Tech

Vast amounts of valuable energy, agricultural nutrients, and water could potentially be recovered from the world's fast-rising volume of municipal wastewater, according to a new study by UN University's Canadian-based Institute for Water, Environment and Health (UNU-INWEH).

Today, some 380 billion cubic meters (m3 = 1000 litres) of wastewater are produced annually worldwide - 5 times the amount of water passing over Niagara Falls annually - enough to fill Africa's Lake Victoria in roughly seven years, Lake Ontario in four, and Lake Geneva in less than three months.

Furthermore, the paper says, wastewater volumes are increasing quickly, with a projected rise of roughly 24% by 2030, 51% by 2050.

Today, the volume of wastewater roughly equals the annual discharge from the Ganges River in India. By the mid-2030s, it will roughly equal the annual volume flowing through the St. Lawrence River, which drains North America's five Great Lakes.

Among major nutrients, 16.6 million metric tonnes of nitrogen are embedded in wastewater produced worldwide annually, together with 3 million metric tonnes of phosphorus and 6.3 million metric tonnes of potassium. Theoretically, full recovery of these nutrients from wastewater could offset 13.4% of global agricultural demand for them.

Beyond the economic gains of recovering these nutrients are critical environmental benefits such as minimizing eutrophication - the phenomenon of excess nutrients in a body of water causing dense plant growth and aquatic animal deaths due to lack of oxygen.

The energy embedded in wastewater, meanwhile, could provide electricity to 158 million households - roughly the number of households in the USA and Mexico combined.

The study's estimates and projections are based on theoretical amounts of water, nutrients, and energy that exist in the reported municipal wastewater produced worldwide annually.

The authors underline that information on wastewater volumes -- generated, available, and reused - is scattered, infrequently monitored and reported, or unavailable in many countries. They also acknowledge the limitations of current resource recovery opportunities.

Nonetheless, says lead author Manzoor Qadir, Assistant Director of UNU-INWEH, in Hamilton, Canada: "This study offers important insights into the global and regional potential of wastewater as a source of water, nutrients, and energy. Wastewater resource recovery will need to overcome a range of constraints to achieve a high rate of return but success would significantly advance progress against the Sustainable Development Goals and others, including adaptation to climate change, 'net-zero' energy processes, and a green, circular economy."

Among many findings:

The energy value in 380 billion m3 of wastewater is estimated to be 53.2 billion m3 methane - enough to provide electricity for up to 158 million households, or 474 million to 632 million people, assuming an average of three to four persons per household. Given the foreseen wastewater increases, that number rises to 196 million households in 2030, and 239 million households in 2050.

In agriculture, the volume of water potentially recoverable from wastewater could irrigate up to 31 million hectares - equal to almost 20% of the farmland in the European Union (assuming two crops and a maximum 12,000 m3 of water per hectare per year). "The reclaimed water can be used to irrigate new areas or replace valuable freshwater where crops are already irrigated."

World wastewater production is expected to reach 470 billion m3 by 2030, the year by which the SDGs are supposed to be met - a 24% increase from today. And by 2050, it will reach 574 billion m3, a 51% increase.

Asia is the largest wastewater producer with an estimated 159 billion cubic meters, representing 42% of urban wastewater generated globally, with expectations of that proportion rising to 44% by 2030

Other regions producing large volumes of wastewater: North America (67 billion m3) and Europe (68 billion cubic meters) - virtually equal volumes despite Europe's higher urban population (547 million vs. North America's 295 million. The difference is explained by per capita generation of wastewater: Europe 124 cubic meters; North America 231 cubic meters). By contrast, Sub-Saharan Africa produces 46 cubic meters of wastewater per capita - about half of the global average (95 cubic meters), reflecting limited water supply and poorly-managed wastewater collection systems in most urban settings.

Full recovery from wastewater could, theoretically, offset 14.4% of global demand for nitrogen as a fertilizer nutrient; phosphorus 6.8% and potassium 18.6%. Based on current levels of nitrogen, phosphorus, and potash use in agriculture worldwide (estimated at 193 million metric tonnes in 2017), the study says about 13.4% of the global fertilizer nutrient demand could be supplemented by full nutrient recovery from wastewater.

The nutrients in wastewater could theoretically generate revenue of $13.6 billion globally: $9.0 billion from the recovery of nitrogen, $2.3 billion from phosphorus, and $2.3 billion from potassium.

The paper cites prior research showing that human urine is responsible for 80% of the nitrogen and 50% of phosphorus entering municipal wastewater treatment plants. "Removing these nutrients in time would not only be environmentally beneficial," the paper says, "resulting in less eutrophication, it would reduce the cost of wastewater treatment while supporting closed-loop processes."

Current wastewater nutrient recovery technologies have made significant progress. In the case of phosphorous, recovery rates range from 25% to 90%.

The paper points out that maximizing economically the potential use of thermal energy in wastewater swings on several basic requirements, including a minimum flow rate of 15 litres per second, short distances between heat source and sink, and high-performance heat pumps.

Says Vladimir Smakhtin, Director of UNU-INWEH, a global leader in research related to unconventional water sources: "Municipal wastewater was and often still is seen as filth. However, attitudes are changing with the growing recognition that enormous potential economic returns and other environmental benefits are available as we improve the recovery of the water, nutrients and energy from wastewater streams."

Co-authors comments

"Safely managed wastewater is the key to water-related sustainable development at a time when the world is embarking on achieving SDGs, particularly SDG 6.3, which calls on us to half the proportion of untreated wastewater and substantially increase recycling and safe reuse globally by 2030."

