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Comment by Dr. Krishna Kumari Challa on October 14, 2021 at 12:03pm

Photosynthesizing algae injected into the blood vessels of tadpoles supply oxygen to their brains

Leading a double life in water and on land, frogs have many breathing techniques—through the gills, lungs, and skin—over the course of their lifetime. Now German scientists have developed another method that allows tadpoles to "breathe" by introducing algae into their bloodstream to supply oxygen. The method developed, presented October 13 in the journal iScience, provided enough oxygen to effectively rescue neurons in the brains of oxygen-deprived tadpoles.

The algae actually produced so much oxygen that they could bring the nerve cells back to life. For many people, it sounds like science fiction, but after all, it's just the right combination of biological schemes and biological principles.

This is an idea to combine plant physiology with neuroscience: harnessing the power of photosynthesis to supply nerve cells with oxygen. The idea didn't seem far-fetched. In nature, algae live harmoniously in sponges, corals, and anemones, providing them with oxygen and even nutrients. Why not in vertebrates like frogs?

To explore the possibility, researchers injected green algae, Chlamydomonas renhardtii) or cyanobacteria (Synechocystis) into tadpoles' hearts. With each heartbeat, the algae inched through blood vessels and eventually reached the brain, turning the translucent tadpole bright green. Shining light on these tadpoles prompted both algae species to pump out oxygen to nearby cells.

After distributing algae to the brain, the researchers isolated the tadpole's head and placed it in an oxygen bubble bath with essential nutrients that would preserve the functioning of the cells, allowing the team to monitor neural activity and oxygen levels. As the researchers depleted oxygen from the bath, the nerves ceased firing and fell silent. However, illuminating the tadpole head restarted the neural activity within 15 to 20 minutes, which is about two times faster than replenishing the bath with oxygen without the algae. The revived nerves also performed as well or even better than before oxygen depletion, showing that the researchers' method was quick and efficient.

The team's next step is to see whether the injected algae can survive inside living tadpoles and continue oxygen production without causing an immune response that wreaks havoc on the animals.

iScience, Özugur et al.: "Green oxygen power plants in the brain rescue neuronal activity" www.cell.com/iscience/fulltext … 2589-0042(21)01126-3 , DOI: 10.1016/j.isci.2021.103158

https://phys.org/news/2021-10-photosynthesizing-algae-blood-vessels...

Comment by Dr. Krishna Kumari Challa on October 13, 2021 at 8:37am

When breezy, wear masks outdoors to prevent coronavirus exposure

As the highly infectious delta variant of the coronavirus continues to spread  guidelines from experts recommend even the vaccinated wear masks indoors to prevent exposure and transmission.

However, it is less clear what people should do when outside.

In Physics of Fluids, researchers from the Indian Institute of Technology Bombay found when a person coughs outdoors, wind flowing in the same direction can propagate the virus faster over longer distances than in calm conditions.

The study is significant in that it points to the increased infection risk that coughing in the same direction as the wind could bring about. Based on the results, experts recommend wearing masks outdoors, particularly in breezy conditions.

Other guidelines, such as coughing in an elbow or turning the face away while coughing, should be followed to reduce transmission when socializing outdoors.

Most studies model cough flow using puffs of air or a simple pulsating profile. But a real cough is more complicated, exhibiting turbulent flow with prominent vortical structures swirling like mini whirlpools.

To investigate these vortices, the researchers used a large eddy simulation, a numerical model in computational fluid dynamics that simulates turbulence. They modeled cough jets in breezy conditions and in calm conditions representing a typical indoor environment.

These simulations show even a light breeze of about 5 mph extends effective social distancing by around 20%, from 3-6 feet to 3.6-7.2 feet, depending on cough strength. At 9-11 mph, spreading of the virus increases in distance and duration.

The researchers found the vortices enable bigger droplets to persist in the air longer than has been typically assumed, increasing the time it takes to adequately dilute the viral load in fresh air. As the cough jet evolves and spreads, it interacts with the wind flowing in the same direction, and the bigger infected droplets become trapped in the jet's vortices instead of falling relatively quickly to the ground under gravity.

The increase in residential time of some of the larger droplets will increase the viral load transmitting through the cough jet and, therefore, the chances of infection. Overall, the study highlights increased chances of infection in the presence of even a light breeze.

