Tech

LA JOLLA--(January 29, 2021) As scientists learn more about the microorganisms that colonize the body--collectively called the microbiota--one area of intense interest is the effect that these microbes can have on the brain. A new study led by Salk Institute scientists has identified a strain of E. coli bacteria that, when living in the guts of female mice, causes them to neglect their offspring.

The findings, published January 29, 2021, in the journal Science Advances, show a direct link between a particular microbe and maternal behavior. Although the research was done in mice, it adds to the growing body of science demonstrating that microbes in the gut are important for brain health and can affect development and behavior.

"To our knowledge, this is the first demonstration that the intestinal microbiota is important for promoting healthy maternal behavior and bonding between mom and offspring in an animal model," says Professor Janelle Ayres, Laboratory Head of Salk's Molecular and Systems Physiology Laboratory and senior author of the paper. "It adds to the ever-growing evidence that there's a gut-brain connection, and that microbes are important for regulating the behavior of the host that they're inhabiting."

The ways in which the microbiota can impact mental health and neurological disorders is a growing area of research. The makeup of the gut microbiota in people has been linked to depression, anxiety, autism and other conditions. But it has been difficult to study how individual strains of bacteria exert their influence on human behavior, a connection often called the microbiota-gut-brain axis.

In her lab, Ayres uses mice to study how body systems and the brain interact with each other to promote health. This includes focusing on how body processes are regulated by microbes and the ways in which microbes affect growth and behavior. In the current experiments, she and her team were investigating groups of mice that each had a single strain of E. coli in their gut. Mice with one particular strain of E. coli, called O16:H48 MG1655, mothered offspring that had stunted growth. Further examination revealed that the mice were smaller because they were malnourished.

"We found that the pups' behavior was normal, and the milk made by the mothers was of normal, healthy composition and was being produced in normal amounts," Ayres says. "We eventually figured out that being colonized with this particular bacteria led to poor maternal behavior. The mice were neglecting their pups."

Additional experiments revealed that the mice could be rescued from stunted growth, either by giving them a growth factor called IGF-1 or handing them off to foster mouse mothers that could take care of them properly. This confirmed that the cause of stunted growth was coming from the mothers' behavior rather than something in the pups themselves.

"Our study provides an unprecedented understanding of how the intestinal microbiota can disrupt maternal behavior and how this can negatively impact development of an offspring," says first author Yujung Michelle Lee, a former graduate student in Ayres' lab and now a postdoctoral fellow at Genentech. "It is very interesting to me that establishment of a healthy mother-infant relationship is driven by factors beyond hormones, and that the microorganisms residing in our bodies play a significant role in it."

Ayres and her team plan to study how these microbes provoke changes in mouse behavior. Early findings suggest the bacteria might be affecting levels of serotonin, the hormone associated with feelings of happiness and well-being, but more work is needed.

"It's very hard to study these relationships in humans, because the human microbiota contains hundreds of different species of microorganisms," says Ayres, who holds the Helen McLoraine Developmental Chair. "But once we understand more about the mechanisms in animal models, we may be able translate our findings to humans to determine whether the microbes and their effects might be the same."

The O16:H48 MG1655 strain has been found in human guts and was previously believed to have no positive or negative effects.

New research has revealed how an invasion of the alien evergreen tree, Prosopis juliflora seriously diminishes water resources in the Afar Region of Ethiopia, consuming enough of this already scarce resource to irrigate cotton and sugarcane generating some US$ 320 million and US$ 470 million net benefits per year.

A team of Ethiopian, South African and Swiss scientists, including lead author Dr Hailu Shiferaw, Dr Tena Alamirew, and Dr Gete Zeleke from the Water and Land Resource Centre of Addis Ababa University, Ethiopia, and Dr Sebinasi Dzikiti from Stellenbosch University, South Africa, and Dr Urs Schaffner, Head Ecosystems Management, CABI, have been assessing water use of prosopis and its impacts on catchment water budget and rural livelihoods in the dry Afar Region of Ethiopia, since 2015 as part of a long-term collaboration in the framework of the CABI-led Woody Weeds project.

Their new study, published in Scientific Reports, provides evidence that this alien tree, which has invaded both the floodplains of the Awash River and the surrounding dryland habitats, uses excessive amounts of water by consuming approximately 3.1-3.3 billion m3/yr of water throughout the year in the Afar Region.

Dr Shiferaw said, "We found that single trees of the evergreen prosopis consume between 1-36 liters of water per day, depending on stem diameter and site conditions. Prosopis trees not only use water throughout the year, but even consume more water during the dry season, when almost all native plants have shed their leaves. The high sap flow of prosopis in the drylands throughout the year may be due to exceptionally deep roots that penetrate up to 50m below the surface, where they tap into groundwater that cannot be used by native trees with shorter roots."

In the context of climate change and an increasing frequency of drought events in dry regions of Sub-Saharan Africa, the report concludes that this invasive tree is likely to have serious consequences for sustainable livelihoods in the region unless its spread is contained and its density reduced.

Dr Urs Schaffner, senior author and Head Ecosystems Management at CABI in Switzerland, said, "Since its introduction in the Afar Region in the 1980s, prosopis has invaded 1.2 million ha of land. Thus, unless the spread of prosopis is contained and the density reduced in areas where it has become established, this invasive tree is likely to have serious consequences for sustainable livelihoods in the region. The estimated net benefits from water savings alone would strongly justify the implementation of a coordinated control programme."

The report clearly supports findings from work undertaken in South Africa on water use by invasive tree species. Prof Brian van Wilgen from Stellenbosch University, South Africa, previous scientific advisor to the 'Working for Water' programme in South Africa and partner of the Woody Weeds project, said, "In South Africa, invasive alien trees are estimated to reduce surface water runoff by between 1.5 and 2.5 billion m3 per year, and this could increase substantially as the invasions continue to spread. In addition, invasive trees in drier parts of the country have substantially reduced water in groundwater aquifers on which local farmers and towns are totally reliant."

