Tech

Tsukuba, Japan - A researcher at the University of Tsukuba has offered a new explanation for how superconductors exposed to a magnetic field can recover--without loss of energy--to their previous state after the field is removed. This work may lead to a new theory of superconductivity and a more eco-friendly electrical distribution system.

Superconductors are a class of materials with the amazing property of being able to conduct electricity with zero resistance. In fact, an electrical current can circle around a loop of superconducting wire indefinitely. The catch is that these materials must be kept very cold, and even so, a strong magnetic field can cause a superconductor to revert back to normal.

It was once assumed that the superconducting-to-normal transition caused by a magnetic field could not be reversed easily, since the energy would be dissipated by the usual process of Joule heating. This mechanism, by which the resistance in normal wires converts electrical energy into heat, is what allows us to use an electric stovetop or space heater.

"Joule heating is usually considered negatively, because it wastes energy and can even cause overloaded wires to melt," explains Professor Hiroyasu Koizumi of the Division of Quantum Condensed Matter Physics, the Center for Computational Sciences at the University of Tsukuba. "However, it has been known for a long time from experiments that, if you remove the magnetic field, a current-carrying superconductor can, in fact, be returned to its previous state without loss of energy,"

Now, Professor Koizumi has proposed a new explanation for this phenomenon. In the superconducting state, elections pair up and move in sync, but the true cause of this synchronized motion is the presence of so-called "Berry connection," characterized by the topological quantum number. It is an integer and if it is nonzero, current flows. Thus, this supercurrent can be switched off abruptly by changing this number to zero without Joule heating.

The founder of modern electromagnetic theory, James Clerk Maxwell, once postulated a similar molecular vortex model that imagined space being filled with the rotation of currents in tiny circles. Since everything was spinning the same way, it reminded Maxwell of "idle wheels," which were gears used in machines for this purpose.

"The surprising thing is that a model from the early days of electromagnetism, like Maxwell's idle wheels, can help us resolve questions arising today," Professor Koizumi says. "This research may help lead to a future in which energy can be delivered from power plants to homes with perfect efficiency."

Previous research has demonstrated a variety of health benefits associated with the Mediterranean diet, which is rich in olive oil, cereals, fruit and vegetables, fish, and a moderate amount of dairy, meat, and wine. Now results from an analysis published in Arthritis & Rheumatology suggest that the diet may also help prevent rheumatoid arthritis in individuals who smoke or used to smoke.

The analysis included 62,629 women from France who have been taking part in a questionnaire-based study assessing dietary intake since 1990. In total, 480 women developed rheumatoid arthritis.

Adherence to the Mediterranean diet was not associated with rheumatoid arthritis risk overall; however, among women who smoked or used to smoke, it was associated with a decreased risk: 383 cases of rheumatoid arthritis per 1 million people per year among those with high adherence to the Mediterranean diet, compared with 515 cases per 1 million people per year among those with low adherence to the diet. (Among women who never smoked and had high adherence to the diet, there were 358 cases per 1 million people per year.)

Researchers at McMaster University have developed a new technique to tease ancient DNA from soil, pulling the genomes of hundreds of animals and thousands of plants - many of them long extinct - from less than a gram of sediment.

The DNA extraction method, outlined in the journal Quarternary Research, allows scientists to reconstruct the most advanced picture ever of environments that existed thousands of years ago.

The researchers analyzed permafrost samples from four sites in the Yukon, each representing different points in the Pleistocene-Halocene transition, which occurred approximately 11,000 years ago.

This transition featured the extinction of a large number of animal species such as mammoths, mastodons and ground sloths, and the new process has yielded some surprising new information about the way events unfolded, say the researchers. They suggest, for example, that the woolly mammoth survived far longer than originally believed.

In the Yukon samples, they found the genetic remnants of a vast array of animals, including mammoths, horses, bison, reindeer and thousands of varieties of plants, all from as little as 0.2 grams of sediment.

The scientists determined that woolly mammoths and horses were likely still present in the Yukon's Klondike region as recently as 9,700 years ago, thousands of years later than previous research using fossilized remains had suggested.

"That a few grams of soil contains the DNA of giant extinct animals and plants from another time and place, enables a new kind of detective work to uncover our frozen past," says evolutionary geneticist Hendrik Poinar, a lead author on the paper and director of the McMaster Ancient DNA Centre. "This research allows us to maximize DNA retention and fine-tune our understanding of change through time, which includes climate events and human migration patterns, without preserved remains."

The technique resolves a longstanding problem for scientists, who must separate DNA from other substances mixed in with sediment. The process has typically required harsh treatments that actually destroyed much of the usable DNA they were looking for. But by using the new combination of extraction strategies, the McMaster researchers have demonstrated it is possible to preserve much more DNA than ever.

