Tech

Warm mix asphalt (WMA) is gaining attention in the asphalt industry as an eco-friendly and sustainable technology. WMA reduces energy consumption while simultaneously minimizing vapors and greenhouse gas emissions during the production of asphalt mixtures in comparison to conventional asphalt. However, high moisture susceptibility and ageing of asphalt make WMA less durable on the roads.

To address both issues in WMA technology, a team from the Energy Safety Research Institute (ESRI) at Swansea University and Braunschweig Pavement Engineering Centre (ISBS) at the Technical University of Braunschweig have discovered potential for fumed silica nanoparticles (FSNs) to be used as an anti-ageing binder that can not only serve to reduce temperature but also significantly overcome limitations caused by moisture susceptibility.

Lead researcher Goshtasp Cheraghian said: "The presented research covers existing gaps in WMA technology. FSNs with large surface area are ideal candidate as a cost-effective and non-toxic materials which can meaningfully impact on shielding asphalt in WMA technology. In addition, our findings on the concept of the molecular interaction between nanoparticle and asphalt binders can open new avenues for the application of nanotechnology in asphalt engineering."

Co-author Sajad Kian said: "It's possible that someday these high surface area NPs will be used in the asphalt and build longer-lasting roadways by minimizing asphalt-related emissions (VOC and CO2) in real world conditions."

Professor Andrew Barron, the Founder and Director of ESRI and the Sêr Cymru Chair of Low Carbon Energy and Environment at Swansea University, said: "Reducing energy and resources is a key goal of ESRI and vital for industry as it moved towards Net Zero."

Lifestyle changes for demand-side climate change mitigation is gaining more and more importance and attention. A new IIASA-led study set out to understand the full potential of behavior change and what drives such changes in people's choices across the world using data from almost two billion Facebook profiles.

Modern consumption patterns, and especially livestock production in the agricultural sector to sustain the world's growing appetite for animal products, are contributing to and speeding the advance of interconnected issues like climate change, air pollution, and biodiversity loss. Our current way of life is simply not sustainable. It is clear that there needs to be a step-change in our behavior and consumption patterns to ensure that those that come after us have a healthy, life-sustaining planet to call home. Getting a large number of people with vastly different beliefs and values to change their consumption patterns and behavior is however not a simple matter.

While many previous studies have looked into the drivers of low-carbon lifestyles in general and sustainable diets in particular, the data they employed have often been based on a limited number of countries, or a limited number of survey respondents whose reported information sometimes varied from their actual behavior. In their study published in Environmental Research Letters, IIASA researcher Sibel Eker and her colleagues, made use of online social media data, particularly anonymous Facebook audience size data, as a global data source to represent the online behavior of billions of people in order to complement more traditional empirical studies.

"We were interested in finding out if we could use the data available on the social media platform Facebook to quantify the level of interest in sustainable diets, such as vegetarianism, in different countries around the world and to determine whether their online activity actually represents a real-life interest in vegetarianism and consumption patterns," Eker explains. "In addition, we wanted to see what other factors such as education level, age, gender, or the GDP per capita, play a role in determining people's interest in sustainable diets in different countries."

In this regard, Eker and her colleagues created a dataset of daily and monthly active users who indicated having an interest in sustainable lifestyles, particularly vegetarianism. Their choice of the term vegetarianism was motivated by the breadth of the term compared to other terms like "plant-based diets" or "sustainable diets", and its availability as a pre-defined interest choice on the Facebook advertising platform.

"Our choice of vegetarianism and sustainable living as interest categories relevant for low-carbon lifestyles was based on a keyword search on the Facebook Marketing API in which they emerged as the ones with the highest global audience size among the available interest categories. A person's interest in vegetarianism can stem from a number of things ranging from animal welfare, to health, or religion. In the context of this study, we saw vegetarianism in particular, as an indicator of the spread of meat-free diets, which is more relevant for estimating food demand, rather than as an indicator of people's interest in a vegetarian lifestyle purely for environmental reasons," notes Eker.

The publicly available and anonymous data was retrieved from the Facebook marketing Application Programming Interface (API) at multiple points between September 2019 and June 2020 for the interest category, age, gender, education level, and country of each user. The dataset used covers a total of 131 countries and around 1.9 billion people, of which 210 million indicated an interest in vegetarianism, and 33 million indicated an interest in sustainable living.

The results indicate that the fraction of the Facebook audience interested in vegetarianism positively correlates with the rate of decline of meat consumption at the country level (in the countries with high vegetarianism interest) - in other words, the more people are interested in following a vegetarian diet, the steeper the declining trend of meat consumption in the country. Meat consumption levels overall were higher in high-income countries than in the low-income ones, but the interest in sustainable diets, as much as it is expressed online, seemed to be higher in those countries too, which, according to the researchers, is promising for trends towards more sustainable and equitable meat consumption.

Education, which has previously been shown to be a catalyst to achieve the SDGs, could be a catalyst here too, unless superseded by high-income levels, since it emerged as the most important factor affecting interest in vegetarianism. This effect was more pronounced in low-income countries. Gender also emerged as a very strong distinguishing factor, with women tending to have a higher interest in vegetarianism than men. GDP per capita and age followed these two indicators in terms of their effect on people's interest in a vegetarian lifestyle.

"Our study shows that online social media data can indeed be useful to analyze and estimate food consumption trends. While the importance of education, income, and gender was previously known based on local studies, we ranked them for the first time on a global scale," says Eker. "Policies that are designed to stimulate adoption of sustainable diets, especially communication policies, should take the social heterogeneity and existing tendencies - which could be low hanging fruit - into account. Heterogeneity across countries also plays an important role, and studies like ours help to understand international differences and to design local customized policies."

