Tech

Tsukuba, Japan - Lymphomas are a diverse group of cancers of the immune system, which is the body's primary defense against autoimmune disease, infections, and malignancy. Now, researchers at the University of Tsukuba have clarified risk factors and molecular mechanisms underlying primary and adaptive resistance to cancer immunotherapy. This knowledge may inform treatment strategies against aggressive Non-Hodgkin lymphomas (NHL) including Burkitt lymphoma and diffuse large B-cell lymphoma.

One way cancer treatments fail is because malignant cells survive radiation, chemotherapy or endogenous immune surveillance by evading apoptosis. Apoptosis, or "programmed cell death," is an ordered and orchestrated cellular suicide, executed by regulatory proteins in response to internal stress or external signals. The Fas receptor, a cell-surface death receptor, binds with its ligand FasL and activates initiator and executioner caspases that methodically degrade proteins and inexorably kill the cell. Apoptosis pathways can be blocked by inhibitor of apoptosis (IAP) family proteins that directly inhibit caspase and pro-caspase. Elucidating these interlinked molecular mechanisms whereby cancer cells evade apoptosis is key to developing effective immunotherapeutic protocols.

To facilitate gene manipulations and molecular analyses, the researchers first modeled mature B-cell lymphoma in syngeneic mice. "We demonstrated that Fas downregulation is required both for mature B-cell lymphomagenesis and for lymphoma cell survival," explains Associate Professor Eiji Sugihara, lead author. "Additionally, we showed that activation of CD40 signaling, which restores Fas expression, sensitized lymphoma cells to FasL-induced apoptosis and prolonged mouse survival. Extending these findings to eleven human NHL cell lines, we confirmed that downregulated Fas expression could be restored by CD40 activation in most human cell lines, and this conferred susceptibility to Fas-mediated apoptosis in about half the cell lines studied."

The researchers further showed that the melanoma inhibitor of apoptosis protein (Livin) promoted resistance to Fas-mediated apoptosis in lymphoma cells. Moreover, BET family proteins (specifically BRD4 and BRD2) enhance Livin expression in lymphoma cells to protect them from immune cytotoxicity. Additionally, the researchers demonstrated that BV6, an IAP antagonist that degrades Livin, extended the survival of mice transplanted with lymphoma cells previously rendered resistant to Fas-mediated apoptosis.

"We have gained a deeper insight into lymphomagenesis and the patterns of resistance to immunotherapy," explains Associate Professor Sugihara. "Inducing apoptosis in cancer cells by combining CD40-mediated Fas expression with specific targeting of Livin using IAP inhibitors or BET inhibitors is a promising immunotherapeutic strategy against aggressive B-cell lymphomas and other intractable tumors."

"All the roads of learning begin in the darkness and go out into the light."

This quote is often attributed to Hippocrates and exhibits a double level of relevance in photosynthesis research. The use of light by plant leaves to drive photosynthesis is often studied in steady state environments, but most plant leaves are required to adjust to fluctuations in incident light every day. The research into use of fluctuating light by plant leaves has expanded in recent decades. A study from the Western Pacific Tropical Research Center at the University of Guam has shown that accurate results in this subdiscipline of plant physiology can only be obtained when methods employ leaves that were grown in fluctuating light prior to experimental methods. The results have been published in a recent issue of the journal Plants (doi: 10.3390/plants9070905).

The experimental results confirmed that leaves which were constructed under homogeneous shade such as commercial shade fabric did not respond to fluctuating light in a manner that was similar to leaves which were constructed under fluctuating light. To expand the applicability of the results, three model species were employed for this study. Soybean represented eudicot angiosperms, corn represented monocot angiosperms, and the native cycad species in Guam represented gymnosperms.

The experimental approach called on traditional response variables to ensure applicability of the results to the established literature. One response variable was the speed of increase in photosynthesis when a leaf that is acclimated to deep shade is suddenly challenged with saturating incident light, a response that physiologists call induction. A second response variable was the influence of a short sunfleck on photosynthetic induction during a subsequent sunfleck, a response that physiologists call priming.

"As expected, the leaves that developed under fluctuating light exhibited more rapid photosynthetic induction and more successful priming than the leaves that developed in homogeneous shade," said Thomas Marler, author of the paper. This new knowledge indicates a substantial percentage of the established leaf physiology literature concerning use of sunflecks includes results that are dubious because the sunfleck methods used experimental leaves that were grown under shadecloth.

The study also reveals the value of off-site conservation germplasm collections. "Ubiquitous invasive insect herbivores in Guam create difficulties for research on the native cycad species," said Marler. "The ex situ germplasm collections in several countries allow scientists to sustain relevant research on this important cycad species." This study, for example, was conducted in one of these managed gardens in the Philippines where the plants are not threatened by the insects.

When new knowledge illuminates a fallacy in established experimental methods, a search for an empirical approach for salvaging the published information is appropriate. If a universal conversion factor could be identified, for example, then the published data could be corrected with that conversion. Unfortunately, there were quantitative differences among the three model species with regard to how the homogeneous shade leaves behaved compared to the heterogeneous shade leaves. Therefore, the published sunfleck use literature based on methods that employed homogeneous shade-grown leaves should be interpreted with caution.

Low-dimensional perovskite-related metal halides have emerged as a new class of light-emitting materials with tunable broadband emission from self-trapped excitons (STEs). Although various types of low-dimensional structures have been developed, fundamental understating of the structure-property relationships for this class of materials is still very limited, and further improvement of their optical properties remains greatly important.

