Tech

The universe mainly consists of a novel substance and an energy form that are not yet understood. This 'dark matter' and 'dark energy' are not directly visible to the naked eye or through telescopes. Astronomers can only provide proof of their existence indirectly, based on the shape of galaxies and the dynamics of the universe. Dark matter interacts with normal matter via the gravitational force, which also determines the cosmic structures of normal, visible matter.

It is not yet known whether dark matter also interacts with itself or with normal matter via the other three fundamental forces - the electromagnetic force, the weak and the strong nuclear force - or some additional force. Even very sophisticated experiments have so far not been able to detect any such interaction. This means that if it does exist at all, it must be very weak.

In order to shed more light on this topic, scientists around the globe are carrying out various new experiments in which the action of the non-gravitational fundamental forces takes place with as little outside interference as possible and the action is then precisely measured. Any deviations from the expected effects may indicate the influence of dark matter or dark energy. Some of these experiments are being carried out using huge research machines such as those housed at CERN, the European Organization for Nuclear Research in Geneva. But laboratory-scale experiments, for example in Düsseldorf, are also feasible, if designed for maximum precision.

The team working under guidance of Prof. Stephan Schiller from the Institute of Experimental Physics at HHU has presented the findings of a precision experiment to measure the electrical force between the proton ("p") and the deuteron ("d") in the journal Nature. The proton is the nucleus of the hydrogen atom (H), the heavier deuteron is the nucleus of deuterium (D) and consists of a proton and a neutron bound together.

The Düsseldorf physicists study an unusual object, HD+, the ion of the partially deuterated hydrogen molecule. One of the two electrons normally contained in the electron shell is missing in this ion. Thus, HD+ consists of a proton and deuteron bound together by just one electron, which compensates for the repulsive electrical force between them.

This results in a particular distance between the proton and the deuteron, referred to as the 'bond length'. In order to determine this distance, the HHU physicists have measured the rotation rate of the molecule with eleven digits precision using a spectroscopy technique they recently developed. The researchers used concepts that are also relevant in the field of quantum technology, such as particle traps and laser cooling.

It is extremely complicated to derive the bond length from the spectroscopy results, and thus to deduct the strength of the force exerted between the proton and the deuteron. This is because this force has quantum properties. The theory of quantum electrodynamics (QED) proposed in the 1940s must be used here. A member of the author team spent two decades to advance the complex calculations and was recently able to predict the bond length with sufficient precision.

This prediction corresponds to the measurement result. From the agreement one can deduce the maximum strength of a modification of the force between a proton and a deuteron caused by dark matter. Prof. Schiller comments: "My team has now pushed down this upper limit more than 20-fold. We have demonstrated that dark matter interacts much less with normal matter than was previously considered possible. This mysterious form of matter continues to remain undercover, at least in the lab!"

According to a study by Charité - Universitätsmedizin Berlin, the northern Italian city of Nembro recorded more deaths during March 2020 than between January and December 2019. However, only approximately half of all deaths recorded this spring were classified as confirmed COVID-19 deaths. The study shows that the health impacts of the COVID-19 pandemic may go far beyond official COVID-19 death counts. It also shows the important role of all-cause mortality in quantifying the full impact of the pandemic. The study's findings have been published in The BMJ*.

During the current pandemic, the northern Italian region of Lombardy has been one of the most severely affected areas in Europe. Despite high death counts officially attributed to COVID-19 during the worst part of the pandemic, doubts were soon raised over the accuracy of these data. Official figures did not appear to reflect actual, observable pressures on the health care system. This was also the case in Nembro, a small town in the Bergamo province of Lombardy, which has a population of 11,500. In order to quantify the true impact of the pandemic on the local health care system, a team of researchers led by Tobias Kurth, MD, ScD, Director of Charité's Institute of Public Health (IPH), studied overall mortality figures, looking at all deaths regardless of their cause. Working alongside colleagues from the Centro Medico Santagostino in Milan, the researchers found the following: During the height of the pandemic in the spring of 2020, the number of all-cause deaths was approximately double that of confirmed COVID-19-related deaths.

In order to accurately quantify mortality rate regardless of cause of death - known as all-cause mortality - the researchers used data for the period between January 2012 and mid-April 2020. They obtained data from several sources: the Italian National Institute of Statistics (ISTAT), Nembro's registration office, and the Lombardy region COVID-19 dashboard. "Nembro is a small town with a very stable population and very little immigration and emigration over time," explains Prof. Kurth. He adds: "Given its size and the availability of quality data sources, this town provided the ideal conditions for a robust, descriptive epidemiological study to quantify the impact of the current COVID-19 pandemic as well as its impact on the health of this local community."

According to the researchers' analyses, in recent years the town typically recorded all-cause death counts just over 100 per year. In 2018 and 2019, for instance, the town recorded 128 and 121 deaths, respectively. This contrasts sharply with the 194 deaths seen during the three-and-a-half-month period between 1 January 2020 and 11 April 2020; of these, 151 occurred in March 2020 alone. This corresponds to a monthly all-cause mortality of 154 deaths per 1,000 person years for March 2020, nearly eleven times the rate recorded for the same month of the previous year (14 deaths per 1,000 person years). The largest increase in mortality recorded during the pandemic was seen among people aged 65 and over, with men disproportionately affected. 14 deaths involved people younger than 65.

"In the light of Nembro's otherwise extremely stable all-cause mortality figures, the massive increase in mortality seen during March 2020 can only be interpreted as a consequence of the coronavirus pandemic", says the study's first author, Marco Piccininni, who is a researcher at the IPH. Out of a total of 166 deaths recorded during the pandemic (late February to early April 2020), only 85 had tested positive and were subsequently recorded as deaths from COVID-19. "This represents an enormous discrepancy and shows that the pandemic's impact on the health of the population was significantly more pronounced than the official COVID-19 death count would suggest," explains Piccininni. The study's authors believe there are two main reasons for this discrepancy. Firstly, it is likely that not all infected people were identified as such. This is probably attributable to a shortage of materials needed for testing and the fact that not all suspected cases were tested. Secondly, this could be due to people with non-COVID-related conditions having impaired access to health care, either because health system capacities had been exhausted by COVID-19 cases or because of individuals' reluctance to visit the hospital for fear of infection.