Praem Mehta, UNU-INWEH / McMaster University, Hamilton, Canada

"This data can be used to develop national action plans aiming at water resources management, pollution control measures, nutrient and fertilizer access, and energy recovery and energy production systems."

Younggy Kim, McMaster University, Hamilton, Canada

"It is important to note that many innovations are available and are being refined to bridge the gap between current resource recovery levels and resource recovery potential."

Blanca Jiménez Cisneros, UNESCO and the National Autonomous University of Mexico

"For countries to progress, there is a need to invest in a supportive regulatory and financial environment towards a green economy, and to leverage private capital for resource recovery-related business models that are financially feasible and increase cost recovery from municipal wastewater."

Pay Drechsel, International Water Management Institute, Sri Lanka

"There is a need to facilitate and expedite implementation of resource recovery innovations particularly in low- and middle-income countries where most municipal wastewater still goes into the environment untreated. This concerns mainly the growing small and medium-size towns where agricultural land is still in proximity but also urban agricultural areas around larger cities."

Amit Pramanik, Water Research Foundation, Alexandria, VA, USA

"The SDG challenge is on, and step-wise approaches are needed which should involve both the public and emerging private sectors which often struggle with inadequate regulatory frameworks, limited finance, and the lack of capacity to develop or evaluate bankable business plans about resource recovery and reuse. As the demands for freshwater are ever-growing and scarce water resources are increasingly stressed, ignoring the opportunities leading to safely managed wastewater is nothing less than unthinkable in the context of a circular economy."

Oluwabusola Olaniyan, Winnipeg Water and Waste Department, Canada.

New research by engineers at MIT and elsewhere could lead to batteries that can pack more power per pound and last longer, based on the long-sought goal of using pure lithium metal as one of the battery's two electrodes, the anode.

The new electrode concept comes from the laboratory of Ju Li, the Battelle Energy Alliance Professor of Nuclear Science and Engineering and professor of materials science and engineering. It is described in the journal Nature, in a paper co-authored by Yuming Chen and Ziqiang Wang at MIT, along with 11 others at MIT and in Hong Kong, Florida, and Texas.

The design is part of a concept for developing safe all-solid-state batteries, dispensing with the liquid or polymer gel usually used as the electrolyte material between the battery's two electrodes. An electrolyte allows lithium ions to travel back and forth during the charging and discharging cycles of the battery, and an all-solid version could be safer than liquid electrolytes, which have high volatility and have been the source of explosions in lithium batteries.

"There has been a lot of work on solid-state batteries, with lithium metal electrodes and solid electrolytes," Li says, but these efforts have faced a number of issues.

One of the biggest problems is that when the battery is charged up, atoms accumulate inside the lithium metal, causing it to expand. The metal then shrinks again during discharge, as the battery is used. These repeated changes in the metal's dimensions, somewhat like the process of inhaling and exhaling, make it difficult for the solids to maintain constant contact, and tend to cause the solid electrolyte to fracture or detach.

Another problem is that none of the proposed solid electrolytes are truly chemically stable while in contact with the highly reactive lithium metal, and they tend to degrade over time.

Most attempts to overcome these problems have focused on designing solid electrolyte materials that are absolutely stable against lithium metal, which turns out to be difficult. Instead, Li and his team adopted an unusual design that utilizes two additional classes of solids, "mixed ionic-electronic conductors" (MIEC) and "electron and Li-ion insulators" (ELI), which are absolutely chemically stable in contact with lithium metal.

The researchers developed a three-dimensional nanoarchitecture in the form of a honeycomb-like array of hexagonal MIEC tubes, partially infused with the solid lithium metal to form one electrode of the battery, but with extra space left inside each tube. When the lithium expands in the charging process, it flows into the empty space in the interior of the tubes, moving like a liquid even though it retains its solid crystalline structure. This flow, entirely confined inside the honeycomb structure, relieves the pressure from the expansion caused by charging, but without changing the electrode's outer dimensions or the boundary between the electrode and electrolyte. The other material, the ELI, serves as a crucial mechanical binder between the MIEC walls and the solid electrolyte layer.

"We designed this structure that gives us three-dimensional electrodes, like a honeycomb," Li says. The void spaces in each tube of the structure allow the lithium to "creep backward" into the tubes, "and that way, it doesn't build up stress to crack the solid electrolyte." The expanding and contracting lithium inside these tubes moves in and out, sort of like a car engine's pistons inside their cylinders. Because these structures are built at nanoscale dimensions (the tubes are about 100 to 300 nanometers in diameter, and tens of microns in height), the result is like "an engine with 10 billion pistons, with lithium metal as the working fluid," Li says.

Because the walls of these honeycomb-like structures are made of chemically stable MIEC, the lithium never loses electrical contact with the material, Li says. Thus, the whole solid battery can remain mechanically and chemically stable as it goes through its cycles of use. The team has proved the concept experimentally, putting a test device through 100 cycles of charging and discharging without producing any fracturing of the solids.

Li says that though many other groups are working on what they call solid batteries, most of those systems actually work better with some liquid electrolyte mixed with the solid electrolyte material. "But in our case," he says, "it's truly all solid. There is no liquid or gel in it of any kind."