"All of the DNA from those animals and plants is bound up in a tiny speck of dirt," explains Tyler Murchie, a PhD candidate in the Department of Anthropology and a lead author of the study.

"Organisms are constantly shedding cells throughout their lives. Humans, for example, shed some half a billion skin cells every day. Much of this genetic material is quickly degraded, but some small fraction is safeguarded for millenia through sedimentary mineral-binding and is out there waiting for us to recover and study it. Now, we can conduct some remarkable research by recovering an immense diversity of environmental DNA from very small amounts of sediment, and in the total absence of any surviving biological tissues."

An over a century-long mystery has been surrounding the Taiwanese butterfly fauna ever since the "father of zoogeography" Alfred Russel Wallace, in collaboration with Frederic Moore, authored a landmark paper in 1866: the first to study the lepidopterans of the island.

Back then, in their study, Moore dealt with the moths portion and Wallace investigated the butterflies. Together, they reported 139 species, comprising 93 nocturnal 46 diurnal species, respectively. Of the latter, five species were described as new to science. Even though the correct placements of four out of those five butterflies in question have been verified a number of times since 1886, one of those butterflies: Lycaena nisa, would never be re-examined until very recently.

In a modern-day research project on Taiwanese butterflies, scientists retrieved the original type specimen from the Wallace collection at The History Museum of London, UK. Having also examined historical specimens housed at the Taiwan Agricultural Research Institute, in addition to newly collected butterflies from Australia and Hong Kong, Dr Yu-Feng Hsu of the National Taiwan Normal University finally resolved the identity of the mysterious Alfred Wallace's butterfly: it is now going by the name Famegana nisa (comb. nov.), while two other species names (Lycaena alsulus and Zizeeria alsulus eggletoni) were proven to have been coined for the same butterfly after the original description by Wallace. Thereby, the latter two are both synonymised with Famegana nisa.

Despite having made entomologists scratch their heads for over a century, in the wild, the Wallace's butterfly is good at standing out. As long as one knows what else lives in the open grassy habitats around, of course. Commonly known as 'Grass Blue', 'Small Grass Blue' or 'Black-spotted Grass Blue', the butterfly can be easily distinguished amongst the other local species by its uniformly grayish white undersides of the wings, combined with obscure submarginal bands and a single prominent black spot on the hindwing.

However, the species demonstrates high seasonal variability, meaning that individuals reared in the dry season have a reduced black spot, darker ground colour on wing undersides and more distinct submarginal bands in comparison to specimens from the wet season. This is why Dr Yu-Feng Hsu notes that it's perhaps unnecessary to split the species into subspecies even though there have been up to four already recognised.

Alfred Russel Wallace, a British naturalist, explorer, geographer, anthropologist, biologist and illustrator, was a contemporary of Charles Darwin, and also worked on the debates within evolutionary theory, including natural selection. He also authored the famed book Darwinism in 1889, which explained and defended natural selection.

While Darwin and Wallace did exchange ideas, often challenging each other's conclusions, they worked out the idea of natural selection each on their own. In his part, Wallace insisted that there was indeed a strong reason why a certain species would evolve. Unlike Darwin, Wallace argued that rather than a random natural process, evolution was occurring to maintain a species' fitness to the specificity of its environment. Wallace was also one of the first prominent scientists to voice concerns about the environmental impact of human activity.

WEST LAFAYETTE, Ind. - Vancomycin-resistant enterococcus (VRE) is among the leading causes of hospital-acquired infections in the United States. An estimated 20,000 people in the U.S. become infected with it each year, and nearly 10% of people who get it die from it.

These superbugs typically develop from infections in the intestinal tract, where the bacteria become resistant to the antibiotic vancomycin. People who stay in a hospital have the highest odds of getting VRE.

A pair of Purdue University researchers from the College of Pharmacy and the College of Veterinary Medicine developed small molecules to combat deadly, drug-resistant enterococcus.

They created their molecules by repurposing a drug that has been used for more than 80 years to treat glaucoma, congestive heart failure and some other health issues. Their work is published in the Journal of Medicinal Chemistry.

"The potency of these molecules and the ability to tune the molecules' properties to target VRE in different compartments of the body make this an exciting project," said Daniel Flaherty, an assistant professor of medicinal chemistry and molecular pharmacology. "I believe our discovery may help to change the way people treat VRE in the future.

"We can have molecules that can be used to treat deadly systemic VRE infections, or through manipulation of the properties of the molecule, design a compound that will reside solely in the gastrointestinal tract to reduce VRE colonization. By working across disciplines at Purdue, we have been able to improve the effectiveness of this drug 600 times better than where we started in treating VRE."

Mohamed Seleem, a professor of microbiology, who co-created the molecules with Flaherty, said the problem with antibiotics on the market is that they are used for a wide variety of illnesses.

