Tuesday, January 19, 2021

Glass frogs living near roaring waterfalls wave hello to attract mates

UC Berkeley conservationist discovers the first evidence of visual communication among tropical glass frogs

UNIVERSITY OF CALIFORNIA - BERKELEY

Berkeley -- Most frogs emit a characteristic croak to attract the attention of a potential mate. But a few frog species that call near loud streams -- where the noise may obscure those crucial love songs -- add to their calls by visually showing off with the flap of a hand, a wave of a foot or a bob of the head. Frogs who "dance" near rushing streams have been documented in the rainforests of India, Borneo, Brazil and, now, Ecuador.

Conservation ecologist Rebecca Brunner, a Ph.D. candidate at the University of California, Berkeley, has discovered that the glass frog Sachatamia orejuela can be added to the list of species that make use of visual cues in response to their acoustic environments. This is the first time a member of the glass frog family (Centrolenidae) has been observed using visual communication in this manner.

"A handful of other frog species around the world use visual signaling, in addition to high-pitched calls, to communicate in really loud environments," Brunner said. "What's interesting is that these species are not closely related to each other, which means that these behaviors likely evolved independently, but in response to similar environments -- a concept called convergent evolution."

Sachatamia orejuela glass frogs are native to the rainforests of Ecuador and Colombia. They are especially unique because they are almost exclusively found on rocks and boulders within the spray zones of waterfalls, where rushing water and slippery surfaces offer some protection against predators, and their green-gray color and semi-transparent skin make them nearly impossible to spot. As a result, little is known about this species' mating and breeding behavior.

Brunner, who studies the bioacoustics of different ecological environments, was chest-deep in an Ecuadorean rainforest stream recording the call of a Sachatamia orejuela when she first observed this visual signaling behavior. As soon as she saw the frog repeatedly raising its front and back legs, Brunner climbed a slippery rock face and balanced on one foot to get video footage of the behavior.

"I was already over the moon because I had finally found a calling male after months of searching. Before our publication, there was no official record of this species' call, and basic information like that is really important for conservation," Brunner said. "But then I saw it start doing these little waves, and I knew that I was observing something even more special."

While she filmed, the frog continued to wave its hands and feet and bob its head. She also observed another male Sachatamia orejuela glassfrog a few meters away performing the same actions.

"This is a really exhilarating discovery because it's a perfect example of how an environment's soundscape can influence the species that live there. We've found that Sachatamia orejuela has an extremely high-pitched call, which helps it communicate above the lower-pitched white noise of waterfalls. And then to discover that it also waves its hands and feet to increase its chances of being noticed -- that's a behavior I've always loved reading about in textbooks, so it is beyond thrilling to be able to share another amazing example with the world," said Brunner.

Though the COVID-19 pandemic has put a pause on Brunner's fieldwork, she hopes to return to Ecuador soon to continue her research, which links bioacoustics and conservation.

"One of the best things about fieldwork is that nature is always full of surprises -- you never know what discoveries you may happen upon," Brunner said. "I hope our findings can serve as a reminder that we share this planet with incredible biodiversity. Conserving ecosystems that support species like Sachatamia orejuela is important not only for our well-being, but also for our sense of wonder."

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Juan M. Guayasamin, professor of biology at Universidad San Francisco de Quito, is a co-author of this research, which appears in the journal Behaviour. Brunner's fieldwork was supported by a National Geographic Explorer Grant (EC-57058R-19) and a National Science Foundation Graduate Research Fellowship.

Youtube video: https://www.youtube.com/watch?v=U6prmVIyxXI&feature=emb_title

Large mammals make soil more fertile in tropical forests

A study conducted by scientists at São Paulo State University demonstrates that animals like peccaries and tapirs boost soil levels of nitrogen, an essential element to plant growth.

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO

Research News

IMAGE: ANIMALS LIKE PECCARIES AND TAPIRS BOOST SOIL LEVELS OF NITROGEN, AN ESSENTIAL ELEMENT TO PLANT GROWTH view more
CREDIT: JOÃO PAULO KRAJEWSKI

The White-lipped peccary Tayassu pecari is a boar-like hoofed mammal found throughout Central and South America. These animals roam the forest in bands of 50 to 100 individuals, eating a wide variety of foods. In Brazil's Atlantic Rainforest, they prefer the fruit of the jussara palm Euterpe edulis.