The new system could lead to safe anodes that weigh only a quarter as much as their conventional counterparts in lithium-ion batteries, for the same amount of storage capacity. If combined with new concepts for lightweight versions of the other electrode, the cathode, this work could lead to substantial reductions in the overall weight of lithium-ion batteries. For example, the team hopes it could lead to cellphones that could be charged just once every three days, without making the phones any heavier or bulkier.

One new concept for a lighter cathode was described by another team led by Li, in a paper that appeared last month in the journal Nature Energy, co-authored by MIT postdoc Zhi Zhu and graduate student Daiwei Yu. The material would reduce the use of nickel and cobalt, which are expensive and toxic and used in present-day cathodes. The new cathode does not rely only on the capacity contribution from these transition-metals in battery cycling. Instead, it would rely more on the redox capacity of oxygen, which is much lighter and more abundant. But in this process the oxygen ions become more mobile, which can cause them to escape from the cathode particles. The researchers used a high-temperature surface treatment with molten salt to produce a protective surface layer on particles of manganese- and lithium-rich metal-oxide, so the amount of oxygen loss is drastically reduced.

Even though the surface layer is very thin, just 5 to 20 nanometers thick on a 400 nanometer-wide particle, it provides good protection for the underlying material. "It's almost like immunization," Li says, against the destructive effects of oxygen loss in batteries used at room temperature. The present versions provide at least a 50 percent improvement in the amount of energy that can be stored for a given weight, with much better cycling stability.

The team has only built small lab-scale devices so far, but "I expect this can be scaled up very quickly," Li says. The materials needed, mostly manganese, are significantly cheaper than the nickel or cobalt used by other systems, so these cathodes could cost as little as a fifth as much as the conventional versions.

Coastal plant communities are a crucial element of global sea defences but are increasingly threatened by the human-induced effects of climate change, according to new research.

Rising sea levels and the increased frequency and intensity of extreme storm events are having a visible, global impact on beaches, cliff faces and coastal infrastructure.

But a new report suggests their impact on coastal plants, an integral part of shoreline defences, needs to be placed in greater focus.

The research was led by the University of Plymouth, in conjunction with scientists at Utrecht University and Manchester Metropolitan University, and is published in a special edition of the journal Annals of Botany.

It follows a recent assessment by the Intergovernmental Panel on Climate Change (IPCC 2019), which asserted that anthropogenically-driven climate change poses a severe environmental threat to estuarine and coastal ecosystems.

This report not only reviews how the flood and erosion threats posed by a combination of sea level rise and storms can affect coastal sub-, inter- and supra-tidal plant communities, but also highlights the contribution that habitats like saltmarshes, mangrove forests, sand dunes and kelp beds make to coastal protection.

Dr Mick Hanley, Associate Professor (Reader) in the School of Biological and Marine Sciences at the University of Plymouth, led the research. He said: "It has been suggested that by 2050, it could cost well over $50billion to protect the world's largest cities from coastal flooding. In contrast, coastal vegetation can offer natural protection against erosion and flooding for a fraction of the costs associated with constructing so-called hard defences like concrete walls. Society is only just beginning to appreciate this, but estuarine and coastal ecosystems can be integrated into a dynamic, low-cost flood defence strategy to meet the ever increasing challenges posed by rising sea-levels and storms."

As well as highlighting that the threats posed by extreme weather to coastal plant communities are undoubtedly severe, the study calls for biologists and ecologists to work alongside coastal scientists, environment agencies and land managers to identify the key species and habitats for coastal defence and how they can be both promoted and protected in the future.

Central to that objective, the authors argue, is the need to develop and combine long-term monitoring with flood risk models to better predict where and how storms and other climate change-driven phenomenon influence coastal ecosystems and services.

Dr Hanley, who also co-edited the Annals of Botany special edition focusing on the vulnerability to, and management of, plant communities in the face of increased flood risk, added: "The realisation that coastlines globally are now facing increased threats provides the impetus for understanding how hurricanes, typhoons, cyclones and other extreme weather events can affect coastal vegetation. That is critical to ensure we can effectively manage risk over the coming decades, but considerable work is needed to ensure the potential power of plants to defend our coastlines is not lost before it's fully understood."

A team of researchers led by the University of California San Diego has created a device that measures how "sticky" cancer cells are, which could improve prognostic evaluation of patient tumors. The device is built with a microfluidic chamber that sorts cells by their physical ability to adhere to their environment.

Researchers found that weakly adherent cells migrated and invaded other tissues more than the strongly adherent cells from the same tumor. Also, the genes that identify these weakly adherent cells make patients' tumors five times more likely to reoccur within five years.

The team reported their findings in a study published in Cancer Research.

Their work addresses a longstanding problem in the field of cancer research: it has been difficult to find biological markers to universally identify and select the most aggressive cells in tumors. This study may provide a much-needed physical marker that identifies highly metastatic cells within a heterogeneous tumor cell population.

"This new device could be the first step to better assess how likely tumor recurrence is," said Adam Engler, bioengineering professor at the UC San Diego Jacobs School of Engineering and senior author of the study. "Patients with few of these aggressive cells lying dormant in their surrounding tissue may be less likely to see a tumor reoccur 5, 10, or 20 years later." Engler noted that by knowing a patient's risk, follow-up treatments could be better tailored to the individual.

The device that Engler's team built consists of a microfluidic chamber coated with an adhesive protein. Cancer cells are placed in the chamber and after they adhere, a fluid is pushed through to detach cells. The faster the fluid moves, the higher the shear stress that the cells experience. The team can isolate cells that detach at specific shear stresses and analyze them. Cells collected at lower shear stress are weakly adherent, while those collected at higher shear stresses are strongly adherent.