"If we are to accurately quantify the health impact of the pandemic, we must not rely on confirmed COVID-19 deaths as the sole metric," emphasizes Prof. Kurth. "To better adapt containment measures to the local situation, consideration should also be given to current data on all-cause mortality from within the relevant region. Unfortunately, it is not always possible to access up-to-date all-cause mortality data. I am pleased that Germany has recently started to make preliminary figures available."

Infrared imagery from NASA's Aqua satellite and radar imagery revealed that Tropical Storm Arthur remains poorly organized. Strongest storms, according to the Aqua data, appeared along and off the southeastern coast of North Carolina.

Warnings and Watches

On May 18, a Tropical Storm Warning is in effect from Surf City to Duck, North Carolina, and for the Pamlico and Albemarle Sounds.

Satellite Imagery

NASA's Aqua satellite used infrared light to analyze the strength of storms and found the center of circulation was displaced from the bulk of them. Infrared data provides temperature information, and the strongest thunderstorms that reach high into the atmosphere have the coldest cloud top temperatures.

On May 18 at 2:35 a.m. EDT (0635 UTC), the MODIS instrument that flies aboard NASA's Aqua satellite showed strongest storms in Tropical Storm Arthur were along the southeastern coast of North Carolina and just off-shore. Those strong storms contained cloud top temperatures were as cold as minus 63 degrees Fahrenheit (minus 52.7 Celsius). Cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall.

MODIS imagery showed the low-level center located near the southwestern edge of a complex of ragged convective bands.

Status on May 18, 2020

At 8 a.m. EDT (1200 UTC), the National Hurricane Center (NHC) reported the center of Tropical Storm Arthur was located near latitude 34.5 north, longitude 75.9 west. Arthur was moving toward the north-northeast near 15 mph (24 kph).  A turn toward the northeast with an increase in forward speed is expected later today, followed by a turn toward the east on Tuesday.

Maximum sustained winds are near 45 mph (75 kph) with higher gusts. While some strengthening is forecast during the next 48 hours, Arthur is likely to lose its tropical characteristics on Tuesday. Tropical-storm-force winds extend outward up to 90 miles (150 km) mainly to the east of the center.

The estimated minimum central pressure reported from an Air Force Reserve Hurricane Hunter aircraft is 1001 millibars.

Rip Currents and Life-Threatening Surf Along Coastal Areas

Swells generated by Arthur are affecting portions of the southeast U.S. coast and are expected to spread northward along the U.S. mid-Atlantic coast during the next day or two. NHC cautioned, "These swells could cause life-threatening surf and rip current conditions."

Arthur's Forecast Path

At 5 a.m. EDT on May 18, 2020, NOAA's National Hurricane Center noted that Arthur's movement is going to be affected by two factors: "A baroclinic trough (elongated area of low pressure) and associated surface front approaching from the west should cause Arthur to turn northeastward during the next several hours. The forecast track shows the center passing near or just offshore of the North Carolina Outer Banks.  By Tuesday and Tuesday night, Arthur will be entering the strong mid-latitude Westerlies, which will steer cyclone eastward in a day or two."

When NASA's Aqua satellite passed over the Northern Indian Ocean on May 18, it gathered water vapor data that showed the intensity of powerful Tropical Cyclone Amphan. Amphan is the equivalent of a Category 5 hurricane on the Saffir-Simpson Hurricane Wind Scale.

Water vapor analysis of tropical cyclones tells forecasters how much potential a storm has to develop. Water vapor releases latent heat as it condenses into liquid. That liquid becomes clouds and thunderstorms that make up a tropical cyclone. Temperature is important when trying to understand how strong storms can be. The higher the cloud tops, the colder and the stronger the storms.

NASA's Aqua satellite passed over Tropical Cyclone Amphan on May 18 at 3:40 a.m. EST (0740 UTC), and the Moderate Resolution Imaging Spectroradiometer or MODIS instrument gathered water vapor content and temperature information. The MODIS image showed highest concentrations of water vapor and coldest cloud top temperatures circled the visible eye.

MODIS data showed coldest cloud top temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius) in those storms. Storms with cloud top temperatures that cold have the capability to produce heavy rainfall.

NASA-NOAA's Suomi NPP satellite provided a visible image of the huge Tropical Cyclone Amphan on May 18, just off the eastern coast of India. The image showed the extent of the storm, which was over open ocean, stretching from just north of Sri Lanka, north, past the Indian states of Tamil Nadu to Andrha Pradesh.

At 5 a.m. EDT (0900 UTC) on May 18, the Joint Typhoon Warning Center (JTWC) noted that Amphan's eye was centered near latitude 13.6 degrees north and longitude 86.4 degrees east, about 301 nautical miles southeast of Visakhapatnam, India. Amphan was moving to the north and had maximum sustained winds 140 knots (161 mph/259 kph).

Amphan will move north and is expected to strengthen slightly. JTWC said the storm will then gradually weaken prior to landfall near Kolkata, India in two days.

NASA's Aqua satellite is one in a fleet of NASA satellites that provide data for hurricane research.

Tropical cyclones/hurricanes are the most powerful weather events on Earth. NASA's expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.

CLEMSON, South Carolina - Clemson University scientists have taken another step forward in their quest to find a cure for a notorious parasite that has infected more than 40 million Americans and many times that number around the world.

A newly released study led by Zhicheng Dou of the College of Science provides evidence that disrupting heme production in Toxoplasma gondii could be an effective therapeutic strategy to control this common and sometimes deadly infection. Their work focuses on a metabolic pathway for heme production in the parasites. Heme is a key molecule that occurs naturally in almost all living organisms and allows blood to carry oxygen throughout our bodies.

Dou's collaborative research has been published in PLOS Pathogens, a high-profile microbiology journal. The study is titled "Toxoplasma gondii requires its plant-like heme biosynthesis pathway for infection."

