Comment

Comment by Dr. Krishna Kumari Challa on January 14, 2021 at 11:57am

These tiny oceanic creatures are essential to tackling climate change

The ocean withdraws about one third of the CO₂ in the atmosphere, mitigating climate change and making life possible on Earth. An important share of this CO2 is removed thanks to phytoplankton, tiny marine creatures that use light to do photosynthesis, just as plants or trees on land. These cells fix CO2 to build up biomass and multiply, and take it down to the deep ocean when they die and sink. Phytoplankton are thus the basis of the marine food chain, and their productivity not only affects CO2 levels, but also fish catch and world economy.

--

Wormholes may be lurking in the universe—and new studies are propos...

Albert Einstein's theory of general relativity profoundly changed our thinking about fundamental concepts in physics, such as space and time. But it also left us with some deep mysteries. One was black holes, which were only unequivocally detected over the past few years. Another was "wormholes"—bridges connecting different points in spacetime, in theory providing shortcuts for space travelers.

Comment by Dr. Krishna Kumari Challa on January 14, 2021 at 11:56am

Researchers at Brazil's space institute discover why lightning branches and flickers

Researchers have recorded for the first time the formation and branching of luminous structures by lightning strikes.

Analyzing images captured by a super slow motion camera, they discovered why lightning strikes bifurcate and sometimes then form luminous structures interpreted by the human eye as flickers.

The researchers used ultra high speed digital video cameras to record more than 200 upward flashes during summer thunderstorms in São Paulo City (Brazil) and Rapid City, South Dakota (USA) between 2008 and 2019. Upward lightning strikes start from the top of a tall building or other ground-based structure and propagate upward to the overlying cloud.

The upward flashes they recorded were triggered by positively charged cloud-to-ground lightning discharges, which are much more common, as described by the same INPE research group in a previous study.

"Upward lightning originates at the top of a tower or the lightning conductor on a skyscraper, for example, when the storm's electrical field is disturbed by a cloud-to-ground discharge as far away as 60 kilometers.

Although the study conditions were very similar in Brazil and the US, luminous structures were observed in only three upward flashes, recorded in the US. These were formed by a positive leader discharge propagating toward the cloud base.

"The advantage of recording images of upward lightning is that they let us see the entire trajectory of these positive leaders from ground to cloud base. Once inside the cloud, they can no longer be seen.

The researchers found that a low-luminosity discharge with a structure resembling a paintbrush sometimes forms at the tip of the positive leader. It was observed that this discharge, often referred to as a corona brush, may change direction, split in two, and define the path of the lightning flash and how it branches.

When an upward flash branches successfully, it may proceed to the left or right. When branching fails, the corona brush may give rise to very short segments as bright as the leader itself. These segments first appear milliseconds after the corona brush splits, and pulsate as the leader propagates upward toward the cloud base, the videos show.

The flickers are recurring failed attempts to start a branch, the flickers may explain why multiple lightning discharges are frequent, but more studies are needed to verify this theory.

Marcelo M. F. Saba et al, Optical observation of needles in upward lightning flashes, Scientific Reports (2020). DOI: 10.1038/s41598-020-74597-6

https://phys.org/news/2021-01-brazil-space-lightning-flickers.html?...

**

Comment by Dr. Krishna Kumari Challa on January 14, 2021 at 11:43am

Researchers identify nanoparticles that could deliver therapeutic mRNA before birth

Researchers have identified ionizable lipid nanoparticles that could be used to deliver mRNA as part of fetal therapy. The proof-of-concept study, published today in Science Advances, engineered and screened a number of lipid nanoparticle formulations for targeting mouse fetal organs and has laid the groundwork for testing potential therapies to treat genetic diseases before birth.

This is an important first step in identifying nonviral mediated approaches for delivering cutting-edge therapies before birth.

These lipid nanoparticles may provide a platform for in utero mRNA delivery, which would be used in therapies like fetal protein replacement and gene editing.

Having identified the lipid nanoparticles that were able to accumulate within fetal livers, lungs, and intestines with the highest efficiency and safety, the researchers also tested therapeutic potential of those designs by using them to deliver erythropoietin (EPO) mRNA, as the EPO protein is easily trackable. They found that EPO mRNA delivery to liver cells in mouse fetuses resulted in elevated levels of EPO protein in the fetal circulation, providing a model for protein replacement therapy via the liver using these lipid nanoparticles.

"Ionizable lipid nanoparticles for in utero mRNA delivery" Science Advances (2021). DOI: 10.1126/sciadv.aba1028

https://phys.org/news/2021-01-nanoparticles-therapeutic-mrna-birth....

Comment by Dr. Krishna Kumari Challa on January 14, 2021 at 11:39am

Grey camouflage 'better than zebra stripes'

Dull, featureless camouflage provides better protection from predators than zebra stripes, according to a new study.