An international team led by Dr. Xujie Lü and Dr. Wenge Yang from the Center for High Pressure Science and Technology Advanced Research (HPSTAR) and Prof. Biwu Ma from the Florida State University discovered that pressure can sufficiently suppress the non-radiative loss in 1D metal halide C4N2H14PbB4, and lead to the photoluminescent quantum yield (PLQY) increasing from initial 20% to over 90% at 2.8 GPa. In-situ optical characterization and theoretical analysis revealed that the suppressed non-radiative loss is directly related to the pressure-tuned STE binding energy and confined motion of organic cations. Importantly, for the first time, PLQYs were quantitatively determined under gigapascal pressures. The findings were recently published in J. Am. Chem. Soc.

Pressure has been utilized as an effective and clean stimulus to regulate the structure and optoelectronic properties of various types of materials. The soft lattices of metal halides render them sensitive to pressure and lead to effective modifications under a mild pressure range. Despite exciting pressure-enhanced/induced emission results reported in hybrid metal halides, the microscopic origins are not fully understood yet. It is well-known that PL efficiency is highly dependent on the competition between radiative and nonradiative recombination rates. However, the influences of structural evolution on radiative and nonradiative rates, especially nonradiative rate, have not been well elucidated.

In this work, the team systematically investigated the pressure-dependent properties of the 1D hybrid metal halide C4N2H14PbB4. Previous studies found that C4N2H14PbB4 possesses strong electron-phonon coupling and exhibits a broadband emission with a PLQY of about 20%. During compression, the PLQY of STE emission was found to increase remarkably from 20% to 90%. Time-resolved optical measurements revealed that pressure induced a remarkably suppressed nonradiative loss by 33 times and a promoted radiative recombination rate by 18%, which together contribute to the PL enhancement. Both experimental and computational findings suggest that pressure modulates the STE binding energy and the molecular confinement, resulting in highly localized excitons with reduced scattering by defects and phonons.

This work not only discovers an effective approach to enhancing the PLQY of broadband emission in the 1D metal halide but also provides insights into the microscopic mechanisms that could guide future materials' design for highly efficient low-D metal halides for light-emitting applications.

With almost two decades of mid-infrared (IR) imaging from the largest observatories around the world including the Subaru Telescope, a team of astronomers was able to capture the spiral motion of newly formed dust streaming from the massive and evolved binary star system Wolf-Rayet (WR) 112. Massive binary star systems, as well as supernova explosions, are regarded as sources of dust in the Universe from its early history, but the process of dust production and the amount of the ejected dust are still open questions. WR 112 is a binary system composed of a massive star in the very late stage of stellar evolution losing a large amount of mass and another massive star at the main sequence. Dust is expected to be formed in the region where stellar winds from these two stars are colliding. The study reveals the motion of the dusty outflow from the system and identifies WR 112 as a highly efficient dust factory that produces an entire Earth mass of dust every year.

Dust formation, which is typically seen in the gentle outflows from cool stars with a Sun-like mass, is somewhat unusual in the extreme environment around massive stars and their violent winds. However, interesting things happen when the fast winds of two massive stars in a binary interact.

"When the two winds collide, all Hell breaks loose, including the release of copious shocked-gas X-rays, but also the (at first blush surprising) creation of copious amounts of carbon-based aerosol dust particles in those binaries in which one of the stars has evolved to He-burning, which produces 40% C in their winds," says co-author Anthony Moffat (University of Montreal). This dust formation process is exactly what is occurring in WR 112. (Note 1)

This binary dust formation phenomenon has been revealed in other systems such as WR 104 by co-author Peter Tuthill (University of Sydney). WR 104, in particular, reveals an elegant trail of dust resembling a 'pinwheel' that traces the orbital motion of the central binary star system (see http://www.physics.usyd.edu.au/~gekko/pinwheel/movie_11.gif)

However, the dusty nebula around WR 112 is far more complex than a simple pinwheel pattern. Decades of multi-wavelength observations presented conflicting interpretations of the dusty outflow and orbital motion of WR 112. After almost 20 years uncertainty on WR 112, images from the COMICS instrument on the Subaru Telescope taken in Oct 2019 provided the final--and unexpected--piece to the puzzle.

"We published a study in 2017 on WR 112 that suggested the dusty nebula was not moving at all, so I thought our COMICS observation would confirm this," explained lead author Ryan Lau (ISAS/JAXA). "To my surprise, the COMCIS image revealed that the dusty shell had definitely moved since the last image we took with the VLT in 2016. It confused me so much that I couldn't sleep after the observing run--I kept flipping through the images until it finally registered in my head that the spiral looked like it was tumbling towards us."

Lau collaborated with researchers at the University of Sydney including Prof. Peter Tuthill and undergraduate Yinuo Han, who are experts at modeling and interpreting the motion of the dusty spirals from binary systems like WR 112. "I shared the images of WR 112 with Peter and Yinuo, and they were able to produce an amazing preliminary model that confirmed that the dusty spiral stream is revolving in our direction along our line of sight," said Lau.

The animation above shows a comparison between the models of WR 112 created by the research team alongside the actual mid-IR observations. The appearance of the model images shows a remarkable agreement with the real images of WR 112. The models and the series of imaging observations revealed that the rotation period of this dusty "edge-on" spiral (and the orbital period of the central binary system) is 20 years.

With the revised picture of WR 112, the research team was able to deduce how much dust this binary system is forming. "Spirals are repetitive patterns, so since we understand how much time it takes to form one full dusty spiral turn (~20 years), we can actually trace the age of dust produced by the binary stars at the center of the spiral," says Lau. He points out that "there is freshly formed dust at the very central core of the spiral, while the dust we see that's 4 spiral turns away is about 80 years old. Therefore, we can essentially trace out an entire human lifetime along the dusty spiral stream revealed in our observations. So I could actually pinpoint on the images the dust that was formed when I was born (right now, it's somewhere in between the first and second spiral turns)."

