It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Ithaca, NY--Famous for their uncanny ability to imitate other birds and even mechanical devices, researchers find that Australia's Superb Lyrebird also uses that skill in a totally unexpected way. Lyrebirds imitate the panicked alarm calls of a mixed-species flock of birds while males are courting and even while mating with a female. These findings are published in the journal Current Biology.
"The male Superb Lyrebird creates a remarkable acoustic illusion," says Anastasia Dalziell, currently a Cornell Lab of Ornithology Associate and recent Cornell Lab Rose Postdoctoral Fellow, now at the University of Wollongong, Australia. "Birds gather in mobbing flocks and the ruckus they make is a potent cue of a predator nearby. The lyrebird recreates that sound when a potential mate tries to leave a displaying male without copulating, or during copulation itself. These two moments are key to male reproductive success, suggesting that mimicking a mobbing flock is a crucial sexual behavior for males."
Dalziell says while it's not clear exactly how males benefit from their extraordinary mimicry, they seem to be setting a "sensory trap" for females. The males may gain a reproductive advantage by tricking the female into responding as if she may be at risk from a predator.
"It's a bit like saying, 'Baby, it's dangerous out there. Stay here with me,'" Dalziell says. The stalling tactic might allow for copulation to happen in the first place or last longer, preventing females from leaving before sperm has been successfully transferred.
The findings also suggest that elaborate bird songs aren't always an honest signal. Instead, sexual conflict and deception could lead to increasingly elaborate mimetic vocalizations. This idea represents an important departure from conventional explanations for song evolution that rely on females' preferences for extravagant male singers.
The researchers have lots of other questions about the odd mating behaviors of the Superb Lyrebird. For example, Dalziell says, they've observed that during copulation, the male holds his wings over the female's head. "Are males 'blindfolding' females to prevent females from detecting the male's deception?" she wonders.
CAPTION
Female Superb Lyrebird
CREDIT
Alex Maisey, University of Wollongong
This work was supported by the Cornell Lab of Ornithology Rose Postdoctoral Fellowship Program, the National Science Foundation, the Australian National University, the University of Wollongong, the Hawkesbury Institute for the Environment, the Australian Research Council, BirdLife Australia's Stuart Leslie Award program, and the Australian Geographic Society.
Reference: Anastasia Dalziell, Alex C. Maisey, Robert D. Magrath, and Justin A. Welbergen. Male lyrebirds create an acoustic illusion of a mobbing flock during courtship and copulation. Current Biology, Feb. 2021. DOI: 10.1016/j.cub.2021.02.003.
Internet fiber optics could provide valuable insight into geological phenomena
IMAGE: BIRD'S EYE VIEW OF THE FIBER-OPTIC CABLES USED FOR THE FORESEE PROJECT IN WHICH SCIENTISTS USED PRE-EXISTING CABLES TO MONITOR GEOLOGICAL EVENTS. view more
CREDIT: FORESEE, PENN STATE
Fiber-optic cables run underneath nearly all city grids across the United States and provide internet and cable TV to millions, but what if those systems could also provide valuable information related to hazardous events such as earthquakes and flooding? A team of researchers at Penn State have found they can do just that.
The scientists are using fiber-optic distributed acoustic sensing (DAS) technology to turn existing telecommunication infrastructure that is already installed underground into a valuable resource for monitoring ground vibrations.
"We discovered the fibers could pick up a wide variety of signal vibrations, from thunderstorms to human walking steps to music concerts," said Tieyuan Zhu, assistant professor of geophysics at Penn State and principal investigator on the project. "We can even distinguish the specific song at a concert by the patterns of the high and low tones. That's a great demonstration of the sensitivity of these sensors."
Traditional seismic monitoring devices, called geophones, are difficult to deploy in urban areas. Obtaining permission and space to install sensors, protecting sensors against theft and vandalism, and the high costs to maintain them makes it prohibitive to gain reliable long-term data, the scientists said.
DAS technology allows scientists to plug into unused fiber, called dark fiber, greatly reducing the cost and setup time that hinders traditional seismic monitoring devices. A laser interrogator unit simply needs to be plugged into one end of a stretch of fiber to begin collecting data, the scientists said.
"Several experiments in California have been carried out by teams using existing telecommunication infrastructure," Zhu said. "But deploying this technology on the East Coast is important because we have very special geology here."