"Toxoplasma is a eukaryotic pathogen, which means it shares similar metabolic pathways as human cells," said Dou, an assistant professor in the department of biological sciences. "For example, in this paper, we studied the heme metabolism in parasites. In our own cells, we have very similar pathways of heme production."

But in Toxoplasma, Dou's research found that heme metabolism carries some plant-like features.

"This is very interesting," said Dou, a faculty member in Clemson's Eukaryotic Pathogens Innovation Center (EPIC). "The parasite has a plant-like organelle inside. Part of the heme metabolism is encapsulated inside this organelle. Parasites have some plant-like genes and some animal-like genes. We call Toxoplasma parasite 'hybrid.' "

Toxoplasma is an extremely common parasite that can lie dormant for an infected person's entire lifetime. But for some people, it is far from harmless.

"Most people don't know they have the infection," Dou said. "Most people will not feel any symptoms because their immune system is strong enough to resist the infection. The parasite can hide in the human body. But if immunity is compromised, the parasite can be reactivated."

For example, the parasite poses a danger to cancer patients and organ transplant recipients who take immune-suppressing drugs as part of their treatment. In pregnant women, the parasite can affect the developing fetus.

After identifying the plant-like part of the heme biosynthesis pathway in the parasites, Dou's research focused on the possibility of using herbicides to inhibit the heme metabolism, denying the parasite an essential nutrient. In this proof-of-concept study, one class of herbicide was found to work.

"We found several herbicides within the same category that can inhibit the parasite's growth," Dou said.

The research started with a commercially available herbicide that was not sufficiently potent. Dou then called on a colleague to modify the original herbicide.

"I'm part of the same center that studies eukaryotic pathogens, but my training is very different than his," said Daniel Whitehead, an associate professor in the department of chemistry who is also a faculty member of EPIC. "My group is a synthetic organic chemistry group. What we specialize in is the ability to make molecules. I think his study uncovers a druggable target that might be useful to treat infections of Toxoplasma."

Dou's research uncovered what Whitehead called a "molecular scaffold" that can be built around to create more potent derivatives. Dou said the results are encouraging.

"He can generate new molecules in his lab, and we can test the new molecules in my lab, and we'll work together," Dou said. "Modify, test, modify, test."

Whitehead said the research highlights the purpose of EPIC.

"If we blend our expertise, we can accomplish things that neither one of us can accomplish alone," Whitehead said. "Without the co-mingling of expertise, these types of opportunities can be missed."

A new way of creating carbon fibers -- which are typically expensive to make -- could one day lead to using these lightweight, high-strength materials to improve safety and reduce the cost of producing cars, according to a team of researchers. Using a mix of computer simulations and laboratory experiments, the team found that adding small amounts of the 2D graphene to the production process both reduces the production cost and strengthens the fibers.

For decades, carbon fibers have been a mainstay of airplane production. If created in the right way, these long strands of carbon-based atoms, narrower than human hair, are lightweight, stiff and strong -- a perfect application for keeping passengers safe in a vehicle soaring miles above the ground.

"Even though carbon fibers have really nice features, they would make a car far more expensive" with the way carbon fibers are manufactured now, said Adri van Duin, professor of mechanical and chemical engineering, Penn State. "If you can get these properties easier to manufacture then you can make cars significantly lighter, lower the cost of them and make them safer."

Carbon fiber sells for about $15 per pound today, and the team, which includes researchers from Penn State, the University of Virginia and Oak Ridge National Laboratory, in collaboration with industry partners Solvay and Oshkosh, wants to reduce that to $5 per pound by making changes to the complex production process. A lower production cost will increase carbon fiber's potential applications, including in cars. Further, the team's research may lower the cost of producing other types of carbon fibers, some of which sell for up to $900 per pound today.

"Currently most carbon fibers are produced from a polymer known as polyacrylonitrile, or PAN, and it is pretty costly," said Ma?gorzata Kowalik, researcher in Penn State's Department of Mechanical Engineering. "The price of PAN makes up about 50% of the production cost of carbon fibers."

PAN is used to create 90% of carbon fibers found in the market today, but its production requires an enormous amount of energy. First, PAN fibers have to be heated to 200-300 degrees Celsius to oxidize them. Next, they must be heated to 1,200-1,600 degrees Celsius to transform the atoms into carbon. Finally, they have to be heated to 2,100 degrees Celsius so that the molecules are aligned properly. Without this series of steps, the resulting material would lack its needed strength and stiffness.

The team reported in a recent issue of Science Advances that adding trace amounts of graphene -- only 0.075% concentration by weight -- to the first stages of this process allowed the team to create a carbon fiber that had 225% greater strength and 184% greater stiffness than the conventionally made PAN-based carbon fibers.

The team gleaned insight into the chemical reactions taking place through a series of small- and large-scale computer simulations conducted on several supercomputers, the Institute for Computational and Data Sciences (ICDS) Advanced CyberInfrastructure; the National Science Foundation (NSF)-funded CyberLAMP, which is maintained by ICDS; and the NSF-funded Extreme Science and Engineering Discovery Environment (XSEDE), a multi-institute network of supercomputers and related resources. They also studied the properties of each material using laboratories in Penn State's Materials Research Institute (MRI).

"We connected experiments of different scales to not only show that this process works, but it gave us an atomistic-scale reason why these types of additives work," said van Duin, also the director of the MRI's Materials Computation Center and an ICDS associate. "That knowledge allows us to optimize the process further."

The flat structure of graphene helps to align PAN molecules consistently throughout the fiber, which is needed in the production process. Further, at high temperatures graphene edges have a natural catalytic property so that "the rest of PAN condenses around these edges," said van Duin.

With the new knowledge gained from this study, the team is exploring ways to further use graphene in this production process using cheaper precursors, with a goal of cutting out one or more of the production steps altogether, thereby reducing costs even more.

HOUSTON -- (May 18, 2020) -- U.S. and German physicists have found surprising evidence that one of the most famous phenomena in modern physics -- the quantum Hall effect -- is "reincarnated" in topological superconductors that could be used to build fault-tolerant quantum computers.

The 1980 discovery of the quantum Hall effect kicked off the study of topological orders, electronic states with "protected" patterns of long-range quantum entanglement that are remarkably robust. The stability of these protected states is extremely attractive for quantum computing, which uses quantum entanglement to store and process information.