To their surprise, the team found WR 112 is a highly efficient dust factory that outputs dust at a rate of 3x10-6 solar mass per year, which is equivalent to producing an entire Earth mass of dust every year. This was unusual given WR 112's 20-yr orbital period--the most efficient dust producers in this type of WR binary star system tend to have shorter orbital periods less than a year like WR 104 with its 220-day period. WR 112 therefore demonstrates the diversity of WR binary systems that are capable of efficiently forming dust and highlights their potential role as significant sources of dust not only in our Galaxy but galaxies beyond our own.

Lastly, these results demonstrate the discovery potential of multi-epoch mid-IR imaging with the MIMIZUKU instrument on the upcoming Tokyo Atacama Observatory (TAO). The mid-IR results from this study notably utilize the largest observatories in the world and set the stage for the next decade of astronomical discoveries with 30-m class telescopes and the upcoming James Webb Space Telescope.

Scientists from the Skolkovo Institute of Science and Technology (Skoltech), the Institute of Bioorganic Chemistry (IBCh RAS) and Lomonosov Moscow State University (MSU) undertook a detailed study on green-to-red photoconversion (light-induced conversion) of the Green Fluorescent Protein (GFP). Their research was published in Frontiers of Molecular Biosciences.

Initially found in jellyfish, GFP sparked off a technological revolution in biology and was the first genetically encoded tag making a wealth of cellular processes available for analysis and visualization. In 1997, GFP was noted to turn from green to red if exposed to light in an oxygen-free environment, offering the first evidence of its red fluorescence capability. However, the photoconversion mechanism remained poorly understood for a long while, as the conversion products were too unstable for researchers to apply standard structure identification methods, such as X-ray structural analysis.

In their recent study, a group of scientists from Skoltech, IBCh RAS and MSU defined intermediate spectral forms appearing in the course of GFP green-to-red photoconversion. Computational studies enabled the researchers to propose the structures of the corresponding states of the chromophore (a part of the molecule responsible for its color) and, for the first time ever, describe the molecular mechanism of photoconversion in detail.

According to Konstantin Lukyanov, Professor at the Skoltech Center for Life Sciences (CLS), photoconversion research has various practical implications: "First, redox photoconversions are to blame for fast photobleaching of GFP in microscopy, an effect strongly limiting the practical use of GFP. Second, photoconversion intensity can be indicative of the cell's oxygen saturation and oxidative stress caused by excessive reactive oxygen species. Finally, photoconversion research may be the key to understanding the primary functions of ancestral GFP-like proteins. As they emerged very early in the evolutionary process in the animal kingdom, no one around had eyes to detect fluorescence, which suggests that "ancient" fluorescent proteins performed other "basic" functions, such as protection from too much sunlight or transfer of electrons."

Researchers at the Hybrid Photonics Laboratories in Skoltech and Southampton (UK), in collaboration with Lancaster University (UK), have demonstrated a new optical method to synthesize artificial solid-state crystal structures for cavity-polaritons using only laser light. The results could lead to the realization of field-programmable polariton circuitry and new strategies to create guided light and robust confinement of coherent light sources. The results were recently published in the journal Nature Communications.

Creating artificial lattices for quantum particles permits us to explore physics in an environment that might not be conventionally found in nature. Artificial lattices are especially appealing since their symmetries lead often to exactly solvable models and a transparent understanding of their properties. Designing them is, however, a challenging task with limited flexibility. Materials need to be irreversibly engineered to get the job done and even optical lattice techniques for cold atoms cannot attain arbitrary lattice shapes.

The researchers, Dr. Lucy Pickup (Southampton), Dr. Helgi Sigurdsson (Southampton and Skoltech), Prof Janne Ruostekoski (Lancaster), and Prof Pavlos Lagoudakis (Skoltech and Southampton) recognized and overcame this challenge by developing a new method to create arbitrarily shaped and reprogrammable artificial lattices using only structured laser light. The "reprogrammable" feature meant that the cavity-polariton system could be changed from one lattice to another without the costly need to engineer a new system from scratch.

When the laser light hits a semiconductor quantum well it excites a lot of electrons, holes, and bound states of the two known as excitons. When the quantum well is put between two mirrors, forming a trap (or a cavity) for the photons, some of the exciton particles start becoming "dressed" in photons, forming new exotic half-light, half-matter quasiparticles known as exciton-polaritons or cavity-polaritons.

Exciton-polaritons are very interactive and bounce frequently off one another. However, they also bounce off normal electrons, holes, and excitons in the background around them. The researchers could then show that by applying laser light in a geometrically structured fashion the exciton-polaritons started bouncing of the excited electrons, holes, and excitons following the shape of the laser. In other words, the exciton-polaritons started experiencing a synthetic potential landscape imprinted by the laser.

The laser-generated potential landscapes are only felt by the exciton-polaritons and not the photons inside the cavity, making the system uniquely different from photonic crystals. By creating a laser pattern with translational symmetry, the researchers produced the fundamental signature of solid-state systems, the formation of crystal energy bands for exciton-polaritons, just like one would observe for electrons in solid-state materials.

"The results open a path to study dissipative many-body quantum physics in a lattice environment with properties that cannot be reproduced in normal Hermitian quantum systems," Dr. Lucy Pickup, article co-author, says.

Dr. Helgi Sigurdsson adds: "It is an exciting development for the relatively new field of non-Hermitian topological physics."

The produced bands could be reconfigured by simply adjusting the laser pattern, permitting a non-invasive method to access quantum physics in artificial lattices. The results could be useful in a variety of applications from optical-based communications and information processing, to high sensitivity detectors for biomedical purposes and topologically protected lasing. The results also open a path to study fundamental many-body lattice physics in an open (non-Hermitian) quantum environment.

The alcohol industry is increasingly funding academic research into the impacts of alcohol consumption - with some studies making claims about the health benefits of alcohol, new research suggests.