The jussara is very abundant in this biome, probably thanks to vast amounts of dung, urine, and soil trampling by peccaries as well as tapirs (Tapirus terrestris) and other fruit-eating animals, or frugivores. This behavior releases forms of nitrogen, a key element in plant growth.

A study supported by São Paulo Research Foundation - FAPESP and published in the journal Functional Ecology showed that in areas free of these frugivores the level of ammonium, a form of nitrogen in soil, was up to 95% lower. The findings evidence for the first time the importance of these animals to the nitrogen cycle and serve as yet another warning of the ecosystem losses caused when large mammals disappear from tropical forests.

"Any farmer knows how crucial the nitrogen cycle is to achieve high crop yields. Studies in other environments have already shown that the presence of ruminants stimulates the growth of grasses thanks to the effect of their excretions on the nitrogen cycle, including optimization of microorganism activity. Our latest study has now shown that large fruit-eating mammals provide the same service in tropical forests," said Nacho Villar, first author of the article. Villar is a researcher affiliated with São Paulo State University's Institute of Biosciences (IB-UNESP) in Rio Claro, Brazil. Currently he is a postdoctoral fellow at the Netherlands Institute of Ecology (NIOO-KNAW).

The study also shows that these animals redistribute nitrogen, fertilizing areas that would otherwise be nutrient-poor, and hence sustain plant growth. According to the researchers' estimates, such areas receive four times more ammonium and 50 times more nitrate than areas without frugivores.

The study was part of the Thematic Project "Ecological consequences of defaunation in the Atlantic Rainforest", for which the principal investigator was Mauro Galetti, a professor at IB-UNESP, and was conducted under the auspices of FAPESP's Research Program on Biodiversity Characterization, Conservation, Restoration and Sustainable Use (BIOTA-FAPESP)).

The researchers used South America's leading herbivore exclosure experiment, comprising 86 forest plots measuring 15 square meters in Serra do Mar State Park (São Paulo State), Brazil's largest continuous Atlantic Rainforest reserve. Half the plots have been fenced since 2010 to prevent the entry of large mammals. All animals can roam freely into and out of the other plots.

Camera traps on fenced and open plots demonstrated the presence or absence of White-lipped peccaries, Collared peccaries (Pecari tajacu) and tapirs, among other frugivores.

Microorganisms, ammonium and nitrate

In this study, the researchers analyzed soil samples from eight exclusion plots and their paired open controls, collected in the wet and dry seasons. Jussara palm abundance varied across the different plots.

In soil from open plots, ammonium levels were 95% higher, and rates of nitrification (conversion of ammonium to nitrate) were also higher owing to the frugivore-driven abundance of microorganisms in the soil. Although plants absorb ammonium, their metabolism can immediately use nitrate, which is therefore considered more valuable in terms of plant growth.

"Peccaries account for 80% to 90% of the total mammal biomass in the Atlantic Rainforest. Large groups of these animals roam extensive territories, fertilizing the forest," Villar said. "Tapir density is lower, so their contribution to the nitrogen cycle isn't as great, but the amount excreted by each individual is considerable, as is each animal's range as it disperses seeds." Another study by the same group had already shown how peccaries and tapirs contribute to plant species diversity and abundance (read more at: https://agencia.fapesp.br/31840).

This large frugivore biomass is attracted by the vast amount of fruit from jussara palms, whose abundance is due to fertilization of the soil by the animals' excretions (which also probably increase the palms' fruit-bearing capacity). The outcome is a virtuous cycle for animals, plants and soil microorganisms (also stimulated by the excretions), leading the researchers to propose the term "fruiting lawns" as a description of such areas. The term is considered analogous to the concept of grazing lawns, which refers to the positive feedback between ruminant food consumption and food availability in African savannas and other grassland landscapes.

The next steps in the group's research will include investigating whether the increase in nitrogen due to plants' interaction with large mammals boosts their carbon absorption and reduces the release of greenhouse gases from the soil. If so, plant-animal interaction should play a major role in regulating global climate change.