Their analysis led the team to another critical finding: weakly adherent cells have a unique genetic signature that identifies them and enables them to migrate and invade faster. Comparing this signature to thousands of patients in the Cancer Genome Atlas (TCGA) database, researchers found that patients with tumors high in this "weakly adherent signature" experienced tumor recurrence occurred earlier and more frequently.

Building on these findings, Engler and his team hope to "prime" tumors with weakly adherent cells to see if they indeed metastasize faster and more frequently.

"If our mouse model shows that these cells indeed reduce cancer-free survival times, it will pave the way for substantial prognostic studies in humans with these types of solid tumors," said first author Pranjali Beri, a bioengineering Ph.D. student in Engler's lab. Beri also noted that nearly any solid tumor should exhibit this physical marker, and the team has so far tested cells from breast, prostate, and lung tumors.

In the future, the team hopes that clinicians will use this microfluidic device to examine tumor biopsies to estimate the likelihood of metastasis and adjust treatment at earlier disease stages.

Engler's clinical collaborator, Dr. Anne Wallace, director of the Comprehensive Breast Health Center at UC San Diego Health who will provide patient samples for follow-up studies, concurred and confirmed this approach. "Many cancers that we see in the clinic, such as ductal carcinoma in situ or DCIS, remain dormant for years. It is nearly impossible for us to predict which fraction of that population will reoccur," she noted. The team's device could be the first to address these hard to predict recurrences.

Children diagnosed with ADHD inconsistently take their prescribed medication, going without treatment 40 per cent of the time, a new study has found.

The research, led by the Murdoch Children's Research Institute (MCRI) and published in Archives of Disease in Childhood, shows the average medication coverage, the total time on drug between the first and the last redeemed prescription, was just 60 per cent.

Lead author and MCRI Associate Professor Daryl Efron said medication use was relatively high in the first few months, then progressively decreased, only increasing again after five or six years of treatment.

Additionally, children from socially disadvantaged families who were prescribed ADHD medication were less likely to consistently take it.

"We know low socio economic families can find it more difficult to attend medical appointments, with factors including appointment costs, transport difficulties and missed work all potentially contributing," he said.

The study showed the average medication coverage was 81 per cent in the first 90 days dropping to 54 per cent after 90 days.

Associate Professor Efron said little had been known about the longer term adherence to medication by children with ADHD until now.

"About 90 per cent of children with ADHD respond well to at least one of the stimulant ADHD medications," he said.

"ADHD is a chronic condition and so there is a strong argument that treatment should be provided consistently for several years in most cases. But adherence with ADHD medications is often inconsistent."

The study of 3,537 children looked at all redeemed ADHD prescriptions of the three frontline treatments, methylphenidate, dexamphetamine, and atomoxetine, by participants in the Longitudinal Study of Australian Children.

The study found that 166 children (3.6 per cent) had ever redeemed a prescription for an ADHD medication. Boys were four times more likely to be prescribed ADHD medication than girls.

Associate Professor Efron said the findings have important clinical implications.

About one in 20 children in Australia has ADHD, according to ADHD Australia.

"Effort should be made to continue to engage children who stop taking medications and their families to ensure they are able to access appropriate interventions, which may include medication alongside other interventions such as mental health and educational supports," Associate Professor Efron said.

Amsterdam, NL, February 3, 2020 - Individuals at risk for Alzheimer's disease (AD) because of family history or genetic predisposition who engaged in six months of aerobic exercise training improved their brain glucose metabolism and higher-order thinking abilities (e.g., planning and mental flexibility) called executive function; these improvements occurred in conjunction with increased cardiorespiratory fitness. The results of this study are published in a special issue of Brain Plasticity devoted to Exercise and Cognition.

Drugs currently available to treat AD have limited therapeutic capacity. At a time when both the human and monetary costs of the disease are projected to rise dramatically in the coming decades, there is a critical need to provide individuals with readily-deployable strategies that can decrease the likelihood of acquiring the disease or slow its progression. Researchers therefore investigated whether exercise training in asymptomatic individuals harboring risk for AD improves markers associated with AD.

"This study is a significant step toward developing an exercise prescription that protects the brain against AD, even among people who were previously sedentary," explained lead investigator Ozioma C. Okonkwo, PhD, of the Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health.

The study investigated 23 cognitively normal, relatively young older adults with a family history or genetic risk for AD. All patients had a sedentary lifestyle. They underwent a battery of assessments, including cardiorespiratory fitness testing, measurement of daily physical activity, brain glucose metabolism imaging (a measure of neuronal health), and cognitive function tests.

Half of the participants were randomly assigned to receive information about maintaining an active lifestyle but no further intervention. The other half participated in a moderate intensity treadmill training program with a personal trainer, three times per week for 26 weeks.

Compared to the participants maintaining their usual level of physical activity, individuals assigned to the active training program improved their cardiorespiratory fitness, spent less time sedentary after the training program ended, and performed better on cognitive tests of executive functioning (but not episodic memory). Executive function, an aspect of cognition that is known to decline with the progression of AD, comprises the mental processes enabling individuals to plan, focus attention, remember instructions, and juggle multiple tasks successfully. The participants' improved cardiorespiratory fitness was associated with increased brain glucose metabolism in the posterior cingulate cortex, an area of the brain linked to AD.