He further explained that, "These losses have serious consequences for a country where water scarcity limits economic activity and growth. The government in South Africa has responded by creating a multi-million dollar, national-scale programme, dubbed 'Working for Water', to control invasive alien trees, and has also passed legislation preventing further propagation of invasive alien trees and requiring landowners to control them."

Engineers at Tufts University have created and demonstrated flexible thread-based sensors that can measure movement of the neck, providing data on the direction, angle of rotation and degree of displacement of the head. The discovery raises the potential for thin, inconspicuous tatoo-like patches that could, according to the Tufts team, measure athletic performance, monitor worker or driver fatigue, assist with physical therapy, enhance virtual reality games and systems, and improve computer generated imagery in cinematography. The technology, described today in Scientific Reports, adds to a growing number of thread-based sensors developed by Tufts engineers that can be woven into textiles, measuring gases and chemicals in the environment or metabolites in sweat.

In their experiments, the researchers placed two threads in an "X" pattern on the back of a subject's neck. Coated with an electrically conducting carbon-based ink, the sensors detect motion when the threads bend, creating strain that changes the way they conduct electricity. When the subject performed a series of head movements, the wires sent signals to a small Bluetooth module, which then transmitted data wirelessly to a computer or smartphone for analysis.

The data analysis involved sophisticated machine learning approaches to interpret the signals and translate them to quantitate head movements in real time, with 93% accuracy. In this way, the sensors and processor track motion without interference from wires, bulky devices, or limiting conditions such as the use of cameras, or confinement to a room or lab space.

While algorithms will need to be specialized for each location on the body, the proof of principle demonstrates that thread sensors could be used to measure movement in other limbs, according to the researchers. The skin patches or even form-fitting clothing containing the threads could be used to track movement in settings where the measurements are most relelvant, such as in the field, the workplace, or a classroom. The fact that a camera is not needed provides for additional privacy.

"This is a promising demonstration of how we could make sensors that monitor our health, performance, and environment in a non-intrusive way," said Yiwen Jiang, an undergraduate student at Tufts University School of Engineering and first author of the study. "More work needs to be done to improve the sensors' scope and precision, which in this case could mean gathering data from a larger array of threads regularly spaced or arranged in a pattern, and developing algorithms that improve the quantification of articulated movement."

Other types of wearable motion sensor designs have included 3-axis gyroscopes, accelerometers and magnetometers to detect movement of the subject in relation to their surroundings. Those sensors are based on inertial measurements - quantifying how the body accelerates, rotates or moves up and down -and tend to be bulkier and more inconvenient. For example, with other systems, in order to measure head movement, it is necessary to place one sensor on the forehead and another on the neck above the vertebrae. The obtrusive placement of equipment can interfere with the subjects' free movement or simply the convenience of not being conscious of being measured.

For situations such as on the athletic field, the novel thread-based sensor paradigm could be a game changer. By placing thin tatoo-like patches on different joints, an athlete could carry motion sensors to detect their physical movement and form, while thread-based sweat sensors, described in earlier work by the Tufts team, could also potentially track their electrolytes, lactate and other biological markers of performance in sweat.

On the road, a thread sensor patch could alert to truck driver fatigue or other situations where tracking operator alertness is critical, monitoring the head movements of someone about to nod off.

"If we can take this technology further, there could be a wide range of applications in healthcare as well," said Jiang. "For example, those researching Parkinson's disease and other neuromuscular diseases could also track movements of subjects in their normal settings and daily lives to gather data on their condition and the effectiveness of treatments."

"The objective in creating thread-based sensors is to make them 'disappear' as far as the person wearing them is concerned," said Sameer Sonkusale, professor of electrical and computer engineering at Tufts' School of Engineering, director of the Tufts Nanolab, and corresponding author of the study. "Creating a coated thread capable of measuring movement is a remarkable achievement, made even more notable by the fact that Yiwen developed this invention as an undergraduate. We look forward to refining the technology and exploring its many possibilities."

The Covid-19 pandemic has made home offices, virtual meetings and remote learning the norm, and it is likely here to stay. But are people paying attention in online meetings? Are students paying attention in virtual classrooms? Researchers Jens Madsen and Lucas C. Parra from City College of New York, demonstrate how eye tracking can be used to measure the level of attention online using standard web cameras, without the need to transfer any data from peoples computers, thus preserving privacy. In a paper entitled "Synchronized eye movements predict test scores in online video education," published in the Proceedings of the National Academy of Sciences, they show that just by looking at students eyes they can predict how well students will do on quizzes based on educational videos.

"Experienced teachers pay close attention to their students, adjusting their teaching when students seem lost. This dynamic interaction is missing in online education," said Madsen. "But in our study, we proposed to measure attention to online videos remotely by tracking eye movements and hypothesized that attentive students follow videos similarly with their eyes."

The CCNY team, was able to show that inter-subject correlation of eye-movements during educational video presentation is substantially higher for attentive students, and that synchronized eye movement are predictive of individual test scores on the material presented in the video.

"These findings replicate for videos in a variety of production styles, learning scenarios and for recall and comprehension questions alike," noted Parra. "We were able to reproduce the results using standard web cameras to capture eye-movements in a classroom setting, and with over 1,000 participants at home, without the need to transmit user data."

Their results suggest that online education can be made adaptive to a student's level of attention in real-time. "The internet has turned attention into a commodity. With video content increasing online, remote sensing of attention to video at scale may have applications beyond education, including entertainment, advertising, or politics. The applications are limitless."

Scientists at Johannes Gutenberg University Mainz (JGU) and ETH Zurich have developed a process to produce commodity chemicals in a much less hazardous way than was previously possible. Such commodity chemicals represent the starting point for many mass-produced products in the chemical industry, such as plastics, dyes, and fertilizers, and are usually synthesized with the help of chlorine gas or bromine, both of which are extremely toxic and highly corrosive. In the current issue of Science, the researchers report that they have been able to utilize electrolysis, i.e., the application of an electric current, to obtain chemicals known as dichloro and dibromo compounds, which can then be used to synthesize commodity chemicals. "Chlorine gas and bromine are difficult to handle, especially for small laboratories, as they require strict safety procedures," said Professor Siegfried Waldvogel, spokesperson for JGU's cutting-edge SusInnoScience research initiative, which helped develop the new process. "Our method largely eliminates the need for safety measures because it does not require the use of chlorine gas or bromine. It also makes it easy to regulate the reaction in which the desired chemicals are synthesized by controlling the supply of electric current."