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About São Paulo Research Foundation (FAPESP)

The São Paulo Research Foundation (FAPESP) is a public institution with the mission of supporting scientific research in all fields of knowledge by awarding scholarships, fellowships and grants to investigators linked with higher education and research institutions in the State of São Paulo, Brazil. FAPESP is aware that the very best research can only be done by working with the best researchers internationally. Therefore, it has established partnerships with funding agencies, higher education, private companies, and research organizations in other countries known for the quality of their research and has been encouraging scientists funded by its grants to further develop their international collaboration. You can learn more about FAPESP at http://www.fapesp.br/en and visit FAPESP news agency at http://www.agencia.fapesp.br/en to keep updated with the latest scientific breakthroughs FAPESP helps achieve through its many programs, awards and research centers. You may also subscribe to FAPESP news agency at http://agencia.fapesp.br/subscribe.

Designer cytokine makes paralyzed mice walk again

Paraplegia

RUHR-UNIVERSITY BOCHUM

Research News

The researchers published their report in the Journal Nature Communications from 15 January 2021.

When the communication breaks down

Spinal cord injuries caused by sports or traffic accidents often result in permanent disabilities such as paraplegia. This is caused by damage to nerve fibers, so-called axons, which carry information from the brain to the muscles and back from the skin and muscles. If these fibers are damaged due to injury or illness, this communication is interrupted. Since severed axons in the spinal cord can't grow back, the patients suffer from paralysis and numbness for life. To date, there are still no treatment options that could restore the lost functions in affected patients.

Designer protein stimulates regeneration

In their search for potential therapeutic approaches, the Bochum team has been working with the protein hyper-interleukin-6. "This is a so-called designer cytokine, which means it doesn't occur like this in nature and has to be produced using genetic engineering," explains Dietmar Fischer. His research group already demonstrated in a previous study that hIL-6 can efficiently stimulate the regeneration of nerve cells in the visual system.

In their current study, the Bochum team induced nerve cells of the motor-sensory cortex to produce hyper-Interleukin-6 themselves. For this purpose, they used viruses suitable for gene therapy, which they injected into an easily accessible brain area. There, the viruses deliver the blueprint for the production of the protein to specific nerve cells, so-called motoneurons. Since these cells are also linked via axonal side branches to other nerve cells in other brain areas that are important for movement processes such as walking, the hyper-interleukin-6 was also transported directly to these otherwise difficult to access essential nerve cells and released there in a controlled manner.

Applied in one area, effective in several areas

"Thus, gene therapy treatment of only a few nerve cells stimulated the axonal regeneration of various nerve cells in the brain and several motor tracts in the spinal cord simultaneously," points out Dietmar Fischer. "Ultimately, this enabled the previously paralyzed animals that received this treatment to start walking after two to three weeks. This came as a great surprise to us at the beginning, as it had never been shown to be possible before after full paraplegia."

The research team is now investigating to what extent this or similar approaches can be combined with other measures to optimize the administration of hyper-Interleukin-6 further and achieve additional functional improvements. They are also exploring whether hyper-interleukin-6 still has positive effects in mice, even if the injury occurred several weeks previously. "This aspect would be particularly relevant for application in humans," stresses Fischer. "We are now breaking new scientific ground. These further experiments will show, among other things, whether it will be possible to transfer these new approaches to humans in the future."

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Funding

The German Research Foundation funded the study.

Original publication

Marco Leibinger, Charlotte Zeitler, Philipp Gobrecht, Anastasia Andreadaki, Günter Gisselmann, Dietmar Fischer: Transneuronal delivery of hyper-IL-6 enables functional recovery after severe spinal cord injury in mice, in: Nature Communications, 2021, DOI: 10.1038/s41467-020-20112-4,
https://rdcu.be/cdCob

Disclaimer: AAAS and EurekAlert

Artificial Intelligence beats us in chess, but not in memory

The brain strategy for storing memories is more efficient than AI's one, a new study reveals

SCUOLA INTERNAZIONALE SUPERIORE DI STUDI AVANZATI

Research News

IMAGE: THE BRAIN STRATEGY FOR STORING MEMORIES MAY LEAD TO IMPERFECT MEMORIES, BUT IN TURN, ALLOWS IT TO STORE MORE MEMORIES, AND WITH LESS HASSLE THAN AI. view more
CREDIT: SHAHAB MOHSENIN

In the last decades, Artificial Intelligence has shown to be very good at achieving exceptional goals in several fields. Chess is one of them: in 1996, for the first time, the computer Deep Blue beat a human player, chess champion Garry Kasparov. A new piece of research shows now that the brain strategy for storing memories may lead to imperfect memories, but in turn, allows it to store more memories, and with less hassle than AI. The new study, carried out by SISSA scientists in collaboration with Kavli Institute for Systems Neuroscience & Centre for Neural Computation, Trondheim, Norway, has just been published in Physical Review Letters.

