LHC, have found evidence that the Higgs boson decays into a pair of elementary particles called muons. The muon is a heavier version of the electron, and both muons and electrons belong to a class of particles known as fermions, as described in the widely accepted model of particles called the Standard Model. The Standard Model classifies all particles as either fermions or bosons. Generally, fermions are building blocks of all matter, and bosons are the force carriers.

A muon is also what is known as a second-generation particle. First-generation fermion particles such as electrons are the lightest of particles; second- and third-generation particles can decay to become first-generation particles. The new finding represents the first evidence that the Higgs boson interacts with second-generation fermions.

In addition, this result provides further evidence that the decay rate of the Higgs to fermion pairs is proportional to the square of the mass of the fermion. This is a key prediction of the Higgs theory. With more data, the LHC experiments are expected to confirm that indeed the Higgs gives the fundamental particles their mass.

Joseph Lykken et al. The future of the Higgs boson, Physics Today (2013). DOI: 10.1063/PT.3.2212

https://phys.org/news/2020-10-extremely-rare-higgs-boson.html?utm_s...

Comment by Dr. Krishna Kumari Challa on October 8, 2020 at 5:51am

Traveling brain waves help detect hard-to-see objects

Imagine that you're late for work and desperately searching for your car keys. You've looked all over the house but cannot seem to find them anywhere. All of a sudden you realize your keys have been sitting right in front of you the entire time. Why didn't you see them until now?

A team of scientists has uncovered details of the neural mechanisms underlying the perception of objects. They found that patterns of neural signals, called traveling brain waves, exist in the visual system of the awake brain and are organized to allow the brain to perceive objects that are faint or otherwise difficult to see.

They have discovered that faint objects are much more likely to be seen if visualizing the object is timed with the traveling brain waves. The waves actually facilitate perceptual sensitivity, so there are moments in time when you can see things that you otherwise could not. It turns out that these traveling brain waves are an information-gathering process leading to the perception of an object.

They found that the brain's ability to recognize targets was directly related to when and where the traveling brain waves occurred in the visual system: when the traveling waves aligned with the stimulus. There is a spontaneous level of activity in the brain that appears to be regulated by these traveling waves.

Spontaneous travelling cortical waves gate perception in behaving primates, Nature (2020). DOI: 10.1038/s41586-020-2802-y , www.nature.com/articles/s41586-020-2802-y

https://medicalxpress.com/news/2020-10-brain-hard-to-see.html?utm_s...

Comment by Dr. Krishna Kumari Challa on October 8, 2020 at 5:42am

Scientists clarify how the brain separates present from past dangers

A team of neuroscientists has identified processes the brain undergoes to distinguish real and present dangers from those linked to past experiences in mice. The findings have implications for our understanding of post-traumatic stress disorder (PTSD)—an affliction marked by the inability to distinguish between past and present dangers or to recognize "safe" situations.

Memories of a traumatic episode can last for a long time. But we are able to use such memories selectively: to predict and respond to a subsequent, related danger while also recognizing when threats do not exist. This is especially important for survival behaviour in an uncertain environment such as a conflict zone or at times of social unrest.

This has significant implications for memory disorders such as PTSD, where patients have difficulty distinguishing between safety and threat cues.

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Learning to identify and appropriately respond to cues in an uncertain environment is crucial for animal survival, the researchers note. Specifically, cues that reliably predict danger prompt behaviors such as freezing in order to escape detection. However, along with the threat-predicting cues, an uncertain environment can present cues that predict safety—or, specifically, lack of danger. Animals, then, need to respond to the threat-predicting cue with defensive behaviors and, conversely, to safety cues by ceasing a threat response and resuming normal behaviors.

 the scientists sought to identify the cellular molecules, or substrates, for long-term storage of threat and safety-cue-associated memories.

It has been long established that a region of the brain, the amygdala, plays a fundamental role in the processing and storing of emotion-related information. Less understood, however, are the cellular engines and architecture that underlie it—specifically, the identity of cell types that store cue-related information and allow animals to respond appropriately even after considerable time has elapsed after the initial threat exposure.

Also well understood are the formation and consolidation of long-lasting memories, which occur through changes in the cellular landscape of proteins—a dynamic that captures significant features of an event, in part by synthesis of new proteins.

In the new work, the scientists aimed to better understand these mechanisms by disrupting key steps in protein synthesis in specific cell types—a maneuver that would reveal their significance. This procedure allowed the researchers to identify key players in this intricate process.

Amygdala inhibitory neurons as loci for translation in emotional memories, Nature (2020). DOI: 10.1038/s41586-020-2793-8 , www.nature.com/articles/s41586-020-2793-8

https://medicalxpress.com/news/2020-10-scientists-brain-dangers.htm...

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