The study found that since 2009, there has been a 56% increase in research funded by alcohol companies or affiliated organisations.

The scale of alcohol industry sponsorship of scientific research raises concerns over the potential for bias, conflicts of interest and selective reporting of outcomes, the researchers say.

The research team from the University of York found just under 13,500 studies are directly or indirectly funded by the alcohol industry.

Co-author of the study, Dr Su Golder from the Department of Health Sciences at the University of York, said: "Our study identified a worrying trend - While there has been a steep decline in the alcohol industry conducting its own research on health at the same time there has been an increase in the alcohol industry funding such research, by providing financial support to researchers or via alcohol related organisations.

"This allows alcohol companies to exploit a 'transparency loophole' as many people assume these organisations are charities and don't realise the connection to the industry.

"While there are many legitimate fields for research funded by the alcohol industry - such as studies into ingredients and environmental impacts - their involvement in health research is particular cause for concern. Many of these studies make claims about the protective cardiovascular effects of alcohol and suggest that substance abuse problems are down to individual choices rather than industry behaviours."

The researchers believe that the level of alcohol industry involvement in research they uncovered is likely to be just the tip of the iceberg.

Co-author of the study, Professor Jim McCambridge from the Department of Health Sciences at the University of York, added: "While researchers are meant to declare funders in peer reviewed research publications this often doesn't happen and we don't get the level of transparency we should have.

"It is well known that by sponsoring research pharmaceutical and tobacco companies successfully conspired to subvert the scientific evidence-base in order to influence policy for decades and so, while more research is needed, the scale, nature and breadth of the alcohol industry's influence on scientific research provides cause for concern.

"While alcohol companies may claim they are carrying out a civic duty through their funding of research, these are studies that independent academics would be much better placed to conduct."

Research findings from Aarhus University and the Central Denmark Region's Child and Adolescent Psychiatric Centre show that quality of life is poorer for preschool children with ADHD compared to children from the control population. But the children's quality of life can be significantly improved using treatment without medication.

Hyperactivity, difficulty concentrating, impulsive behaviour and problems adapting to the social ground rules. These are some of the areas in which children with ADHD struggle and which affect their everyday lives. For the first time, researchers have now systematically examined the quality of life of preschool children with ADHD.

The study shows that children with ADHD have a reduced quality of life, especially with regard to the psychosocial aspect of quality of life compared to children without a diagnosis, whereas there was not found any major difference in the physical aspect. The child's psychosocial quality of life has an effect on a wide range of behaviour and activities connected with social, psychological and emotional well-being.

Specialised parental training

However, the good news is that the children's well-being significantly increased after treatment.

"We examined whether treating ADHD symptoms with non-pharmalogical treatment had a positive effect on the quality of life and the factors that help improve the quality of life," explains medical student Liva Bundgaard Larsen, who, under the supervision of senior researchers, was the research year student behind the study .

As part of a larger treatment study (D'SNAPP) which included 164 children aged between three and seven with severe ADHD requiring treatment, the parents were asked to complete questionnaires about their child's overall quality of life before the treatment started, immediately after the treatment, and 36 weeks after the end of the treatment.

"Half of the participants received the usual treatment without medication, while the other half received specialised parental training targeted at the individual family. We looked at the effect of both types of treatment, and in both cases the children scored significantly higher on the psychosocial score in quality of life after completing the treatment," says Liva Bundgaard Larsen and emphasises that the improvement of the quality of life was shown to last 36 weeks after the treatment was completed.

Better social skills

The study also showed that parents gained more self-confidence and the family's level of stress was lower. This also had a positive effect on the child's quality of life.

"We can improve the quality of life of preschool children with ADHD through targeted efforts in relation to their parents. In the long term, this may have great significance for their prognosis," explains the researcher.

Improved quality of life may have an impact on the child's self-esteem and increase the likelihood of gaining better social skills. Later in life this increases the chances that the child complete an education and joining the labour market.

Researchers of Karlsruhe Institute of Technology (KIT) and Heidelberg University have developed a photoresist for two-photon microprinting. It has now been used for the first time to produce three-dimensional polymer microstructures with cavities in the nano range. In Advanced Materials, the scientists involved in the joint Cluster of Excellence 3D Matter Made to Order report how porosity can be controlled during printing and how this affects light scattering properties of the microstructures. (DOI: 10.1002/adma.202002044)

Photoresists are printing inks used to print smallest microstructures in three dimensions by so-called two-photon lithography. During printing, a laser beam is moved in all spatial directions through the initially liquid photoresist. The photoresist hardens in the focal point of the laser beam only. Little by little, complex microstructures can be built in this way. In a second step, a solvent is used to remove those areas that were not exposed to radiation. Complex polymer architectures in the micrometer and nanometer ranges remain.

Two-photon polymerization - or two-photon microprinting based on this process - has been studied extensively for some years now, in particular as regards the production of microoptics, so-called metamaterials, and microscaffolds for experiments with single biological cells. To expand the spectrum of applications, new printable materials are required. This is the point of departure of the scientists involved in the Cluster of Excellence 3D Matter Made to Order (3DMM2O) of KIT and Heidelberg University. "With the help of conventional photoresists, it was possible to print transparent, glassy polymers only," says Frederik Mayer, physicist of KIT and main author of the study. "Our new photoresist for the first time enables printing of 3D microstructures from porous nanofoam. This polymer foam has cavities of 30 to 100 nm in size, which are filled with air."

From Transparent to White

"There has never been a photoresist for 3D laser microprinting, with which "white" material can be printed," Frederik Mayer points out. As in a porous eggshell, the many small air holes in the porous nanoarchitectures make them appear white. Mixing white particles into a conventional photoresist would not have this effect, because the photoresist must be transparent for the (red) laser beam during printing. "Our photoresist," Mayer says, "is transparent prior to printing, but the printed objects are white and have a high reflectivity." The researchers from Karlsruhe and Heidelberg demonstrated this by printing an Ulbricht ball (an optical component) as fine as a hair.