"This research shows that a lifestyle behavior - regular aerobic exercise - can potentially enhance brain and cognitive functions that are particularly sensitive to the disease. The findings are especially relevant to individuals who are at a higher risk due to family history or genetic predisposition," noted Dr. Okonkwo. The lead author on the study, Max Gaitán, MEd, of the Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, remarked that "an important next step would be to conduct a larger, more definitive, study. If these findings are replicated, they would have a tremendous impact on quality of later life, providing individuals with more years of independent living, active engagement with loved ones, and building memories."

A novel salt-tolerant bacterium cultured from the Red Sea effectively removes nitrogen from salty wastewater, suggests research from Pascal Saikaly's team at KAUST. The bacterium could be used to treat sewage coming from toilets that use seawater for flushing in place of freshwater.

Less than one percent of Earth's water is fresh and also accessible for human use. The world's population is expected to grow to about ten billion by 2050 and will continue to place increasing pressure on this already rare resource.

Currently, toilet flushing accounts for about 30 percent of the world's total domestic water demand, with an average human flushing a whopping 50 liters per day. Using seawater to flush toilets could partially alleviate pressure on freshwater resources.

"Seawater toilet flushing is already in practice in Hong Kong, Singapore and Tokyo," says KAUST research scientist Muhammad Ali. "More coastal cities are likely to follow suit to reduce their dependence on freshwater resources and energy-intensive desalination. But the high salt content in the wastewater from seawater toilet flushing limits the performance of conventional nitrogen-removing bacteria used in treatment processes because they have low salt tolerance."

Muhammad Ali and Ph.D. candidate Dario Rangel Shaw, both in Pascal Saikaly's lab, conducted three years of tests to find whether the bacterium Candidatus Scalindua sp. AMX11, which they cultured from the Red Sea, could effectively remove nitrogen from salty wastewater.

Nitrogen needs to be removed from wastewater due to its negative effects on the environment and human health. Currently, the most energy-efficient method to do this involves the use of granules containing two types of nitrogen-removing bacteria. But one of these, an anaerobic ammonium oxidation bacteria, or anammox bacteria for short, has a very low tolerance for and effectiveness in saltwater.

KAUST's Candidatus Scalindua sp. AMX11 was around 90 percent effective in treating wastewater with a salinity of about 1.2 percent and demonstrated high nitrogen removal rates. The tests were on real seawater--unlike other studies that used artificial versions.

"The findings demonstrate a proof of concept, and the next step is to demonstrate this technology in a microbial granular system containing Candidatus Scalindua sp. AMX11 bacteria and the other types of bacteria necessary for a full-scale wastewater treatment process," explains Saikaly.

The team is also working with a Saudi fertilizer company to test its bioprocess for treating industrial wastewater.

Maybe words such as ethyl butanoate and octalactone sound unfamiliar to most people who drink wine. However, these substances are some of the ones that give this popular drink its own scent. A recent piece of research published by the University of Cordoba and the Gheorghe Asachi Technical University in Romania identified a total of 17 key compounds in the aroma of red wine, made from a red grape variety harvested in the wine region in northeast Romania.

In the study, over 80 volatile compounds were analyzed. These compounds are chemical substances that greatly influence the sensory characteristics of wine and are also responsible for producing certain scents. According to the results, out of all the analyzed elements, 17 make up 95% of the total detected aroma, meaning they play a crucial role in wine fragrance.

As explained by one of the researchers in charge of the study at UCO, researcher Rafael Peinado, in order to arrive at this conclusion, gas mass chromatography techniques were applied. This method allows for separating and identifying volatile components present in complex mixtures.

These 17 key compounds are related to fruity, woody, toasted and citric aromas, among others. During the study, a kind of fingerprint was found of the different kinds of wine that were analyzed by means of grouping these volatiles in aroma families.

In search of alternative methods

Though most of the wine produced worldwide is aged in wood barrels, this aging process has some disadvantages compared to other alternative methods. Barrel aging means storing wine for long periods of time, anywhere from six months to several years. In addition, maintenance, handling the barrels and extracting wine are all labor intensive activities, which impact the final price of the wine.

In order to deal with this issue, some countries have been using alternative aging methods instead of barrels for some time now. One involves putting pieces of wood, usually oak, in a tank with wine. These pieces of wood vary in size: chips, cubes or staves, which are small boards of wood. This process aims to reduce the length of aging time and the amount of labor required in addition to providing traditional aging aromas, thus making it possible to put wine on the market in a shorter period of time.

In particular, the research, done in collaboration with the VITENOL group at the University of Cordoba, focuses on these kinds of wines. As pointed out by another head researcher on the study, Nieves López de Lerma, the project was able to establish a relation between this kind of wine's aroma and factors such as aging time, kinds of pieces and the degree to which the wood was toasted.

According to the study's conclusions, the wines that have the highest concentration of aromatic compounds were aged with oak staves, contributing to a higher concentration, a longer aging duration and higher degree of wood toasting.

Though it would be a mistake to extrapolate a priori all these conclusions for any kind of wine - as the study was performed using a specific grape variety and the wine was made with alternative methods other than the classic barrel ones- according to Peinado, the research could help guide a wine's organoleptic profile by making certain aroma combinations stronger. The results, therefore, could be used to obtain more affordable wines with a particular aromatic profile based on the tastes of those who drink them.

A new deep learning model developed by researchers at the University of Eastern Finland can identify sleep stages as accurately as an experienced physician. This opens up new avenues for the diagnostics and treatment of sleep disorders, including obstructive sleep apnoea.