In a study published online this month in Physical Review X (PRX), theoretical physicists from Rice University, the University of California, Berkeley (UC Berkeley), and the Karlsruhe Institute of Technology (KIT) in Karlsruhe, Germany, presented strong numerical evidence for a surprising link between 2D and 3D phases of topological matter. The quantum Hall effect was discovered in 2D materials, and laboratories worldwide are in a race to make 3D topological superconductors for quantum computing.

"In this work we've shown that a particular class of 3D topological superconductors should exhibit 'energy stacks' of 2D electronic states at their surfaces," said Rice co-author Matthew Foster, an associate professor of physics and astronomy and member of the Rice Center for Quantum Materials (RCQM). "Each of these stacked states is a robust 'reincarnation' of a single, very special state that occurs in the 2D quantum Hall effect."

The quantum Hall effect was first measured in two-dimensional materials. Foster uses a "percolation" analogy to help visualize the strange similarities between what occurs in 2D quantum Hall experiments and the study's 3D computational models.

"Picture a sheet of paper with a map of rugged peaks and valleys, and then imagine what happens as you fill that landscape with water," he said. "The water is our electrons, and when the level of fluid is low, you just have isolated lakes of electrons. The lakes are disconnected from one another, and the electrons can't conduct across the bulk. If water level is high, you have isolated islands, and in this case the islands are like the electrons, and you also don't get bulk conduction."

In Foster's analogy the rugged landscape is the electric potential of the 2D material, and the level of ruggedness corresponds to amount of impurities in the system. The water level represents the "Fermi energy," a concept in physics that refers to the filling level of electrons in a system. The edges of the paper map are analogous to the 1D edges that surround the 2D material.

"If you add water and tune the fluid level precisely to the point where you have little bridges of water connecting the lakes and little bridges of land connecting the islands, then it's as easy to travel by water or land," Foster said. "That is the percolation threshold, which corresponds to the transition between topological states in quantum Hall. This is the special 2D state in quantum Hall.

"If you increase the fluid level more, now the electrons are trapped in isolated islands, and you'd think, 'Well, I have the same situation I had before, with no conduction.' But, at the special transition, one of the electronic states has peeled away to the edge. Adding more fluid doesn't remove the edge state, which can go around the whole sample, and nothing can stop it."

The analogy describes the relationship between robust edge conduction and bulk fine-tuning through the special transition in the quantum Hall effect. In the PRX study, Foster and co-authors Bjo?rn Sbierski of UC Berkeley and Jonas Karcher of KIT studied 3D topological systems that are similar to the 2D landscapes in the analogy.

"The interesting stuff in these 3D systems is also only happening at the boundary," Foster said. "But now our boundaries aren't 1D edge states, they are 2D surfaces."

Using "brute-force numerical calculations of the surface states," Sbierski, Karcher and Foster found a link between the critical 2D quantum Hall state and the 3D systems. Like the 1D edge state that persists above the transition energy in 2D quantum Hall materials, the calculations revealed a persistent 2D boundary state in the 3D systems. And not just any 2D state; it is exactly the same 2D percolation state that gives rise to 1D quantum Hall edge states.

"What was a fine-tuned topological quantum phase transition in 2D has been 'reincarnated' as the generic surface state for a higher dimensional bulk," Foster said. "In 2018 study, my group identified an analogous connection between a different, more exotic type of 2D quantum Hall effect and the surface states of another class of 3D topological superconductors. With this new evidence, we are now confident there is a deep topological reason for these connections, but at the moment the mathematics remain obscure."

Topological superconductors have yet to be realized experimentally, but physicists are trying to create them by adding impurities to topological insulators. This process, known as doping, has been widely used to make other types of unconventional superconductors from bulk insulators.

"We now have evidence that three of the five 3D topological phases are tied to 2D phases that are versions of the quantum Hall effect, and all three 3D phases could be realized in 'topological superconductors,'" Foster said.

Foster said conventional wisdom in condensed matter physics has been that topological superconductors would each host only one protected 2D surface state and all other states would be adversely affected by unavoidable imperfections in the solid-state materials used to make the superconductors.

But Sbierski, Karcher and Foster's calculations suggest that isn't the case.

"In quantum Hall, you can tune anywhere and still get this robust plateau in conductance, due to the 1D edge states," Foster said. "Our work suggests that is also the case in 3D. We see stacks of critical states at different energy levels, and all of them are protected by this strange reincarnation of the 2D quantum Hall transition state."

The authors also set the stage for experimental work to verify their findings, working out details of how the surface states of the 3D phases should appear in various experimental probes.

"We provide precise statistical 'fingerprints' for the surface states of the topological phases," Foster said. "The actual wave functions are random, due to disorder, but their distributions are universal and match the quantum Hall transition."

TODAY'S young people can be dubbed the "Coronavirus Generation" and the pandemic will have a long-lasting effect on their lives, according to a University of Huddersfield lecturer who has helped analyse the data from a research project that aimed to appraise the impact of the virus on UK youth.

Findings include statistics which show that more than 90 per cent of young people were stringently observing the lockdown and that 80 per cent of them are seeking news not from social media but from traditional outlets, including ministerial briefings.

"We assume that the young have rejected these traditional forms of media. But the research shows that they don't feel secure in navigating the social media world of 'fake news'. Many young people are using traditional media - maybe for the first time - because they can consume it with a certain amount of reliability," said Dr Andrew Mycock, who is the University's Reader in Politics.

He has collaborated on the production of the 65-page report named Take the Temperature, compiled by the organisation Beatfreeks, which researches national youth trends.

During late March and early April it surveyed 1,535 young people, aged 16-25. It was found that 91% of respondents said that they are strictly adhering to government advice. But there are negative strains on young people's family relationships and 65% of young people said they were worried about their mental health in light of Covid-19.

The report makes a series of recommendations, including a call for the Government to establish a National Young Person's Response Unit. Also, local authorities and businesses need to build young people into their recovery task forces and there should be statutory digital citizenship education programmes to provide young people with the digital literacy to equip them for life in the 'new normal'.