The soil and shallow bedrock in the Allegheny Mountains region create complex near-surface geophysical properties. The underlying bedrock can slowly dissolve due to circulating groundwater, which can form sinkholes and caverns. Especially in urban areas, sinkhole collapse and settling issues can threaten human safety and property. In addition, strong seasonal variations in temperature and precipitation create a very different environment to that of California.
Zhu and his research team created the Penn State Fiber-Optic foR Environmental SEnsEing (FORESEE) project, the first deployment of the DAS technology in the eastern U.S. The goal of this project was to address the long-standing challenge of real-time monitoring of environmental and subsurface physical, chemical and biological changes in urban areas. FORESEE also aims to develop the DAS fiber sensing arrays to turn the Penn State University Park campus and surrounding areas into a living lab for the collection of high-resolution data on environmental, energy and infrastructure systems. The researchers report their results in Solid Earth.
The team gained access to dark fiber-optic cables beneath the campus and converted the cable to 2,300 seismic sensors using DAS. They then continuously recorded ground vibration data along the 3-mile stretch starting in April 2019. The experiment generated many tens of terabytes of data, which was stored in a network-attached storage server. The server was then connected to an internet network, providing the scientists with remote data access in real time. The density of the DAS recordings provided extraordinary resolution that enabled insight into their cause and allowed the researchers to distinguish between various signals, the scientists said.
The preliminary results suggest DAS has the capability to sense broadband vibrations and discriminate between the seismic signatures of different earthquakes and anthropogenic sources from events such as mining blasts, vehicles, music concerts and walking steps.
But DAS does not come without limitations. Traditional geophones have three components, two horizontal sensors and one vertical sensor, allowing them to capture vibrations in all directions. DAS technology, however, is only able to sense vibrations horizontally as there is no need for vertical sensors in fiber-optic cables meant for internet and cable. Therefore, the data is not as comprehensive as data from traditional geophones.
"We know this is a limitation," Zhu said. "Hopefully in the next five years, this can be overcome by new fiber-optic technology."
In addition to its geological uses, DAS can yield insights into varying patterns of human activities relevant to public health and urban planning. Traffic monitoring and redirection that does not require private cell phone data, gunshot detection, industrial noise pollution monitoring and subsurface water utility monitoring may all be improved through the use of DAS technology, the scientists said. The value of DAS has also been recognized in inaccessible and harsh environments, enabling offshore ocean observations and the ability to monitor permafrost stability in the Arctic.
Now that the researchers know what the technology can do, Zhu said their next step is using DAS to monitor smaller events long-term, like the underground movements that lead to sinkholes and flooding. They also want to look at the events that occur where the atmosphere meets the earth since there is currently no way to monitor how a thunderstorm's energy impacts the solid earth's near surface.
"DAS arrays utilizing existing telecommunication fibers can play an increasing role in the development of resilient, sustainable cities," Zhu said.
###
Other contributing researchers included Junzhu Shen, doctoral student, and Sam Hone, graduate student, both in geosciences at Penn State; and Eileen R. Martin, assistant professor of computational mathematics at Virginia Tech.
The U.S. Department of Energy partially supported this work.
Post-wildfire landslides becoming more frequent in southern California
American Geophysical Union U.S. Geological Survey Joint Release
WASHINGTON--Southern California can now expect to see post-wildfire landslides occurring almost every year, with major events expected roughly every ten years, a new study finds. The results show Californians are now facing a double whammy of increased wildfire and landslide risk caused by climate change-induced shifts in the state's wet and dry seasons, according to researchers who mapped landslide vulnerability in the southern half of the state.
"This is our attempt to get people thinking about where these hazards are going to be before there's even a fire," said Jason Kean, a hydrologist at the U.S. Geological Survey in Denver and lead author of the new study in Earth's Future, AGU's journal for interdisciplinary research on the past, present and future of our planet and its inhabitants. "By proactively thinking about hazards, you can start to develop more detailed response plans for their inevitability."
Damage from a major post-wildfire landslide that occurred on 9 January 2018 near Montecito, Santa Barbara County as a result of the 2017 Thomas Fire. Credit: USGS/Jason Kean.
Wildfires make the landscape more susceptible to landslides when rainstorms pass through, as the water liquefies unstable, dry soil and burned vegetation. Geologists routinely conduct landslide hazard assessments after wildfires occur, but there is often not enough time between a fire and a rainstorm to implement an effective emergency response plan, Kean said.