Obstructive sleep apnoea (OSA) is a nocturnal breathing disorder that causes a major burden on public health care systems and national economies. It is estimated that up to one billion people worldwide suffer from obstructive sleep apnoea, and the number is expected to grow due to population ageing and increased prevalence of obesity. When untreated, OSA increases the risk of cardiovascular diseases and diabetes, among other severe health consequences.

The identification of sleep stages is essential in the diagnostics of sleep disorders, including obstructive sleep apnoea. Traditionally, sleep is manually classified into five stages, which are wake, rapid eye movement (REM) sleep and three stages of non-REM sleep. However, manual scoring of sleep stages is time-consuming, subjective and costly.

To overcome these challenges, researchers at the University of Eastern Finland used polysomnographic recording data from healthy individuals and individuals with suspected OSA to develop an accurate deep learning model for automatic classification of sleep stages. In addition, they wanted to find out how the severity of OSA affects classification accuracy.

In healthy individuals, the model was able to identify sleep stages with an 83.7% accuracy when using a single frontal electroencephalography channel (EEG), and with an 83.9% accuracy when supplemented with electrooculogram (EOG). In patients with suspected OSA, the model achieved accuracies of 82.9% (single EEG channel) and 83.8% (EEG and EOG channels). The single-channel accuracies ranged from 84.5% for individuals without OSA to 76.5% for severe OSA patients. The accuracies achieved by the model are equivalent to the correspondence between experienced physicians performing manual sleep scoring. However, the model has the benefit of being systematic and always following the same protocol, and conducting the scoring in a matter of seconds.

According to the researchers, deep learning enables automatic sleep staging for suspected OSA patients with a high accuracy. The study was published in IEEE Journal of Biomedical and Health Informatics.

The Sleep Technology and Analytics Group, STAG, at the University of Eastern Finland solves sleep diagnostics challenges by using a variety of different approaches. The methods developed by the group are based on wearable, non-intrusive sensors, better diagnostic parameters and modern computational solutions that are based on artificial intelligence. The new methods developed by the group are expected to significantly improve OSA severity assessment, promote individualised treatment planning and more reliable prediction of OSA-related daytime symptoms and comorbidities.

A new study from Harvard University and the Field Museum of Natural History sheds light on how and when changes in the spine happened in mammal evolution. The research reveals how a combination of developmental changes and adaptive pressures in the spines of synapsids, the extinct forerunners of mammals, laid the groundwork for the diversity of backbones seen in mammals today.

By comparing the biomechanics of two modern animals, cat and lizard, and CT scans of synapsid fossils, the researchers overturned the traditional notion that the gradual accumulation of different regions (or independent sections) of the spine alone account for its evolving complexity. New evidence suggests that regions (like the thorax and lower back) evolved long before new spinal functions, such as bending and twisting. The study points to the idea that the right selective pressures or animal behaviors combined with existing physical regions played a significant role in the evolution of their unique functions.

The findings by Stephanie Pierce, Associate Professor of Organismic and Evolutionary Biology and Curator of Vertebrate Paleontology at Harvard, and postdoctoral researcher Katrina Jones tap into the larger question of how mammals, including humans, evolved over millions of years.

Modern mammals, for instance, have developed compartmentalized spinal regions that take on a number of diverse shapes and functions without affecting other spinal regions. This has allowed the animals to adapt to different ways of life, explained Jones.

In previous research, the authors showed that extinct pre-mammalian land animals developed these small but distinct regions during evolution.

"What we were able to show in 2018 was that even though all the vertebrae looked very similar in early mammal ancestors they had subtle differences and those subtle differences created distinct developmental regions," Pierce said. "What we're showing with this new study is that those distinct regions were really important as they provided the raw material that facilitated functional differentiation to happen. Basically, if you don't have these distinct developmental regions in place and you have a selective pressure, all the vertebrae are going to adapt in the same way."

It's long been thought that developing different spinal regions is one important step in evolving backbones with many functions, but Pierce and Jones show that this isn't enough. An evolutionary trigger was also required, in this case the evolution of a highly active lifestyle that put new demands on the backbone.

Jones said, "We're trying to get at something that's quite a fundamental evolutionary question which is: How does a relatively simple structure evolve into a complex one that can do lots of different things? Is that determined by the limitations of development or natural selection related to the behavior of the animal?"

The researchers compared the spines of two animals essentially on opposite ends of the evolutionary and anatomical spectrum: cat, which has highly developed spinal regions, and lizard, which has a pretty uniform backbone. They looked at how each animal's spinal joints bent in different directions to measure how the form of the vertebrae reflects their function. They determined that while some spinal regions can function differently from one to the other, others do not; for example, the lizard's backbone comprised several distinct regions, but they all acted in the same way.

Researchers including Kenneth Angielczyk from the Field Museum of Natural History then turned their focus to finding out when different regions started taking on different functions in the evolution of mammals. They took the cat and lizard data showing that if two joints in the spine looked different, then they tended to have different functions. With that, they mapped out how spinal function in those fossils changed through time.

"The earliest ancestors of mammals have a remarkably good fossil record, considering that those animals lived between about 320 and 250 million years ago," Angielczyk said.

The researchers found that despite having developmental regions capable of performing different functions, the level of functional variation seen in mammals today did not start to take hold until late in synapsid evolution.

"We then hypothesized that maybe it was the evolution of some new mammalian behaviors that helped trigger this [in these late synapsids] and provided the natural selection that could exploit the regions that were already there," Jones said.