"These antibiotics can really rip apart the guts and destroy good bacteria," Seleem said. "Then someone can develop Clostridium difficile, also known as C. diff, which kills about 30,000 people each year in the United States. Scientists across the globe are working on better solutions, but I think we are far away from seeing narrow-spectrum antibiotics proliferate the market."

The Purdue team's small molecules have been shown to target VRE and have the properties necessary to treat VRE in both systemic circulation or in the GI tract, where all VRE infections originate.

A radio telescope in outback Western Australia has completed the deepest and broadest search at low frequencies for alien technologies, scanning a patch of sky known to include at least 10 million stars.

Astronomers used the Murchison Widefield Array (MWA) telescope to explore hundreds of times more broadly than any previous search for extraterrestrial life.

The study, published today in Publications of the Astronomical Society of Australia, observed the sky around the Vela constellation. But in this part of the Universe at least, it appears other civilisations are elusive, if they exist.

The research was conducted by CSIRO astronomer Dr Chenoa Tremblay and Professor Steven Tingay, from the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR).

Dr Tremblay said the telescope was searching for powerful radio emissions at frequencies similar to FM radio frequencies, that could indicate the presence of an intelligent source.

These possible emissions are known as 'technosignatures'.

"The MWA is a unique telescope, with an extraordinarily wide field-of-view that allows us to observe millions of stars simultaneously," she said.

"We observed the sky around the constellation of Vela for 17 hours, looking more than 100 times broader and deeper than ever before.

"With this dataset, we found no technosignatures--no sign of intelligent life."

Professor Tingay said even though this was the broadest search yet, he was not shocked by the result.

"As Douglas Adams noted in The Hitchhikers Guide to the Galaxy, 'space is big, really big'."

"And even though this was a really big study, the amount of space we looked at was the equivalent of trying to find something in the Earth's oceans but only searching a volume of water equivalent to a large backyard swimming pool.

"Since we can't really assume how possible alien civilisations might utilise technology, we need to search in many different ways. Using radio telescopes, we can explore an eight-dimensional search space.

"Although there is a long way to go in the search for extraterrestrial intelligence, telescopes such as the MWA will continue to push the limits--we have to keep looking."

The MWA is a precursor for the instrument that comes next, the Square Kilometre Array (SKA), a 1.7 billion Euro observatory with telescopes in Western Australia and South Africa. To continue the Douglas Adams references, think of the MWA as the city-sized Deep Thought and the SKA as its successor: the Earth. 

"Due to the increased sensitivity, the SKA low-frequency telescope to be built in Western Australia will be capable of detecting Earth-like radio signals from relatively nearby planetary systems," said Professor Tingay.

"With the SKA, we'll be able to survey billions of star systems, seeking technosignatures in an astronomical ocean of other worlds."

The MWA is located at the Murchison Radio-astronomy Observatory, a remote and radio quiet astronomical facility established and maintained by CSIRO--Australia's national science agency. The SKA will be built at the same location but will be 50 times more sensitive and will be able to undertake much deeper SETI experiments.

The evolution of sex chromosomes is of crucial importance in biology as it stabilises the mechanism underlying sex determination and usually results in an equal sex ratio. An international team of scientists, led by researchers from Uppsala University, now reports that they have been able to reconstruct the birth of a male sex chromosome in the Atlantic herring. The male-specific region is tiny and contains only three genes: a sex-determining factor and two genes for sperm proteins. The study is published in PNAS.

It is hard to study the early evolution of sex chromosomes because it usually happened a long time ago and the sex-determining chromosomes usually rapidly degenerate and accumulate repetitive sequences. For instance, humans have an X/Y system of sex determination and the presence of Y determines male sex. The human Y chromosome, which was established more than 100 million years ago, evolved from a chromosome identical to the X chromosome but has since lost most of the genes present on X and is now only about a third the size of the X chromosome. The Atlantic herring also has an X/Y system but it is young and evolved much more recently. In the herring X and Y are almost identical in gene content, the only difference being that Y has three additional genes: a sex-determining factor (BMPR1BBY) and two sperm protein genes predicted to be essential for male fertility.

"The unique feature of this study is that we have been able to reconstruct the birth of a sex chromosome. The evolution of the herring Y chromosome in fact resembles the process when my son makes a construction with pieces of Lego," says Nima Rafati, scientist at Uppsala University and first author on the paper.

Two of the building blocks were formed when extra copies of two different genes emerged and were translocated to what became a male-specific region that cannot exchange genetic material with the X chromosome. This was followed by the incorporation of a third gene to the male-specific region and its loss from the X chromosome.

"The Y-specific gene BMPR1BBY is most certainly the sex-determining factor in Atlantic herring since it belongs to a family of proteins with a critical role in inducing the development of testis. The evolution of BMPR1BBY is a wonderful example of molecular evolution in action. It shows how random mutations and natural selection can 'create' a new gene," says Amaury Herpin, scientist at INRAE, France's new National Research Institute for Agriculture, Food and Environment, and one of the shared first authors.