In the new study, Kean and his colleague combined historical fire, rainfall and landslide data with computer simulations to forecast where post-wildfire landslides are likely to occur in southern California, how big those landslides might be and how often they can be expected to happen. Their goal was to map which regions of the state are most vulnerable to landslides before they happen, in a manner similar to how geologists map earthquake hazards.
Their results show small landslides can now be expected to occur almost every year in southern California. Major landslides capable of damaging 40 or more structures can be expected every 10 to 13 years - about as frequently as magnitude 6.7 earthquakes occur in California, according to the study. The results also suggest more intense rainfall, which is likely to happen in the coming decades, could make landslides much more frequent.
Combined with recent research showing California's wildfire season is getting longer and the rainy season is getting shorter and more intense, the new findings suggest Californians face a higher risk of wildfires and post-wildfire landslides that can damage property and endanger people's lives.
"We're going to have a longer season to burn and then when it does rain, it's going to come down harder. And that's a bad recipe for these post-fire debris flows," Kean said. "The reason you can expect one just about every year is because it doesn't take very much rain to cause one. The rainstorms that can trigger debris flows - they're kind of garden-variety storms."
Damage from a major post-wildfire landslide that occurred on 9 January 2018
near Montecito, Santa Barbara County as a result of the 2017 Thomas Fire.
Credit: USGS/Jason Kean.
California's central coast has already seen a significant landslide this year. A portion of Highway 1 near Big Sur was washed out in a landslide in late January after a severe rainstorm. Kean hopes the new study's results can help emergency managers plan out evacuation zones for landslides before they happen.
"We'll still always do hazard assessments after fires because we really want to know the details of the actual fire, but these wildfires scenarios and storm scenarios are useful because we can start looking ahead and have the luxury of time to make a better plan," he said.
###
AGU (http://www.agu.org) supports 130,000 enthusiasts to experts worldwide in Earth and space sciences. Through broad and inclusive partnerships, we advance discovery and solution science that accelerate knowledge and create solutions that are ethical, unbiased and respectful of communities and their values. Our programs include serving as a scholarly publisher, convening virtual and in-person events and providing career support. We live our values in everything we do, such as our net zero energy renovated building in Washington, D.C. and our Ethics and Equity Center, which fosters a diverse and inclusive geoscience community to ensure responsible conduct.
Notes for Journalists
This research study is open access. Download a PDF copy of the paper here. Neither the paper nor this press release is under embargo.
Paper title:
"Forecasting the frequency and magnitude of postfire debris flows across southern California"
Authors:
Jason W. Kean, Dennis M. Staley: U.S. Geological Survey, Denver, Colorado, United States.
New treatment location challenges thoughts on addiction
MUSC researchers prove motor cortex is successful target for pain and addiction treatment, which suggests an overlooked area of the brain in TMS treatment
IMAGE: THE MOTOR CORTEX IS LOCATED NEAR THE MIDDLE OF THE SKULL, AND THE DLPFC IS CLOSER TO THE FRONT. AN ELECTROMAGNETIC COIL IS THEN PLACED AGAINST THE HEAD, AND MAGNETIC... view more
CREDIT: HANLON LAB
Researchers have discovered that there may be a new pathway in the brain that provides pain relief and reduces cravings for opioids.
Over a third of the U.S. population suffers from chronic pain, with little to no reported relief from medication. Transcranial magnetic brain stimulation (TMS) is a noninvasive form of brain stimulation that may offer a new treatment option for these underserved members of our community.
In a recent paper in Drug and Alcohol Dependence, researchers at the Medical University of South Carolina evaluated two different strategies for relieving pain with TMS: applying TMS to the motor cortex and the dorsolateral prefrontal cortex (DLPFC).
Colleen Hanlon, Ph.D., a professor in the department of psychiatry and behavioral sciences at MUSC and the principal investigator for this paper, expected to support her hypothesis that the DLPFC would be the most effective target for TMS treatment, but the results show just the opposite.
Historically, TMS-based treatments have targeted the DLPFC. In addition to being an FDA-approved target for managing depression, data show that the DLPFC is important in regulating emotions as well as addiction to substances like tobacco, cocaine and alcohol. While the motor cortex has been a popular target for TMS pain relief studies, there was no data to suggest it could also be helpful in opiate users. The new study points to its success as a target.