Their findings fit with observations that the group in which this functional diversity occurs -- the cynodonts, which directly preceded mammals -- have a number of mammalian features, including evidence they could breathe like a mammal. The researchers believe that these mammal-like features shifted the job of breathing away from the backbone and ribs to the newly evolved diaphragm muscle, releasing the spine from an ancient biomechanical constraint. This enabled the backbone to adapt to interesting new behaviors, such as grooming fur, and take on new functions.

The next step for Pierce and Jones is to clarify what those functions looked like in these extinct animals.

When choosing between multiple alternatives, people usually focus their attention on the two most promising options. The quicker we do that, the faster we make the decision. Psychologists from the University of Basel have reported these findings in the scientific journal Nature Human Behaviour.

How can we make quick yet efficient decisions in a world with ever more options and choices? This is the question that a team from the University of Basel's Center for Decision Neuroscience asked themselves. One key element for the researchers when tackling this challenge was identifying the attention of their participants, which were measured by recording eye movements with an eye tracker.

Choice of foods

In two experiments, 139 participants were asked to choose between three different foods that changed over multiple rounds. Based in these experiments, the psychologists determined that people did not distribute their attention equally, but increasingly focused on the two options that they found most promising. This led to faster decisions; the easier it was to discount the worst option, the more quickly the participant was able to decide between the two remaining options.

In earlier studies on this topic, participants were usually only given two options to choose between; in recent years, however, research has increasingly turned to decisions with three or more alternatives. This is because people can behave in many contradictory and inconsistent ways when multiple related options are available. For example, someone who initially selects chicken over pasta may change their preference when another vegetarian option such as salad is added - and may then suddenly find the pasta more appealing.

Ever more choices

Such inconsistencies when making decisions have important implications for decision theories in economics, psychology and neuroscience. On the basis of their new results, the Basel researchers have proposed a mathematical model that describes the dynamic interactions of preference formation and eye movements when making decisions between multiple alternatives.

"One goal of our research," says study leader Professor Sebastian Gluth, "is to understand how people act in a world with ever more options, as you have with online stores or large shopping malls." The results of the study should help to advance our understanding of decision-making in today's real-life environments: "Usually, we don't have to choose between an apple and an orange - but between tens or hundreds of different apples and oranges."

A multidisciplinary team of researchers at Japan's Tohoku University has found that a gene regulator, called BACH1, facilitates the spread of pancreatic cancer to other parts of the body. The scientists, who published their findings in the journal Cancer Research, say drugs that control BACH1 could improve disease prognosis.

"Pancreatic cancer is a malignant disease with one of the poorest prognoses," says biochemist Kazuhiko Igarashi, who led the study. "One of the reasons for this is that pancreatic cancer cells undergo rapid, profound metastasis to other organs, like the liver. We found how pancreatic cancer cells acquire this ability for metastasis."

Igarashi, surgeon-scientist Michiaki Unno and their team investigated the effects of silencing and over-expressing the BACH1 transcription factor in pancreatic cancer cells. Previous studies had already identified a role for this gene regulator in promoting breast cancer metastasis. But its role in pancreatic cancer was unknown. The team also grafted pancreatic cancer cells with and without the BACH1 gene disruption into mice. Finally, they studied BACH1 protein levels in human pancreatic cancer tissues and compared them to their survival rates.

Their investigations showed that BACH1 reduces the expression of some genes involved in cell-to-cell interaction, and enhances the expression of others that cause cells to lose their 'stickiness' to each other, making them more mobile and invasive.

For example, BACH1 was found to play a role in repressing the gene FOXA1 and activating the gene SNAI2, which ultimately leads to the suppression of a gene called CDH1. This gene codes for a protein called E-cadherin, one of the most important cell surface molecules involved in cell-to-cell adhesion.

"By reducing or abolishing BACH1 activity, the metastatic potential of pancreatic cancer cells was greatly reduced in a mouse model," adds Igarashi. "We also found that patients at Tohoku University Hospital showed poorer prognoses when their pancreatic cancer cells expressed higher levels of BACH1."

Further investigations into BACH1's roles in pancreatic cancer metastasis could lead to the development of therapeutic strategies that reduce metastasis and thus improve the prognosis for people with pancreatic cancer, Igarashi explains.

The team next plans to look for other genes targeted by BACH1 in pancreatic cancer cells, which could have effects other than promoting metastasis.

Scientists from the University of Bristol and Université Paris-Saclay have discovered a new class of material - non-sticky gels.

Until now gels have been made of particles that stick to one another to form a network.

The research team, whose findings are published in the journal Proceedings of the National Academy of Sciences, have now shown that networks and from and persist without the particles sticking to one another if the particles behave as liquid crystals.

Professor C Patrick-Royall, from the University of Bristol's School of Chemistry, said: "Networks of micron -- and sub-micron -- sized colloidal particles, gels, are absolutely the stuff of everyday life.

"They are found from cosmetics to food and even in biological tissue. Yet our understanding of colloidal gels lags far behind their utility: Gels are out-of-equilibrium, so their properties change over time, often with significant consequences, such as failure or collapse.

"However, until now, we were confident of one thing: To aggregate into a network, the colloidal particles need to attract one another."

Working with Dr Jeroen van Duijnevelt, also from Bristol, and Claudia Ferreiro-Cordova at Université Paris-Saclay, the team discovered that in fact the colloidal particles don't need to stick together to form gels.

This new class of material "non-sticky gels", forms when the colloids instead behave as a liquid crystal.