BMPR1BBY contains about 50 mutations compared with the autosomal copy but it maintains its ability to promote testis development and has evolved an ability to act independently of some of the cofactor the autosomal copy requires. It therefore provides a shortcut to the induction of testis development.

"It has previously been proposed that the presence of a sex-determining factor is not sufficient for the evolution of a sex chromosome, it requires a close association between a sex-determining factor and one or more genes beneficial for that sex," explains Manfred Schartl, professor at Würzburg University and one of the co-authors of the study. "This is exactly what the herring Y chromosome provides, a male-determining factor (BMPR1BBY) and two genes for sperm proteins predicted to be essential for male fertility."

"We are now working on a follow-up study by making an assembly of the sprat genome. Sprat is a close relative to the herring and this analysis will allow us to make a more precise estimate of when this Y chromosome evolved, how stable it is and how rapidly it evolves," says Professor Leif Andersson, Uppsala University, who led the study.

The Nagoya University Institute of Transformative Bio-Molecules (WPI-ITbM) research team of Professor Cathleen Crudden, Designated Lecturer Masakazu Nambo, JSPS Postdoctoral Fellow Yuki Maekawa and Associate Professor Daisuke Yokogawa have developed a new synthesis method for the efficient production of fluorinated alkenes. This method offers a practical solution for the shortening of the synthesis process of existing bioactive compounds through the simple addition of an organic magnesium reagent, or Grignard reagent.

As bonds between carbon and fluorine are comparatively stronger than those between carbon and hydrogen, the addition of fluorine is known to increase stability in metabolism and oxidation. Thus, organic fluorine compounds are found in the majority of agrochemicals and organic materials, with their importance in this field only growing. 'Difluoroalkene' is the generic name for a compound with a structure into which two fluorine atoms have been introduced. Although a number of synthesis methods for difluoroalkenes have previously been developed, these often require the use of dangerously toxic and highly reactive fluoride reagents and are complex and multi-staged. Although some methods not requiring hazardous reagents have been reported in recent years, generic synthesis methods for particularly useful gem-difluoroalkenes have remained severely limited.

The research group aimed to develop a new synthesis method for fluorinated compounds using triflones, a variety of a group of organosulfur compounds called sulfones. They succeeded in carrying out a Ramberg-Bäcklund reaction to produce gem-difluoroalkenes, reacting triflones with an organic magnesium (Grignard) reagent. As a variety of carbon substituents can be introduced to the raw material of the triflone, this method greatly speeds up the previously very challenging gem-difluoroalkene synthesis process.

This method represents a great step forward for synthesis strategies in organic synthetic chemistry. Its ability to use easy to obtain and prepare reagents means that it is expected to find widespread use and contribute to the discovery of new agrochemicals and organic materials.

The Fracture Risk Assessment Tool (FRAX®) is a widely used calculation tool that integrates clinical information in a quantitative manner to predict a 10-year probability of major osteoporotic fracture for both women and men in different countries.1

A recent article from the New England Journal of Medicine (NEJM) questioned the use of race or ethnicity in risk assessment algorithms, including FRAX.2 In response to this article, the new editorial 'FRAX and Ethnicity' in the journal Osteoporosis International, authored by experts from the International Osteoporosis Foundation (IOF), sets out key messages and considerations related to the inclusion of race/ethnicity in FRAX algorithms.3

Professor John Kanis, lead author, IOF Honorary President, and Director of the Centre for Metabolic Bone Diseases at Sheffield and Professor at the Catholic University of Australia, stated:

"It is important to understand the reality of fracture epidemiology and risk assessment. Fracture probability varies markedly in different regions of the world due to differences in fracture risk and mortality. In the case of hip fracture there is a ten-fold range in probability which far exceeds the differences in incidence between the sexes within a country. Ethnicity-specific risk often exceeds the differences between the sexes as well. Therefore failure to include ethnicity-specific models where applicable and where data is available, would negate the integrity of fracture risk assessment, resulting in large and avoidable errors in the stratification of risk."

The editorial highlights the following key considerations:

-Fracture ethnicity is not a direct input variable in the FRAX model. FRAX models are calibrated for specific national fracture and mortality rates. In addition to 73 country-specific models, ethnicity-specific models have been calibrated specifically for the most common ethnicities in the USA, South Africa and Singapore. As variations in ethnicity-specific risk often exceed the differences in risk between sexes, failure to calibrate for ethnicity would have adverse consequences greater than failure to calibrate for sex.