As well as bright colours and subtle scents, flowers possess many invisible ways of attracting their pollinators, and a new study shows that bumblebees may use the humidity of a flower to tell them about the presence of nectar, according to scientists at the Universities of Bristol and Exeter.

This new research has shown that bumblebees are able to accurately detect and choose between flowers that have different levels of humidity next to the surface of the flower.

The study, published this week in the Journal of Experimental Biology, showed that bees could be trained to differentiate between two types of artificial flower with different levels of humidity, if only one of the types of flower provided the bee with a reward of sugar water.

To make sure that the artificial flowers mimicked the humidity patterns seen in real flowers, the researchers built a robotic sensor that was able to accurately measure the shape of the humidity patterning.

Dr Michael Harrap carried out the research whilst based at the University of Bristol's School of Biological Sciences and is lead author of the study. He said: "We know that different species of plants produce flowers that have distinct patterns of humidity, which differ from the surrounding air. Knowing that bees might use these patterns to help them find food shows that flowers have evolved a huge variety of different ways of attracting pollinators, that make use of all the pollinators' senses."

Professor Natalie Hempel de Ibarra, Associate Professor at the University of Exeter's School of Psychology, explained: "Our study shows that bumblebees not only use this sensory information to make choices about how they behave, but are also capable of learning to distinguish between humidity patterns in a similar way to how they learn to recognise the colour or smell of a flower."

Dr Sean Rands, Senior Lecturer in the University of Bristol's School of Biological Sciences, added: "If humidity patterns are important for attracting pollinators, they are likely to be one of several different signals (such as colour, scent and pattern) that a flower is using at the same time, and could help the bee to identify and handle the flower more efficiently.

"The effectiveness of humidity patterns may depend upon the humidity of the environment around the flower; climate change may affect this environmental humidity, which in turn could have a negative effect on a visiting bee because the effectiveness of the humidity pattern will be altered."

Coastal wetlands like seagrass meadows, mangroves, and salt marshes play vital roles along the shoreline, from providing a buffer against storm surges, to providing critical habitat for animals, to capturing atmospheric carbon.

We are still just beginning to comprehend the intricate workings of these highly productive ecosystems and their role in mitigating the climate crisis, but UConn researchers are one step closer to understanding how salt marsh vegetation, their bacterial communities, and vegetation can help predict a marsh's potential to be a blue carbon reservoir. The research was recently published in the journal Estuaries and Coasts.

"Coastal marshes are increasingly recognized as important ecosystems because they sequester and store a lot of carbon. There is increasing interest in understanding these blue carbon ecosystems because of our current climate crisis," says Beth Lawrence, co-author and College of Agriculture, Health, and Natural Resources Assistant Professor of Wetland and Plant Ecology in the Department of Natural Resources and the Environment and Center for Environmental Science and Engineering.

Lawrence explains how salt marshes serve as focal ecosystems in conservation and restoration. They are habitat for a wide range of species, including endangered species like the salt marsh sparrow. Located at the interface between land and sea, these ecosystems buffer storm energy and perform other important functions, like the removal of excess nitrogen from water making its way to estuaries where it may otherwise lead to algal blooms and oxygen-deprived "dead zones."

Development leads to changes in the movement of water (see side bar) and Lawrence says that, often, tide-restricted salt marshes become less salty and wet, leading to shifts in what plants grow there. Plants that thrive in these brackish conditions can be invasive, like Phragmites australis, which has become the bane of coastal managers, Lawrence says.

Tidal restoration aims to reconnect marshes cut off from the ocean to improve habitat. Increasing the size of culverts underneath roads, railroads or bridges or removing tide gates can restore tidal flow and the organisms that rely on it.

To observe how tidal restoration may alter carbon cycling and soil microbes, the researchers sampled from several marsh locations in Connecticut, including less-disturbed "reference" marshes, and formerly restricted marshes that have since undergone restoration.

"Tidally restored and the unrestored references differed in carbon density and how much carbon is in the soil. Highly restricted sites presumably had dried out to some degree and lost some carbon," says Lawrence.

This makes sense, Lawrence says, because in wetter soils, microbes do not break down carbon-rich plant material as efficiently as in dry soil, therefore the material and the carbon within it remains. When microbes can feast away on the plant matter in drier, more oxygenated conditions, the carbon is lost to the atmosphere in the form of carbon gas, in a process called mineralization.

Other measurements between tidally restored and undisturbed marshes were the same across the suite of parameters used in the researchers' measurements, including soil chemistry, plant biomass, and microbial communities. However, there were large differences across vegetation zones.

"The key difference we saw were across plant communities," Lawrence says. "We saw differences in microbial respiration as well as the microbial communities living in the soils in different vegetation zones. These findings suggest that both plants and microbes are responding to differences in environmental conditions."

With the knowledge of which plants thrive where, the researchers can get a glimpse into the biological processes at play within the marsh by noting which plants are present.

"I think one of the key takeaways from our study is that these bands of vegetation are good indicators of what's going on hydrologically and biogeochemically," says Lawrence. "For example, if we see native Spartina alterniflora growing, we know the environment is saltier than where Phragmites is growing. These soils are likely to have different bacterial community composition and process carbon and nitrogen differently than in a higher, drier community."

Considering the importance of salt marshes and the need for further restoration work, Lawrence says managers could use satellite imagery or drones to look at the vegetation at greater spatial scales to get an indication of growing conditions as well as a system's carbon capture capacity. This could help in focusing restoration efforts and monitoring.

"Managers are really interested in scaling up," Lawrence says. "Quantifying carbon and nutrient cycling is very time-consuming and detailed so an important implication of this work is that the dominant vegetation in salt marshes can be used as a proxy for some biogeochemical processes. We have to carefully consider how we're spending our limited conservation dollars."

