Tech

Combining powerful lasers and bright x-rays, Imperial and STFC researchers have demonstrated a technique that will allow new extreme experiments.

The new technique would be able to use a single x-ray flash to capture information about extremely dense and hot matter, such as can be found inside gas giant planets or on the crusts of dead stars.

The same conditions are also found in fusion experiments, which are trying to create a new source of energy that mimics the Sun.

The technique, reported this week in Physical Review Letters, was developed by a team led by Imperial College London scientists working with colleagues including those at the UK's Central Laser Facility at the Science and Technology Facilities Council (STFC) Rutherford Appleton Laboratory, and was funded by the European Research Council.

The researchers wanted to improve ways to study 'warm dense matter' - matter that has the same density as a solid, but is heated up to 10,000?C. Researchers can create warm dense matter in the lab, recreating the conditions in the hearts of planets or crucial for fusion power, but it is difficult to study.

The team used the Gemini Laser, which has two beams - one which can create the conditions for warm dense matter, and one which can create ultrashort and bright x-rays to probe the conditions inside the warm dense matter.

Previous attempts using lower-powered lasers required 50-100 x-ray flashes to get the same information that the new technique can gain in just one flash. The flashes last only femtoseconds (quadrillionths of a second), meaning the new technique can reveal what is happening within warm dense matter across very short timescales.

First author Dr Brendan Kettle, from the Department of Physics at Imperial, said: "We will now be able to probe warm dense matter much more efficiently and in unprecedented resolution, which could accelerate discoveries in fusion experiments and astrophysics, such as the internal structure and evolution of planets including the Earth itself."

The technique could also be used to probe fast-changing conditions inside new kinds of batteries and memory storage devices.

In the new study, the team used their technique to examine a heated sample of titanium, successfully showing that it could measure the distribution of electrons and ions.

Lead researcher Dr Stuart Mangles, from the Department of Physics at Imperial, said: "We are planning to use the technique to answer key questions about how the electrons and ions in this warm dense matter 'talk' to each other, and how quickly can energy transfer from the electrons to the ions."

The Central Laser Facility's Gemini Laser is currently one of the few places the right conditions for the technique can be created, but as new facilities start operating around the world, the team hope the technique can be expanded and used to do a whole new class of experiments.

Dr Rajeev Pattathil, Gemini Group Leader at the Central Laser Facility, said: "With ultrashort x-ray flashes we can get a freeze-frame focus on transient or dynamic processes in materials, revealing key new fundamental information about materials here and in the wider Universe, and especially those in extreme states."

WESTMINSTER, Colorado - December 19, 2019 - Australian growers have made significant inroads against herbicide-resistance weeds in recent years by focusing on harvest-time weed seed controls. One of the most popular strategies is the use of an impact mill that intercepts chaff as it exits the harvester. The mill destroys weed seeds and then deposits the residue on the field for moisture conservation and nutrient cycling.

In a recent study featured in the journal Weed Science, a team of researchers explored whether impact mills could help U.S. growers fight Palmer amaranth and other herbicide-resistant weeds in soybean crops.

The two-year study showed milling was highly effective in destroying seeds of 12 weed species common to soybean fields in the Midwest and Mid-Atlantic regions. It produced a success rate that ranged from 93.5 to 99.8 percent in year one and from 85.6 to 100 percent in year two.

"Even seeds that appeared to be intact after passing through the impact mill were prone to rapid decay due to damage incurred during processing," says Lovreet Shergill, a postdoctoral researcher with the USDA's Agricultural Research Service and the University of Delaware. "We found that less than 0.4 percent of them were viable."

What do these results mean for weed management in U.S. soybean crops? Palmer amaranth and other problematic weeds that remain in the field at harvest time are likely to be resistant to early season weed controls. Many retain a high proportion of their seeds at maturity, which is concurrent with the crop harvest window.

"If seeds of these resistant weeds are destroyed during the harvest, the weed seed bank can be reduced over time in support of long-term weed management," Shergill says.

Sediment flux (SF) in the Tuotuo River on the central Tibetan Plateau (TP), considered the main headwater of the Yangtze River, has significantly increased over the past three decades, according to new research by scientists from the Institute of Tibetan Plateau Research of the Chinese Academy of Sciences (ITPCAS), China Agricultural University, National University of Singapore, and Utrecht University.

Sediment flux refers to the total amount of sediment passing through a given cross section per unit time. Increasing SF in the upper reaches of a river is often accompanied by intensifying soil erosion, land degradation, river channel siltation and reduced operating life of downstream reservoirs. It is an important indicator of major environmental changes with broad economic effects.

"Riverine sediment is not only an important pathway for nutrient and pollutant transport, but also a sensitive indicator of soil erosion and environmental changes in the river basin," said Dr. ZHANG Fan, lead author of the study. ZHANG noted that four of eight rivers in the TP for which long-term monitoring data are available have shown significant increases of SF over the last five decades.

The researchers chose the Tuotuo River in order to better understand sediment transport changes in the TP and their underlying processes. Annual time series data on hydro-meteorological variables showed significant increases in air temperature, precipitation, ground temperature, river discharge, suspended sediment concentration (SSC) and SF for the period from 1986 to 2014. Mean values were appreciably higher during 1998-2014 period as compared with 1986-1997. This difference could potentially be attributed to the strong 1997 El Niño event.