-The significance of ethnicity varies by location. Black people in the USA have lower fracture probabilities than Caucasians, but the probability of fracture in Black people in the USA is much higher than in Black people in African countries, partly due to the higher fracture rates and lower mortality risks in the US Black population. Differences are also found for Chinese from Hong Kong, mainland China and Singapore.

-The efficacy of pharmacological interventions has been tested worldwide in randomised controlled trials so that ethnicity and location have a high level of evidence indicating their suitability for inclusion in risk assessment.

-In contrast to risk assessment and treatment decisions based solely on DXA-derived bone mineral density (BMD) values, the use of FRAX as a gateway for pharmaceutical intervention helps to resolve rather than exacerbate racial inequalities. As well as BMD, FRAX considers individual clinical factors not attributable to ethnicity such as age, parental fractured hip, weight, smoking, use of glucocorticoids, and alcohol use.

-FRAX has in fact permitted therapeutic care gaps to be recognized. Disparities in treatment gaps are common and attributable to many factors, including reimbursement issues for DXA in the USA, or focus on rare side effects of bisphosphonates. In the USA, the Women's Health Initiative revealed that those at high risk and Asian ethnicity had a much higher likelihood (by 45%) of being on treatment compared to White women, while at-risk Black/African American women had half the likelihood of being prescribed appropriate osteoporosis medication compared to Caucasians. Treatment gaps are also seen in men compared to women, and community-dwelling older adults versus those in long-term care.

Professor Cyrus Cooper, IOF President and Professor at the MRC Lifecourse Epidemiology Unit, Universities of Southampton and Oxford, UK, stated:

"The use of ethnicity in FRAX is not the major problem and indeed, FRAX helps to resolve inequalities rather than increase them. The key problem is that, as a disease, osteoporosis suffers from undertreatment worldwide. Fewer than 20% of individuals who fracture receive therapies to reduce the risk of future fracture within the year following a fracture. This crisis of undertreatment in osteoporosis clearly contrasts with the situation following myocardial infarction, in which 75% of patients receive beta blockers to prevent recurrent myocardial infarction."

"Disparities in the osteoporosis treatment gap can be addressed through good clinical judgement. Fracture risk estimates derived from FRAX should not be used uncritically in the management of patients. Used well, FRAX helps direct treatment to those most at need and avoids unnecessary intervention in those at low risk, amongst all segments of society."

X-ray detection is becoming increasingly important in areas from daily life for industry, the military, and scientific research. The process of scintillation materials is converting the X-ray, gamma-ray, and particle radiation into visible or ultraviolet (UV) light. Among the properties of the scintillator, the large scale, stability, and quantum yield for uses in various fields from low to high energy are key performance indicators. However, the conventional scintillators such as CsI, Gd2O2S, and organic scintillators (PPO+POPOP) are hardly manufactured to various forms from flexible plastic, solid to liquid for specific tasks. Additionally, there seems to be no practical way to considerably enhance the scintillation efficiency (quantum yield) of the existing scintillators. Hence, there has been a strong demand for developing a new kind of scintillator materials which can be widely exploited in various fields.

In a new paper published in Light Science & Application, a team of scientists, led by Professors Hyunsik Im, Hyungsang Kim and Jungwon Kwak from Division of Physics and Semiconductor Science, Dongguk University and Department of Radiation Oncology, Asan Medical Center, Korea and co-workers have developed perovskite metal halide nanocrystals based hybrid materials with high quantum yields for detecting X-rays efficiently and high-resolution X-ray imaging. Using the hybrid nanomaterial scintillators, they designed a scalable and cost-effective X-ray detector panel in liquid form. The hybrid nanomaterial scintillator works under X-ray irradiation typically employed in both diagnosis and treatment. More interestingly, the hybrid scintillator has a faster scintillation decay process over the conventional scintillators, which is beneficial for digital motion X-ray. The reported method and scintillation mechanism will be extended to enhance the quantum yield of various types of scintillators, enabling low-dose radiation detection in various fields including fundamental science and imaging.

The highly-efficient X-ray scintillation of the hybrid nanomaterial scintillator is based on a new scintillation mechanism, i.e., X-ray photon-induced charge transfer from the organic molecule to the perovskite nanocrystal (NC). The charge transfer can be allowed via surface hybridization of the NC with the organic molecule, and the extra charges in the NC, which are generated and transferred from the organic molecule further amplify the number of energetic electrons in the NC, thereby significantly improving quantum yield. These scientists summarize the working mechanism of their hybrid nanomaterial scintillators:
"We devise a method to enhance the X-ray scintillation efficiency (quantum yield) in perovskite metal halide NCs for efficiently detecting X-rays and high-resolution X-ray imaging. The enhancement of the scintillation efficiency of the NCs is achieved by hybridizing the NCs with organic molecules that provide X-ray induced energetic electrons to the NCs."