Another factor that opens up new applications is the extremely large internal surface area of the porous material. It might be useful for filtration processes on smallest space, highly water-repellent coatings, or the cultivation of biological cells.

The collaboration of three of the nine research thrusts of the Cluster of Excellence revealed the uses for which the novel photoresist is suited and how it can be applied in the best possible way. By means of electron microscopy scans and optical experiments, researchers showed how the cavities are distributed in printed structures and how their formation can be controlled by varying the printing parameters and in particular the intensity of the laser pulses. Work in the cluster of excellence was carried out by materials scientists from Heidelberg University as well as chemists and physicists from KIT.

Researchers at the Microsoft Quantum Materials Lab and the University of Copenhagen, working closely together, have succeeded in realizing an important and promising material for use in a future quantum computer. For this end, the researchers have to create materials that hold the delicate quantum information and protect it from decoherence.

The so called topological states seem to hold this promise, but one of the challenges has been that a large magnetic field had to be applied. With the new material, it has become possible to realize topological states without the magnetic field. "The result is one of many new developments needed before an actual quantum computer is realized, but along the way better understanding of how quantum systems work, and might be applied to medicine, catalysts or materials, will be some of the positive side effects to this research", Professor Charles Marcus explains. The scientific article is now published in Nature Physics

Topological states are promising - but there are many challenges along the way

Topological states in condensed-matter systems have generated immense excitement and activity in the last decade, including the 2016 Nobel Prize in Physics. There is a natural fault-tolerance of the so called Majorana zero modes, which makes topological states ideally suited for quantum computing. But progress in realizing topological Majorana zero modes has been hampered by the requirement of large magnetic fields to induce the topological phase, which comes at a cost: the system must be operated in the bore of a large magnet, and every topological segment must be precisely aligned along the direction of field.

The new results report a key signature of topological superconductivity, but now in the absence of an applied magnetic field. A thin layer of the material europium sulfide (EuS), whose internal magnetism naturally aligns with the axis of the nanowire and induces an effective magnetic field (more than ten thousand times stronger than the Earth's magnetic field) in the superconductor and semiconductor components, appears sufficient to induce the topological superconducting phase.

Professor Charles Marcus explains the progress this way: "The combination of three components into a single crystal - semiconductor, superconductor, ferromagnetic insulator--a triple hybrid--is new. It's great news that it forms a topological superconductor at low temperature. This gives us a new path to making components for topological quantum computing, and gives physicists a new physical system to explore".

The new results will soon be applied to engineering the qubit

The next step will be to apply these results in order to get closer to realizing the actual working qubit. So far the researchers have worked on the physics and now they are about to embark on engineering an actual device. This device, the qubit, is essentially to a quantum computer what the transistor is to the ordinary computer we know today. It is the unit performing the calculations, but this is where the comparison ends. The potential for the performance of a quantum computer is so large that today we are not even really able to imagine the possibilities.

Collaboration is the key to success

Scientific results are more often than not the work of a close collaboration between many people. The myth about the lonely genius going "Heureka!", is truly a myth. In this case, Professor Peter Krogstrup, Scientific Director at the Microsoft Materials Lab and Yu Liu, postdoc at the Niels Bohr Institute grew the materials, Saulius Vaitiekenas, Lead experimentalist at the Microsoft Quantum Materials Lab carried out the measurements and built the devices, and Professor Charles Marcus at the Niels Bohr Institute, along with everyone else, interpreted the ensuing data. Charles Marcus says: "There may be different roles and competences involved, but the process of collaborating on science is most times a very fluid and open ended process".

The Arctic is warming faster than any other region on the planet. As a result, permafrost that is thousands of years old is now being lost to erosion. As measurements gathered on the Lena River by AWI experts show, the scale of erosion is alarming: every year, roughly 15 metres of the riverbanks crumble away. In addition, the carbon stored in the permafrost could worsen the greenhouse effect.

Today, the permafrost soils found on the Arctic coasts of Canada, Russia and Alaska, frozen for thousands of years, are increasingly eroding away due to the effects of waves and river currents - especially because the warm season there is steadily growing longer. As experts from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) have determined, this thawing has now taken on enormous proportions. By conducting a detailed analysis of historical satellite images from Siberia, Matthias Fuchs and his team were able to show that permafrost erosion in the Lena Delta has steadily worsened since the 1960s. Whereas in the 1960s the river, at a width of ca. 1.7 kilometres, gnawed away an average of five metres of land per year, between 2015 and 2018 that number rose to nearly 16 metres. In total the banks - more in some places, less in others - lost between 322 and 679 metres from 1965 to 2018.

The researchers focused their efforts on the 1.5-kilometre-long Sobo-Sise Cliff, a steep yedoma cliff from which permafrost plummets into a branch of the Lena River. At its highest point, it is 27 metres tall - as tall as a several-storey house. As Matthias Fuchs explains, "Major quantities of permafrost have been eroding away across the Arctic for many years now. Nevertheless, the Sobo-Sise Cliff is definitely a hotspot. There are very few other regions where the loss of land is so substantial." The worrisome aspect: the fact that the thawing and permafrost loss have intensified so massively in the last several years.

Fuchs and his colleagues not only analysed satellite data; they also took a closer look at how much carbon and nitrogen are released every year by the erosion. The cliff's permafrost, which is ca. 50,000 years old and formed during the last Ice Age, consists of 88 percent ice. The remainder is mainly peat, silt and sand. Especially the peat, which consists of partially decomposed ancient mosses and sedges, contains a great amount of carbon and nitrogen, formerly stored in the plants. The AWI experts collected soil samples on site and then analysed their carbon and nitrogen content in the lab. "It's amazing that the Sobo-Sise Cliff contains so much organic material, even though it's predominantly composed of ice. On average, we find roughly 26 kilograms of carbon and two kilograms of nitrogen per cubic metre." That means from 2015 to 2018 alone, ca. 15,000 metric tons of carbon and at least 1,000 metric tons of nitrogen landed in the Lena River, where they were washed away.