The researchers said the increase in meltwater shown in the research is attributable more to warming than an increase in precipitation. They also said the increase in SSC mainly resulted from enhanced transport capacity and erosive power associated with precipitation and discharge. However, this increase was buffered by a decrease in sediment sources due to the shift in maximum monthly rainfall from June-July to July-August, since denser vegetation cover in July-August prevents soil erosion. In addition, increases in both discharge and SSC equally contributed to the increase of SF.

By offering further insights into the processes underlying recent SF changes in the Yangtze River headwater, this study provides guidance for water and soil management on the TP.

Hamilton, ON (Dec. 20, 2019) - A major study has found that Canadian First Nations communities with greater socio-economic advantages, educational opportunities, social support of family members and greater trust between community members, have lower cardiac risk factors.

On the other hand, First Nations communities with difficulty accessing routine health care or affordable prescription medicines have a greater burden of cardiac risk factors.

The study is the first cohort study of First Nations communities across the country, and involved First Nation community members working along with academic researchers across eight communities in Canada. The study was coordinated by the Population Health Research Institute (PHRI) of McMaster University and Hamilton Health Sciences (HHS).

A paper from the Canadian Alliance of Healthy Hearts and Minds First Nations cohort study was published by the journal Lancet Planetary Health today.

"We know that Indigenous people around the world have higher rates of chronic diseases and lower life expectancy compared to non-Indigenous people," said Sonia Anand, principal investigator for the study.

"This is largely attributable to the effects of colonisation and government policies that led to worse socio-economic circumstances and a shift away from many traditional practices and ways of knowing of Indigenous peoples.

"Understanding what factors protect some First Nations communities from having a high burden of cardiovascular risk factors and what places others at risk can help First Nations communities and governments develop short and long-term policies to improve the health access and outcomes for First Nations peoples. This is the primary objective of our study," she said.

Darlene Davis, a First Nations research nurse and study coordinator, said: "This was the first time other First Nations were invited to participate, and I was glad that eight First Nations from the east to west coast of Canada took part. It's important we pay attention to these cardiac risks, as we need to improve our health status and increase our life expectancy."

The study involved 1,300 men and women who answered lifestyle questionnaires and had physical measures, blood samples and magnetic resonance imaging (MRI) completed.

Community audits were also conducted to assess transportation accessibility; physical environment, availability and prices of tobacco, alcohol, healthy and unhealthy foods. The study noted a lower variety of fruits and vegetables on reserves, and all foods were more expensive on reserves, except for milk. As well, half of the communities were difficult to walk for exercise.

The study also found that almost six of 10 participants (58%) had spent three-quarters of their lives in their community, and more than half reported having a high affinity to their heritage culture. As well, almost half of the participants reported having high optimism for their community's future. However, more than a third (37%) of people was concerned about community members being exposed to racism when off reserve.

The study found that communities with lower cardiovascular risk had a greater socio-economic advantage shown by greater employment, income and long-term marital partnerships; greater trust between community members; a higher proportion of people with a high school education, and higher social support shown by many close relationships with family members.

More risk factors were found in communities with difficulty accessing primary care and people with medical prescriptions who could not afford to fill them.

"The MRIs showed a strong relationship between the cardiac risk factor and potential vascular disease, and that implies that a reduction of these risk factors is of paramount importance to lowering vascular disease risk," said Anand, who is a professor of medicine at McMaster and a vascular medicine specialist for HHS.

The First Nations communities involved in the study included Gitxsan of B.C.; Maskwacis of Alberta; Fort McKay of Alberta; Lac La Ronge of Saskatchewan; Oneida of Ontario; Six Nations of Ontario; Wendake of Quebec and Pictou Landing of N.S.

Nadine Caron is a surgeon and co-director of the Centre for Excellence in Indigenous Health at the University of British Columbia. Although not involved in the research study, she said it was important to examine the strengths in communities that result in lower cardiac risk including social support of families, trust, advanced education, income and jobs.

"We need to partner with First Nations communities to achieve these goals. This cannot replace the responsibility of our healthcare system to also address the lack of access to primary care and prescription drugs. These issues of health equity must be addressed to prevent and reduce cardiovascular disease in First Nations communities."

The Earth's inner core is hot, under immense pressure and snow-capped, according to new research that could help scientists better understand forces that affect the entire planet.

The snow is made of tiny particles of iron - much heavier than any snowflake on Earth's surface - that fall from the molten outer core and pile on top of the inner core, creating piles up to 200 miles thick that cover the inner core.

The image may sound like an alien winter wonderland. But the scientists who led the research said it is akin to how rocks form inside volcanoes.

"The Earth's metallic core works like a magma chamber that we know better of in the crust," said Jung-Fu Lin, a professor in the Jackson School of Geosciences at The University of Texas at Austin and a co-author of the study.

The study is available online and will be published in the print edition of the journal JGR Solid Earth on December 23.

Youjun Zhang, an associate professor at Sichuan University in China, led the study. The other co-authors include Jackson School graduate student Peter Nelson; and Nick Dygert, an assistant professor at the University of Tennessee who conducted the research during a postdoctoral fellowship at the Jackson School.

The Earth's core can't be sampled, so scientists study it by recording and analyzing signals from seismic waves (a type of energy wave) as they pass through the Earth.