"Since the hybrid nanomaterials can be shaped into any form ranging plastic, solid to liquid, their use and applicability will be diverse in various fields. In addition, their scintillation decay time is remarkably faster than those of conventional scintillators, making them to be exploited for digital motion X-ray. " they added.

"While the fundamentals of scintillation in these halide perovskite NCs+PPO hybrid nanomaterials require further elucidation, these hybrid nanocrystals hold substantial promise for advancing the industrial applications of X-ray sensing and producing intriguing scintillation in hybrid nanomaterials. The presented method can also be applicable to develop efficient photo-sensors in various fields." the scientists forecast.

The escalating carbon dioxide (CO2) emissions and the consequent acceleration of climate change are alarming, and it has proven challenging to find feasible ways to actively reduce the concentration of CO2 in the atmosphere. What if we drew inspiration from photosynthesis, the process by which plants use sunlight to convert CO2 and water into useful chemicals?

In a recent study published in Applied Catalysis B: Environmental, Prof Su-Il In and researchers from Daegu Gyeongbuk Institute of Science and Technology (DGIST) in Korea developed a novel photocatalyst for converting CO2 into hydrocarbon fuels. Their approach is based around the concept of "Z-scheme" charge transfer mechanism in heterostructured photocatalysts, where the interfaces between two different materials play a central role in chemical processes that resemble the electron transfers in natural photosynthesis.

They reinforced reduced titanium nanoparticles edges with dicopper oxide (Cu2O) nanoparticles through photo-deposition, a unique yet relatively simple and inexpensive procedure. The rich electron density of reduced titania at the interface helps neutralize positive charges, called "electron holes," in Cu2O, which otherwise accumulate excessively and lead to photocorrosion. Moreover, the geometric configuration of the resulting interfaces allows both materials to be exposed to the reactive medium and jointly enhance photocatalytic performance, in contrast to core-shell structures previously developed to avoid photocorrosion. Apart from its remarkable CO2 conversion capabilities, the proposed photocatalyst has other benefits, as Prof In explains: "Aside from showing stable performance for 42 hours under continuous operation, the proposed photocatalyst is composed of earth-abundant materials, which greatly adds to its economic viability."

The development and adoption of viable methods to convert CO2 into fuel would have both environmental and economic benefits. In this regard, Prof In remarks: "Photocatalytic CO2 reduction is applicable in processes that produce huge volumes of CO2, like thermal power stations and industrial fermentation facilities (distilleries). Integrating this technology in such facilities will give them access to inexpensive and abundant fuel and cuts in carbon emission taxes." Needless to say, cheaper energy would have positive ripple effects in all the economy, and this study shows a promising way to get there while going green at the same time.

Not all fish oils are high quality oils, so scientists have developed a superior method to help produce better dietary Omega-3 health and dietary supplements.

The new process, explained in a new Nature Partner Journals (npj) Science of Food paper, defines how vortex fluidic device processing lifts the quality of active ingredients of the polyunsaturated fatty acids (PUFAs) in fish oil. The process was used to enrich Omega-3 fatty acid content of apple juice, remarkably without changing its sensory values which is important for the consumer.

Published in partnership with Guangzhou University, the University of Cincinnati, and the Australian Nuclear Science and Technology Organisation (ANSTO), the research is further proof of the value of rapid vortex fluidic green chemistry processing.

Compared to regular homogenisation processing, the device was able to raise PUFA levels and purity by lowering oxidation and dramatically improving shelf life. Natural bioactive molecules were used in processing showing that the fish oil medium can take up flavonoids and other health supplements.

The researchers on the project also developed a world first technique for studying how the process occurs in the vortex fluidic device (VFD) - real time.

Flinders University Professor of Clean Technology Colin Raston says the VFD also has the capability to scientifically measure and control the requirements for better outcomes in food processing.

Iron minerals and bacteria can be the main agents of carbon dioxide emissions from the soil. A soil scientist from RUDN University made this conclusion after studying the process of organic plant waste decomposition of the micro-level. Iron and hydrogen peroxide enter into a reaction, as a result of which active oxygen forms (oxygen radicals) are formed. The radicals destroy plant waste in the soil and promote carbon dioxide emissions. The results of the study were published in the Geoderma journal.

Carbon dioxide is considered one of the main reasons for global warming, and almost half of it is released to the atmosphere from the soil. The most active 'soil breathing' areas usually contain decomposing plant waste. Such areas tend to have hotspots: local zones up to 1 cm3 in volume where the decomposition process is almost 100 times faster. Due to a combination of high moisture and good aeration, these hotspots offer perfect living conditions to soil microorganisms. Previously, microbial activity had been considered the reason for active CO2 emissions. However, a soil scientist from RUDN University confirmed that it was in fact oxidation-reduction transitions of soil iron that caused them.