According to Professor Siegfried Waldvogel, electrolysis can be used to obtain dichloro and dibromo compounds for example from solvents that would ordinarily be used to produce PVC. "This is even much simpler than synthesizing dichloro and dibromo products from chlorine gas or bromine, respectively." The research team, he claims, has demonstrated that the novel process functions as intended for more than 60 different substrates. "The process can be used for molecules of different sizes and is thus broadly applicable. It is also easy to scale up, and we have already been able to employ it to transform larger quantities in the multi-gram range," Waldvogel added. The chemist is particularly enthusiastic about the discovery that electrolysis can also be used to separate chlorine atoms from molecules of certain insecticides that have been banned, yielding the desired dichloro products. "There is virtually no natural degradation of such insecticides," he pointed out. "They persist in the environment for extremely long periods and have now even been detected in the Arctic. Our process could help in eliminating such toxic substances and actually exploit them to our benefit in future."

There's a better end for used food than taking up space in landfills and contributing to global warming.

UC Riverside scientists have discovered fermented food waste can boost bacteria that increase crop growth, making plants more resistant to pathogens and reducing carbon emissions from farming.

"Beneficial microbes increased dramatically when we added fermented food waste to plant growing systems," said UCR microbiologist Deborah Pagliaccia, who led the research. "When there are enough of these good bacteria, they produce antimicrobial compounds and metabolites that help plants grow better and faster."

Since the plants in this experiment were grown in a greenhouse, the benefits of the waste products were preserved within a closed watering system. The plant roots received a fresh dose of the treatment each time they were watered.

"This is one of the main points of this research," Pagliaccia said. "To create a sustainable cycle where we save water by recycling it in a closed irrigation system and at the same time add a product from food waste that helps the crops with each watering cycle."

These results were recently described in a paper published in the journal Frontier in Sustainable Food Systems.

Food waste poses a serious threat to the planet. In the U.S. alone, as much as 50% of all food is thrown away. Most of this waste isn't recycled, but instead, takes up more than 20% of America's landfill volume.

This waste represents not only an economic loss, but a significant waste of freshwater resources used to produce food, and a misuse of what could otherwise feed millions of low-income people who struggle with food security.

To help combat these issues, the UCR research team looked for alternative uses for food waste. They examined the byproducts from two kinds of waste that is readily available in Southern California: beer mash -- a byproduct of beer production -- and mixed food waste discarded by grocery stores.

Both types of waste were fermented by River Road Research and then added to the irrigation system watering citrus plants in a greenhouse. Within 24 hours, the average population of beneficial bacteria were two to three orders of magnitude greater than in plants that did not receive the treatments, and this trend continued each time the researchers added treatments.

UCR environmental scientist Samantha Ying then studied nutrients such as carbon and nitrogen in the soil of the treated crops. Her analysis showed a spike in the amount of carbon after each waste product treatment, followed by a plateau, suggesting the beneficial bacteria used the available carbon to replicate.

Pagliaccia explained that this finding has an impact on the growth of the bacteria and on the crops themselves. "If waste byproducts can improve the carbon to nitrogen ratio in crops, we can leverage this information to optimize production systems," she said.

Another finding of note is that neither the beer mash nor the mixed food waste products tested positive for Salmonella or other pathogenic bacteria, suggesting they would not introduce any harmful element to food crops.

"There is a pressing need to develop novel agricultural practices," said UCR plant pathologist and study co-author Georgios Vidalakis. "California's citrus, in particular, is facing historical challenges such as Huanglongbing bacterial disease and limited water availability," said Georgios Vidalakis, a UCR plant pathologist.

The paper's results suggest using these two types of food waste byproducts in agriculture is beneficial and could complement the use synthetic chemical additives by farmers -- in some cases relieving the use of such additives altogether. Crops would in turn become less expensive.

Pagliaccia and Ying also recently received a California Department of Food and Agriculture grant to conduct similar experiments using almond shell byproducts from Corigin Solutions to augment crops. This project is also supported with funding from the California Citrus Nursery Board, Corigin Solutions, and by the California Agriculture and Food Enterprise.

"Forging interdisciplinary research collaborations and building public-private sector partnerships will help solve the challenges facing global agri-food systems," said UCR co-author Norman Ellstrand, a distinguished professor of genetics.

When companies enable growers to use food waste byproducts for agricultural purposes, it helps move society toward a more eco-friendly system of consumption.

"We must transition from our linear 'take-make-consume-dispose' economy to a circular one in which we use something and then find a new purpose for it. This process is critical to protecting our planet from constant depletion of natural resources and the threat of greenhouse gases," Pagliaccia said. "That is the story of this project."

Support for policies prohibiting smoking and the use of tobacco products on Oregon State University's Corvallis campus grew substantially over a five-year span, especially among tobacco users, a recent OSU study found.

The study, published earlier this month in the journal Preventive Medicine, is unique in its analysis of support for smoke- and tobacco-free campus policies over a long period of time. Most other studies of attitudes toward smoking policies only assess a single point in time.

"Tobacco-free policies are one of the most effective things we can do to reduce the burden of tobacco use, and they are highly supported and growing in popularity," said Marion Ceraso, co-author on the study and an associate professor of practice and Extension Specialist in OSU's College of Public Health and Human Sciences.

Tobacco use is still the leading cause of preventable death in the U.S., and people are most likely to start using tobacco in their adolescence and early 20s, so intervening during college years is crucial, she said.

"These policies are effective in several ways: They reduce exposure to secondhand smoke, prevent initiation and help people quit, especially when cessation support is accessible," Ceraso said.