However, aberrations between recent seismic wave data and the values that would be expected based on the current model of the Earth's core have raised questions. The waves move more slowly than expected as they passed through the base of the outer core, and they move faster than expected when moving through the eastern hemisphere of the top inner core.

The study proposes the iron snow-capped core as an explanation for these aberrations. The scientist S.I. Braginkskii proposed in the early 1960s that a slurry layer exists between the inner and outer core, but prevailing knowledge about heat and pressure conditions in the core environment quashed that theory. However, new data from experiments on core-like materials conducted by Zhang and pulled from more recent scientific literature found that crystallization was possible and that about 15% of the lowermost outer core could be made of iron-based crystals that eventually fall down the liquid outer core and settle on top of the solid inner core.

"It's sort of a bizarre thing to think about," Dygert said. "You have crystals within the outer core snowing down onto the inner core over a distance of several hundred kilometers."

The researchers point to the accumulated snow pack as the cause of the seismic aberrations. The slurry-like composition slows the seismic waves. The variation in snow pile size - thinner in the eastern hemisphere and thicker in the western - explains the change in speed.

"The inner-core boundary is not a simple and smooth surface, which may affect the thermal conduction and the convections of the core," Zhang said.

The paper compares the snowing of iron particles with a process that happens inside magma chambers closer to the Earth's surface, which involves minerals crystalizing out of the melt and glomming together. In magma chambers, the compaction of the minerals creates what's known as "cumulate rock." In the Earth's core, the compaction of the iron contributes to the growth of the inner core and shrinking of the outer core.

And given the core's influence over phenomena that affects the entire planet, from generating its magnetic field to radiating the heat that drives the movement of tectonic plates, understanding more about its composition and behavior could help in understanding how these larger processes work.

Bruce Buffet, a geosciences professor at the University of California, Berkley who studies planet interiors and who was not involved in the study, said that the research confronts longstanding questions about the Earth's interior and could even help reveal more about how the Earth's core came to be.

"Relating the model predictions to the anomalous observations allows us to draw inferences about the possible compositions of the liquid core and maybe connect this information to the conditions that prevailed at the time the planet was formed," he said. "The starting condition is an important factor in Earth becoming the planet we know."

CHAMPAIGN, Ill. -- A new study in rats suggests that caffeine may offset some of the negative effects of an obesogenic diet by reducing the storage of lipids in fat cells and limiting weight gain and the production of triglycerides.

Rats that consumed the caffeine extracted from mate tea gained 16% less weight and accumulated 22% less body fat than rats that consumed decaffeinated mate tea, scientists at the University of Illinois found in a new study.

The effects were similar with synthetic caffeine and that extracted from coffee.

Mate tea is an herbal beverage rich in phytochemicals, flavonoids and amino acids that's consumed as a stimulant by people in southeastern Latin American countries. The amount of caffeine per serving in mate tea ranges from 65-130 milligrams, compared with 30-300 milligrams of caffeine in a cup of brewed coffee, according to the study.

For four weeks, the rats in the study ate a diet that contained 40% fat, 45% carbohydrate and 15% protein. They also ingested one of the forms of caffeine in an amount equivalent to that of a human who drinks four cups of coffee daily.

At the end of the four-week period, the percentage of lean body mass in the various groups of rats differed significantly. The rats that ingested caffeine from mate tea, coffee or synthetic sources accumulated less body fat than rats in the other groups.

The study, published recently in the Journal of Functional Foods, adds to a growing body of research that suggests mate tea may help fight obesity in addition to providing other beneficial health effects associated with the phenolic compounds, vitamins and flavonoids it contains.

"Considering the findings, mate tea and caffeine can be considered anti-obesity agents," said Elvira Gonzalez de Mejia, a co-author of the study and director of the division of nutritional sciences at the U. of I. "The results of this research could be scaled to humans to understand the roles of mate tea and caffeine as potential strategies to prevent overweight and obesity, as well as the subsequent metabolic disorders associated with these conditions."

In the rats, the accumulation of lipids in the adipocytes was significantly associated with greater body weight gain and increased body fat, according to the study.

To determine the mechanism of action, the scientists performed cell culture studies in which they exposed adipose cells from mice to synthetic caffeine or the coffee or mate caffeine extracts. They found that regardless of its source, caffeine decreased the accumulation of lipids in adipose cells by 20%-41%.

The scientists also tracked the expression of several genes associated with obesity and lipid metabolism. These included the fatty acid synthase gene (Fasn), an enzyme compound involved in the synthesis of fatty acids from glucose; and the lipoprotein lipase gene (Lpl), which codes for an enzyme that breaks down triglycerides.

All of the caffeine treatments, regardless of origin, significantly downregulated the expression of both Fasn and Lpl. In the cell cultures, Fasn expression diminished by 31%-39%, while Lpl expression decreased by 51%-69% among cells treated with synthetic caffeine or the caffeine from mate tea or coffee, they found.

In the rats that consumed the mate tea caffeine, expression of Fasn decreased by 39% in their fat tissue and by 37% in their livers, the researchers found.

The decreased expression of Fasn and two other genes in the liver evoked lower production of low-density lipoprotein cholesterol and triglycerides in the liver as well, according to the study.