"Previously we used to believe that the reason for carbon dioxide emissions from hotspots were microorganisms that treated plant waste with special enzymes and turned it into gas. However, we demonstrated that a big part of this process was due not only to enzymes. Iron facilitates the formation of active oxygen forms (radicals) that affect insoluble organic matter, destroy it, and turn it into the soluble state," said Yakov Kuzyakov, a PhD in Biology, and the Head of the Center for Mathematical Modeling and Design of Sustainable Ecosystems at RUDN University.

The scientist also pointed out that microorganisms accelerate plant waste decomposition only several times, not hundreds of times. In the course of their activity bacteria release hydrogen peroxide that can react with iron and take one electron from it, creating active oxygen forms, i.e. substances with one free unpaired electron. This type of oxygen is chemically active and quickly oxidizes organic matter, causing its destruction.

To confirm that active oxygen forms cause CO2 emissions, the team created an artificial hotspot. To do so, they put 300 g of soil in a container, added plant waste (straw), and a solution of iron sulfate. The moisture level in the container was kept at 90%. The team measured the volume of CO2 emitted from the container for 40 days and then compared the results to measurement data collected from soils without iron and straw, and with low (45%) moisture levels. The sample in the container turned out to release 22 mg of CO2 per 1 kg of soil, which was approximately 22 times more than the volume released by low-moisture soil and soil without plant waste. After that, the team measured the changes in the volume of iron, carbon, hydrogen peroxide, and active oxygen forms in the vicinity of the hotspot. Based on the ratio of all these substances the team concluded that iron reacted with hydrogen peroxide and produced active oxygen.

"Unlike earlier theories, ours is focused on the primary role of active oxygen forms. It is a simple scenario. At first, plant waste stimulates the growth of bacteria. When there are enough bacteria, they consume almost all oxygen. These are perfect conditions for the concentration of iron which otherwise would oxidize. Then the iron reacts with hydrogen peroxide, and organic matter is decomposed under the influence of active oxygen forms. In its decomposed state it attracts even more bacteria, and the process intensifies several times," added Yakov Kuzyakov.

The study was the first one to confirm that biological processes in soil hotspots are driven by the activity of free radicals (i.e. substances with a free electron). According to the team, this mechanism might also take place in other hotspots, for example, those found in the rhizosphere (the soil around plant roots). In the future, this data can be used to reduce CO2 emissions from the soil.

An iron-dependent burst of hydroxyl radicals stimulates straw decomposition and CO2 emission from soil hotspots: Consequences of Fenton or Fenton-like reactions,

The diets of hunter-gatherers are changing at a fast pace, as in the contemporary world, they are increasingly being deprived of their access to land and natural resources and urged to adapt to sedentary lifestyle. An interdisciplinary study from the University of Helsinki brings forth the underlying causes of food and nutrition insecurity among a San group in Namibia.

The Khwe San tribe living in North-East Namibia, are still among the few so-called "bushman" groups, who reside on their ancestral land. However, their contemporary diet includes surprisingly little food from their surrounding environment, but mostly consists of maize meal transported from far away.

Why do the Khwe San, a former hunter-gatherer group living in woodland savannah surrounded by an abundance of wildlife and flora wait for the government to feed them maize? And why does food insecurity persist in these communities in the 21st century?

The doctoral research of Anita Heim, from the University of Helsinki sheds light in these questions and further by taking an interdisciplinary approach in exploring how the Khwe San navigate in their heavily transformed food environment, what do they eat and how they make their food choices.

Banned from hunting and restricted in gathering

The transitioning food system of a former hunter-gatherer group posed an interesting challenge for Heim to conceptualize and analyse food environment and food choices among the Khwe, as such studies in rural settings of low- and middle-income countries are extremely rare. The Khwe reside in a national park, where trophy hunting by foreigners are a common practice but the Khwe, who lived in the area for centuries, are banned of hunting and restricted in gathering. These conditions have contributed to a dietary transition, diverging from their traditional diets based on wild berries, tubers, mushrooms, insects and game meat. Yet, the transition did not follow the common pattern of a foraging society shifting into agricultural society.

- While prevailing developmental policies and practices have focused on agriculture as a pathway to achieve an increased food security, I discovered that the shift has hardly been successful, or meaningful in the fight against hunger. Therefore, the centralised food and financial assistance by the state has been indispensable for the Khwe communities, says Heim.

When hunger is a daily challenge

Today, the Khwe are trapped in a vicious cycle of malnutrition due to a dysfunctional local food system, in which they have no agency over food sources and are deprived of accessing their natural food resources on their traditional lands. These living conditions raise concerns regarding the United Nations Declaration on the Rights of Indigenous Peoples and the human right to food.