Neural networks, real or artificial, learn by tweaking the connections between neurons. Making them stronger or weaker, some neurons become more active, some less, until a pattern of activity emerges. This pattern is what we call "a memory". The AI strategy is to use complex long algorithms, which iteratively tune and optimize the connections. The brain does it much simpler: each connection between neurons changes just based on how active the two neurons are at the same time. When compared to the AI algorithm, this had long been thought to permit the storage of fewer memories. But, in terms of memory capacity and retrieval, this wisdom is largely based on analysing networks assuming a fundamental simplification: that neurons can be considered as binary units.

The new research, however, shows otherwise: the fewer number of memories stored using the brain strategy depends on such unrealistic assumption. When the simple strategy used by the brain to change the connections is combined with biologically plausible models for single neurons response, that strategy performs as well as, or even better, than AI algorithms. How could this be the case? Paradoxically, the answer is in introducing errors: when a memory is effectively retrieved this can be identical to the original input-to-be-memorized or correlated to it. The brain strategy leads to the retrieval of memories which are not identical to the original input, silencing the activity of those neurons that are only barely active in each pattern. Those silenced neurons, indeed, do not play a crucial role in distinguishing among the different memories stored within a same network. By ignoring them, neural resources can be focused on those neurons that do matter in an input-to-be-memorized and enable a higher capacity.

Overall, this research highlights how biologically plausible self-organized learning procedures can be just as efficient as slow and neurally implausible training algorithms.

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Study: X-Rays surrounding 'Magnificent 7' may be traces of sought-after particle

Researchers say they may have found proof of theorized axions, and possibly dark matter, around group of neutron stars

DOE/LAWRENCE BERKELEY NATIONAL LABORATORY

Research News

IMAGE: AN ARTISTIC RENDERING OF THE XMM-NEWTON (X-RAY MULTI-MIRROR MISSION) SPACE TELESCOPE. A STUDY OF ARCHIVAL DATA FROM THE XMM-NEWTON AND THE CHANDRA X-RAY SPACE TELESCOPES FOUND EVIDENCE OF HIGH LEVELS... view more
CREDIT: D. DUCROS; ESA/XMM-NEWTON, CC BY-SA 3.0 IGO

A new study, led by a theoretical physicist at the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), suggests that never-before-observed particles called axions may be the source of unexplained, high-energy X-ray emissions surrounding a group of neutron stars.

First theorized in the 1970s as part of a solution to a fundamental particle physics problem, axions are expected to be produced at the core of stars, and to convert into particles of light, called photons, in the presence of a magnetic field.

Axions may also make up dark matter - the mysterious stuff that accounts for an estimated 85 percent of the total mass of the universe, yet we have so far only seen its gravitational effects on ordinary matter. Even if the X-ray excess turns out not to be axions or dark matter, it could still reveal new physics.

A collection of neutron stars, known as the Magnificent 7, provided an excellent test bed for the possible presence of axions, as these stars possess powerful magnetic fields, are relatively nearby - within hundreds of light-years - and were only expected to produce low-energy X-rays and ultraviolet light.

"They are known to be very 'boring,'" and in this case it's a good thing, said Benjamin Safdi, a Divisional Fellow in the Berkeley Lab Physics Division theory group who led a study, published Jan. 12 in the journal Physical Review Letters, detailing the axion explanation for the excess.

Christopher Dessert, a Berkeley Lab Physics Division affiliate, contributed heavily to the study, which also had participation by researchers at UC Berkeley, the University of Michigan, Princeton University, and the University of Minnesota.

If the neutron stars were of a type known as pulsars, they would have an active surface giving off radiation at different wavelengths. This radiation would show up across the electromagnetic spectrum, Safdi noted, and could drown out this X-ray signature that the researchers had found, or would produce radio-frequency signals. But the Magnificent 7 are not pulsars, and no such radio signal was detected. Other common astrophysical explanations don't seem to hold up to the observations either, Safdi said.