WASHINGTON, June 22, 2021 -- About 2.2 billion people globally lack reliable access to clean drinking water, according to the United Nations, and the growing impacts of climate change are likely to worsen this reality.

Solar steam generation (SSG) has emerged as a promising renewable energy technology for water harvesting, desalination, and purification that could benefit people who need it most in remote communities, disaster-relief areas, and developing nations. In Applied Physics Letters, by AIP Publishing, Virginia Tech researchers developed a synthetic tree to enhance SSG.

SSG turns solar energy into heat. Water from a storage tank continuously wicks up small, floating porous columns. Once water reaches the layer of photothermal material, it evaporates, and the steam is condensed into drinking water.

One major challenge in scaling up SSG technology is the limit in the capillary force beyond a certain column height, when the water cannot wick fast enough to keep up with the evaporation process. The capillary force, based on the surface tension that causes water to "climb" a porous paper towel, drives the water toward the evaporator.

Inspired by mangrove trees thriving along coastlines, the researchers bypassed this hurdle by creating a synthetic tree to replace the capillary action with transpiration, the process of water movement through a plant and its evaporation from leaves, stems, and flowers. Transpiration can pump water up insulating tubes of any desired height.

In real trees, transpiration begins at the roots, which suck up water through hollow vessels made from xylem tissue. As the water warms, it releases as vapor through pores on the underside of leaves.

The synthetic tree consists of a 19-tube array, covered by a nanoporous ceramic disk, which serves as the leaf. Each plastic tube, imitating the xylem conduits, is 6 centimeters high, just under 2.5 inches, with an inner diameter of 3.175 millimeters, about a tenth of an inch.

The setup enables the evaporating interface to thermally separate from the bulk water in the tank, so the evaporator does not dry out. Water evaporating from the disk is replenished by suction, which continuously pumps more water from a bottom tank up the tube array.

"We expect our tree-based solar steam generator will be of interest for applications in underground water extraction and purification," author Jonathan Boreyko said. "The ultimate goal is to achieve a suction pressure strong enough to pull ocean water through a salt-excluding filter without requiring a mechanical pump, analogous to how mangrove trees are able to grow in ocean water."

Future research could focus on fabricating taller trees, adding more leaves to increase the area over which evaporation occurs, and incorporating desalination membranes at the tube inlets to prevent salt buildup.

A team of scientists from the Leibniz Institute for Food Systems Biology at the Technical University of Munich has now discovered that the odorant receptor OR5K1 is specialized to recognize pyrazines in both humans and domesticated animals. These are volatile substances that contribute to the typical odor of many vegetables or are formed when food is heated. In addition, pyrazines also play a role as signaling substances in intra- or interspecific communication. The new research results contribute to a better understanding of the molecular mechanisms underlying the odor perception of food as well as olfactory communication.

Olfactory perception is crucial for the recognition and selection of food as well as for the enjoyment when eating. Everyone knows this at the latest when nothing tastes good anymore due to a blocked nose. The perception of odors also influences the behavior of many animals.

For 80 percent, the odor spectrum is unknown

The genes for the receptors with which we perceive odors have been known for over 30 years. However, despite intensive research, the specific odorant spectrum detected by about 80 percent of human olfactory receptors is still unknown.

New findings in this area could help to develop biobased "artificial noses" that can be used, for example, to monitor the sensory quality and authenticity of food. In addition, they could provide insight into the physiological functions of these receptors that go beyond the sensory perception of food.

"In particular, odorants such as pyrazines are interesting in this regard. This is because some of them, as key odorants, shape the typical aroma of food and, at the same time, play a major role as volatile signaling substances in olfactory communication of animals. A good example is wolves, which leave scent messages in their territory via their urine and thus mark it," says team leader Dietmar Krautwurst.

Pyrazine with a dual function

Trimethylpyrazine is one such substance. It is formed during roasting processes, and its scent is reminiscent of baked potatoes, roasted nuts and cocoa. It is therefore a frequently used flavoring agent in the food industry. Likewise, this substance is naturally present in the urine of foxes and wolves and puts mice on alert as soon as they smell it.

However, it was previously unknown which of the human olfactory receptors react to pyrazines. Therefore, the research team used a cellular assay system established at the institute to investigate the responses of over 600 human receptor variants to trimethylpyrazine. As the study results show, the odorant receptor OR5K1 was the only one of the tested variants to react to the substance. A check of the receptor with further odorants showed that it selectively recognizes 18 other pyrazines. For the test, the team used, among other volatiles, 178 key odorants that shape the aroma of food, including some pyrazines.

"Strikingly, those pyrazines, which activate the receptor most potently, function both as food odorants and signaling substances in the animal kingdom," reported Franziska Haag of the Leibniz Institute of Food Systems Biology at the Technical University of Munich, who, together with her former colleague Patrick Marcinek, played a key role in the study. As the study results also showed, corresponding (homologous) olfactory receptors of domestic and farm animals, but also of mice, responded in a similar way to the tested pyrazines as the human receptor. "We therefore assume that the recognition spectrum of the OR5K1 odorant receptor has evolved under the influence of domestication," explains Dietmar Krautwurst. Veronika Somoza, director of the Leibniz Institute adds, "In the future, we will use our unique, extensive odorant and receptor collection at the institute to decipher the function of human olfactory receptors."

A single measurement result is not a proof - this has been shown again and again in science. We can only really rely on a research result when it has been measured several times, preferably by different research teams, in slightly different ways. In this way, errors can usually be detected sooner or later.

However, a new study by Prof. Andrej Pustogow from the Institute of Solid State Physics at TU Wien together with other international research teams shows that this can sometimes take quite a long time. The investigation of strontium ruthenate, a material that plays an important role in unconventional superconductivity, has now disproved an experiment that gained fame in the 1990s: it was believed that a novel form of superconductivity had been discovered. As it now turns out, however, the material behaves very similarly to other well-known high-temperature superconductors. Nevertheless, this is an important step forward for research.