Dr Mycock, who is a co-investigator for the Leverhulme Trust-funded Lowering the Voting Age in the UK project, was called on to help analyse the results of the Take the Temperature survey.

"Most young people are observing the lockdown in an exemplary manner, but are increasingly anxious about their future prospects, their careers, their educational progress and the direction of society," said Dr Mycock.

"Many of the structures that underpin transition to adulthood have completely and utterly fragmented. And the young feel isolated because policy makers haven't been particularly engaged with them when making decisions that have profound effects on young people's lives."

The published Take the Temperature report is now landing on the desks of policy makers and the Government needs to think about how it brings young people into debates as the country comes out of lockdown into a world that will be very different, continued Dr Mycock.

"We have made a strong effort to ensure that the people who make policies pick up on this report," he added, describing today's young people as the Covid-19 or Coronavirus Generation.

"The effects of this are not going to work themselves out in one or two years. It may well be that this is the generation whose lives are fundamentally changed forever," said Dr Mycock, who is continuing working with Beatfreeks on charting the views of UK youth over the next 18 months.

It sounds like a riddle: What do you get if you take two small diamonds, put a small magnetic crystal between them and squeeze them together very slowly?

The answer is a magnetic liquid, which seems counterintuitive. Liquids become solids under pressure, but not generally the other way around. But this unusual pivotal discovery, unveiled by a team of researchers working at the Advanced Photon Source (APS), a U.S. Department of Energy (DOE) Office of Science User Facility at DOE’s Argonne National Laboratory, may provide scientists with new insight into high-temperature superconductivity and quantum computing.

Though scientists and engineers have been making use of superconducting materials for decades, the exact process by which high-temperature superconductors conduct electricity without resistance remains a quantum mechanical mystery. The telltale signs of a superconductor are a loss of resistance and a loss of magnetism. High-temperature superconductors can operate at temperatures above those of liquid nitrogen (−320 degrees Fahrenheit), making them attractive for lossless transmission lines in power grids and other applications in the energy sector.

But no one really knows how high-temperature superconductors achieve this state. This knowledge is needed to increase these materials’ operating temperature towards ambient temperature, something that would be required for full-scale implementation of superconductors in energy-conserving power grids.

“A quantum spin liquid is a superposition of spin states, fluctuating but entangled. It’s fair to say that this process, should it create a quantum spin liquid with quantum superposition, will have made a qubit, the basic building block of a quantum computer.” — Daniel Haskel, physicist and group leader, XSD

One idea put forth in 1987 by the late theorist Phil Anderson of Princeton University involves putting materials into a quantum spin liquid state, which Anderson proposed could lead to high-temperature superconductivity. The key is the spins of the electrons in each of the material’s atoms, which under certain conditions can be nudged into a state where they become “frustrated” and unable to arrange themselves into an ordered pattern.

To relieve this frustration, electron spin directions fluctuate in time, only aligning with neighboring spins for short periods of time, like a liquid. It is these fluctuations that may aid in the electron pair formation needed for high-temperature superconductivity.

Pressure provides a way to “tune” the separation between electron spins and drive a magnet into a frustrated state where magnetism goes away at a certain pressure and a spin liquid emerges, according to Daniel Haskel, the physicist and group leader in Argonne’s X-ray Science Division (XSD) who led a research team through a series of experiments at the APS to do just that. The team included Argonne assistant physicist Gilberto Fabbris and physicists Jong-Woo Kim and Jung Ho Kim, all of XSD.

Haskel is careful to say that his team’s results, recently published in Physical Review Letters, do not conclusively demonstrate the quantum nature of the spin liquid state, in which the atomic spins would continue to move even at absolute zero temperatures — more experiments would be needed to confirm that.

But they do show that, by applying slow and steady pressure, some magnetic materials can be pushed into a state similar to a liquid, in which the electron spins become disordered and magnetism disappears, while preserving the crystalline arrangement of the atoms hosting the electron spins. Researchers are confident they have created a spin liquid, in which the electron spins are disordered, but are not certain if those spins are entangled, which would be a sign of a quantum spin liquid.

If this is a quantum spin liquid, Haskel said, the ability to create one by this method would have wide implications.

“Some types of quantum spin liquids can enable error-free quantum computing,” Haskel said. “A quantum spin liquid is a superposition of spin states, fluctuating but entangled. It’s fair to say that this process, should it create a quantum spin liquid with quantum superposition, will have made a qubit, the basic building block of a quantum computer.”

So what did the team do, and how did they do it? That brings us back to the diamonds, part of a unique experimental setup at the APS. Researchers used two diamond anvils, cut in a similar way to what you’d see in jewelry stores, with a wide base and a narrower, flat edge. They positioned the smaller flat edges together, inserted a sample of magnetic material (in this case a strontium-iridium alloy) between them, and pushed.

“The idea is that as you pressurize it, it brings the atoms closer together,” said Fabbris. “And since we can do that slowly, we can do that continuously, and we can measure the properties of the sample as we go up in pressure.”

When Fabbris says that pressure was applied slowly, he isn’t kidding — each one of these experiments took about a week, he said, using a sample of about 100 microns in diameter, or about the width of a thin sheet of paper. Since researchers didn’t know at what pressure magnetism would disappear, they had to carefully measure with each very slight increase.

And see it disappear they did, at around 20 gigapascals — equivalent to 200,000 atmospheres, or about 200 times more pressure than can be found at the bottom of the Mariana Trench in the Pacific Ocean, the deepest trench on Earth. The spins of the electrons remained correlated over short distances, like a liquid, but remained disordered even at temperatures as low as 1.5 Kelvin (−457 degrees Fahrenheit).

The trick, Haskel said — and the key to creating a spin liquid state — was to preserve the crystalline order and symmetry of the atomic arrangement, since the unwanted effect of random disorder in atomic positions would have led to a different magnetic state, one without the unique properties of the spin liquid state. Haskel likens the electron spins to neighbors on a city block — as they get closer, they all want to make each other happy, changing their spin direction to match their neighbors’. The goal is to get them so close together that they cannot possibly keep all of their neighbors happy, thereby “frustrating” their spin interactions, while still maintaining the structure of the city block.