The researchers used two surveys conducted at OSU, one in 2013 and one in 2018, that asked members of the campus community about their smoking and tobacco-use habits and their support for two separate policies: smoke-free campus and tobacco-free campus.

Smoke-free campus policies prohibit only combustible tobacco products, usually including vaping devices. Tobacco-free policies are broader, applying to any kind of tobacco product, including non-combustible products such as chew, snus and snuff.

OSU enacted a smoke-free campus policy in 2012, a few months before the first survey was conducted.

In the 2013 survey, 72% of students and 77% of faculty and staff were in favor of a smoke-free campus. Support was highest among non-tobacco users. Among self-reported tobacco users, only 36% of students and 29% of faculty and staff supported a smoke-free policy.

Five years later, overall support rose to 73% among students and 84% among faculty and staff. But approval among tobacco users jumped dramatically: The 2018 survey found 48% of students and 49% of faculty and staff supported the smoke-free policy.

Researchers found an even more dramatic shift in support for a fully tobacco-free campus. In 2013, only 19% of student tobacco users and 16% of faculty and staff tobacco users supported a tobacco-free policy. In 2018, those numbers rose to 35% and 28%, respectively.

Overall support for the tobacco-free policy grew significantly, too: from 52% to 62% among all students and from 59% to 70% among all faculty and staff. In 2019, in large part because of the positive responses in the 2018 survey, OSU enacted a tobacco-free policy that applies to its Corvallis and Bend campuses, county Extension offices and other locations.

The increased support among tobacco users was especially telling, said Marc Braverman, lead author on the study and a professor and Extension Specialist in the College of Public Health and Human Sciences.

"These policies hinder tobacco users from engaging in that practice, and yet, almost half of them think the university should be smoke-free," he said. "They are putting the health of the community over their own immediate convenience with regard to tobacco use."

Arguments for smoke-free spaces center on the effects of smoke on other people, so it's easier to make the case for smoke-free policies than for banning smokeless forms of tobacco, Braverman said.

"But the fact that tobacco-free policies are gaining support is an indication that tobacco is becoming less acceptable overall. It's just not standard anymore," he said. "There seems to be increasing acceptance of the view that universities can take steps to protect the health of their communities through comprehensive tobacco-free policies."

Ceramic matrix composites (CMCs) are incredibly strong materials used in jet engines, gas turbines, and cutting tools for nickel superalloys. Aluminum oxide (Al2O3) is hard and chemically inert, and tungsten carbide (WC) is used as a superhard material, but past efforts to create an Al2O3-WC CMC yielded unsatisfactory results. Recently, a study by Japanese scientists, published in Scientific Reports, shows that adding zirconium atoms results in improved Al2O3-WC CMCs.

Given the potential utility of Al2O3-WC CMCs as superhard materials, researchers around the world have tested several formulations to identify one with a high bending strength, which is a measure of the physical stress a material can be subjected to before it becomes permanently bent or broken. Previously, no group had developed an Al2O3-WC CMC with a bending strength greater than 1 gigapascal, which meant that those earlier Al2O3-WC CMCs could not outperform the existing CMC materials. In an attempt to achieve a greater bending strength, the aforementioned team of scientists from Japan carried out a study, which was led by scientists from Nagoya University, in collaboration with NGK Spark Plug Co., Ltd. In their study, the scientists experimented with adding in small amounts of zirconium dioxide (ZrO2) during the creation of Al2O3-WC CMCs. This addition yielded "superhard" Al2O3-WC CMCs with bending strengths greater than 2 gigapascals. As lead investigators Dr. Tomohiro Nishi and Dr. Katsuyuki Matsunaga note, "This is an all-time high in the field."

Notably, the investigators achieved these considerable bending strength improvements with a relatively modest addition of ZrO2. The additive represented less than 5% of the mass of the finished Al2O3-WC CMCs, which is less than the amount of additive usually present in additive-enhanced CMCs. When the investigators studied the structures of their superhard ZrO2-enhanced Al2O3-WC CMCs using a method called atomic-resolution scanning transmission electron microscopy, they found that the Zr atoms were located in thin layers between sheets of Al2O3 and WC. With respect to the interfaces between the Al2O3 and WC sheets, Dr. Nishi and Dr. Matsunaga state, "Such interfaces are generally weak points with respect to mechanical properties." Therefore, the interface between the sheets is a plausible location for Zr atoms to exert effects that strengthen the Al2O3-WC CMCs. Indeed, when the investigators modeled the effects of the Zr atoms using techniques from a field of mathematical physics known as density functional theory, their results indicated that an interfacial layer of Zr atoms would enhance the stability of their CMCs.

The investigators foresee a bright future for their novel CMCs. Commenting on their potential applications, Dr. Matsunaga states, "The materials we developed can be used as superhard materials in metalworking devices for cutting hard metallic components to be used in airplanes and automobiles." In fact, they note that engineers at NGK Spark Plug Co., Ltd. have already commercialized the materials as components in cutting tools.

The creation of these enhanced Al2O3-WC CMCs serves as an example of the considerable improvements in physical properties that can be achieved with relatively minor additions to a material.

A new paper in the Review of Economic Studies, published by Oxford University Press, finds that a generous parental leave policy nurses enjoyed in Denmark caused nursing shortages, which resulted in a decline in the quality of hospital and nursing home care. The study estimates a large increase in nursing home mortality.

Beginning in 1994 a parental-leave program in Denmark offered any parent the opportunity to take up to a full year off work, paid, for every child under the age of nine. The researchers find that many nurses in Denmark took advantage of this program. Nurses, however, could not be replaced on net despite the Danish government's efforts to expand education and immigration to cover the gap.

The researchers find that the parental leave program reduced hospital and nursing home nurse employment by 15% and 10%, respectively. This reduction resulted in a large increase in 30-day readmission rates among acute myocardial infarction patients (heart attack patients).

The researchers here also find large increases in nursing home mortality. One possible explanation, discussed in the study, is that the nurse reduction deteriorates the monitoring ability of nurses and an on-time response to adverse health shocks. The paper estimates suggest that a one percent reduction in nurse employment increases the one-year nursing home mortality rate among the elderly aged 85 and older by 1.9%.