"Carbon and nitrogen are important nutrients for microorganisms," Fuchs explains. "Due to the erosion and thawing of permafrost, microorganisms now enjoy access to both." And this can have a number of consequences. When the microbes break down the carbon, they release carbon dioxide - just like we humans do when we breathe. When that happens, the loss of permafrost worsens the greenhouse effect by 're-mobilising' carbon that was previously stored away. In addition, the intensive input of carbon and nitrogen in the Lena is changing the nutrient supply in its waters. "This could significantly influence, or even transform, the river's natural food webs," says Fuchs.

The researchers can't yet say precisely what the consequences will be. To do so, in future studies they'll need to examine the nutrient flows in, and the biology of, the Lena river in more detail. But with their latest efforts and their assessment of the permafrost erosion, which has just been published in the journal Frontiers in Earth Science, the AWI experts have provided an important basis for additional investigations.

Researchers from the Moscow Institute of Physics and Technology and King's College London cleared the obstacle that had prevented the creation of electrically driven nanolasers for integrated circuits. The approach, reported in a recent paper in Nanophotonics, enables coherent light source design on the scale not only hundreds of times smaller than the thickness of a human hair but even smaller than the wavelength of light emitted by the laser. This lays the foundation for ultrafast optical data transfer in the manycore microprocessors expected to emerge in the near future.

Light signals revolutionized information technologies in the 1980s, when optical fibers started to replace copper wires, making data transmission orders of magnitude faster. Since optical communication relies on light -- electromagnetic waves with a frequency of several hundred terahertz -- it allows transferring terabytes of data every second through a single fiber, vastly outperforming electrical interconnects.

Fiber optics underlies the modern internet, but light could do much more for us. It could be put into action even inside the microprocessors of supercomputers, workstations, smartphones, and other devices. This requires using optical communication lines to interconnect the purely electronic components, such as processor cores. As a result, vast amounts of information could be transferred across the chip nearly instantaneously.

Getting rid of the limitation on data transmission will make it possible to directly improve microprocessor performance by stacking more processor cores, to the point of creating a 1,000-core processor that would be virtually 100 times faster than its 10-core counterpart, which is pursued by the semiconductor industry giants IBM, HP, Intel, Oracle, and others. This in turn will make it possible to design a true supercomputer on a single chip.

The challenge is to connect optics and electronics at the nanoscale. To achieve this, the optical components cannot be larger than hundreds of nanometers, which is about 100 times smaller than the width of a human hair. This size restriction also applies to on-chip lasers, which are necessary for converting information from electrical signals to optical pulses that carry the bits of the data.

However, light is a kind of electromagnetic radiation with a wavelength of hundreds of nanometers. And the quantum uncertainty principle says there is a certain minimum volume that light particles, or photons, can be localized in. It cannot be smaller than the cube of the wavelength. In crude terms, if one makes a laser too small, the photons will not fit into it. That said, there are ways around this restriction on the size of optical devices, which is known as the diffraction limit. The solution is to replace photons with surface plasmon-polaritons, or SPPs.

SPPs are collective oscillations of electrons that are confined to the surface of a metal and interact with the surrounding electromagnetic field. Only a few metals known as plasmonic metals are good to work with SPPs: gold, silver, copper, and aluminum. Just like photons, SPPs are electromagnetic waves, but at the same frequency they are much better localized -- that is, they occupy less space. Using SPPs instead of photons makes it possible to "compress" light and thus overcome the diffraction limit.

The design of truly nanoscale plasmonic lasers is already possible with current technologies. However, these nanolasers are optically pumped, that is, they have to be illuminated with external bulky and high-power lasers. This may well be convenient for scientific experiments, but not outside the laboratory. An electronic chip intended for mass production and real-life applications has to incorporate hundreds of nanolasers and operate on an ordinary printed circuit board. A practical laser needs to be electrically pumped, or, in other words, powered by an ordinary battery or DC power supply. So far such lasers are only available as devices that operate at cryogenic temperatures, which is not suitable for most practical applications, since maintaining liquid nitrogen cooling is not typically possible.

The physicists from the Moscow Institute of Physics and Technology (MIPT) and King's College London have proposed an alternative to the conventional way electrical pumping works. Usually the scheme of electrical pumping of nanolasers requires an ohmic contact made of titanium, chromium, or a similar metal. Moreover, that contact has to be a part of the resonator -- the volume where the laser radiation is generated. The problem with that is titanium and chromium strongly absorb light, which harms resonator performance. Such lasers suffer from high pump current and are susceptible to overheating. This is why the need for cryogenic cooling emerges, along with all the inconveniences it entails.

The proposed new scheme for electrical pumping is based on a double heterostructure with a tunneling Schottky contact. It makes the ohmic contact with its strongly absorbing metal redundant. The pumping now happens across the interface between the plasmonic metal and semiconductor, along which SPPs propagate. "Our novel pumping approach makes it possible to bring the electrically driven laser to the nanoscale, while retaining its ability to operate at room temperature. At the same time, unlike other electrically pumped nanolasers, the radiation is effectively directed to a photonic or plasmonic waveguide, making the nanolaser fit for integrated circuits," Dr. Dmitry Fedyanin from the Center for Photonics and 2D Materials at MIPT commented.