If the X-ray excess detected around the Magnificent 7 is generated from an object or objects hiding out behind the neutron stars, that likely would have shown up in the datasets that researchers are using from two space satellites: the European Space Agency's XMM-Newton and NASA's Chandra X-ray telescopes.

Safdi and collaborators say it's still quite possible that a new, non-axion explanation arises to account for the observed X-ray excess, though they remain hopeful that such an explanation will lie outside of the Standard Model of particle physics, and that new ground- and space-based experiments will confirm the origin of the high-energy X-ray signal.

"We are pretty confident this excess exists, and very confident there's something new among this excess," Safdi said. "If we were 100% sure that what we are seeing is a new particle, that would be huge. That would be revolutionary in physics." Even if the discovery turns out not to be associated with a new particle or dark matter, he said, "It would tell us so much more about our universe, and there would be a lot to learn."

Raymond Co, a University of Minnesota postdoctoral researcher who collaborated in the study, said, "We're not claiming that we've made the discovery of the axion yet, but we're saying that the extra X-ray photons can be explained by axions. It is an exciting discovery of the excess in the X-ray photons, and it's an exciting possibility that's already consistent with our interpretation of axions."

If axions exist, they would be expected to behave much like neutrinos in a star, as both would have very slight masses and interact only very rarely and weakly with other matter. They could be produced in abundance in the interior of stars. Uncharged particles called neutrons move around within neutron stars, occasionally interacting by scattering off of one another and releasing a neutrino or possibly an axion. The neutrino-emitting process is the dominant way that neutron stars cool over time.

Like neutrinos, the axions would be able to travel outside of the star. The incredibly strong magnetic field surrounding the Magnificent 7 stars - billions of times stronger than magnetic fields that can be produced on Earth - could cause exiting axions to convert into light.

Neutron stars are incredibly exotic objects, and Safdi noted that a lot of modeling, data analysis, and theoretical work went into the latest study. Researchers have heavily used a bank of supercomputers known as the Lawrencium Cluster at Berkeley Lab in the latest work.

Some of this work had been conducted at the University of Michigan, where Safdi previously worked. "Without the high-performance supercomputing work at Michigan and Berkeley, none of this would have been possible," he said.

"There is a lot of data processing and data analysis that went into this. You have to model the interior of a neutron star in order to predict how many axions should be produced inside of that star."

Safdi noted that as a next step in this research, white dwarf stars would be a prime place to search for axions because they also have very strong magnetic fields, and are expected to be "X-ray-free environments."

"This starts to be pretty compelling that this is something beyond the Standard Model if we see an X-ray excess there, too," he said.

Researchers could also enlist another X-ray space telescope, called NuStar, to help solve the X-ray excess mystery.

Safdi said he is also excited about ground-based experiments such as CAST at CERN, which operates as a solar telescope to detect axions converted into X-rays by a strong magnet, and ALPS II in Germany, which would use a powerful magnetic field to cause axions to transform into particles of light on one side of a barrier as laser light strikes the other side of the barrier.

Axions have received more attention as a succession of experiments has failed to turn up signs of the WIMP (weakly interacting massive particle), another promising dark matter candidate. And the axion picture is not so straightforward - it could actually be a family album.

There could be hundreds of axion-like particles, or ALPs, that make up dark matter, and string theory - a candidate theory for describing the forces of the universe - holds open the possible existence of many types of ALPs.

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The study was supported by the U.S. Department of Energy Office of Science Early Career Research Program; Advanced Research Computing and the Leinweber Graduate Fellowship at the University of Michigan, Ann Arbor; the National Science Foundation; the Mainz Institute for Theoretical Physics (MITP) of the Cluster of Excellence PRISMA+; the Munich Institute for Astro- and Particle Physics (MIAPP) of the DFG Excellence Cluster Origins; and the CERN Theory department.

Founded in 1931 on the belief that the biggest scientific challenges are best addressed by teams, Lawrence Berkeley National Laboratory and its scientists have been recognized with 14 Nobel Prizes. Today, Berkeley Lab researchers develop sustainable energy and environmental solutions, create useful new materials, advance the frontiers of computing, and probe the mysteries of life, matter, and the universe. Scientists from around the world rely on the Lab's facilities for their own discovery science. Berkeley Lab is a multiprogram national laboratory, managed by the University of California for the U.S. Department of Energy's Office of Science.