Biologists explaining the existence of such stripes have proposed the "motion dazzle hypothesis", which suggests that high-contrast patterns can make it difficult for predators to track a moving target.

University of Exeter scientists tested this using a touch-screen game called Dazzle Bug in which visitors to Cornwall's Eden Project had to catch a moving rectangular "bug".

Bug patterns were programmed to "evolve" to find the best camouflage strategy.

"Surprisingly, targets evolved to lose patterns and instead match their backgrounds. 

The new study results indicate that low-contrast, featureless targets were hardest to catch when in motion. These findings provide the clearest evidence to date against the motion dazzle hypothesis and suggest that protection in motion may rely on completely different mechanisms to those previously assumed.

 An online version of the game is available to play at www.dazzle-bug.co.uk

The evolution of patterning during movement in a large-scale citizen science game, Proceedings of the Royal Society B, rspb.royalsocietypublishing.or … .1098/rspb.2020.2823

https://phys.org/news/2021-01-grey-camouflage-zebra-stripes.html?ut...

**

Comment by Dr. Krishna Kumari Challa on January 14, 2021 at 11:33am

Could we harness energy from black holes?

A remarkable prediction of Einstein's theory of general relativity—the theory that connects space, time, and gravity—is that rotating black holes have enormous amounts of energy available to be tapped.

For the last 50 years, scientists have tried to come up with methods to unleash this power. Nobel physicist Roger Penrose theorized that a particle disintegration could draw energy from a black hole; Stephen Hawking proposed that black holes could release energy through quantum mechanical emission; while Roger Blandford and Roman Znajek suggested electromagnetic torque as a main agent of energy extraction.

Now, in a study published in the journal Physical Review D, physicists Luca Comisso from Columbia University and Felipe Asenjo from Universidad Adolfo Ibanez in Chile, found a new way to extract energy from black holes by breaking and rejoining magnetic field lines near the event horizon, the point from which nothing, not even light, can escape the black hole's gravitational pull.

"Black holes are commonly surrounded by a hot 'soup' of plasma particles that carry a magnetic field. This new theory theory shows that when magnetic field lines disconnect and reconnect, in just the right way, they can accelerate plasma particles to negative energies and large amounts of black hole energy can be extracted.

This finding could allow astronomers to better estimate the spin of black holes, drive black hole energy emissions, and might even provide a source of energy for the needs of an advanced civilization.

Luca Comisso and Felipe A. Asenjo. Magnetic reconnection as a mechanism for energy extraction from rotating black holes. Phys. Rev. D. DOI: 10.1103/PhysRevD.103.023014 , journals.aps.org/prd/accepted/ … 304179756dd56a93a764

https://phys.org/news/2021-01-harness-energy-black-holes.html?utm_s...

Comment by Dr. Krishna Kumari Challa on January 14, 2021 at 11:27am

Fish-inspired robots coordinate movements without any outside control

Schools of fish exhibit complex, synchronized behaviors that help them find food, migrate and evade predators. No one fish or team of fish coordinates these movements nor do fish communicate with each other about what to do next. Rather, these collective behaviors emerge from so-called implicit coordination—individual fish making decisions based on what they see their neighbors doing.

This type of decentralized, autonomous self-organization and coordination has long fascinated scientists, especially in the field of robotics.

Now, a team of researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and the Wyss Institute for Biologically Inspired Engineering have developed fish-inspired robots that can synchronize their movements like a real school of fish, without any external control. It is the first time researchers have demonstrated complex 3-D collective behaviours with implicit coordination in underwater robots.

F. Berlinger el al., "Implicit coordination for 3D underwater collective behaviors in a fish-inspired robot swarm," Science Robotics (2021). robotics.sciencemag.org/lookup … /scirobotics.abd8668

https://techxplore.com/news/2021-01-fish-inspired-robots-movements....

Comment by Dr. Krishna Kumari Challa on January 14, 2021 at 11:19am

Melting icebergs key to sequence of an ice age, scientists find

Scientists claim to have found the 'missing link' in the process that leads to an ice age on Earth.

Melting icebergs in the Antarctic are the key, say the team from Cardiff University, triggering a series of chain reactions that plunges Earth into a prolonged period of cold temperatures.

The findings have been published today in Nature from an international consortium of scientists from universities around the world.

It has long been known that ice age cycles are paced by periodic changes to Earth's orbit of the sun, which subsequently changes the amount of solar radiation that reaches the Earth's surface.

However, up until now it has been a mystery as to how small variations in solar energy can trigger such dramatic shifts in the climate on Earth.

In their study, the team propose that when the orbit of Earth around the sun is just right, Antarctic icebergs begin to melt further and further away from Antarctica, shifting huge volumes of freshwater away from the Southern Ocean and into the Atlantic Ocean.