The plasmonic nanolaser proposed by the researchers is smaller -- in each of its three dimensions -- than the wavelength of the light it emits. Moreover, the volume occupied by SPPs in the nanolaser is 30 times smaller than the light wavelength cubed. According to the researchers, their room-temperature plasmonic nanolaser could be easily made even smaller, making its characteristics even more impressive, but that would come at the cost of the inability to effectively extract the radiation into a bus waveguide. Thus, while further miniaturization would render the device poorly applicable to on-chip integrated circuits, it would be still convenient for chemical and biological sensors and near-field optical spectroscopy or optogenetics.

Despite its nanoscale dimensions, the predicted output power of the nanolaser amounts to over 100 microwatts, which is comparable to much larger photonic lasers. Such a high output power allows each nanolaser to be used to transmit hundreds of gigabits per second, eliminating one of the most formidable obstacles to higher-performance microchips. And that includes all sorts of hi-end computing devices: supercomputer processors, graphic processors, and perhaps even some gadgets to be invented in the future.

NASA's Aqua satellite and the NASA-NOAA Suomi NPP satellite provided views of the strength, extent and rainfall potential as Hurricane Sally was making landfall during the morning hours of Sept. 16.

Watches and Warnings  

NOAA's National Hurricane Center has many warnings and watches in place today, Sept. 16. A Storm Surge Warning is in effect from Dauphin Island, Alabama to the Walton/Bay County Line, Florida. A Hurricane Warning is in effect for the Mississippi/Alabama border to the Okaloosa/Walton County line, Florida.

A Tropical Storm Warning is in effect for east of the Okaloosa/Walton County line, Florida to Indian Pass, Florida and from the Mississippi/Alabama border to the Mouth of the Pearl River.

NASA's Infrared Data Reveals Heavy Rainmakers

Tropical cyclones and hurricanes are made up of hundreds of thunderstorms, and infrared data can show where the strongest storms are located. That is because infrared data provides temperature information, and the strongest thunderstorms that reach highest into the atmosphere have the coldest cloud top temperatures.

On Sept. 16 at 4:10 a.m. EDT (0810 UTC) the Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA's Aqua satellite used infrared light to analyze the strength of storms within Sally. MODIS found the most powerful thunderstorms were north of the eye where cloud top temperatures were as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius).

Strong storms with cloud top temperatures as cold as minus 70 degrees Fahrenheit (minus 56.6. degrees Celsius) circled the most powerful storms. NASA research has found that cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall.

NASA's Night-Time View of Sally's Landfall Approach

On Sept. 16 at 4:15 a.m. EDT (0815 UTC), the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NOAA-NASA's Suomi NPP satellite captured an early morning image of Hurricane Sally approaching landfall near Gulf Shores, Alabama as a Category 2 Hurricane. This nighttime image shows the extent of Sally's clouds blotting out the city lights from southern Mississippi to the northwestern coast and panhandle of Florida.

Sally's Official Landfall

NOAA's National Hurricane Center reported that Hurricane Sally made landfall at 5:45 a.m. EDT (4:45 a.m. EDT/0945) near Gulf Shores, Alabama as a as a Category 2 hurricane, with maximum sustained winds of 105 mph (165 kph) and a minimum central pressure of 965 millibars.

Sally's Status at 8 a.m. EDT on Sept. 16

The NHC noted at 8 a.m. EDT (1200 UTC), the center of the eye of Hurricane Sally was located by NOAA Doppler weather radars near latitude 30.4 degrees north and longitude 87.6 degrees west. Sally's eye was just 15 miles (25 km) north-northeast of Gulf Shores, Alabama and 25 miles (40 km) west-southwest of Pensacola, Florida.

Sally is moving toward the north-northeast near 3 mph (6 kph). A north-northeastward to northeastward motion at a slightly faster forward speed is expected later today and tonight, followed by a faster northeastward motion on Thursday. Doppler weather radar data indicate that the maximum sustained winds are near 100 mph (155 kph) with higher gusts.

Hurricane-force winds extend outward up to 40 miles (65 km) from the center and tropical-storm-force winds extend outward up to 125 miles (205 km). A sustained wind of 74 mph (119 kph) and a gust to 92 mph (148 kph) were recently reported at the Pensacola Naval Air Station in Pensacola, Florida. The estimated minimum central pressure based on surface observations is 967 millibars.

NHC Key Messages, Historic and catastrophic flooding is unfolding

The National Hurricane Center issued Key Messages about Rainfall, Wind, Tornadoes and Surf:

RAINFALL:  Through this afternoon, Sally will produce additional rainfall totals of 8 to 12 inches with localized higher amounts possible along and just inland of the central Gulf Coast from west of Tallahassee, Florida to Mobile Bay, Alabama. Storm totals of 10 to 20 inches to isolated amounts of 35 inches is expected.  In addition, this rainfall will lead to widespread moderate to major river flooding.

Sally is forecast to turn northeastward after making landfall today and move across the Southeast through Friday, producing the following rainfall totals:

Southern and central Alabama to central Georgia: 4 to 8 inches, with isolated maximum amounts of 12 inches. Significant flash and urban flooding is likely, as well as widespread minor to moderate flooding on some rivers.

Western South Carolina into western and central North Carolina: 4 to 6 inches, with isolated maximum amounts of 9 inches. Widespread flash and urban flooding is possible, as well as minor to moderate river flooding.

Southeast Virginia: 2 to 5 inches, with isolated maximum amounts of 7 inches. Scattered flash and urban flooding is possible, as well as scattered minor river flooding.

STORM SURGE:  The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline.  The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide.

AL/FL Border to Okaloosa/Walton County Line, FL including Pensacola Bay and Choctawhatchee Bay, 4-7 ft
Okaloosa/Walton County Line, FL to Walton Bay County Line, FL,  2-4 ft
Dauphin Island, AL to AL/FL Border including Bon Secour Bay, 2-4 ft
Walton Bay County Line, FL to Chassahowitzka, FL including Saint Andrew Bay,  1-3 ft

The deepest water will occur along the immediate coast in areas of onshore winds, where the surge will be accompanied by large and damaging waves.  Surge-related flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances.