Two particles with coupled spin

Superconductivity is one of the great mysteries of solid-state physics: certain materials lose their electrical resistance completely at low temperatures. This effect is still not fully understood. What is certain, however, is that so-called "Cooper pairs" play a central role in superconductivity.

In a normal metal, electric current consists of individual electrons that collide with each other and with the metal atoms. In a superconductor, the electrons move in pairs. "This changes the situation dramatically," explains Andrej Pustogow. "It's similar to the difference between a crowd in a busy shopping street and the seemingly effortless motion of a dancing couple on the dance floor." When electrons are bound in Cooper pairs, they do not lose energy through scattering and move through the material without any disturbance. The crucial question is: Which conditions lead to this formation of Cooper pairs?

"From a quantum physics point of view, the important thing is the spin of these two electrons," says Andrej Pustogow. The spin is the magnetic moment of an electron and can point either 'up' or 'down'. In Cooper pairs, however, a coupling occurs: in a 'singlet' state, the spin of one electron points upwards and that of the other electron points downwards. The magnetic moments cancel each other out and the total spin of the pair is always zero.

However, this rule, which almost all superconductors follow, seemed to be broken by the Cooper pairs in strontium ruthenate (Sr2RuO4). In 1998, results were published that indicated Cooper pairs in which the spins of both electrons point in the same direction (then it is a so-called "spin triplet"). "This would enable completely new applications," explains Andrej Pustogow. "Such triplet Cooper pairs would then no longer have a total spin of zero. This would allow them to be manipulated with magnetic fields and used to transport information without loss, which would be interesting for spintronics and possible quantum computers."

This caused quite a stir, not least because strontium ruthenate was also considered a particularly important material for superconductivity research for other reasons: its crystal structure is identical to that of cuprates, which exhibit high-temperature superconductivity. While the latter are deliberately doped with "impurities" to make superconductivity possible, Sr2RuO4 is already superconducting in its pure form.

New measurement, new result

"Actually, we studied this material for a completely different reason," says Andrej Pustogow. "But in the process, we realised that these old measurements could not be correct." In 2019, the international team was able to show that the supposedly exotic spin effect was just a measurement artefact: the measured temperature did not match the actual temperature of the sample studied; in fact, the sample studied at the time was not superconducting at all. With this realisation in mind, the superconductivity of the material was now re-examined with great precision. The new results clearly show that strontium ruthenate is not a triplet superconductor. Rather, the properties correspond to what is already known from cuprates.

However, Andrej Pustogow does not find this disappointing: "It is a result that brings our understanding of high-temperature superconductivity in these materials another step forward. The finding that strontium ruthenate shows similar behaviour to cuprates means two things: On the one hand, it shows that we are not dealing with an exotic, new phenomenon, and on the other hand it also means that we have a new material at our disposal, in which we can investigate already known phenomena." Ultra-pure strontium ruthenate is better suited for this than previously known materials. It offers a much cleaner test field than cuprates.

In addition, one also learns something about the reliability of old, generally accepted publications: "Actually, one might think that results in solid-state physics can hardly be wrong," says Pustogow. "While in medicine you might have to be satisfied with a few laboratory mice or a sample of a thousand test subjects, we examine billions of billions (about 10 to the power of 19) electrons in a single crystal. This increases the reliability of our results. But that does not mean that every result is completely correct. As everywhere in science, reproducing previous results is indispensable in our field - and so is falsifying them."

Cancer cells can become resistant to treatments through adaptation, making them notoriously tricky to defeat and highly lethal. Cold Spring Harbor Laboratory (CSHL) Cancer Center Director David Tuveson and his team investigated the basis of "adaptive resistance" common to pancreatic cancer. They discovered one of the backups to which these cells switch when confronted with cancer-killing drugs.

KRAS is a gene that drives cell division. Most pancreatic cancers have a mutation in the KRAS protein, causing uncontrolled growth. But, drugs that shut off mutant KRAS do not stop the proliferation. The cancer cells find a way to bypass the blockage and keep on dividing. Derek Cheng, the lead author of the study and a former Medical Scientist Training Program student in the Tuveson lab, compares this process to backup engines on a ship. He says:

"You take away your main engine, you're kind of on some backup engines. But it's getting by on those. The ship isn't sinking yet. It's still moving at a slower pace. Ultimately what we want to do is sink the ship."

Tuveson and his team wanted to figure out the "backup engines" in these cancer cells. They used a technique called biotin proximity labeling to identify what other proteins interacted with mutant KRAS. Cheng says, "I basically attach a spray can to my favorite protein, or rather least favorite protein, in this case. And so it attaches biotin, basically spraying biotin 'paint' to nearby proteins, and we're able to analyze it to figure out what proteins were labeled."

The scientists found "biotin paint" on a protein named RSK1, which is part of a complex that keeps a nearby group of proteins, called RAS proteins, dormant. The scientists were surprised to discover that when they inactivated mutant KRAS, the nearby RSK1 complex stopped working as well. This allowed the RAS proteins to activate and take over the work of the missing mutant KRAS.

Stopping pancreatic cancer cells may require drugs that can simultaneously target multiple molecules. Tuveson hopes to uncover more of the players contributing to adaptation in cancer cells to improve future treatments.

The shift to home working brought about by the pandemic could cost the UK economy up to £32bn a year in lost personal income tax.

Highly paid workers who live abroad but work in the UK will pay their income tax in their country of residence, rather than to HMRC - which researchers say could cost billions each year.

This new mobility of the workforce can also affect where corporate income tax is paid and value created, as well as VAT and where goods and services are purchased.