DOE's Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science.

Journal of Clinical Sleep Medicine collection highlights 15 years of scientific discovery

AMERICAN ACADEMY OF SLEEP MEDICINE

Research News

DARIEN, IL - Editors of the Journal of Clinical Sleep Medicine have identified some of the most significant articles in the publication's history, publishing new commentaries on them in a special 15th anniversary collection. The 15 commentaries from associate editors and members of the journal's editorial board describe the impact of the selected articles both at the time of their publication and today.

"The collection highlights some of the most influential publications in clinical sleep research over the past 15 years," JCSM Editor-in-Chief Dr. Nany Collop said. "These studies underscore the remarkable breadth of our field and display the intellectual curiosity and scientific rigor of talented sleep researchers."

First published by the American Academy of Sleep Medicine in 2005, JCSM has grown significantly from its first year, when 22 original articles were published. In 2020 the monthly journal published more than 200 scientific investigations and case reports. The 15th anniversary collection highlights peer-reviewed, original research papers on sleep disorders such as obstructive sleep apnea, insomnia, narcolepsy, and restless legs syndrome. The selected papers also cover other wide-ranging topics including opioids, school start times, caffeine, melatonin, and the impact of binge-watching on sleep.

The most highly cited article is on sleep deprivation: "Behavioral and physiological consequences of sleep restriction," written by Banks and Dinges in 2007. In the commentary, AASM Past President Dr. Nathaniel Watson and sleep scientist Hans Van Dongen, who has a doctorate in chronobiology and sleep, write that this landmark review "crystallized the problem of short sleep from basic science to epidemiology."

Collop and the journal's founding editor, Dr. Stuart Quan, assessed the most-cited and viewed articles, which associate editors helped narrow to the final selection of 15 studies. An expert on each manuscript topic was invited to prepare a commentary on the paper, describing its impact and influence since its original publication.

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The 15th anniversary collection -- comprising the 15 selected articles and the related commentaries along with an introduction from Drs. Collop and Quan -- is available on the JCSM website.

To request a copy of any study or commentary in the Journal of Clinical Sleep Medicine 15th anniversary collection, or to arrange an interview with an author or an AASM spokesperson, please contact the AASM at 630-737-9700 or media@aasm.org.

The monthly, peer-reviewed Journal of Clinical Sleep Medicine is the official publication of the American Academy of Sleep Medicine, a professional membership society that advances sleep care and enhances sleep health to improve lives. The AASM encourages patients to talk to their doctor about sleep problems and visit SleepEducation.org for more information about sleep, including a searchable directory of AASM-accredited sleep centers.

Managing large-scale construction projects to avoid cost overruns

News from the Journal of Marketing

AMERICAN MARKETING ASSOCIATION

Researchers from University of Stavanger, University of Melbourne, and University of Wisconsin-Madison published a new paper in the Journal of Marketing that examines how major projects undertaken by temporary organizations can be better managed so that cost overruns are minimized.

The study forthcoming in the Journal of Marketing is titled "Mobilizing the Temporary Organization: The Governance Roles of Selection and Pricing" and is authored by Elham Ghazimatin, Erik Mooi, and Jan Heide.

When consumers return to the skies again, they may do so in Boeing's 787 Dreamliner. But the project, or "temporary organization," created to make this plane a reality ran much over-budget and created significant dissatisfaction among Boeing's customers. Such cost overruns are a common outcome of major engineering and construction projects. In fact, studies show that nine out of ten have significant cost overruns, with overruns above 100 percent quite common. The implications of cost overruns go beyond financial metrics and can include reputational damage, litigation, and future overreliance on rigid and formalized relationship features.

Managing suppliers and subcontractors, who can run into the hundreds in major projects, is an enormously difficult task. It necessitates considerable coordination and monitoring in a context where parties often have not worked together, they lack shared procedures or rules, and there is a great need to get up to speed quickly. As one of Boeing's engineers put it, "The importance of thorough planning, accounting for all interdependencies, cannot be overestimated."