Further estimates indicate that the cost of saving a statistical life year for an elderly nursing-home resident equals $17,600.

A key difference to studies on US health care markets is the role of tight labor market regulations in Denmark, which are prevalent in many developed countries, making it particularly difficult for hospitals and nursing homes to replace nurses on parental leave.

"Nurses are the largest health profession and play an integral role in the delivery of care, " said the paper's lead author, Benjamin Friedrich. "In this paper, we provide quantitative evidence on the adverse consequences for patient health when nurse shortages remain unaddressed, a topic of growing concern in many OECD countries. At the same time, we document that addressing nurse staffing needs may prove difficult in the short-term in particular when occupational licensing and wage regulations limit the ability of providers to retain and recruit nurses or to hire appropriate substitutes. As such, policy efforts should be made well ahead of time to address future shortages, particularly so in the context of stringent labor market regulations."

If you look deep into the eyes of a fish, it will tell you its life story.

Scientists from the University of California, Davis, demonstrate that they can use stable isotopic analysis of the eye lenses of freshwater fish -- including threatened and endangered salmon -- to reveal a fish's life history and what it ate along the way.

They conducted their study, published today in the journal Methods in Ecology and Evolution, through field-based experiments in California's Central Valley. The study carries implications for managing floodplains, fish and natural resources; prioritizing habitat restoration efforts; and understanding how landscape disturbances impact fish.

The technique had previously been used in marine environments, but this is its first use for freshwater fish, many of which are threatened or endangered in California. Lead author Miranda Bell Tilcock, an assistant specialist with the UC Davis Center for Watershed Sciences, helped pioneer the technique for freshwater fish.

"Even the nerdiest fish biologists say, 'You can do what with fish eyes?'" said co-author and team co-lead Rachel Johnson, a research fisheries biologist with NOAA Fisheries' Southwest Fisheries Science Center and associate with the UC Davis Center for Watershed Sciences. "This is an exciting new tool we can use to measure the value of different habitats and focus conservation work."

THE EYES HAVE IT

Much like tree rings, fish eyeballs are archival. The lenses grow in layers throughout a fish's life, recording as chemical signatures the habitats used while each layer was forming and locking in the dietary value of what the fish ate in each habitat.

"It's like a little diet journal the fish keeps for us, which is really nice," Tilcock said.

To uncover that history, researchers perform what Tilcock said is "like peeling the world's tiniest onion." With fine-tipped forceps, they remove layer after layer, revealing a veritable Russian nesting doll of eye lenses. At the end is a tiny ball, like what you'd find in a silica packet, that can shatter like glass. This is the core, where the fish's eyes first began to develop.

Relative to other archival tissue, fish eyeballs are especially rich in protein. The isotopic values in the food webs bind to protein in the eye, leaving tell-tale geochemical fingerprints that isotopic analysis can uncover.

HABITAT IN THE EYES OF THE BEHOLDER

The first field-based experiments using the technique for freshwater fish took place on the Yolo Bypass of California's Central Valley. Here, fall-run, juvenile chinook salmon grew in three distinct food webs: river, floodplain and hatchery.

Scientists then conducted stable isotope analyses on the eye lenses of an adult salmon to reveal its diet history from birth to death. Stable isotopes are forms of atoms that don't decay into other elements and are incorporated into a fish's tissue through its diet. They can be used to trace origins, food webs and migratory patterns of species.

Taking the premise of "you are what you eat," the study's authors looked at the chemical crumbs of carbon, nitrogen and sulfur values in the eye lenses to determine which food webs and habitats the fish used at various life stages.

They found that fish on the floodplain grew quickly and appeared to grow additional laminae, or layers of lenses, during the 39-day study compared to fish reared in the river or hatchery. Also, the Yolo Bypass is home to rice fields, which decompose to add unique sulfur and carbon values -- a strong clue for researchers tracing which habitats fish use.

"This tool is not just unique to salmon in the Central Valley," Tilcock said. "There are many migratory species all over the world that need freshwater habitat. If you can isolate their habitat and value for diet, you can quantify it for long-term success."

For example, co-author and team co-leader Carson Jeffres, field and lab director at UC Davis' Center for Watershed Science, used the technique recently on fish in Brazil to look at changes in the food web there following a dam's construction.

EYES AND EARS WORK TOGETHER

Tilcock, Johnson and Jeffres are part of an "Eyes and Ears" project at UC Davis funded by the California Department of Fish and Wildlife. The project studies fish life history through eye lenses and otoliths, which are found within a fish's ears.

"You use the otolith to trace the river or hatchery where a fish was born based on the unique geology and water chemistry of the tributaries in the San Francisco Bay watershed," Johnson said. "Then you have the eye lens, which tells you where it's eating to help identify floodplain habitats."

"They really work together to present a fuller picture of how salmon move and what they eat as they use different mosaics of habitats across the landscape over their lifetime" said Jeffres. "Now we have the tool we have been looking for to link juvenile floodplain benefits across the salmon life cycle to adulthood. It's the holy grail of measuring restoration success."

Researchers from Western University, Indiana University, and Washington State University published a new paper in the Journal of Marketing that uses the idea of psychological distance as a way to leverage qualities of existing consumer-brand relationships.

The study, forthcoming in the Journal of Marketing, is titled "They're Just Not That Into You: How to Leverage Existing Consumer-Brand Relationships through Social Psychological Distance" and is authored by Scott Connors, Mansur Khamitov, Matthew Thomson, and Andrew Perkins.

Marketing managers want consumers to form strong connections with their brands. This is reflected in the prevailing brand-management approaches that seek to continually move consumers from weak relationships to stronger ones where the consumer is more attached, connected to, or in love with a brand. But a scan of the marketplace and the branding literature makes it clear that such relationships are rare and that many consumers are relationship-averse or content with the status quo. That is, many consumers likely are unreceptive to marketers' relationship-strengthening tactics. The implication is that marketers are often fixated on building the types of relationships that countless consumers simply do not want, in essence choosing a potentially wasteful relationship-upgrading strategy unaligned with consumer preferences.