In the situation, where hunger is a daily challenge, according to Heim a wide range of context- and culture-specific solutions are necessary, including the elimination of movement restrictions, effective local food policies, nutritious food-aid and climate friendly agroecological production. Most importantly, in order to supplement the diets with key nutritional food groups, such as fruits, vegetables and meat, the support for traditional foodways is the most fundamental solution for a tribe with a strong hunter-gatherer mindset.

- Shockingly, this is a hugely untapped resource base for improving food security, as the regional stakeholders and decision makers show very little appreciation for foraged wild foods, says Heim.

Declining desire for traditional foods

The monetary income received from the government or earned as wages is spent in the informal markets, supplementing the diets with packaged foods, sugary sodas and alcohol.

The modern foods that provide convenience, enhanced taste and larger bulk have suppressed the appetite for traditional foods, at least among the younger generation. Yet Heim's interviews with elderly revealed that the shift in preference away from traditional foods has been strongly influenced by historical events between the 1970-90s, when the easy reach for modern foods and the contested access to the surrounding natural resources made knowledge transfer about traditional food obsolete. Today, there is a serious risk of long-evolved Khwe knowledge around traditional foods disappearing as the Khwe elders pass away without having transmitted their knowledge and skills to the younger generations.

Researchers at Princeton University have created a new and improved way to more precisely control genetically engineered bacteria: by simply switching the lights on and off. Working in E. coli, the workhorse organism for scientists to engineer metabolism, researchers developed a system for controlling one of the key genetic circuits needed to turn bacteria into chemical factories that produce valuable compounds such as the biofuel isobutanol.

"All you need is illumination," said José Avalos, an assistant professor of chemical and biological engineering at Princeton University and at the Andlinger Center for Energy and the Environment", and senior author of the findings, published in Nature Chemical Biology. "There are lots of potential benefits, one of them being the ability to easily tune and reverse the induction signal."

The new work builds on Avalos and his colleagues' previous work, described in Nature in 2018, in which they engineered of yeast to produce chemicals in the presence or absence of light. E. coli, however, is even more widely used by scientists and engineers than yeast.

Avalos and his colleagues are not the first to create E. coli whose gene expression is controlled by light. But they are the first to use light to control production of chemicals. They also are the first to use light to control the lac operon, a group of genes that is most commonly utilized for chemical induction in E. coli. "The lac operon is the gold standard circuit that people have used for decades," Avalos said. "It's not an understatement to say that harnessing the lac operon is one of those key achievements that enabled the explosion in biotechnology."

When scientists engineer E. coli to produce a protein or chemical through the lac operon, they typically make that function inducible rather than something that occurs all the time. This way, the bacteria culture can grow normally until scientists are ready to put it to use. Usually, researchers rely on adding a chemical to trigger the expression of the genetically engineered trait in question. But this method has some serious limitations. "If you add a chemical, that's it, you've committed," Avalos said. "It's done and you cannot easily remove the chemical, so you just have to wait and see if you added the right dose."

Instead of relying on a chemical inducer, Avalos and his colleagues' newly engineered bacteria uses the absence of light to induce reactions that lead to chemical or protein production. This allows researchers to slow or stop the reaction by simply turning on the light. Light also allows them to control where the reaction occurs. In one demonstration, Avalos and his colleagues darkened only certain sections of their bacterial Petri dish with a stencil of a tiger, creating a fluorescent tiger print through the selectively activated bacteria's reaction. "Again, that's something you couldn't easily do with a chemical, because you wouldn't be able to control the diffusion of the chemical as easily," Avalos said. Light, unlike chemicals, is also relatively inexpensive, he adds, so using it will reduce costs and probably the carbon footprint of processes.

OptoLac, Avalos and his colleagues' new optogenetic--or light-based--method, now gives scientists the ability to harness the strength of preexisting lac operon technologies with added precision and control.

"The work was well-executed and adds a novel tool to the toolbox of optogenetic gene expression activators in E. coli," said Mustafa Khammash, a professor of control theory and systems biology at ETH Zürich, who was not involved in the research. "Optogenetic gene expression offers the possibility to use light instead of small molecules to control a great variety of biological processes with minimal effort, and the authors illustrate this convincingly by demonstrating the use of OptoLAC to achieve impressive improvements in chemical and protein production in E. coli."

E. coli is currently used for industrial production of a wide range of commodity and specialty chemicals, from building blocks of plastics and synthetic fibers, to high-end chemicals like pigments and fragrances. E. coli also is often used by scientists to better understand basic principles of metabolism, biosynthetic pathways and beyond. Therefore, this technology could have important implications not only in biotechnology, but also in basic research, Avalos said.

Avalos plans to explore further applications enabled by OptoLAC, including fine-tuning complex metabolic pathways, improving production of proteins that are difficult to make and controlling other interesting bacterial functions. "In a sense, a big part of our motivation was to break the mold of the way things are done now," Avalos said. "One question we keep asking ourselves is, 'How can we do this better?'"