WIND:  Hurricane conditions are spreading onshore within the hurricane warning area in Florida and Alabama.  Tropical storm conditions will continue in portions of the warning areas through tonight.

TORNADOES:  A few tornadoes may occur today and tonight across portions of the Florida Panhandle, southern Alabama, and southwestern Georgia.

SURF:  Swells from Sally will continue to affect the coast from the Florida Big Bend westward to southeastern Louisiana during the next couple of days. These swells are likely to cause life-threatening surf and rip current conditions.

Sally's Forecast from NHC

Weakening is expected as the center moves inland today and tonight. On the forecast track, the center of Sally will move across the extreme western Florida panhandle and southeastern Alabama through early Thursday, and move over central Georgia Thursday afternoon through Thursday night.

About NASA's EOSDIS Worldview

NASA's Earth Observing System Data and Information System (EOSDIS) Worldview application provides the capability to interactively browse over 700 global, full-resolution satellite imagery layers and then download the underlying data. Many of the available imagery layers are updated within three hours of observation, essentially showing the entire Earth as it looks "right now."

NASA Researches Earth from Space

For more than five decades, NASA has used the vantage point of space to understand and explore our home planet, improve lives and safeguard our future. NASA brings together technology, science, and unique global Earth observations to provide societal benefits and strengthen our nation. Advancing knowledge of our home planet contributes directly to America's leadership in space and scientific exploration.

For updated forecasts, visit: http://www.nhc.noaa.gov

By Rob Gutro
NASA's Goddard Space Flight Center

Although Earth is uniquely situated in the solar system to support creatures that call it home, different forms of life could have once existed, or might still exist, on other planets. But finding traces of past or current lifeforms on other worlds is challenging. Now, researchers reporting in ACS' Analytical Chemistry have developed a fully automated microchip electrophoresis analyzer that, when incorporated into a planetary rover, could someday detect organic biosignatures in extraterrestrial soil.

One critical piece of evidence for life beyond Earth is the presence of certain organic molecules. Previous missions to Mars have relied on gas chromatography coupled to mass spectrometry (GC-MS) to separate and detect compounds. However, the technique has limitations for the analysis of some molecules, such as organic acids, especially when water, minerals or salts are also in the sample. Microchip electrophoresis (ME)-based separations, followed by laser-induced fluorescence (LIF) detection, would be ideal, but current instruments are only partially automated, which wouldn't work for interplanetary missions. Peter Willis and colleagues wanted to develop a portable, battery-powered ME-LIF instrument that could accept a sample and perform labeling, separation and detection of organic molecules, all in a fully automated fashion.

The researchers made a device that included two microchips -- one for processing and labeling a liquid sample, and the other (the ME chip) for separating compounds -- and an LIF detection system. After optimizing the device, the researchers put it to the test in a simulated Mars mission in a Chilean desert. The team coupled the analyzer to a portable subcritical water extractor on a remotely deployed rover system. The rover drilled into the soil to collect samples, which were delivered to the extractor. Then, water was added to the soil samples, and they were heated to extract compounds for analysis. The device detected parts per billion levels of amino acids in soil from three of four drilling locations. Importantly, the sensitivity was three orders of magnitude higher than that reported for GC-MS-based methods. Although more work is needed to ready the instrument for spaceflight and extraterrestrial conditions, this research lays the foundation for developing ME-LIF instruments for missions seeking signs of life beyond Earth, the researchers say.

The authors acknowledge funding from NASA.

The abstract that accompanies this paper can be viewed here.

The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS' mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and its people. The Society is a global leader in providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a specialist in scientific information solutions (including SciFinder® and STN®), its CAS division powers global research, discovery and innovation. ACS' main offices are in Washington, D.C., and Columbus, Ohio.
 

To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.
 

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In response to the COVID-19 pandemic, public transport agencies across North America have made significant adjustments to services, including cutting trip frequency in many areas while increasing it in others. In many cases, these changes, especially service cuts, have disproportionately affected areas where lower-income and more vulnerable groups live, according to a new study from McGill University.

The study published in Transport Findings compares changes in public transport service levels across 30 U.S. and 10 Canadian cities, linking these changes to average income levels and regional sociodemographic characteristics like education and unemployment.

"Transport agencies faced major financial and operating challenges as ridership declined dramatically in North American cities--even as the pandemic magnified their role as a critical service, ferrying essential, often low-income workers with limited alternatives to their jobs," says lead author James DeWeese, a research assistant in urban planning at McGill University.

Equity unaccounted for in service cuts

Major service adjustments were applied at different rates in different cities. "Many transit agencies did not account for equity factors, so they ended up cutting services in low- income areas that serve vulnerable groups," says co-author Ahmed El-Geneidy, a professor in the School of Urban Planning at McGill University. Among these are Cincinnati and Toronto. "Only a handful of cities, like San Francisco and Portland, had fewer cuts to services passing through areas with a higher concentration of vulnerable groups."

The few that did show more sensitivity toward vulnerable groups employed varying approaches, say the researchers. While a couple focused on vertical equity (providing more to those in need of the service) in their service adjustments, the rest concentrated on horizontal equity (providing adjustments equally to all groups). New York, Los Angeles, and Miami added and cut services almost equally across the different income groups.

"Service cuts need to be revised to make sure vulnerable groups who do not have much choice but to travel during the pandemic are getting the appropriate public transit service they need," says El-Geneidy. The group is undertaking further research to understand why these decisions were made and how to avoid service cuts that harm lower income and more vulnerable groups, many of whom are essential workers.