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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

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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

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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.

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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...

Comment by Dr. Krishna Kumari Challa on January 13, 2021 at 12:03pm

Washing your clothes can create microplastic pollution

Households in Europe and North America are flooding the oceans with plastic pollution simply by washing their clothes, scientists said Tuesday after research found the majority of microplastics in Arctic seawater were polyester fibres.

Plastic particles have infiltrated even the most remote and seemingly-pristine regions of the planet.

These tiny fragments have been discovered inside fish in the deepest recesses of the ocean—the Mariana Trench—peppering Arctic sea ice and blanketing the snows on the Pyrenees mountains between France and Spain.

But questions remain over exactly where this plastic contamination is coming from.

In the new study by the Ocean Wise conservation group and Canada's Department of Fisheries and Oceans, researchers sampled seawater from across the Arctic and found synthetic fibres made up around 92 percent of microplastic pollution.

Of this, around 73 percent was found to be polyester, resembling the dimensions and chemical identities of synthetic textiles—particularly clothing.

"The striking conclusion here is that we now have strong evidence that homes in Europe and North America are directly polluting the Arctic with fibres from laundry (via wastewater discharge)

 Pervasive distribution of polyester fibres in the Arctic Ocean is driven by Atlantic inputs, Nature Communications, DOI: 10.1038/s41467-020-20347-1 , www.nature.com/articles/s41467-020-20347-1

https://phys.org/news/2021-01-arctic-microplastic-pollution.html?ut...

Comment by Dr. Krishna Kumari Challa on January 13, 2021 at 11:55am

Researchers develop oral insulin nanoparticles that could be an alternative to jabs

Scientists have developed insulin nanoparticles that may one day become the basis for an oral medicine, and an alternative to insulin injections for diabetic patients.
In a pre-clinical study, the scientist team fed insulin-containing nanoparticles to rats and found that insulin increased in their blood minutes later.
Insulin therapy is often an important part of treatment for diabetes, a metabolic disease that affects 422 million people globally .
Delivering insulin orally would be preferable over insulin jabs for patients because it causes less pain than jabs, and could thus lead to improved patient compliance. But oral dosage remains a challenge. As insulin is a protein, it gets broken down in the gastrointestinal tract before it can even reach the bloodstream to regulate blood glucose.
To overcome this challenge, the interdisciplinary team designed a nanoparticle loaded with insulin at the core, then coated with alternating layers of insulin and chitosan, a natural sugar. Dosing is achieved by controlling the number of layers in the nanoparticle.
Through lab experiments using cell cultures and rat models, the team demonstrated that this layer-by-layer coated nanoparticle is stable as it passes through the stomach into the small intestine with minimal insulin release, and is able to pass through the intestinal walls into the bloodstream.

 Yiming Zhang et al. Layer-by-layer coated nanoliposomes for oral delivery of insulin, Nanoscale (2020). DOI: 10.1039/D0NR06104B

https://phys.org/news/2021-01-oral-insulin-nanoparticles-alternativ...

Comment by Dr. Krishna Kumari Challa on January 13, 2021 at 11:49am

Discovery of quantum behavior in insulators suggests possible new particle

In a surprising discovery, Princeton physicists have observed an unexpected quantum behavior in an insulator made from a material called tungsten ditelluride. This phenomenon, known as quantum oscillation, is typically observed in metals rather than insulators, and its discovery offers new insights into our understanding of the quantum world. The findings also hint at the existence of an entirely new type of quantum particle.

The discovery challenges a long-held distinction between metals and insulators, because in the established quantum theory of materials, insulators were not thought to be able to experience quantum oscillations.

If scientists' interpretations are correct, we are dealing with a fundamentally new form of quantum matter.

The observation of quantum oscillations has long been considered a hallmark of the difference between metals and insulators. In metals, electrons are highly mobile, and resistivity—the resistance to electrical conduction—is weak. Nearly a century ago, researchers observed that a magnetic field, coupled with very low temperatures, can cause electrons to shift from a "classical" state to a quantum state, causing oscillations in the metal's resistivity. In insulators, by contrast, electrons cannot move and the materials have very high resistivity, so quantum oscillations of this sort are not expected to occur, no matter the strength of magnetic field applied.

The discovery was made when the researchers were studying a material called tungsten ditelluride, which they made into a two-dimensional material. They prepared the material by using standard scotch tape to increasingly exfoliate, or "shave," the layers down to what is called a monolayer—a single atom-thin layer. Thick tungsten ditelluride behaves like a metal. But once it is converted to a monolayer, it becomes a very strong insulator.

This material has a lot of quantum properties.

 Pengjie Wang et al, Landau quantization and highly mobile fermions in an insulator, Nature (2021). DOI: 10.1038/s41586-020-03084-9

https://phys.org/news/2021-01-discovery-quantum-behavior-insulators...

Comment by Dr. Krishna Kumari Challa on January 13, 2021 at 10:32am

Breakthrough technology promises earlier detection for Alzheimer’s disease

Comment by Dr. Krishna Kumari Challa on January 12, 2021 at 1:40pm

Why does ice float on water?

https://www.sciencefocus.com/science/why-does-ice-float-on-water/?u...

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Scientist develops method to find toxic chemicals in drinking water

Most consumers of drinking water in the United States know that chemicals are used in the treatment processes to ensure the water is safe to drink. But they might not know that the use of some of these chemicals, such as chlorine, can also lead to the formation of unregulated toxic byproducts.

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How does Wi-Fi work?

https://theconversation.com/how-does-wi-fi-work-an-electrical-engin...

Comment by Dr. Krishna Kumari Challa on January 12, 2021 at 1:32pm

Most Covid-19 patients have at least one symptom 6 months on: study

More than three quarters of people hospitalised with Covid-19 still suffered from at least one symptom after six months, according to a study published Saturday that scientists said shows the need for further investigation into lingering coronavirus effects. The research, which was published in the Lancet medical journal and involved hundreds of patients in the Chinese city of Wuhan, is among the few to trace the long-term symptoms of Covid-19 infection. It found that fatigue or muscle weakness were the most common symptoms, while people also reported sleeping difficulties. "Because Covid-19 is such a new disease, we are only beginning to understand some of its long-term effects on patients' health," said lead author Bin Cao, of the National Center for Respiratory Medicine. The professor said the research highlighted the need for ongoing care for patients after they have been discharged from hospital, particularly those who have had severe infections.

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