As the Southern Ocean gets saltier and the North Atlantic gets fresher, large-scale ocean circulation patterns begin to dramatically change, pulling CO₂ out of the atmosphere and reducing the so-called greenhouse effect.

This in turn pushes the Earth into ice age conditions.

As part of their study the scientists used multiple techniques to reconstruct past climate conditions, which included identifying tiny fragments of Antarctic rock dropped in the open ocean by melting icebergs.

Antarctic icebergs reorganize ocean circulation during Pleistocene glacials, Nature (2021). DOI: 10.1038/s41586-020-03094-7 , www.nature.com/articles/s41586-020-03094-7

https://phys.org/news/2021-01-icebergs-key-sequence-ice-age.html?ut...

Comment by Dr. Krishna Kumari Challa on January 13, 2021 at 1:01pm

Study Just Identified 6 Distinct Types of Prediabetes

People with prediabetes have a higher than normal blood sugar level, and sometimes – but not always – go on to develop type 2 diabetes. Doctors should now be able to better manage that risk, thanks to a study identifying six different subtypes of prediabetes.

In an analysis covering 25 years of data and 899 individuals, researchers were able to categorise these six subtypes through a series of shared biomarkers, including glucose levels, liver fat, body fat distribution, blood lipid levels, and genetic risk.

The six subtypes (or "clusters") carry different levels of risk when it comes to developing type 2 diabetes, and that should help health professionals in tailoring treatments to match, as well as managing prediabetes and the secondary issues that come with it.

Clusters 1, 2 and 4 represent a low diabetes risk: they include participants who aren't overweight, or who are overweight but have a relatively healthy metabolism. Clusters 3, 5 and 6, meanwhile, are linked to an increased risk of diabetes and secondary diseases. 

Those in cluster 3 produce too little insulin naturally, as well as showing other biomarkers such as higher intima-media thickness (IMT) in their arteries. Cluster 5 includes people more resistant to the effects of insulin and also with higher amounts of liver fat.

Those in cluster 6 have higher levels of particular types of body fat (visceral and renal sinus). While these individuals have a lower risk of developing diabetes compared with clusters 3 and 5, there is a higher mortality risk and more chance of kidney malfunction in this group.

https://www.nature.com/articles/s41591-020-1116-9

**

https://www.sciencealert.com/a-new-25-year-study-has-identified-six...

Comment by Dr. Krishna Kumari Challa on January 13, 2021 at 12:57pm

The properties and anatomy of an unfixed brain.

WARNING: The video contains graphic images

--
Error-protected quantum bits entangled for the first time

Error-protected quantum bits entangled for the first time

For the first time, physicists from the University of Innsbruck have entangled two quantum bits distributed over several quantum objects and successfully transmitted their quantum properties. This marks an important milestone in the development of fault-tolerant quantum computers. The researchers published their report in Nature.

--

Mathematics explains how giant whirlpools form in developing egg cells

Egg cells are among the largest cells in the animal kingdom. If moved only by the random jostlings of water molecules, a protein could take hours or even days to drift from one side of a forming egg cell to the other. Luckily, nature has developed a faster way: cell-spanning whirlpools in the immature egg cells of animals such as mice, zebrafish and fruit flies. These vortices enable cross-cell commutes that take just a fraction of the time. But until now, scientists didn't know how these crucial flows formed.

Comment by Dr. Krishna Kumari Challa on January 13, 2021 at 12:46pm

Scientists Discover a New Type of Chemical Bond, And It's Surprisingly Strong

It's like the hydrogen bonds found in water, but way stronger.

Scientists have recently discovered a totally new type of chemical bond – and it's way stronger than it has any right to be.

The new type of bond shows that the divide between powerful covalent bonds, which bind molecules together, and weak hydrogen bonds, which form between molecules and can be broken by something as simple as stirring salt into a glass of water.

Ionic bonds link metals and non-metals to form salts. Strong covalent bonds bind together molecules like carbon dioxide and water. Far weaker hydrogen bonds form because of an electrostatic type of attraction between hydrogen and a more negatively charged atom or molecule, for instance causing water molecules to attract one another and form droplets or crystalline ice.

Ionic, covalent, and hydrogen bonds are all relatively stable; they tend to last for extended periods of time and have effects are easily observable.

But researchers have long known that during a chemical reaction, as chemical bonds are forming or breaking, the story is more complicated and involves "intermediate states" that may exist for tiny fractions of a second and are more difficult to observe. 

In the new study, the researchers managed to keep these intermediate states going for long enough to make a detailed examination. What they found was a hydrogen bond with the strength of a covalent bond, binding atoms together into something resembling a molecule.

https://www.livescience.com/new-chemical-bond-discovered.html

https://www.sciencealert.com/scientists-discover-a-new-type-of-chem...

• ‹ Previous
• 1
• …
• 722
• 723
• 724
• 725
• 726
• …
• 1113
• Next ›
• Page