"The consumption of caffeine from mate or from other sources alleviated the negative impact of a high-fat, high-sucrose diet on body composition due to the modulation of certain lipogenic enzymes in both adipose tissue and the liver," de Mejia said. "The decreased expression of Fasn and Lpl brought about lower synthesis and accumulation of triglycerides in the adipose tissue."

PHILADELPHIA -- (Dec. 19, 2019) -- A study from The Wistar Institute demonstrated that NAMPT, an enzyme critical for NAD+ biosynthesis, mediates selection of stem-like chemoresistant cells following cisplatin treatment. Researchers showed that a combination of cisplatin treatment with pharmacological inhibition of NAMPT suppresses the outgrowth of resistant cancer cells in vitro and prolongs survival in a preclinical model. These findings were published online in Cancer Research.

Epithelial ovarian cancer is the leading cause of death by gynecologic cancers in the United States, with treatment options still limited to surgery and chemotherapy. Unfortunately, chemoresistance to platinum-based drugs represents a major challenge as most patients ultimately relapse and succumb to the disease.

"Based on previous findings from our laboratory, we have identified a molecule that can be pharmacologically blocked to get rid of resistant cells while preserving the beneficial anticancer power of cisplatin, which still remains the standard of care for this disease," said Rugang Zhang, Ph.D., deputy director of The Wistar Institute Cancer Center, professor and co-program leader of the Gene Expression and Regulation Program, and senior author on the paper.

Platinum-based therapies trigger cellular senescence that is accompanied by the emergence of drug-resistant, more malignant cells. Senescent cells stop dividing suppressing tumor growth, but, at the same time, produce a variety of inflammatory molecules. Collectively known as the senescence-associated secretory phenotype (SASP), these molecules can promote proliferation and survival of neighboring cells, ultimately contributing to tumor progression.

Zhang and colleagues previously showed that the NAMPT enzyme drives the activation of the SASP in ovarian cancer cells and that pharmacological inhibition of NAMPT suppresses the SASP.

Drug-resistant cancer cells also possess stem-like properties including expression of the CD133 surface marker and elevated activity of the aldehyde dehydrogenase (ALDH1) enzyme. Since inhibition of ALDH activity sensitizes cancer cells to chemotherapy, it's been suggested that acquisition of the stem-like phenotype is a key step in the emergence of resistance.

In this new study, the team demonstrated that the NAMPT-regulated SASP mediates therapy-induced emergence of senescence-associated stem-like cancer cells.

Importantly, combining cisplatin treatment with NAMPT inhibitors blocked the expression of stem-like markers, suppressed the outgrowth of chemoresistant stem-like cells in vitro and delayed tumor relapse in vivo, significantly prolonging survival of a mouse model of epithelial ovarian cancer.

"NAMPT blockage removes the tumor-promoting effects of cellular senescence while not interfering with its tumor-suppressive functions," said Zhang. "Our findings suggest that clinically applicable NAMPT inhibitors may be applied to enhance the therapeutic effect of cisplatin and improve the platinum-based standard of care in epithelial ovarian cancer."

'Whoopi' the manta ray - a regular visitor to Western Australia's Ningaloo Reef - has helped University of Queensland and Murdoch University scientists study rays' impressive ability to heal.

Whoopi, who has swum with thousands of tourists WA's over the years, was hit by a boat in 2015, suffering propeller cuts measuring up to 20 centimetres to the edge of her wing.

Dr Christine Dudgeon from UQ's School of Biomedical Sciences said such a strike was relatively rare, but could cause significant injuries to the animal.

"Manta rays don't surface to breathe, which you think would reduce their susceptibility to boat strike," Dr Dudgeon said.

"But these rays, like whale sharks, tiger sharks and other sharks and rays, spend considerable time in surface waters for activities like basking and feeding.

"Most wounds in these species have been attributed to predation, mating attempts and fishing-related injuries or entanglement, but boats do end up hitting some rays - and Whoopi had the cuts to prove it."

Manta rays and other sharks and rays are considered to have high healing capacity.

"This is likely due, in part at least, to a unique adaptive immune system," Dr Dudgeon said.

"However, few studies have investigated the rate of wound healing in sharks and rays, and these have mostly focused on the impacts of external and internal tagging procedures, not boat strikes."

To investigate this phenomenon further, the team compared underwater photographs taken in the Ningaloo Coast World Heritage Area of WA over the past 15 years, and found evidence of greater incidence of boat strike on manta rays than previously thought.

Professor Anthony Richardson from UQ's Centre for Applications in Natural Resource Mathematics said the results were impressive.

"Whoopi showed us just how fast these beautiful creatures can heal," he said.

"Her significant wounds had healed by 50 per cent only 46 days after the boat strike, and by day 295 had healed by 95 per cent."

Dr Dudgeon said the research could be used to inform policy for designing adequate spatial management for the region.

"It's imperative we reduce the impact of vessels on manta rays and protect their critical habitat," she said.

"Such management may include speed restrictions during high usage periods, vessel free zones, the use of propeller guards or alternative motors - like jet motors - and public education on vessel-wildlife conflict."

"Manta rays are incredible healers, but it's important we keep them safe in the first place."

Soft pressure sensors have received significant research attention in a variety of fields, including soft robotics, electronic skin, and wearable electronics. Wearable soft pressure sensors have great potential for the real-time health monitoring and for the early diagnosis of diseases.