This study highlights the value for marketers to embrace the relationship status quo. As Connors explains, "We are the first to show advantages, like increased consumer spending, by employing communication tactics tailored to consumers' existing relationships with the brand. We focus on the idea of psychological distance as a way of conceptualizing how close to or far from a brand that consumers themselves feel. We build on the idea that nearly all current approaches to assessing the strength of consumer-brand relationships are tied to this psychological distance." Because it is such a pervasive idea, and because it can be measured robustly with a single, theoretically-informed item, psychological distance has exceptional practical power. For example, the research shows that if managers understand the psychological distance between consumers and brands, they can match that distance with different kinds of language in their marketing communications to form a mindset congruency. When the psychological distance to a brand and choice of language are congruent, information about that brand is more easily processed, which improves outcomes like brand spending and charitable donations. Khamitov adds, "Specifically, if consumers feel psychologically distant to a brand, we find they respond better to abstract, high-level language, whereas we find that concrete language is preferred among consumers who feel very close to a brand."

As an example, one of the studies finds that for more distant brands, donations were 67% higher when an advertisement featured high-level, abstract (compared to low-level, concrete) language, whereas for closer brands, donations were 88% higher when the ad featured low-level, concrete (as compared to high-level, abstract) language. Another study documents that for more distant brands, consumers paid 35% more for a product when they saw an ad featuring abstract (versus concrete) language, but for close brands, consumers paid 28% more when the ad featured concrete (versus abstract) language.

The research also identifies conditions that make these mindset-congruency effects more or less likely to emerge. For example, the mindset congruency effect operates only in conditions where consumers are at least modestly involved with a particular product category. "We surmise that consumers who are very uninvolved with a category simply do not care enough to pay attention to marketing communications about associated products. Similarly, if a brand already has a deeply entrenched position in the marketplace, such as where the brand is thought of as extremely competent or extremely warm, we find that consumers' perception of the brand resists updating. In those instances, no strategic alteration of marketing communications is likely to break through consumers' robust prior beliefs about the brand," says Thomson. Perhaps most interesting, for brands characterized predominantly by search attributes--those where qualities of the brand can be determined prior to purchase (versus experience attributes that require a consumer to use a brand to properly evaluate it)--the mindset congruency effect is reversed. In those instances, marketers should focus on abstract (concrete) language for close (distant) search brands.

Overall, the study's combination of field and lab studies presents a simple, yet powerful, theoretical and empirical account that allows marketers to leverage qualities of existing consumer-brand relationships rather than attempting the expensive and often ineffective strategy of 'upgrading' consumers into new and ever more committed relationships.

Our genetic codes control not only which proteins our cells produce, but also - to a great extent - in what quantity. This ground-breaking discovery, applicable to all biological life, was recently made by systems biologists at Chalmers University of Technology, Sweden, using supercomputers and artificial intelligence. Their research, which could also shed new light on the mysteries of cancer, was recently published in the scientific journal Nature Communications.

DNA molecules contain instructions for cells for producing various proteins. This has been known since the middle of the last century when the double helix was identified as the information carrier of life.

But until now, the factor which determines what quantity of a certain protein will be produced has been unclear. Measurements have shown that a single cell can contain anything from a few molecules of a given protein, up to tens of thousands.

With this new research, our understanding of the mechanisms behind this process, known as gene expression, has taken a big step forward. The group of Chalmers scientists have shown that most of the information for quantity regulation is also embedded in the DNA code itself. They have demonstrated that this information can be read with the help of supercomputers and AI.

Comparable to an orchestral score

Assistant Professor Aleksej Zelezniak, of Chalmers' Department of Biology and Biological Engineering, leads the research group behind the discovery.

"You could compare this to an orchestral score. The notes describe which pitches the different instruments should play. But the notes alone do not say much about how the music will sound," he explains.

Information for the tempo and dynamics of the music are also required, for example. But instead of written instructions such as allegro or forte in connection with the notation, the language of genetics spreads this information over large areas of the DNA molecule. "Previously, we could read the notes, but not how the music should be played. Now we can do both," states Aleksej Zelezniak.

"Another comparison could be that now we have found the grammar rules for the genetic language, where perhaps before we only knew the vocabulary."

What then is this grammar, which determines the quantity of gene expression? According to Aleksej Zelezniak, it takes the form of reoccurring patterns and combinations of the four 'notes' of genetics - the molecular building blocks designated A, C, G and T. These patterns and combinations are known as 'motifs'.

The crucial factors are the relationships between these motifs - how often they repeat and at exactly which positions in the DNA code they appear.

"We discovered that this information is distributed over both the coding and non-coding parts of DNA - meaning, it is also present in the areas that used to be referred to as 'junk DNA'."

A discovery that applies to all biological life

Although there are other factors that also affect cells' gene expression, according to the Chalmers researchers' study, the information embedded in the genetic code accounts for about 80 per cent of the process.

The researchers tested the method in seven different model organisms - from yeast and bacteria to fruit flies, mice, and humans - and found that the mechanism is the same. The discovery they have made is universal, valid for all biological life.

According to Aleksej Zelezniak, the discovery would have not been possible without access to state-of-the-art supercomputers and AI. The research group conducted huge computer simulations both at Chalmers University of Technology and other facilities in Sweden.

"This tool allows us to look at thousands of positions at the same time, creating a kind of automated examination of DNA. This is essential for being able to identify patterns from such huge amounts of data."

Jan Zrimec, postdoctoral researcher in the Chalmers group and first author of the study, agrees, saying:

"With previous technologies, researchers had to tell the system which motifs in the DNA code to search for. But thanks to AI, the system can now learn on its own, identifying different motifs and motif combinations relevant to gene expression."

He adds that the discovery is also due to the fact they were examining a much larger part of DNA in a single sweep than had previously been done.

Fast value for the pharmaceutical industry

Aleksej Zelezniak believes that the discovery will generate great interest in the research world, and that the method could become an important tool in several research fields - genetics and evolutionary research, systems biology, medicine, and biotechnology.