"Effect of co-flow on fluid dynamics of a cough jet with implications in spread of COVID-19" Physics of Fluids, aip.scitation.org/doi/10.1063/5.0064104

https://phys.org/news/2021-10-breezy-masks-outdoors-coronavirus-exp...

Comment by Dr. Krishna Kumari Challa on October 12, 2021 at 6:53am

Lightning strikes may trigger short-term thinning in the ozone layer

Crack! Lightning strikes are bright and loud—violent enough to shake your bones and light up the sky. Now, a new study led by the University of Colorado Boulder suggests that these powerful events may also alter the chemistry of Earth's atmosphere, even affecting Earth's all-important ozone layer.

--

Chemists develop new blueprint for enzyme involved in cancer Scientists have known for decades that a certain class of enzymes is an important player in cell biology because they frequently mutate and become major drivers of cancer. -- Chemists create chemical probe to better understand immune response A trio of chemists at Indiana University Bloomington has created a new sensor to detect chemical changes in immune cells during the breakdown of pathogens. The work could potentially contribute to the early diagnosis and treatment of infectious diseases, such as tuberculosis, that evade certain elements of the body's immune response.

Comment by Dr. Krishna Kumari Challa on October 12, 2021 at 6:50am

Myth busted: General anesthesia just as safe as spinal anesthesia after broken hip surgery

New research shows that the rates of survival, functional recovery, and post-operative delirium are similar for patients whether they underwent general anesthesia or spinal anesthesia for hip fracture surgery. This work, from the largest randomized study ever conducted to compare the two anesthesia techniques, challenges common thinking that patients who get spinal anesthesia fare better. 

The study was published in the New England Journal of Medicine and presented at Anesthesiology 2021, the annual meeting of the American Society of Anesthesiologists (ASA).

During general anesthesia, inhaled and intravenous medications are used to make patients unconscious, which often requires temporary breathing tube placement to support the lungs during surgery. For spinal anesthesia, medications are used to numb the lower part of the body through an injection into the spinal column; while patients may receive sedation for comfort, they are typically able to breathe on their own during surgery and rarely require a breathing tube.

Most recent comparisons of general anesthesia versus spinal anesthesia come from studies that hadn't randomized their populations, some of which have suggested lower rates of cognitive and medical complications with spinal. While some patients may choose spinal anesthesia with the goal of avoiding complications, others opt for general anesthesia to avoid a spinal injection or out of fears of inadequate sedation during surgery.

Researchers enrolled 1,600 patients from 46 hospitals across the United States and Canada. The patients were all at least 50 years old, had broken a hip, and had previously been able to walk. Hip fractures are particularly worrisome among older populations, like the patients in the study, since they can lead to a loss of mobility, which is associated with doubling or even tripling the risk of near-term death. What set Neuman's study apart from past work in the subject area was that it randomly divided the enrolled patients into two equal groups: Those who were set to receive general anesthesia and those who were scheduled for spinal anesthesia. Approximately 800 patients were in each group. To get a fuller picture of the potential outcomes associated with each form of anesthesia, the researchers combined subsequent patient death rates and whether they regained the ability to walk, whether on their own or with a cane or walker. By 60 days after surgery, 18.5 percent of patients assigned to spinal anesthesia had either died or become newly unable to walk versus 18 percent of patients who received general anesthesia. When looking at mortality at 60 days alone, 3.9 percent of patients who received spinal anesthesia died versus 4.1 percent who got general anesthesia. Additionally, to examine how the different forms of anesthesia factored into potential cognitive complications, the researchers also examined post-operative delirium. Roughly 21 percent of patients assigned to spinal anesthesia experienced delirium versus 20 percent of those assigned to general anesthesia. "What our study offers is reassurance that general anesthesia can represent a safe option for hip fracture surgery for many patients," said Neuman. "This is information that patients, families, and clinicians can use together to make the right choice for each patient's personalized care."

 Spinal Anesthesia versus General Anesthesia for Hip Surgery in Older Adults, New England Journal of Medicine, 2021.

https://medicalxpress.com/news/2021-10-myth-anesthesia-safe-spinal-...