Professor Rita de la Feria, Chair in Tax Law in the University of Leeds' School of Law, co-led the new research with Dr Giorgia Maffini, Tax Policy expert, at PWC, London.

Their paper, The Impact of Digitalisation on Personal Income Taxes, is published in British Tax Review.

Professor de la Feria said: "The acceleration of digitalisation and the spread of remote working internationally as a result of the pandemic poses very significant challenges to personal income taxes.

"New mobile workers are likely to be at top of the income distribution, and even a small number could result in significant revenue losses to the UK, of between £6bn and £32bn.

"The likely effect will be a tightening of employment rules, introduction of new tax avoidance rules, and increased personal income taxes competition with countries fighting to attract new mobile workers.

"The impact of these labour changes is likely to be more significant in countries like the UK, which relies heavily on income tax - especially from a small number of high-income - and now potentially mobile - taxpayers.

"How big these challenges are, and how countries will react to them, will be a key issue in the coming years."

Total income tax paid in the UK in 2018-19 was £187 billion, with 35% paid by the 4.2 million higher rate taxpayers, and 31% from additional rate taxpayers.

An estimated 31% of UK jobs can be carried out remotely - of which an as-yet unknown share will be internationally mobile.

Assuming only higher and additional rate taxpayers are internationally mobile, the researchers say the potential loss in income tax would be between 2% and 10% of the total revenue - between £3.8bn and £19bn a year.

Including Social Security contribution losses of between £2.7bn and £13bn a year, the total income tax revenue loss would amount to between £6.5 billion and £32.5 billion a year.

The researchers say recent global tax discussions have focussed on solving challenges to corporation tax posed by digitalisation, but the pandemic-led shift to remote working could pose an even bigger crisis.

Professor de la Feria said: "This crisis has the potential for much wider economic and societal ramifications than the challenges to corporation tax. The challenges of adapting our tax systems to a digital economy are far from over; indeed, they have just started."

(SACRAMENTO, Calif.) -- The secret to healthier skin and joints may reside in gut microorganisms. A study led by UC Davis Health researchers has found that a diet rich in sugar and fat leads to an imbalance in the gut's microbial culture and may contribute to inflammatory skin diseases such as psoriasis.

The study, published in the Journal of Investigative Dermatology, suggests that switching to a more balanced diet restores the gut's health and suppresses skin inflammation.

"Earlier studies have shown that Western diet, characterized by its high sugar and fat content, can lead to significant skin inflammation and psoriasis flares," said Sam T. Hwang, professor and chair of dermatology at UC Davis Health and senior author on the study. "Despite having powerful anti-inflammatory drugs for the skin condition, our study indicates that simple changes in diet may also have significant effects on psoriasis."

What is psoriasis?

Psoriasis is a stubborn skin condition linked to the body's immune system. When immune cells mistakenly attack healthy skin cells, they cause skin inflammation and the formation of scales and itchy red patches.

Up to 30% of patients with psoriasis also have psoriatic arthritis with symptoms such as morning stiffness and fatigue, swollen fingers and toes, pain in joints and changes to nails.

Diet affects the microbial balance in the intestines and skin inflammation

Food is one of the major modifiable factors regulating the gut microbiota, the community of microorganisms living in the intestines. Eating a Western diet can cause rapid change to the gut's microbial community and its functions. This disruption in microbial balance - known as dysbiosis- contributes to gut inflammation.

Since bacteria in the gut may play key roles in shaping inflammation, the researchers wanted to test whether intestinal dysbiosis affects skin and joint inflammation. They used a mouse model to study the effect of diet on psoriasis and psoriatic arthritis. They injected mice with Interleukin-23 (IL-23) minicircle DNA to induce a response mimicking psoriasis-like skin and joint diseases.

IL-23 is a protein generated by the immune cells responsible for many inflammatory autoimmune reactions, including psoriasis and inflammatory bowel disease (IBD).

Hwang and his colleagues found that a short-term Western diet appears sufficient to cause microbial imbalance and to enhance susceptibility to IL-23?mediated psoriasis-like skin inflammation.

"There is a clear link between skin inflammation and changes in the gut microbiome due to food intake," Hwang said. "The bacterial balance in the gut disrupted shortly after starting a Western diet, and worsened psoriatic skin and joint inflammation."

One critical finding of their work was identifying the intestinal microbiota as a pathogenic link between diet and the displays of psoriatic inflammation. The study also found that antibiotics block the effects of the Western diet, reducing skin and joint inflammation.

Is the damage caused by an unhealthy diet reversible?

The researchers wanted to test if switching to a balanced diet can restore the gut microbiota, despite the presence of IL-23 inflammatory proteins. They fed mice a Western diet for six weeks before giving them an IL-23-inducing agent to trigger psoriasis and psoriatic arthritis features. Then, they randomly divided the mice into two groups: a group that continued the Western diet for another four weeks and a group that switched to a balanced diet for the same duration.

Their study showed that eating a diet high in sugar and fat for 10 weeks predisposed mice to skin and joint inflammation. Mice that were switched to a balanced diet had less scaling of the skin and reduced ear thickness than mice on a Western diet. The improvement in skin inflammation for mice taken off the Western diet indicates a short-term impact of the Western diet on skin inflammation.

This suggests that changes in diet could partially reverse the proinflammatory effects and alteration of gut microbiota caused by the Western diet.

"It was quite surprising that a simple diet modification of less sugar and fat may have significant effects on psoriasis," said Zhenrui Shi, visiting assistant researcher in the UC Davis Department of Dermatology and lead author on the study. "These findings reveal that patients with psoriatic skin and joint disease should consider changing to a healthier dietary pattern."