The new knowledge could also make it possible to better understand how mutations can affect gene expression in the cell and therefore, eventually, how cancers arise and function. The applications which could most rapidly be significant for the wider public are in the pharmaceutical industry.

"It is conceivable that this method could help improve the genetic modification of the microorganisms already used today as 'biological factories' - leading to faster and cheaper development and production of new drugs," he speculates.

RICHLAND, Wash.?Unless radon gas is discovered in a home inspection, most people remain blissfully unaware that rocks like granite, metal ores, and some soils contain naturally occurring sources of radiation. In most cases, low levels of radiation are not a health concern. But some scientists and engineers are concerned about even trace levels of radiation, which can wreak havoc on sensitive equipment. The semiconductor industry, for instance, spends billions each year to source and "scrub" ultra-trace levels of radioactive materials from microchips, transistors and sensitive sensors.

Now chemists at the U.S. Department of Energy's Pacific Northwest National Laboratory have developed a simple and reliable method that holds promise for transforming how ultra-trace elements are separated and detected. Low levels of troublesome naturally occurring radioactive elements like uranium and thorium atoms are often tucked among valuable metals like gold and copper. It has been extraordinarily difficult, impractical, or even impossible, in some cases, to tease out how much is found in samples of ore mined across the globe.

Yet sourcing materials with very low levels of natural radiation is essential for certain types of sensitive instruments and detectors, like those searching for evidence of currently undetected particles that many physicists believe actually comprise most of the universe.

"We are really pushing the envelope on detection," said chemist Khadouja Harouaka. "We want to measure very low levels of thorium and uranium in components that go into some of the most sensitive detectors in the world. It is particularly difficult to measure low levels of thorium and uranium in precious metals like the gold that goes into the electrical components of these detectors. With this new technique, we can overcome that challenge and achieve detection limits as low as 10 parts per trillion in gold."

That's like trying to find one four-leaf clover in about 100 thousand acres of clover?an area larger than New Orleans.

Colliding worlds of particles

The scientists locate their extraordinarily rare "four-leaf clover" atoms from the huge field of ordinary atoms by sending their samples through a series of isolation chambers. These chambers first filter and then collide the rare atoms with simple oxygen, creating a "tagged" molecule of a unique molecular weight that can then be separated by its size and charge.

The effect is like finding a way to tie a helium balloon to each target thorium or uranium atom so that it floats above the sea of gold sample and can be counted. In this case, the sophisticated counter is a mass spectrometer. The research is featured on the cover of the December 2020 issue of Journal of Analytical Atomic Spectrometry.

The central innovation is the collision cell chamber, where charged atoms of thorium and uranium react with oxygen, increasing their molecular weight and allowing them to separate from other overlapping signals that can disguise their presence.

"I had an aha moment," said Greg Eiden, the original PNNL inventor of the patented collision cell, which is used to perform these reactions, thereby reducing unwanted interference in the instrument readout by a factor of a million. "It was this miracle chemistry that gets rid of the bad stuff you don't want in your sample so you can see what you want to see."

In the current study, Harouaka and her mentor Isaac Arnquist leveraged Eiden's work to tease out the vanishingly small number of radioactive atoms that can nonetheless ruin sensitive electronic detection equipment.
Among other uses, the innovation may allow chemists, led by senior chemist Eric Hoppe and his team at PNNL, to further hone the chemistry that produces the world's purest electroformed copper. The copper forms a key component of sensitive physics detectors, including those used for international nuclear treaty verification.

Neutrino listening tour

Stanford physicist Giorgio Gratta helps lead a global quest to capture evidence for the fundamental building blocks of the universe. The nEXO experiment, now in the planning stages, is pushing the detection boundaries for evidence of these elusive particles, called Majorana Fermions. The signals they seek come from exceedingly rare events. To detect such an event, the experiments require exquisitely sensitive detectors that are free of stray radiation pings introduced through the materials that make up the detector. That includes the metals in the electronics required to record the exceedingly rare events that trigger detection.

"PNNL is a global leader in ultra-trace radiation detection," said Gratta. "Their unique mix of innovation and application provide an important contribution that enables sensitive experiments like nEXO."

Physicist Steve Elliott of Los Alamos National Laboratory emphasized the lengths to which researchers must go to ensure a scrupulously clean environment for rare particle detection.

"In experimental programs where even human fingerprints are too radioactive and must be avoided, techniques to measure ultra-low radioactive impurity levels are critical," he said, adding that this method could provide an important way to source materials for another of the next generation of rare neutrino event detectors, called LEGEND, being planned for deployment in an underground location in Europe.

Cleaning semiconductors and quantum computers

Semiconductors, the basic building blocks of modern electronics, including integrated circuits, microchips, transistors, sensors and quantum computers are also sensitive to the presence of stray radiation. And the innovation cycle demands each generation pack more and more into ever tinier microchips.

"As the architecture gets smaller and smaller, radiation contamination is an ever-bigger issue that manufacturers have been working around by changing the architecture inside the chips," said Hoppe. "But there's only so far you can go with that, and you really start to become limited by the purity of some of those materials. The industry has set targets for itself that right now it can't achieve, so having a measurement technique like this could make some of those targets achievable."

More broadly, Eiden added, "in the big world of the periodic table there's probably applications for any element that you care about. And what Eric, Khadouja and Isaac are going after here is analyzing any trace impurity in any ultra-pure material."

When it comes to drones, the Singapore public is not as keen for them to be used to provide services around their living spaces, finds a study by researchers at the Nanyang Technological University, Singapore (NTU Singapore). However, they are more accepting of drones being used in areas like recreational spots or industrial areas.

There is growing global interest in the use of drones to provide a range of applications - from building inspection to last mile commercial delivery - that promise productivity gains and cost reductions.

In Singapore, the use of drones is picking up, with the government adopting them for various projects in the Smart Nation drive, where technology is used for direct and positive impact on people's lives.