The research team used the intense X-ray imaging capabilities of the APS to measure the magnetism of the sample, and according to Haskel and Fabbris, the APS is the only facility in the United States where such an experiment could be done. In particular, Fabbris said, the ability to focus in on one type of atom, ignoring all others, was crucial.

“The samples are very small, and if you try to measure magnetism with other techniques in a university lab, you will pick up the magnetic signal from components in the diamond anvil cell,” Fabbris said. “The measurements we did are impossible without a light source like the APS. It is uniquely capable of this.”

Now that the team has achieved a spin liquid state, what’s next? More experimentation is needed to see if a quantum spin liquid has been created. Future experiments will involve probing the nature of spin dynamics and correlations more directly in the spin liquid state. But the recent results, Haskel said, provide a path for realizing these elusive quantum states, one that could lead to new insights into superconductivity and quantum information sciences.

Haskel also pointed forward to the APS Upgrade, a massive project that will see the instrument’s brightness increased up to 1,000 times. This, he said, will allow for much deeper probes into these fascinating states of matter.

“It’s up to anyone’s imagination which surprising quantum mechanical effects are waiting to be discovered,” he said.

Tantalum disulfide is a mysterious material. According to textbook theory, it should be a conducting metal, but in the real world it acts like an insulator. Using a scanning tunneling microscope, researchers from the RIKEN Center for Emergent Matter Science have taken a high-resolution look at the structure of the material, revealing why it demonstrates this unintuitive behavior.
It has long been known that crystalline materials should be good conductors when they have an odd number of electrons in each repeating cell of the structure, but may be poor conductors when the number is even. However, sometimes this formula does not work, with one case being "Mottness," a property based on the work of Sir Nevill Mott. According to that theory, when there is strong repulsion between electrons in the structure, it leads the electrons to become "localized"--paralyzed in other words--and being unable to move around freely to create an electric current. What makes the situation complicated is that there are also situations where electrons in different layers of a 3-D structure can interact, pairing up to create a bilayer structure with an even number of electrons. It has been previously suggested that this "pairing" of electrons would restore the textbook understanding of the insulator, making it unnecessary to invoke "Mottness" as an explanation.

For the current study, published in Nature Communications, the research group decided to look at tantalum disulfide, a material with 13 electrons in each repeating structure, which should therefore be a conductor. However, it is not, and there has been controversy over whether this property is caused by its "Mottness" or by a pairing structure.

To perform the research, the researchers created crystals of tantalum disulfide and then cleaved the crystals in a vacuum to reveal ultra-clean surfaces which they then examined, at a temperature close to absolute zero--with a method known as scanning tunneling microscopy--a method involving a tiny and extremely sensitive metal tip that can sense where electrons are in a material, and their degree of conducting behavior, by using the quantum tunneling effect. Their results showed that there was indeed a stacking of layers which effectively arranged them into pairs. Sometimes the crystals cleaved between the pairs of layers, and sometimes through a pair, breaking it. They performed spectroscopy on both the paired and unpaired layers and found that even the unpaired ones are insulating, leaving Mottness as the only explanation.

According to Christopher Butler, the first author of the study, "The exact nature of the insulating state and of the phase transitions in tantalum disulfide have been long-standing mysteries, and it was very exciting to find that Mottness is a key player, aside from the pairing of the layers. This is because theorists suspect that a Mott state could set the stage for an interesting phase of matter known as a quantum spin liquid."

Tetsuo Hanaguri, who led the research team, said, "The question of what makes this material move between insulating to conducting phases has long been a puzzle for physicists, and I am very satisfied we have been able to put a new piece into the puzzle. Future work may help us to find new interesting and useful phenomena emerging from Mottness, such as high-temperature superconductivity."

DURHAM, N.C. -- A Duke University research team has found a small area of the brain in mice that can profoundly control the animals' sense of pain.

Somewhat unexpectedly, this brain center turns pain off, not on. It's also located in an area where few people would have thought to look for an anti-pain center, the amygdala, which is often considered the home of negative emotions and responses, like the fight or flight response and general anxiety.

"People do believe there is a central place to relieve pain, that's why placebos work," said senior author Fan Wang, the Morris N. Broad Distinguished Professor of neurobiology in the School of Medicine. "The question is where in the brain is the center that can turn off pain."

"Most of the previous studies have focused on which regions are turned ON by pain," Wang said. "But there are so many regions processing pain, you'd have to turn them all off to stop pain. Whereas this one center can turn off the pain by itself."

The work is a follow-up to earlier research in Wang's lab looking at neurons that are activated, rather than suppressed, by general anesthetics. In a 2019 study, they found that general anesthesia promotes slow-wave sleep by activating the supraoptic nucleus of the brain. But sleep and pain are separate, an important clue that led to the new finding, which appears online May 18 in Nature Neuroscience.

The researchers found that general anesthesia also activates a specific subset of inhibitory neurons in the central amygdala, which they have called the CeAga neurons (CeA stands for central amygdala; ga indicates activation by general anesthesia). Mice have a relatively larger central amygdala than humans, but Wang said she had no reason to think we have a different system for controlling pain.

Using technologies that Wang's lab has pioneered to track the paths of activated neurons in mice, the team found the CeAga was connected to many different areas of the brain, "which was a surprise," Wang said.

By giving mice a mild pain stimulus, the researchers could map all of the pain-activated brain regions. They discovered that at least 16 brain centers known to process the sensory or emotional aspects of pain were receiving inhibitory input from the CeAga.

"Pain is a complicated brain response," Wang said. "It involves sensory discrimination, emotion, and autonomic (involuntary nervous system) responses. Treating pain by dampening all of these brain processes in many areas is very difficult to achieve. But activating a key node that naturally sends inhibitory signals to these pain-processing regions would be more robust."

Using a technology called optogenetics, which uses light to activate a small population of cells in the brain, the researchers found they could turn off the self-caring behaviors a mouse exhibits when it feels uncomfortable by activating the CeAga neurons. Paw-licking or face-wiping behaviors were "completely abolished" the moment the light was switched on to activate the anti-pain center.