A KAIST research team led by Professor Inkyu Park from the Department of Mechanical Engineering developed a highly sensitive wearable pressure sensor for health monitoring applications. This work was reported in Advanced Healthcare Materials on November 21 as a front cover article.

This technology is capable of sensitive, precise, and continuous measurement of physiological and physical signals and shows great potential for health monitoring applications and the early diagnosis of diseases.

A soft pressure sensor is required to have high compliance, high sensitivity, low cost, long-term performance stability, and environmental stability in order to be employed for continuous health monitoring. Conventional solid-state soft pressure sensors using functional materials including carbon nanotubes and graphene have showed great sensing performance. However, these sensors suffer from limited stretchability, signal drifting, and long-term instability due to the distance between the stretchable substrate and the functional materials.

To overcome these issues, liquid-state electronics using liquid metal have been introduced for various wearable applications. Of these materials, Galinstan, a eutectic metal alloy of gallium, indium, and tin, has great mechanical and electrical properties that can be employed in wearable applications. But today's liquid metal-based pressure sensors have low-pressure sensitivity, limiting their applicability for health monitoring devices.

The research team developed a 3D-printed rigid microbump array-integrated, liquid metal-based soft pressure sensor. With the help of 3D printing, the integration of a rigid microbump array and the master mold for a liquid metal microchannel could be achieved simultaneously, reducing the complexity of the manufacturing process. Through the integration of the rigid microbump and the microchannel, the new pressure sensor has an extremely low detection limit and enhanced pressure sensitivity compared to previously reported liquid metal-based pressure sensors. The proposed sensor also has a negligible signal drift over 10,000 cycles of pressure, bending, and stretching and exhibited excellent stability when subjected to various environmental conditions.

These performance outcomes make it an excellent sensor for various health monitoring devices. First, the research team demonstrated a wearable wristband device that can continuously monitor one's pulse during exercise and be employed in a noninvasive cuffless BP monitoring system based on PTT calculations. Then, they introduced a wireless wearable heel pressure monitoring system that integrates three 3D-BLiPS with a wireless communication module.

Professor Park said, "It was possible to measure health indicators including pulse and blood pressure continuously as well as pressure of body parts using our proposed soft pressure sensor. We expect it to be used in health care applications, such as the prevention and the monitoring of the pressure-driven diseases such as pressure ulcers in the near future. There will be more opportunities for future research including a whole-body pressure monitoring system related to other physical parameters."

Researchers of the Center for Multidimensional Carbon Materials, within the Institute of Basic Science (IBS, South Korea), have presented a theoretical solution to a long-lasting mystery of carbon nanotubes (CNTs) growth. Published in Physical Review Letters, this study explains why nanoparticles made with an alloy of metals help to synthetize longer CNTs compared with conventional monometallic catalysts.

CNTs are tubular nanostructures made of carbon atoms with exciting potential properties that have kept researchers on the lookout for new advances. One of the most common methods to produce CNTs involves catalyst nanoparticles, which have the function of facilitating the addition of carbon atoms from precursor molecules to the walls of the cylinders. It is common knowledge in the field that alloy catalysts, like Ni-Y, Fe-Mo, Cu-Ni, and Co-Mo, outperform other single metal catalysts, but the reason has been unclear.

IBS researchers performed a systematic molecular dynamics simulation to explore the role of alloy catalysts in CNT growth. "In a molecular dynamics simulation, the motion of every atom can be clearly seen and, therefore, the variation of the shape and structure of the catalyst particle during the carbon nanotube growth can be recorded precisely. This allows us to go beyond the capacity of the best experimental methods." explains Feng Ding, a group leader of the Center and corresponding author of the study.

Through the molecular dynamic simulations, the authors have found that the two metals of the alloy are spatially separated at the rim of the tubes: CNTs tend to attract the more active metal atoms to the open end of the cylinders (growth front), where carbon atoms are inserted into the CNT wall during growth, while the less active metal atoms are pushed above. More simulations show that this is a general phenomenon and can be applied to many types of alloy catalysts.

IBS researchers have also demonstrated that alloy catalysts win over monometallic nanoparticles because the active metal atoms near the rim of the CNT catch the carbon atoms more easily than the less active ones. This will lead to a larger carbon concentration at the vicinal of CNT growth front and a quick addition of the carbon atoms, which contribute to the fast growth of the CNT.

Since the carbon atoms are continuously incorporated to the growing CNTs, the carbon precursors do not accumulate around the alloy nanoparticles. This prevents the formation of a cap made of carbon atoms engulfing the entire nanoparticle.

"This theoretical study addresses a long-term puzzle of the role of the alloy catalysts in carbon nanotube growth. It reveals the advantage of using alloy catalysts in carbon nanotube growth, and the contact-induced phase separation of the alloy catalyst can be considered as a general rule to guide catalyst design for controllable carbon nanotube growth," says Lu Qiu, the first author of the study.

Imagine swarms of robotic insects moving around us as they perform various tasks. It might sound like science fiction, but it's actually more plausible than you might think.

Researchers at EPFL's School of Engineering have developed a soft robotic insect, propelled at 3 cm per second by artificial muscles.