Against this backdrop, an interdisciplinary research team led by Associate Professor Lim Beng Chong from the Nanyang Business School and Professor Low Kin Huat from the School of Mechanical & Aerospace Engineering carried out a study to better understand public attitudes towards the technology.

The study showed that while the Singapore public is ready for extensive drone application in the country, acceptance levels differed significantly depending on the context of use. The public is least welcoming towards drones when flown above residential estates but tend to be more embracing when they are used in industrial zones.

The NTU study was conducted from April to June 2019, using a globally recognised survey model. It involved 1,050 Singaporeans and permanent residents aged 21 to 80.

"We can expect drones to become commonplace in our daily lives in future," said Assoc Prof Lim. "It is thus important for policymakers, businesses, and regulators to understand how the public feels about the technology, as its acceptance levels will have a direct impact on the scope and pace of adoption. Our work can guide efforts to introduce drone use, by providing insights into public perceptions that are specific to a highly urbanised environment like Singapore, including suggestions on how to improve acceptance levels."

Published online in the scientific journal Technology in Society in December 2020, this is believed to be the first study on the perceptions of drone use in a highly urbanised environment in Asia.

Fears and concerns surrounding drone use

Previous studies have focused on drone use in western countries and did not consider the context of drone applications in different contexts. The NTU study looked at public acceptance of drone use in four different types of urban space - residential, recreational, industrial, and commercial areas. It also included the function of the drone (i.e., what it is used for) and its operators.

The NTU research team found that the Singapore public is more accepting of drone use by government, commercial and industrial users than by private individuals. Drones for the purpose of search and rescue by authorities was most welcomed (92%), but the public approved less of commercial and industrial players using drones to transport people (62%). Overall, the study found support for private use is lower than for most other purposes.

The study identified two critical factors influencing public acceptance of drone use. First, the fears and concerns of the public. Among the top four worries indicated by participants were, in descending order: the misuse of drones by unauthorised personnel; inability to identify whether drones are ?lming or not; drones being a threat to one's physical safety if parts of it fall; and the loss of privacy.

Second, the perception of the benefits of the technology. The public believe the technology is more beneficial when used for consumers, the economy and improving workplace safety, but less so for improving neighbourhood security.

The findings highlight that the public differentiates where and how drones are being used. Therefore, the NTU research team said, communication and educational strategies should be adapted and customised to the contexts of drone applications, to effectively improve public acceptance.

For example, when educating the public about drone use in residential areas, the information might be focused on the safety of drone use, instead of its purported benefits.

"Drone technology represents a promising industry with many more uses being developed every day," said Prof Low, co-author, and drone expert from the School of Mechanical & Aerospace Engineering.

"By understanding the relationship between the factors influencing public acceptance and the context of drone use, developers and the authorities can focus their attention on specific things that are problematic to the public. If it is a fear of falling parts when drones are flown in residential areas for example, developers can work on ways to demonstrate that their parts will not become detached. Or the authorities can map out and regulate safe flying routes such as over housing estate rooftops, thus contributing to a better public reception for drones," he said.

Across many animal species there is great evolutionary pressure on males, who often engage in combat for the rights to copulation. This phenomenon, called sexual selection, often ends up favoring males with larger weapons, such as horns or pincers. Interestingly, scientists have noted that males endowed with smaller weapons adopt alternative reproductive tactics in some species. For example, instead of fighting other more powerful males, they may try to sneak around or disperse in search of a lonely female.

Variability in sexual behavior according to a male's weapon size has been widely studied. However, it's worth noting that bigger is not always better. Though larger weapons usually help in fights for reproductive rights, they can also be a hinderance because they lower the animal's overall mobility. This has been proven in males of a species of Japanese rhinoceros beetle, who fall prey to predators more easily when their horns, which they use as weapons, are bigger. Could it be that, just as males with smaller weapons adopt alternative sexual tactics, males with larger weapons adopt different anti-predator strategies?

In a recent study published in Biology Letters, a team of scientists from Okayama University, Japan, proved that this is most likely the case. Led by Professor Takahisa Miyatake, they focused on a species of beetle called Gnathocerus cornutus, the males of which bear large mandibles as weapons for male-on-male combat. When threatened, G. cornutus exhibits two very distinct behaviors: escape or tonic immobility, also called death feigning. The team investigated whether differences in weapon size caused males to behave differently when faced by a predator.

They obtained nearly two hundred male G. cornutus beetles from a laboratory and conducted two types of experiments. First, they pitted male beetles against one of their natural predators, a jumping spider. When attacked by the spider, most beetles froze in place, which seemed to cause the spider to quickly lose interest. On the other hand, the beetles that tried to struggle or run away were repeatedly attacked by the spider and killed. These initial experiments proved that tonic immobility is a useful anti-predator strategy.

In the second series of experiments, the researchers measured the size of the mandibles of male beetles and then tried to get them to exhibit tonic immobility by gently touching their abdomen with a thin stick. Unlike previous behavioral studies, which exclusively focused on the duration of tonic immobility once triggered, the team also quantified the frequency of tonic immobility. Whereas no statistical relationship was found between weapon size and tonic immobility duration, a link was very apparent between weapon size and frequency; individuals with larger mandibles were generally more prone to exhibit tonic immobility when stimulated. Excited about the results, Dr. Kentarou Matsumura remarks: "For animals that fight with weapons, the costs of having larger weapons are well known. However, this is the first time we have scientifically determined that anti-predator tactics can vary among males according to their weapon size."

The results and the research strategy adopted by the team will help biologists unravel the mysteries of the evolution of behaviors, as Miyatake explains: "As the first study of predator-avoidance tactics in animals that have weapons for male-to-male fighting, we believe this is an opportunity to delve deeper on the relationship between the evolution of weapons and anti-predator behavior." Miyatake also states that these new discoveries will spawn a new research topic in the evolution of survival tactics, which in turn will increase our overall scientific understanding of this challenging field in the future.

What other fascinating evolutionary secrets could be hiding out there in the behaviors of different animals? Let us hope this study acts as a springboard for finding the answers!