"It's so drastic," Wang said. "They just instantaneously stop licking and rubbing."

When the scientists dampened the activity of these CeAga neurons, the mice responded as if a temporary insult had become intense or painful again. They also found that low-dose ketamine, an anesthetic drug that allows sensation but blocks pain, activated the CeAga center and wouldn't work without it.

Now the researchers are going to look for drugs that can activate only these cells to suppress pain as potential future pain killers, Wang said.

"The other thing we're trying to do is to (transcriptome) sequence the hell out of these cells," she said. The researchers are hoping to find the gene for a rare or unique cell surface receptor among these specialized cells that would enable a very specific drug to activate these neurons and relieve pain.

New and diverse experiences are linked to enhanced happiness, and this relationship is associated with greater correlation of brain activity, new research has found. The results, which appear in the journal Nature Neuroscience, reveal a previously unknown connection between our daily physical environments and our sense of well-being.

"Our results suggest that people feel happier when they have more variety in their daily routines--when they go to novel places and have a wider array of experiences," explains Catherine Hartley, an assistant professor in New York University's Department of Psychology and one of the paper's co-authors. "The opposite is also likely true: positive feelings may drive people to seek out these rewarding experiences more frequently."

Previous studies using animal subjects had shown similar results.

"Collectively, these findings show the beneficial consequences of environmental enrichment across species, demonstrating a connection between real-world exposure to fresh and varied experiences and increases in positive emotions," adds co-author Aaron Heller, an assistant professor in the University of Miami's Department of Psychology.

The researchers, who conducted the study prior to the onset of the COVID-19 pandemic, recognize that current public-health guidelines and restrictions pose limits on movement. However, they note that even small changes that introduce greater variability into the physical or mental routine--such as exercising at home, going on a walk around the block, and taking a different route to the grocery store or pharmacy--may potentially yield similar beneficial effects.

In the Nature Neuroscience paper, the researchers investigated the following question: Is diversity in humans' daily experiences associated with more positive emotional states?

To do so, they conducted GPS tracking of participants in New York and Miami for three to four months, asking subjects by text message to report about their positive and negative emotional state during this period.

The results showed that on days when people had more variability in their physical location--visiting more locations in a day and spending proportionately equitable time across these locations--they reported feeling more positive: "happy," "excited," "strong," "relaxed," and/or "attentive."

The scientists then sought to determine if this link between exploration and positive emotion had a connection to brain activity.

To do this, about half of the subjects returned to a laboratory and underwent MRI scans.

The MRI results showed that people for whom this effect was the strongest--those whose exposure to diverse experiences was more strongly associated with positive feeling ("affect")--exhibited greater correlation between brain activity in the hippocampus and the striatum. These are brain regions that are associated, respectively, with the processing of novelty and reward-- beneficial or subjectively positive experiences.

"These results suggest a reciprocal link between the novel and diverse experiences we have during our daily exploration of our physical environments and our subjective sense of well-being," observes Hartley, who also has appointments at NYU's Center for Neural Science and NYU Langone Health Neuroscience Institute.

Novel quantum dot solar cells developed at Los Alamos National Laboratory match the efficiency of existing quantum-dot based devices, but without lead or other toxic elements that most solar cells of this type rely on.

"This quantum-dot approach shows great promise for a new type of toxic-element-free, inexpensive solar cells that exhibit remarkable defect tolerance," said Victor Klimov, a physicist specializing in semiconductor nanocrystals at Los Alamos and lead author of the report featured on the cover of the journal Nature Energy.

Not only did the researchers demonstrate highly efficient devices, they also revealed the mechanism underlying their remarkable defect tolerance. Instead of impeding photovoltaic performance, the defect states in copper indium selenide quantum dots actually assist the photoconversion process.

Quantum dots have already found many uses, and more are coming. In particular, they are very efficient light emitters. They are distinct from other types of light-emitting materials, as their color is not fixed and can be easily tuned by adjusting the quantum dot size. This property has been utilized in displays and televisions, and soon will help make more efficient, color-adjustable light bulbs.

The unique physics of nanosized semiconductor crystals prepared by colloidal synthesis has fascinated scientists for decades. Due to their extremely small sizes - a few nanometers across - the properties of the nanocrystals can be manipulated at the most fundamental quantum-mechanical level. Hence, they are called "quantum dots."

Size tunable properties of quantum dots can also help efficiently capture sunlight, which is of great use in solar-energy conversion. The efficiencies of modern quantum dot solar cells rapidly approach those of traditional thin-film photovoltaics. However, in most cases they contain highly toxic heavy metals such as lead and cadmium, which limits their practical utility.

Los Alamos researchers described new, high-efficiency quantum dot solar cells that were free of any toxic elements. The team used a reaction of copper, indium, and selenium, with the addition of zinc to make zinc-doped quantum dots. The dots were incorporated into voids of a highly porous titania film which served as a charge collecting electrode.

Incident solar photons were absorbed by the quantum dots, which resulted in the release of tightly bound electrons into a high-mobility conduction band. These electrons were then transferred to the titania electrode which ultimately produced a photocurrent.

"We were pleasantly surprised by the results of the measurements of our devices," Klimov said. "Due to their very complex composition (four elements are combined in the same nanosized particle), these dots are prone to defects. Despite these imperfections, they showed nearly perfect performance in our solar cells--per each 100 absorbed photons we detected 85 photogenerated electrons, implying that the photon-to-electron conversion efficiency was 85 percent."

The high photoconversion efficiencies combined with the remarkable defect tolerance and toxic-element-free composition make these quantum dots very promising materials for implementing inexpensive, readily scalable and potentially disposable solar cells.

A new study reveals clear evidence highlighting the importance of fish biodiversity to the health of spectacular tropical coral reef ecosystems.

This is the case for reefs that are pristine and also those that have been affected by stresses, such as bleaching events caused by warming oceans.

However, the study's results show that even though strong relationships between diversity and a healthy ecosystem persist, human-driven pressures of warming oceans and invasive species still diminish ecosystems in various ways.