The team developed two versions of this soft robot, dubbed DEAnsect. The first, tethered using ultra-thin wires, is exceptionally robust. It can be folded, hit with a fly swatter or squashed by a shoe without impacting its ability to move. The second is an untethered model that is fully wireless and autonomous, weighing less than 1 gram and carrying its battery and all electronic components on its back. This intelligent insect is equipped with a microcontroller for a brain and photodiodes as eyes, allowing it to recognize black and white patterns, enabling DEAnsect to follow any line drawn on the ground.

DEAnsect was developed by a team at EPFL's Soft Transducers Laboratory (LMTS), working with the Integrated Actuators Laboratory (LAI) and colleagues from the University of Cergy-Pontoise, France. The research was published in Science Robotics.

Vibration propulsion

DEAnsect is equipped with dielectric elastomer actuators (DEAs), a type of hair-thin artificial muscle that propels it forward through vibrations. These DEAs are the main reason why the insect is so light and quick. They also enable it to move over different types of terrain, including undulating surfaces.

The artificial muscles consist of an elastomer membrane sandwiched between two soft electrodes. The electrodes are attracted to one another when a voltage is applied, compressing the membrane, which returns to its initial shape when the voltage is turned off. The insect has such muscles fitted to each of its three legs. Movement is generated by switching the voltage on and off very quickly - over 400 times per second.

The team used nanofabrication techniques to enable the artificial muscles to work at relatively low voltages, by reducing the thickness of the elastomer membrane and by developing soft, highly conductive electrodes only a few molecules thick. This clever design allowed the researchers to dramatically reduce the size of the power source. "DEAs generally operate at several kilovolts, which required a large power supply unit," explains LMTS director Herbert Shea. "Our design enabled the robot, which itself weighs just 0.2 gram, to carry everything it needs on its back." "This technique opens up new possibilities for the broad use of DEAs in robotics, for swarms of intelligent robotic insects, for inspection or remote repairs, or even for gaining a deeper understanding of insect colonies by sending a robot to live amongst them."

"We're currently working on an untethered and entirely soft version with Stanford University," says Shea. "In the longer term, we plan to fit new sensors and emitters to the insects so they can communicate directly with one another."

In the wake of recent disappointments over clinical trials targeting amyloid plaque build-up in Alzheimer's disease, researchers are focusing more attention on misfolded tau protein, another culprit in brain diseases that cause dementia.

New research published in Science Translational Medicine finds that targeting abnormal tau through the suppression of a gene called MSUT2 (mammalian suppressor of tauopathy 2) shows promise.

Tau, like amyloid protein, is another substance that builds up in Alzheimer's disease and damages brain cells.

However, clinical trials targeting tau have been far less numerous in part because tau-targeted drugs have been hard to find.

In this study, researchers concluded that suppressing MSUT2 might protect people from Alzheimer's disease as long as the RNA binding protein PolyA Binding Protein Nuclear 1 (PABPN1) is not depleted. MSUT2 and PABPNI normally work together closely to regulate the biology of tau in the brain.

"If you inhibit MSUT2 and don't affect PABN1, that protects against the effects of tau pathology," said senior author Brian Kraemer, a research associate professor of medicine,
Division of Gerontology and Geriatric Medicine at the University of Washington School of Medicine. He is also a scientist at the Veterans Affairs Puget Sound Health Care System.

Kraemer said his team sees their role as the person kicking the ball down field to provide other researchers and drug companies an opportunity to move the ball towards the ultimate goal: A treatment or cure for Alzheimer's disease.

"Pharmaceutical companies have heavily invested in going after amyloid but so far these efforts haven't moved the needle on dementia treatments," he said. "I think the field needs to think about targeting amyloid and tau together because both amyloid and tau act together to kill neurons in Alzheimer's disease."

Senior author Jeanna Wheeler, a research scientist at the Seattle Institute for Biomedical and Clinical Research and the VA, said what's novel about the study is the discovery of the role of the MSUT2 gene.

"We discovered MSUT2 originally in a completely unbiased way by looking for anything that could make worms resistant to pathological tau protein. Now we have shown that this gene can also affect tau toxicity in mice, and also that there are differences in MSUT2 in human Alzheimer's patients," she said. "If we can use MSUT2 in the future as a drug target, this would be a completely novel approach for treating Alzheimer's and other related disorders."

The study also brings more attention to the role of tau pathology in Alzheimer's disease.

The healthy human brain contains tens of billions of specialized cells or neurons that process and transmit information. By disrupting communication among these cells, Alzheimer's disease results in loss of neuron function and cell death.

Previous studies have shown that abnormal tau burden correlates strongly with cognitive decline in Alzheimer's disease patients, but amyloid does not. Some dementia disorders, such as frontotemporal lobar degeneration, may have only abnormal tau with no amyloid deposits.

"If you could protect the brain from tau alone, you may provide substantial benefit for people with Alzheimer's disease," Kraemer said. "Likewise, targeting tau in tangle-only Alzheimer's disease-related dementia disorders, like frontotemporal lobar degeneration, will almost certainly be beneficial for patients."

This study follows previous work by these researchers that showed very similar results using the worm C. elegans. Worms go from egg to adult in three days so it was easier to do experiments on the biology of aging rapidly. Although worms don't have complex cognitive functions, their movement is affected by tau buildup. Researchers found that they could cure the worm by knocking out the worm sut-2 gene.

The more recent study applied the experiment to mice, whose evolutionary distance to humans is much smaller than the distance between worms and humans.