Comment by Dr. Krishna Kumari Challa on October 12, 2021 at 6:39am

The neurons in the human brain have a large number of computational capabilities with various characteristics, and experience determines which of those capabilities are put to use in various possible ways in combination with other brain regions to perform particular thinking tasks. For example, every healthy brain is prepared to learn the sounds of spoken language, but an infant's experience in a particular language environment shapes which phonemes of which language are learned.

The genius of civilization has been to use these brain capabilities to develop new skills and knowledge. What makes all of this possible is the adaptability of the human brain. We can use our ancient brains to think of new concepts, which are organized along new, underlying dimensions. An example of a "new" physics dimension significant in 20^th century, post-Newtonian physics is "immeasurability" (a property of dark matter, for example) that stands in contrast to the "measurability" of classical physics concepts, (such as torque or velocity). This new dimension is present in the brains of all university physics faculty tested. The scientific advances in physics were built with the new capabilities of human brains.

Another striking finding was the large degree of commonality across physicists in how their brains represented the concepts. Even though the physicists were trained in different universities, languages and cultures, there was a similarity in brain representations. This commonality in conceptual representations arises because the brain system that automatically comes into play for processing a given type of information is the one that is inherently best suited to that processing. As an analogy, consider that the parts of one's body that come into play to perform a given task are the best suited ones: to catch a tennis ball, a closing hand automatically comes into play, rather than a pair or knees or a mouth or an armpit. Similarly, when physicists are processing information about oscillation, the brain system that comes into play is the one that would normally process rhythmic events, such as dance movements or ripples in a pond. And that is the source of the commonality across people. It is the same brain regions in everyone that are recruited to process a given concept.

So the secret of teaching ancient brains new tricks, as the advance of civilization has repeatedly done, is to empower creative thinkers to develop new understandings and inventions, by building on or repurposing the inherent information processing capabilities of the human brain. By communicating these newly developed concepts to others, they will root themselves in the same information processing capabilities of the recipients' brains as the original developers used. Mass communication and education can propogate the advances to entire populations. Thus the march of science, technology and civilization continue to be driven by the most powerful entity on Earth, the human brain.

Robert A. Mason, Reinhard A. Schumacher, Marcel Adam Just. The neuroscience of advanced scientific concepts. npj Science of Learning, 2021; 6 (1) DOI: 10.1038/s41539-021-00107-6

https://medicalxpress.com/news/2021-10-ancient-brains-modern-physic...

Part3

Comment by Dr. Krishna Kumari Challa on October 12, 2021 at 6:38am

For a physicist, some concepts like dark matter, neutrinos or the multiverse, their magnitude is not measureable. And in the physicists' brains, the measureable versus immeasurable concepts are organized separately.

Of course, some parts of the brain organization of the physics professors resembled the organization in physics students' brains such as concepts that had a periodic nature. Light, radio waves and gamma rays have a periodic nature but concepts like buoyancy and the multiverse do not.

part2

Comment by Dr. Krishna Kumari Challa on October 12, 2021 at 6:36am

How modern physicists think

The science of physics has strived to find the best possible explanations for understanding matter and energy in the physical world across all scales of space and time. Modern physics is filled with complex concepts and ideas that have revolutionized the way we see (and don't see) the universe. The mysteries of the physical world are increasingly being revealed by physicists who delve into non-intuitive, unseen worlds, involving the subatomic, quantum and cosmological realms. But how do the brains of advanced physicists manage this feat, of thinking about worlds that can't be experienced?

In a recently published paper in npj Science of Learning, researchers at Carnegie Mellon University have found a way to decode the brain activity associated with individual abstract scientific concepts pertaining to matter and energy, such as fermion or dark matter. They investigated the thought processes of their fellow CMU physics faculty concerning advanced physics concepts by recording their brain activity using functional Magnetic Resonance Imaging (fMRI).

This study's goal was to discover how the brain organizes highly abstract scientific concepts. An encyclopedia organizes knowledge alphabetically, a library organizes it according to something like the Dewey Decimal System, but how does the brain of a physicist do it?

The study examined whether the activation patterns evoked by the different physics concepts could be grouped in terms of concept properties. One of the most novel findings was that the physicists' brains organized the concepts into those with measureable versus immeasurable size.

Part1

Comment by Dr. Krishna Kumari Challa on October 11, 2021 at 11:06am

Chilean scientist plans to clean up mining with 'metal eating' bacteria

Starving microorganisms capable of surviving in extreme conditions have already managed to "eat" a nail in just three days.