"This work reflects a successful collaboration among researchers, especially with Professor Satya Dandekar and her team at the Department of Medical Microbiology and Immunology and Professor Yu-Jui Yvonne Wan at the Department of Medical Pathology and Laboratory Medicine," Hwang said.

Large thunderstorms in the Southern Great Plains of the U.S. are some of the strongest on Earth. In recent years, these storms have increased in frequency and intensity, and new research shows that these shifts are linked to climate variability.

Co-authored by Christopher Maupin, Courtney Schumacher and Brendan Roark, all scientists in Texas A&M University's College of Geosciences, along with other researchers, the findings were recently published in Nature Geoscience.

In the study, researchers analyzed oxygen isotopes from 30,000-50,000 year old stalactites from Texas caves to understand trends in past thunderstorms and their durations, using radar-based calibration for the region's rainfall isotopes. They discovered that when storm regimes shift from weakly to strongly organized on millennial timescales, they coincide with well-known, global abrupt climate shifts during the last glacial period, which occurred between about 120,000 and 11,500 years ago.

Through modern-day synoptic analysis, researchers learned that thunderstorms in the Southern Great Plains are strongly related to changes in wind and moisture patterns occurring at a much larger scale. Understanding these changes and various correlations will not only help reconstruct past thunderstorm occurrences, but also help predict future mid-latitude thunderstorm patterns.

"Proxy records are available in the Southern Great Plains within caves," Maupin said. "There are probably thousands of caves in Southern Great Plains and in southern Texas. Why hasn't more research occurred in those areas? Cave deposits are so promising as proxies."

Schumacher said scientists understand modern-day rainfall patterns, and that large storms can deplete isotopes.

"However, we don't know what will happen in the future, and this work will help predict trends of storms in the future," she said. "If we can run a climate model for the past which is consistent with cave records, and run that same model moving forward, we can trust its findings more if it matched the cave records versus if they didn't. Out of two models, if one really matches the cave isotopes then you can trust that one in understanding storm distribution in the future."

Caves Hold Little-Known Climate Records

Maupin, a paleoclimatologist, described the limitations that exist in capturing the true distribution of weather events across time.

"There are really important questions about what has happened in the past regarding big weather events we get through mesoscale convective systems (large storms) versus non-mesoscale (smaller storms) stuff," Maupin said. "We get so much precipitation from really big storms, and model grids can't capture big weather events, because the grids themselves are so big. Paleoclimatology helps with organizing past events to develop a proxy record of how they respond to mean climate."

Maupin collaborated with National Taiwan University to do uranium thorium dating, and discovered that the stalactites and stalagmites were in fact from around the Ice Age.

Interdisciplinary Collaboration

Schumacher's expertise was needed to make connections with various rainfall events that occurred over time. She had experience working with radar data and rain measurements on a global scale.

"Large storms that cover hundreds of miles provide around 50-80% of rain in Texas," Schumacher said. "In the modern day, these storms have different isotope signatures."

Maupin's research is pushing back on outdated principles in the paleo-world, because you have to study how storms get larger and what influences them, he said.

"These thunderstorms are so big that even if most of the rain occurs in Oklahoma, rain in Texas will still carry isotopic signature of these huge storms," Maupin stated. "You're fingerprinting these systems despite where they occur, and they don't have to be super localized to be recognized. Big storms cause depleted isotopic signatures. You can't explain the variability in stalactites with temperature changes alone."

Research Experience For Aggie Undergraduates

Celia Lorraine McChesney '16 and Audrey Housson '16 were two undergraduate researchers involved in this publication, and both learned a great deal through the field work, collaboration, and high-impact learning experience.

"The samples from the caves were used as a tool for high-impact learning in understanding Texas paleoclimate," Maupin said. "One of the undergraduates started micro-milling the stalactites. I was very fortunate to have access to the College of Geosciences' resources and to work with these talented undergrads on ground-breaking research."

McChesney said her experience working on her senior thesis at the lab was "invaluable," and the research allowed her to travel and go out into the field.

"As an undergraduate research student at Texas A&M, I was proud to be part of one of the first teams to correlate climate change and weather linkages in a paleoclimate record," Housson said. "This whole experience provided great exposure to the academic world, and made me more confident as a scientist. Now, as a geologist and civil engineer, I am working on heavy civil infrastructure projects like tunnels and dams related to water resources. I love how my career ties back into my undergraduate research where knowing the correlation between climate change and weather helps plan for water resources in the future."

A research team from Northwestern Engineering and the University of Messina in Italy have developed a new magnetic memory device that could lead to faster, more robust Artificial Intelligence (AI) systems. Composed of antiferromagnetic materials, the memory technology is immune to external magnetic fields and could one day improve a variety of computing systems, including AI hardware, cryptocurrency mining, and space exploration programs.

A paper outlining the work, titled "Observation of Current-induced Switching in Non-collinear Antiferromagnetic IrMn3 by Differential Voltage Measurements," was published June 22 in the journal Nature Communications. Pedram Khalili, associate professor of electrical and computer engineering at the McCormick School of Engineering, led the study. The team includes joint first authors Sevdenur Arpaci and Victor Lopez-Dominguez, both members of Khalili's laboratory, and Giovanni Finocchio, an associate professor of electrical engineering at the University of Messina, who co-led the research with Khalili.

Other team members at Northwestern Engineering include Matthew Grayson, professor of electrical and computer engineering, and Mark Hersam, Walter P. Murphy Professor of Materials Science and Engineering.

AI applications, from digital voice recognition platforms like Siri to medical image processing in healthcare to interactive content platforms like Netflix, are using increasingly larger datasets to perform, rendering today's existing memory hardware technology inefficient and unsustainable.