The researchers knocked out the MSUT2 gene in mice, thereby, preventing the formation of the tau tangles that kill off brain cells. This lessened learning and memory problems as well.

While examining autopsy brain samples from Alzheimer's patients, the researchers found that cases with more severe disease lacked both MSUT2 protein, and its partner protein, PABPN1. This finding suggests that neurons that lose the MSUT2 -PABPN1 protein partnership may simply die during a patient's life.

Moreover, mice lacking MSUT2 but possessing a normal complement of PABPN1 were strongly protected against abnormal tau and the resulting brain degeneration. Therefore, the researchers concluded that the key to helping people with abnormal tau buildup is blocking MSUT2 while preserving PABPN1 activity.

Research involved investigators from the University of Washington's School of Medicine Alzheimer's Disease Research Center, University of Pennsylvania Center for Neurodegenerative Disease, and Michigan State University.

A new bacterial identification method, called ON-rep-seq, examines selective, strain-specific fragments of the bacterial genome, allowing the generation of results that earlier required DNA sequencing of the entire bacterial genome or tedious approaches like pulsed field gel electrophoresis, which previously has been the golden the standard for strain-level typing of microorganisms. Hence, the method has the potential to change the approach utilized for investigating food-based disease outbreaks by making analysis much less time- and cost consuming.

Today, bacterial detection and identification based on bacterial DNA requires expensive instrumentation and many hours of work by highly trained specialists. Let's imagine, for example, there is a suspected Salmonella outbreak. Usually in order to locate its origin, not only will investigators have to analyze many samples, but the analysis has to be precise in order to distinguish one bacterial strain from another.

"Our new method allows identification and typing of hundreds of samples in less than two hours, and we expect that this will even be reduced to "real time" in a short period of time," says one of the researchers behind the study, Lukasz Krych, Associate Professor at the Department of Food Science at the University of Copenhagen, Denmark.

Method builds on a device that was used for DNA sequencing in space

The new method is based on nanopore sequencing, which is a new, real-time DNA sequencing approach "that will definitely revolutionize the future of DNA sequencing" according to Lukasz Krych.

The research project was carried out in collaboration with the polish company GenXone S.A., which helped to set up a bioinformatics pipeline that is needed to perform fast and efficient analysis of the sequencing data.

The smallest ever sequencer offered by Oxford Nanopore Technologies, called MinION, is a $999 hand-held, USB-powered device that became commercially available in 2015. A year later it was taken to the International Space Station, where it achieved the first DNA sequencing in history performed in zero-gravity conditions. Despite the indisputable revolution in DNA sequencing offered by MinION, it quickly became clear that the data generated with the device are still not perfect due to e.g. sequencing errors while the analysis remained relatively expensive to perform (app. $150 per bacterium).

Small device with fast and cheap analysis offers huge opportunities within food safety

The scientists from the Department of Food Science at the University of Copenhagen have found a way to utilize this technology to analyze hundreds of bacteria at a time, cutting costs to less than $2 per bacterium, while at the same time increasing the accuracy to more than 99%.

"Our method can be used both within food safety, where you can quickly find disease-causing or health-promoting bacteria, and also in the health sector, where you will be able to perform certain analyses that you are not even considering today because of the price and time-consuming nature of traditional analysis," says another of the researchers behind the study, Postdoc Josue Leonardo Castro Mejia.

At the moment, there are several companies testing the method to implement in their systems for establishing rapid screening programmes for thousands of strains.

Estimates used by climate scientists to predict the rate at which the world's ice sheets will melt are still uncertain despite advancements in technology, new research shows.

These ice sheet estimates feed directly into projections of sea-level rise resulting from climate change. They are made by measuring how much material ice sheets are gaining or losing over time, known as mass balance, to assess their long-term health. Snowfall increases the mass of an ice sheet, while ice melting or breaking off causes it to lose mass, and the overall balance between these is crucial.

Although scientists now have a much better understanding of the melting behaviour of ice sheets than they did in previous decades, there are still significant uncertainties about their future melt rates, researchers found.

The new study, published in the scientific journal Earth Science Reviews, shows that despite recent advances in computer modelling of ice sheets in response to climate change, there are still key deficiencies in the models used to estimate the long-term health of ice sheets and related global sea-level predictions. Improving these estimates could prove vital to informing the scale of response needed to mitigate the potential impacts of climate change.

Edward Hanna, Professor of Climate Science and Meteorology at the University of Lincoln, UK, co-ordinated the research in co-operation with a leading international group of glaciologists.

Professor Hanna said: "The ice sheets are highly sensitive indicators of climate change, but despite significant recent improvements in data and knowledge, we still don't understand enough about how rapidly they are likely to lose mass during and beyond the current century.

"Enhanced observations of ice sheets, mainly from satellite data fed into improved computer simulations, are vital to help refine predictions of future sea-level rise that will result from continued global warming. They are urgently needed to assist climate adaptation and impact planning across the world."

In the last decade, the Antarctic and Greenland ice sheets have overtaken thousands of smaller glaciers as the major contributors to rising sea levels - it is thought that combined, the sheets contain enough ice to raise global sea levels by as much as 65 metres. However, while some estimates project a contribution of as much as one and a half metres from Antarctica to global sea-level rise by 2100, others suggest only a few tens of centimetres contribution.