Through studying 429 completed construction projects, the researchers find that supplier selection and pricing format decisions that reflect key characteristics of the project, such as the size of the project, duration, and type of customer, are best at reducing a significant part of the cost overruns observed. They conduct "what-if" analyses to show that the reductions in costs can be substantial. Ghazimatin adds that "We also show that the benefits from getting selection right outweigh those that result from getting pricing right, suggesting that selection should be, relatively speaking, a higher strategic priority for a firm. "

This study is particularly useful to managers who wish to minimize cost overruns in projects. Pricing and selection decisions, which are typically fixed at the start of a project, are predictive of cost overruns that can only be observed after a project is completed, typically after many months or years. The pricing and selection aspects studied--fixed vs. variable pricing and selection on price vs. ability--were proposed by industry representatives and thus have direct managerial relevance. Results also show that simple managerial heuristics, such as only relying on price-based selection or deploying fixed pricing, are unlikely to be effective at minimizing cost overruns.

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Full article and author contact information available at: https://doi.org/10.1177%2F0022242920982545

Dairy product purchasing differs in

households with and without children

Households with children reported purchasing larger quantities of and higher-fat fluid milk compared to households without children, according to research in JDS CommunicationsTM

ELSEVIER

Research News

IMAGE: A NEW STUDY PUBLISHED IN JDS COMMUNICATIONS FOUND THAT HOUSEHOLDS WITH CHILDREN REPORTED PURCHASING LARGER QUANTITIES AND HIGHER-FAT DAIRY PRODUCTS COMPARED TO HOUSEHOLDS WITHOUT CHILDREN. view more
CREDIT: JDS COMMUNICATIONS

Champaign, IL, January 15, 2021 - American dairy consumers are often influenced by a variety of factors that can affect their buying habits. These factors include taste, preference, government information, cultural background, social media, and the news. In an article appearing in JDS Communications, researchers found that households that frequently bought food for children are interested in dairy as part of their diet and purchased larger quantities of fluid milk and more fluid milk with a higher fat content.

To assess the purchasing habits of households that purchase food for children versus those that do not, researchers from Purdue University and Oklahoma State University collected data through an online survey tool, Qualtrics. Respondents, required to be 18 years of age or older, were asked a variety of questions to collect demographic information and dairy product purchasing behavior from US residents. Kantar, an online panel database, was used to obtain participants through their opt-in panel database. "The sample was targeted to be representative of the US population in terms of sex, age, income, education, and geographical region of residence as defined by the US Census Bureau (2016)," said author Mario Ortez, PhD student at Purdue University in West Lafayette, IN, USA.

The survey received a total of 1,440 responses to be assessed. Per the results, 511 respondents indicated they frequently purchased food specifically for children, whereas 929 indicated they did not. Of the 1,440 respondents, 521 indicated that they had at least one child in the household, and 912 indicated they did not have children in their household. The study found that households that frequently purchased food for children generally purchased larger quantities of fluid milk, along with their chosen fluid milk having a higher fat content. Households with children also bought yogurt more frequently than other households.

Other findings from the survey indicated that cheese and milk are most often purchased for part of a meal, and yogurt is bought most frequently as a snack. The survey also found that households largely reported reviewing product attributes of price, expiration date, and nutritional information (in that order) on egg, milk, and meat labels.

"This study demonstrates the continued belief among American consumers that dairy products are an important part of a healthy diet fed to children. The popularity of whole milk, cheese, and yogurt within these households suggests that children enjoy the taste of dairy products and are happy to have them served during regular meals and at snack time," said Matthew Lucy, PhD, Editor-in-Chief of JDS Communications, University of Missouri, Columbia, MO, USA. These findings can influence product marketing efforts and stakeholder decisions in the dairy industry.

"Future studies can build on this work by evaluating whether there is a spillover effect from purchasing specifically for children and the general dairy and protein product purchasing habits of those households," said Dr. Courtney Bir, PhD, coauthor of the study and assistant professor, Oklahoma State University, Stillwater, OK, USA.

Policy makers and companies can use this information to help inform product labeling and better target necessary segments to increase product awareness and better the dairy industry as a whole.