In Chile, a scientist is testing "metal-eating" bacteria she hopes could help clean up the country's highly-polluting mining industry.

In her laboratory in Antofagasta, an industrial town 1,100-kilometers north of Santiago, 33-year-old biotechnologist Nadac Reales has been carrying out tests with extremophiles—organisms that live in extreme environments.

Reales came up with her idea while still at university as she was conducting tests at a mining plant using microorganisms to improve the extraction of copper.

The bacteria "live in an acidic environment that is practically unaffected by relatively high concentrations of most metals.

At first the bacteria took two months to disintegrate a nail."

But when starved, they had to adapt and find a way of feeding themselves.

After two years of trials, the result was a marked increase in the speed at which the bacteria "ate," devouring a nail in just three days. s "chemical and microbiological tests" have proved the bacteria are not harmful to humans or the environment.

https://phys.org/news/2021-10-chilean-scientist-metal-bacteria.html...

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Comment by Dr. Krishna Kumari Challa on October 10, 2021 at 1:10pm

The adult forms of the teeth we use to grind our food into a paste typically emerge from our gums in three stages – at around 6, 12, and 18 years of age (give or take).

Other primates get their adult molars earlier. For all our similarities in growth stages, the chimpanzee (Pan troglodytes) gets their molars at 3, 6, and 12. The yellow baboon (Papio cynocephalus) has its last adult molars out by age seven, and the rhesus macaque (Macaca mulatta) is all done by the time they're six.

One important factor constraining the timing of when teeth can appear is space. If the jaw isn't big enough for an adult-sized dental set, there's no point in squeezing them in.

Humans don't exactly have a lot of mouth space as it is, with impacted wisdom teeth a major problem for our species. But this doesn't explain why they pop up so late in our lives, or why the very back ones seem to be increasingly causing trouble.

Having an empty space for a tooth to grow doesn't make it a good idea to put one there, though. Teeth don't crunch all on their own – there's a whole lot of muscles and bone supporting them, ensuring sufficient pressure can safely tear and grind up our food.

"This study provides a powerful new lens through which the long-known linkages among dental development, skull growth and maturational profiles.

https://www.sciencealert.com/we-now-know-why-we-don-t-get-our-wisdo...

part2

Comment by Dr. Krishna Kumari Challa on October 10, 2021 at 1:09pm

Scientists Finally Know Why Wisdom Teeth Only Emerge When We're Basically Adults

Homo sapiens don't grow their last few teeth until they're nearly out of the teenage years.

This mystery of the molars is a tricky one to solve, in spite of their emergence playing such a critical role in tracking shifts in our evolution. But researchers  now think they might have cracked it.

One of the mysteries of human biological development is how the precise synchrony between molar emergence and life history came about and how it is regulated. Turning the bones and teeth of 21 species of primate into 3D models, the researchers were able to work out that the timing of our adult molars has a lot to do with the delicate balance of biomechanics in our growing skulls.  

And it's 'safety' that seems to be behind our tardy tooth growth.

"It turns out that our jaws grow very slowly, likely due to our overall slow life histories and, in combination with our short faces, delays when a mechanically safe space – or a 'sweet spot,' if you will – is available, resulting in our very late ages at molar emergence.

The back molars in primates sit just in front of two temporomandibular joints, which together form a hinge between your jaw and the skull. Unlike other joints in our body, the two pivots have to operate in perfect sync with one another. They also need to transfer a fair degree of force onto one or more points to get you biting and chewing.

In biomechanics, this three-point-process is governed by principles within something called the constrained level model. Put a tooth in the wrong spot, and the forces produced under this model could be bad news for a jaw that simply isn't big enough to cope.

For species with longer jaws, the time it takes for the skull to develop a suitable structure for teeth closest to the muscles near the hinge is relatively brief.

Humans, with our significantly flatter faces, have no such luck, needing to wait until our skulls have developed to a point that the forces put on each set of adult molars won't damage our growing jaw.

Not only does this give us a new way to evaluate dental conditions, such as impacted molars, but it could help paleontologists to better understand the evolution of our unique jaws among our hominid ancestors.

https://www.science.org/doi/10.1126/sciadv.abj0335

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