The researchers say there is a pressing need for further research that involves enhanced satellite and ground-based observations, together with more sophisticated, interactive computer models that combine ice masses, the atmosphere, ocean and solid Earth systems.

Their study involved analysis of recent estimates of ice sheet and glacier mass balance, as well as highlighting recent advances and limitations in computer-model simulations of ice sheet change as an important basis for future work. The World Climate Research Programme, the Scientific Committee on Antarctic Research and the International Arctic Science Committee part-sponsored the research.

Professor Hanna also contributed to a recent paper in the scientific journal Nature analysing the Greenland Ice Sheet mass balance. That study, involving 96 polar scientists, showed that in the last decade, Greenland has lost ice seven times faster than in the 1990s. This tracks a high-end global warming scenario, with tens of millions more people being exposed to coastal flooding by 2100.

The aim of the OPS-SAT mission, which is being controlled from ESA's European Space Operations Centre in Darmstadt, Germany, is to carry out low-risk tests on space software directly in the course of flight. Until now, such in-orbit tests have been avoided for reasons of reliability. Now, though, the OPS-SAT "flying laboratory" will validate new operating concepts in orbit. These range from the latest satellite control technologies to intelligent software for space vehicles, including on-board automatic image recognition systems and artificial intelligence. This enables ESA to test cutting-edge technology in a low-risk setting. "OPS-SAT gives us room to innovate. Although it is small, this nanosatellite is bursting with potential, such as the opportunity to validate components of future exploration missions in orbit and test complex infrastructure on the ground," says Rolf Densing, ESA's Director of Mission Operations and head of the control centre. Graz University of Technology (TU Graz) is responsible for the technical side of ESA's first CubeSat mission, which has been implemented at a cost of EUR 2.4 million; the administrative main contractor is UniTel IT-Innovation. Subcontractors from Germany, Poland, Denmark and Austria are also involved, alongside with suppliers from France and the UK. The launch service is provided by Tyvak International from Italy.

Flying hardware and software lab

Otto Koudelka, the project manager of the industrial team and head of the Institute of Communication Networks and Satellite Communications at TU Graz, comments: "At present, communication standards dating back to 1994 are still being used in space missions. Radiation-hardened - and as a result very expensive - processors for use in space technology are lagging about ten years behind their terrestrial counterparts." However, these technologies are still around for a reason - ESA and other space agencies put their faith in tried-and-tested technology due to its reliability, which makes it a safe option. In this respect, OPS-SAT is making an important contribution to innovation. "Now it's time for something new," Koudelka sums up. The OPS-SAT mission is a chance for ESA to develop and test new operational space applications. "OPS-SAT is the means for low-risk, cost-effective testing of new high-performance processors, radio and optical data receivers and space software under realistic conditions in space," Otto Koudelka explains.

Over 130 experiments from 12 countries

The core of the 30cm x 10cm x 10cm flying laboratory is a high-powered processor developed at TU Graz. Software developed by OPS-SAT scientists and pre-tested on the ground at the European Space Operation Centre ESOC will be uploaded to the OPS-SAT processor from the ground station in Darmstadt. This processor has access to peripherals including a camera focused on Earth, optical and radio receivers, as well as an experimental altitude control system that will test new algorithms. A cryptography experiment using optical data transmission via laser, between the Lustbuehel Observatory in Graz and OPS-SAT, is also on the agenda. In this data security experiment, a cryptographic key will be used to encrypt the radio channel that will send data to the ground station at speeds of up to 50Mbit per second. Remote sensing experiments using on-board image processing technology will also be carried out. In addition, a programmable radio receiver on the satellite is designed to detect interference signals coming from Earth in certain frequency ranges. OPS-SAT will enable entire software programs and a large programmable logic chip (field-programmable array) to be loaded and modified during flight. This will test ways in which flight software can be updated or modified reliably and securely during a mission, which will generate insights for future ESA missions. Despite its small size, the satellite has an uplink speed of 256kbit per second and a downlink speed of 1Mbit per second - the fastest transmission rate in the telemetry system of any ESA satellite to date; the standard rate is 64kbit per second.

The test phase will begin as soon as the European Space Operations Centre receives the first signals from OPS-SAT, which are due to arrive this evening at around 18:30. The first experiments will be performed after the commissioning phase.

Graz, Austria: a high-profile international space research hub

TU Graz Rector Harald Kainz is delighted with the university's successes in space research: "The TU Graz team headed by Otto Koudelka, the father figure behind the satellite, launched Austria's first satellite, TUGSAT-1, into space and this laid the foundations for further missions like ESA's OPS-SAT nanosatellite that was launched today." TU Graz's achievements in this field have also been supported by close links with major international players and local infrastructure partners. As Harald Kainz explains: "We work very closely with the Austrian Academy of Sciences' Space Research Institute; with the Lustbuehel observatory, an internationally recognised monitoring station for all kinds of space projects; TU Graz's campus is home to the ground station for another international satellite initiative, the BRITE mission; and we have close ties with a number of Austrian pioneers in space research, such as the late Willibald Riedler, with Hans Sünkel and Wolfgang Baumjohann. Without doubt, Austria - and Graz in particular - is a high-profile international hub for space research."

Satellite research is part of TU Graz's Information, Communication and Computing, and Mobility and Production fields of expertise, two of the university's five scientific research focuses.