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Snakes evolve a magnetic way to be resistant to venom

UNIVERSITY OF QUEENSLAND

Research News

IMAGE: THE SUDANASE RED SPITTING COBRA, ANOTHER PREDATOR ANALYSED IN DR FRY'S STUDY. view more
CREDIT: BONNERSCAR

Certain snakes have evolved a unique genetic trick to avoid being eaten by venomous snakes, according to University of Queensland research.

Associate Professor Bryan Fry from UQ's Toxin Evolution Lab said the technique worked in a manner similar to the way two sides of a magnet repel each other.

"The target of snake venom neurotoxins is a strongly negatively charged nerve receptor," Dr Fry said.

"This has caused neurotoxins to evolve with positively charged surfaces, thereby guiding them to the neurological target to produce paralysis.

"But some snakes have evolved to replace a negatively charged amino acid on their receptor with a positively charged one, meaning the neurotoxin is repelled.

"It's an inventive genetic mutation and it's been completely missed until now.

"We've shown this trait has evolved at least 10 times in different species of snakes."

CAPTION

The Pakistan black cobra, a deadly predator of other snakes.

The researchers found that the Burmese python - a slow-moving terrestrial species vulnerable to predation by cobras - is extremely neurotoxin resistant.

"Similarly, the South African mole snake, another slow-moving snake vulnerable to cobras, is also extremely resistant," Dr Fry said.

"But Asian pythons which live in trees as babies, and Australian pythons which do not live alongside neurotoxic snake-eating snake, do not have this resistance.

"We've long known that some species - like the mongoose - are resistant to snake venom through a mutation that physically blocks neurotoxins by having a branch-like structure sticking out of the receptor, but this is the first time the magnet-like effect has been observed."

"It has also evolved in venomous snakes to be resistant to their own neurotoxins on at least two occasions."

The discovery was made after the establishment of UQ's new $2 million biomolecular interaction facility, the Australian Biomolecular Interaction Facility (ABIF).

"There's some incredible technology at the ABIF allowing us to screen thousands of samples a day," Dr Fry said.

"That facility means we can do the kinds of tests that would have just been science fiction before, they would have been completely impossible."

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The research has been published in Proceedings of the Royal Society B (DOI: 10.1098/rspb.2020.2703).

The Australian Biomolecular Interaction Facility (ABIF) was funded through a $1 million Australian Research Council Linkage Infrastructure, Equipment and Facilities (LIEF) grant, with $1 million contributing funding from UQ, Griffith University, Queensland University of Technology, James Cook University, and the University of Sunshine Coast.

Guppies have varying levels of self-control

UNIVERSITY OF EXETER

Research News

Just like humans trying to stick to New Year's resolutions, guppies have varying levels of self-control, a new study shows.

Researchers from the University of Exeter and Ghent University studying the behaviours of Trinidadian guppies tested "inhibitory control" (suppressing unhelpful impulses or urges).
The tiny fish first learned how to swim into a cylinder to get food - then a cover was removed to make the cylinder transparent.

Inhibitory control was measured by whether a guppy resisted the urge to swim directly towards the food - bumping into the cylinder - or still swam around, relying on previous learning.

The findings revealed "consistent individual variation" - some guppies had more self-control than others.

"Studies of inhibitory control have traditionally focussed on a few bird and mammal species, but we now know it exists in a wide range of animals," said Dr Alessandro Macario, of Exeter's Centre for Research in Animal Behaviour.

"As well as finding consistent differences between individual guppies, the population of guppies we studied were, on average, half as able to control impulses as a different strain of guppies tested in a previous study under similar conditions.

"We can't be certain about the causes of this difference, but it's possible that the strain we studied had evolved in different social and environmental conditions - with less need for inhibitory control."

The study examined captive females, with each guppy tested multiple times.

In total, the fish inhibited the urge to swim directly at the food in 28.5% of trials.

No improvement was seen over time, but the researchers say this might have occurred if the guppies had been tested for longer.

Professor Darren Croft, also of the University of Exeter, said: "Our study is a first step towards understanding how inhibitory control has evolved in guppies.

"Guppies live in small rivers alongside predators so, for example, they might need the ability to hide and resist the urge to leave that hiding place to get food.

"The next step in this research is to examine the extent to which this trait affects guppies' chances of survival or reproduction."

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The paper, published in the Journal of Fish Biology, is entitled: "Intraspecific variation in inhibitory motor control in guppies, Poecilia reticulata."

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