Magnetic material-based memories have emerged as the best solution to address this challenge. They are naturally fast and have high endurance - they do not easily wear out during repeated write cycles. During the last decade, the semiconductor industry has invested heavily to develop magnetic random-access memory (MRAM) to respond to this demand.

The current version of MRAM, however, built on ferromagnetic (FM) materials like iron and cobalt, falls short of the demands of high-performance AI applications. To operate fast, MRAM requires large transistors, keeping it from achieving high density and reducing its endurance. It also cannot be scaled to smaller dimensions -- and thus higher densities -- because memory bits made from ferromagnetic materials exhibit magnetic field interactions that prevent them from operating reliably if they are placed too closely to each other.

Enter antiferromagnets (AFM), a class of materials with inherently faster dynamics than FM materials and no macroscopic magnetic poles, which allow AFM materials to avoid unwanted magnetic interaction. This feature, coupled with AFMs' ability to be used at very small dimensions, means AFM-based memory cannot be erased with external magnetic fields -- a major security advantage.

"Antiferromagnetic materials could solve the challenges of ferromagnetic MRAM," Khalili said. "Antiferromagnets show the potential for scalability, high write speed, and immunity to tampering by external magnetic fields - all necessary components to make faster devices to support the rapid growth of the computing, networking, and data storage industries."

Building upon past success

The new work expands on a 2020 study where the research team first demonstrated the electrical writing of information in a silicon-compatible antiferromagnetic (AFM) memory device. The device, composed of platinum manganese (PtMn), was significantly smaller than previous AFM-based devices and operated with record-low electrical current. That device was also the first AFM memory device compatible with existing semiconductor manufacturing practices.

"This was a key milestone, as we demonstrated no new capital expenditure needed by companies that would want to adopt antiferromagnetic MRAM technology," Khalili said. "However, we felt we could make improvements and address several important shortcomings and unanswered questions about the physics of the device."

Using a new manufacturing-friendly antiferromagnetic material system called iridium manganese (IrMn3), the team developed a new memory device that improves on its predecessor in multiple ways.

In addition to being able to write data, the researchers' system provides a simpler and more reliable method to electrically read out the information in the material once it has been written. This is a challenge for AFM materials, which typically have smaller read out signals than their FM counterparts, making it difficult in some applications to distinguish AFM switching from non-magnetic effects, such as electromigration -- the motion of atoms in response to high currents.

"A functioning memory device needs both writing and reading of data to be done electrically, and this new work addresses both requirements simultaneously," Khalili said.

To do so, the researchers designed a new device structure that features six electrical terminals, compared to four in the previous model. This allowed the researchers to separate the device's switching readout signals from non-magnetic signals and measure the difference between the two voltages. This method allowed the team to confirm their device operated based on AFM switching at a variety of currents and voltages.

"This brings new clarity to the underlying physics of these devices and their mechanisms of operation, allowing for more reliable device development and optimization in the future," Khalili said.

Widespread applications, from Crypto to Mars

While the team continues to refine their technology, including making memory devices at smaller geometries and material systems with larger read out signals for more practical applications, Khalili said their work could eventually be applied wherever memory is used in high-performance computing.

For example, cryptocurrency could benefit from more powerful, higher density memory. Currently, cryptocurrency mining is often held back by limited memory bandwidth, which greatly increases the time and energy needed for processing. This causes the mining to be both energy-intensive and slow. A higher-density memory that can be embedded on the same chip doing the mining could help overcome these challenges.

Another opportunity is space travel. Many current space systems, like rovers used on mars, require powerful computing systems to operate large amounts of vision, navigation, and decision making autonomously. This challenge is compounded by a lack of navigational tools, like GPS satellites, near landing sites. Upgraded systems supported by more powerful memory devices with larger bandwidth could speed up the process. Magnetic memories, including AFM-based devices, are inherently resistant to the ionizing radiation that is present in space, making them a strong fit for space applications where reliability and radiation hardness are essential requirements.

"While the applications vary widely, the underlying hardware and memory chips behind them are essentially the same," Khalili said. "Our technology is general-purpose and could be applied anywhere memory is used in high-performance computing systems today."

Poll of 1,161 Ontario students shows attitudes toward cannabis differ from alcohol, creating potentially risky and dangerous driving behaviour

Ontario students are more likely to get behind the wheel of a vehicle after smoking cannabis than drinking alcohol, a new study from researchers at the University of Ottawa's Faculty of Medicine has revealed.

The study, published in Preventive Medicine, found 10 percent of licensed Ontario high school students reported driving within an hour of cannabis use. Driving after drinking alcohol was much less prevalent, with 3.5 percent of students doing so.

The study, led by master's student Nathan Cantor, found that students who favour cannabis legislation and perceive cannabis to be less risky were more likely to report driving after cannabis use. The study found that graduated licencing programs tended to sway behaviours with students holding a G2 licence four times more likely to report driving after cannabis use compared to those with a G1 licence.

"This work reveals that Ontario adolescents perceive cannabis to be less risky than alcohol, and this perception affects other risky behaviours," says principal investigator Dr. Ian Colman, a Full Professor in the School of Epidemiology and Public Health. "The reason this is important is that it suggests that educating adolescents about the risks of cannabis use may be effective in reducing the dangerous practice of driving after cannabis use."

"We need to debunk the myth that cannabis use does not impair drivers," says Cantor, lead author of the study whose data originates from the period prior to the legalization of recreational cannabis in Canada.

"There's a good evidence base that shows acute cannabis consumption is associated with an increased risk of motor vehicle crash, especially for fatal collisions. This association is likely even greater in adolescents - this population has less driving experience, and proportionally represent a higher burden of motor vehicle crashes."

The study polled 1,161 students with valid driver's license about their driving behaviors, drug use, and attitudes regarding cannabis use as part of the 2017 Ontario Student Health and Drug Use Survey. The authors note the prevalence of cannabis-impaired driving should be continuously monitored moving forwards.