This highlights that protecting fish biodiversity is a key factor for improving the survival chances of coral reef ecosystems in the face of rapid environmental change. But the researchers caution that without removing human-driven stressors, protecting biodiversity alone might not be enough.

Dr Casey Benkwitt, of Lancaster Environment Centre and lead author of the study, said: "Our study, which is the first of its kind to look at relatively pristine coral, reveals the strong link between rich biodiversity and a thriving ecosystem. This relationship is still evident even when an ecosystem has been degraded and provides further clarity on just how crucial it is to maintain biodiversity to give tropical coral reefs a fighting chance to thrive in an uncertain future.

"However, the bad news is that the functioning of these fragile ecosystems is still vulnerable and was impaired in different ways by climate change and invasive species on nearby islands."

A team of researchers conducted surveys on coral reefs around ten islands in the remote Chagos Archipelago - the largest uninhabited and unfished coral reef area in the Indian Ocean.

Their surveys counted the number of different fish species on reefs as a measure of biodiversity. They also measured how well an ecosystem was functioning relative to fish biodiversity at different islands using two key indicators -the biomass of fish living on a reef, and a measure of productivity, which is the rate at which biomass is produced.

Dr Benkwitt, said: "We were surprised that the positive effects of biodiversity on ecosystem functions were so strong because such clear patterns are rare in ecological data. These results match previous studies on less pristine coral reefs, and in other terrestrial and marine systems. To see the same patterns in so many places suggests the positive relationship between diversity and ecosystem function may be one of the few general rules in ecology."

Importantly, the researchers also looked at coral reefs under pressure from multiple human-driven factors. This is the first time scientists have measured these kinds of effects outside of a lab.

The scientists had data from before and after a major heatwave in 2016 that caused bleaching and death of corals. This coral loss caused biodiversity to plummet by 17 per cent. Because of the strong relationship between biodiversity and ecosystem function, such losses in biodiversity caused by warming oceans will result in coral ecosystems that are not able to function as well.

Professor Nick Graham of Lancaster University and co-author of the study said: "The large negative effects of coral bleaching on biodiversity is worrisome as warming events are becoming more and more common. Because high diversity is key to ecosystem function, this means that preserving biodiversity may be increasingly important, but also increasingly challenging, in the future."

The scientists also studied coral reefs experiencing a reduction in nutrients caused by invasive rats on nearby islands. The rats, which arrived with people on boats decades ago, decimate wild bird populations, resulting in fewer droppings. These bird droppings act as fertiliser for the reefs when washed off into the sea, increasing fish growth rates and the amount of fish on a reef.

The researchers found that the coral reefs near islands with rats, and therefore with fewer seabird nutrients washing off to reefs, experienced lower levels of biomass. This shows that even when maintaining biodiversity, coral reef ecosystems are still vulnerable to human-caused stressors.

Dr Benkwitt said: "The bleaching event and loss of nutrients each reduced ecosystem functions in different ways. This means that managing each stressor will have complementary benefits for coral reefs. While biodiversity is clearly important to ecosystem function, biodiversity conservation may become more difficult and may not fully sustain ecosystems unless underlying stressors, such as climate change, are reduced."

The findings are outlined in the paper 'Biodiversity increases ecosystem functions despite multiple stressors on coral reefs', which has been published in the journal Nature Ecology and Evolution.

Durham, NC - The results of a clinical trial released today in STEM CELLS Translational Medicine demonstrate how a topical solution made up of stem cells leads to the regrowth of hair for people with a common type of baldness.

Androgenetic alopecia (AGA) - commonly known as male-pattern baldness (female-pattern baldness in women) -- is a condition caused by genetic, hormonal and environmental factors. It affects an estimated 50 percent of all men and almost as many women older than 50. While it is not a life-threatening condition, AGA can lower a person's self-esteem and psychological well-being. There are a few FDA-approved medications to treat hair loss, but the most effective can have side effects such as loss of libido and erectile dysfunction. Therefore, the search continues for a safer, effective treatment.

Adipose tissue-derived stem cells (ADSCs) secrete several growth hormones that help cells develop and proliferate. According to laboratory and experimental studies, growth factors such as hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF), insulin-like growth factor (IGF) and platelet-derived growth factor (PDGF) increase the size of the hair follicle during hair development.

"Recent studies have shown that ADSCs promote hair growth in both men and women with alopecia. However, no randomized, placebo-controlled trial in humans has explored the effects and safety of adipose-derived stem cell constituent extract (ADSC-CE) in AGA. We aimed to assess the efficacy and tolerability of ADSC-CE in middle-aged patients with AGA in our study, hypothesizing that it is an effective and safe treatment agent," said Sang Yeoup Lee, M.D., Ph.D., of the Family Medicine Clinic and Research Institute of Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital in South Korea. He led the group of researchers, which also included colleagues from Pusan National University School of Medicine, Pusan National University Yangsan Hospital and T-Stem Co., Ltd.

The team recruited 38 patients (29 men and nine women) with AGA and assigned half to an intervention group that received the ADSC-CE topical solution and half as a control group that received a placebo. Twice daily, each patient applied the ADSC-CE topical solution or placebo to their scalp using their fingers.

"At the end of 16 weeks, the group that received the ADSC-CEs had a significant increase in both hair count and follicle diameter," reported the study's senior author, Young Jin Tak, M.D., Ph.D.

Dr. Lee added, "Our findings suggest that the application of the ADSC-CE topical solution has enormous potential as an alternative therapeutic strategy for hair regrowth in patients with AGA, by increasing both hair density and thickness while maintaining adequate treatment safety. The next step should be to conduct similar studies with large and diverse populations in order to confirm the beneficial effects of ADSC-CE on hair growth and elucidate the mechanisms responsible for the action of ADSC-CE in humans."

"For the millions of people who suffer from male-pattern baldness, this small clinical trial offers hope of a future treatment for hair regrowth," said Anthony Atala, M.D., Editor-in-Chief of STEM CELLS Translational Medicine and director of the Wake Forest Institute for Regenerative Medicine. "The topical solution created from proteins secreted by stem cells found in fat tissue proves to be both safe and effective. We look forward to further findings that support this work."