Liquid crystals, which are fundamental to display technology, are formed when the constituent molecules line up in one direction, while still remaining liquid.

Here, instead of molecules, the colloidal particles, made of sepiolite clay line up preferentially in one direction and form a highly viscous network like conventional colloidal gels, but without needing attractions between the particles to hold them together.

The particles form a microscopic network with a structure a bit like a bird's nest.

The researchers expect that their discovery will enable the development of new gel formulations with improved mechanical properties and longer shelf-life, which is a major limitation of many products today.

Researchers from Sechenov University and their colleagues summarised the results of various studies devoted to the process that can be described as bacterial cannibalism. Why some microorganisms start to kill their relatives of the same species and whether we can use this phenomenon to combat infectious diseases is explained in the article published in Antibiotics.

Allolysis is a phenomenon that happens when some bacterial cells kill their isogenic (genetically identical) neighbours under certain conditions. This process has been studied for almost two decades and scientists still have some gaps in their understanding of its biological role and its mechanisms. There are lots of questions that are yet to be answered: why do kin bacteria suddenly begin to kill each other, how do the "killers" survive (even though the toxins they produce are deadly for them too), are these toxins used only for kin killing or do they take part in other cellular processes as well? Finding the answers to these questions can help to develop new ways to affect crucial processes within cell communities, something that is especially important nowadays when antibiotics are becoming less and less effective.

"The understanding of how to manage the density of bacterial communities is exciting not only in terms of fundamental research. We believe that this knowledge will help us with developing brand-new antibacterial medicines", said one of the authors, Andrey Zamyatnin, director of the Institute for Molecular Medicine, Sechenov University.

There are several speculations about the reasons why under certain conditions one part of isogenic population acts as "killers" while the other falls "victim" to its relatives either willingly or unwillingly. The most obvious but maybe not the only correct one is that allolysis helps bacterial community to reduce its number when resources are insufficient and thus saves a small number of cells and the species itself. But there is another guess that earned the sympathy of most of the scientists: microorganisms do not need the death of their kin but rather fragments of their DNA available after bacteria's killing. Including these fragments in its genome, a cell can repair damaged or mutant parts or gain useful mutations, e.g. making it resistant to antibacterial drugs.

Researchers that studied allolysis among pneumococci (Streptococcus pneumoniae) suggested that these bacteria can benefit from the death of part of their population since it causes the prompt release of compounds that help bacteria adapt in the host's organism, e.g. pneumococcal pneumolysin. Other bacteria, such as hay bacillus (Bacillus subtilis), may use allolysis to postpone the beginning of sporulation process. When they don't have enough resources for living, bacteria can place their DNA into a spore that is resistant to adverse environmental conditions and thus save the species for many years, but the process of sporulation itself takes too much energy. Using the products of lysis of their relatives ("volunteer victims") for food, part of the population can prolong its existence for some time. Furthermore, allolysis may help communities of Paenibacillus dendritiformis to reduce the population density and prevent "overcrowding". It was also proved that cannibalism plays an important role in biofilm development, since DNA fragments of killed cells are crucial components of the biofilm matrix.

Discovery and study of phenomena similar to bacterial allolysis encourage us to review established concepts and paradigms in microbiology. The death of one part of the population for the benefit (survival) of the other lets scientists consider microbial communities as some kind of multicellular organism with clear differentiation of cells into specialised subpopulations and "division of labour": during starvation, some of them become victims and die while others act as killers and survive, saving the species itself. Such understanding of bacterial communities may help to develop brand new antibacterial drugs that will focus on the complicated system of interrelations within a community rather than on killing single bacterial cell which adapt quickly to any possible impact.

According to the hypothesis, axionic dark matter, provoking structural rearrangement in compact stars with a strong magnetic field, can protect them from a catastrophic loss of magnetic energy, but at the same time allows such objects to rotate abnormally fast.

"Dark matter is a cosmic substance that does not directly interact with photons, and all information about it was obtained by astronomers only indirectly, as a result of gravitational lensing of light from distant galactic sources," comments one of the co-authors, Professor at the Department of Relativity Theory and Gravitation Alexander Balakin. "It is believed that the total mass of dark matter is 23% of the total mass of the Universe. The particles that form dark matter are apparently axions - hypothetical ultralight pseudo-Goldstone bosons. Dozens of laboratories around the world are engaged in their search and identification, applying various approaches and technologies."

The work of Kazan physicists is based on a theoretical prediction that, surrounded by axions, a strong magnetic field generates an electric field, and in such a combined field subtle spectroscopic effects that are accessible to observation should appear.

"Astronomers have many questions when identifying rapidly rotating compact objects with an ultra-strong magnetic field. For example, if the magnetic field of such objects had a typical dipole structure, the so-called "magnetic ears" should have prevented such rapid rotation or even "come off," leading to a catastrophic rearrangement of the magnetic field and a huge loss of energy," said Balakin.

An article published by KFU scientists substantiates their hypothesis that magnetic stars surrounded by axionic dark matter can evolve according to an alternative "peaceful" scenario.

"Under the influence of the axion environment, the energy of the dipole component of the magnetic field is smoothly, without catastrophic losses, redistributed between the quadrupole, octupole and other components, the structure of which is much more compact and therefore does not interfere with the fast rotation of the star. In other words, axionic dark matter, as an ideal moderator, solves two problems at once: it saves full magnetic energy for a star and gives a compact star the ability to spin abnormally fast," concluded Professor Balakin.