Changes in climate resulting from carbon dioxide (CO2) emissions into the Earth's atmosphere are not equal to the climate changes from deliberate CO2 removals--and assuming such a balance could lead to different climate outcomes that may skew climate targets, according to new Simon Fraser University-led research.

"Because of the complexity of the Earth's system, things are not as simple as "one ton of CO2 in, equals one ton of CO2 out," says Kirsten Zickfeld, a distinguished professor of climate science in SFU's Department of Geography, and lead author of a new paper published this week in the journal Nature Climate Change. "CO2 emissions are more effective at raising atmospheric CO2 concentration than CO2 removals are at lowering it."

According to Zickfeld, this "asymmetry" implies that a larger amount of CO2 removal is required to compensate for a given amount of CO2 emissions if the atmospheric CO2 concentration is to remain unchanged.

Researchers used a series of climate model simulations to test whether the change in climate resulting from CO2 emissions and removals is asymmetric. Their results showed that the rise in the atmospheric CO2 concentration following an emission is larger than the decline following a removal of the same magnitude.

Findings of the study infer that balancing a given amount of CO2 emissions with an equal amount of CO2 removals could lead to a different climate outcome than avoiding the CO2 emissions.

"Our study suggests that assuming exact balance between CO2 emissions and an equal amount of CO2 removals in a net-zero framework risks blowing climate targets," she says.

While Zickfeld says that balancing emissions with CO2 removals of the same magnitude could lead to different climate outcomes, further study is needed to learn more about the extent of this effect.

New York, NY--June 22, 2021--Because corporations and governments rely on computers and the internet to run everything from the electric grid, healthcare, and water systems, computer security is extremely important to all of us. It is increasingly being breached: Numerous security hacks just this past month include the Colonial Pipeline security breach and the JBS Foods ransomware attacks where hackers took over the organization's computer systems and demanded payment to unlock and release it back to the owners. The White House is strongly urging companies to take ransomware threats seriously and update their systems to protect themselves. Yet these attacks continue to threaten all of us on an almost daily basis.

Columbia Engineering researchers who are leading experts in computer security recently presented two major papers that make computer systems more secure at the International Symposium on Computer Architecture (ISCA), the premier forum for new ideas and research results in computer architecture. This new research, which has zero to little effect on system performance, is already being used to create a processor for the Air Force Research Lab.

"Memory safety has been a problem for nearly 40 years and numerous solutions have been proposed. We believe that memory safety continues to be a problem because it does not distribute the burden in a fair manner among software engineers and end-users," said Simha Sethumadhavan, associate professor of computer science, whose research focuses on how computer architecture can be used to improve computer security. "With these two papers, we believe we have found the right balance of burdens."

Computer security has been a long-standing issue, with many proposed systems workable in research settings but not in real-world situations. Sethumadhavan believes that the way to secure a system is to first start with the hardware and then, in turn, the software. The urgency of his research is underscored by the fact that he has significant grants from both the Office of Naval Research and the U.S. Airforce, and his PhD students have received a Qualcomm Innovation Fellowship to create practical security solutions.

Sethumadhavan's group noticed that most security issues occur within a computer's memory, specifically pointers. Pointers are used for managing memory and can lead to memory corruption that can open up the system to hackers who hijack the program. Current techniques to mitigate memory attacks use up a lot of energy and can break software. These methods also greatly affect a system's performance--cellphone batteries drain quickly, apps run slowly, and computers crash.

The team set out to address these issues and created a security solution that protects memory without affecting a system's performance. They call their novel memory security solution, ZeRØ: Zero-Overhead Resilient Operation Under Pointer Integrity Attacks.

ZeRO Overview VIDEO - https://www.youtube.com/watch?v=yoQ4HaQ0Bzc

ZeRO features a set of memory instructions and a metadata encoding scheme that protects the code and data pointers of a system. This combination eliminates performance overhead--it will not affect the speed of a system. ZeRO requires minor changes to a system's architecture and it can easily be added to modern processors. Especially critical is that, even when under attack, ZeRO can perform all these functions and avoid crashing a system.

"Zero offers memory security at no cost and it is a perfect complement to systems that mitigate memory attacks," said Mohamed Tarek, a fourth-year PhD student and co-lead author of the studies. "The keys to widespread adoption of security techniques are low-performance overhead and convenience."

The second paper that Sethumadhavan's team will present, No-FAT: Architectural Support for Low Overhead Memory Safety Checks, is a system that makes security checks faster with only a small--8%--effect on the computer's performance which is 10x faster than current software technique for detecting memory errors. The name is an allusion to no-fat milk, which, as the ads say, "has all the goodness of milk with fewer calories."

No-FAT Overview VIDEO - https://www.youtube.com/watch?v=XDGaYZioJBQ

No-FAT speeds up fuzz testing, a type of automated software testing method, and it is very easy for developers to add it when building a system. The technique builds on a recent trend in software towards binning memory allocators, which uses buckets of different sizes to store memory until it is needed by the software. The researchers found that when binning memory allocation is used by the software, it is possible to achieve memory security with little impact on performance and is compatible with existing software.

Both ZeRO and No-Fat are targeted at beefing up memory systems to be more resilient against attacks while having little to no effect on a computer system's speed or power consumption. The bonus is that with both systems, programmers need to do little to nothing to harden their programs. These ideas could transform how memory safety features are currently supported in processors.

"No-FAT & ZeRO are two major steps toward putting an end to a long-standing problem," said Miguel Arroyo PhD '21, who was a co-lead author of the papers. "Memory safety attacks cost the cyber community millions of dollars. Now we can avoid that and keep everyone's data safe--it's a win-win!"