"I think you can even argue that our data suggests the motor cortex is an overlooked brain region in terms of addiction treatment development," said Julia Imperatore, MUSC research coordinator and lab manager for this study. Hanlon agrees.
Each study participant's head was mapped with coordinates to target specific areas of the brain using a swim cap marked with a permanent marker. Head circumferences differ between individuals, and thus so do the locations of the motor cortex and DLPFC. The motor cortex is located near the middle of the skull, and the DLPFC is closer to the front. Once these locations are determined, an electromagnetic coil is placed against the head, and magnetic pulses are painlessly and noninvasively sent through the skull to stimulate nerve cells in the brain.
After two weeks of administering daily TMS sessions and daily pain and opiate urge assessments, Hanlon's research team reported a significant difference in effects between the two locations. The motor cortex was significantly more effective at reducing the urge to use opioids and the study participant's perception of pain both immediately after treatment and during follow-up assessments. Direct magnetic stimulation to the motor cortex led to a 64-70% reduction in pain.
"This is the first study to evaluate a noninvasive therapeutic treatment to help decrease opiate use in chronic pain patients," said Hanlon. "We have no non-pharmacologic-based treatment options for people, and people are really tired of taking pills."
As a pilot study, Hanlon and Imperatore's paper kicks off a new area of research. It represents the first attempt at a randomized comparison of these two potential treatment targets, and it excites Hanlon because it suggests that the motor cortex is an important and influential part of the addiction process.
"Not only pain but also the urge to use, in this case, opiates," she said. "It's a whole new window of opportunity that we can explore."
Imperatore will be leading future studies to expand the knowledge on this topic, as this pilot study used a small sample size. MUSC will be conducting studies alongside Wake Forest School of Medicine and hopes to offer this new therapeutic option to patients suffering from chronic pain and addiction in the near future.
###
As the clinical health system of the Medical University of South Carolina, MUSC Health is dedicated to delivering the highest quality patient care available while training generations of competent, compassionate health care providers to serve the people of South Carolina and beyond. Comprising some 1,600 beds, more than 100 outreach sites, the MUSC College of Medicine, the physicians' practice plan and nearly 275 telehealth locations, MUSC Health owns and operates eight hospitals situated in Charleston, Chester, Florence, Lancaster and Marion counties. In 2020, for the sixth consecutive year, U.S. News & World Report named MUSC Health the No. 1 hospital in South Carolina. To learn more about clinical patient services, visit muschealth.org.
IMAGE: ASTRONOMERS FOUND A ROAMING COMET TAKING A REST STOP BEFORE POSSIBLY CONTINUING ITS JOURNEY. THE WAYWARD OBJECT MADE A TEMPORARY STOP NEAR GIANT JUPITER. THE ICY VISITOR HAS PLENTY OF... view more
CREDIT: CREDITS: NASA, ESA, AND B. BOLIN (CALTECH)
After traveling several billion miles toward the Sun, a wayward young comet-like object orbiting among the giant planets has found a temporary parking place along the way. The object has settled near a family of captured ancient asteroids, called Trojans, that are orbiting the Sun alongside Jupiter. This is the first time a comet-like object has been spotted near the Trojan population.
The unexpected visitor belongs to a class of icy bodies found in space between Jupiter and Neptune. Called "Centaurs," they become active for the first time when heated as they approach the Sun, and dynamically transition into becoming more comet-like.
Visible-light snapshots by NASA's Hubble Space Telescope reveal that the vagabond object shows signs of comet activity, such as a tail, outgassing in the form of jets, and an enshrouding coma of dust and gas. Earlier observations by NASA's Spitzer Space Telescope gave clues to the composition of the comet-like object and the gasses driving its activity.
"Only Hubble could detect active comet-like features this far away at such high detail, and the images clearly show these features, such as a roughly 400,000-mile-long broad tail and high-resolution features near the nucleus due to a coma and jets," said lead Hubble researcher Bryce Bolin of Caltech in Pasadena, California.
Describing the Centaur's capture as a rare event, Bolin added, "The visitor had to have come into the orbit of Jupiter at just the right trajectory to have this kind of configuration that gives it the appearance of sharing its orbit with the planet. We're investigating how it was captured by Jupiter and landed among the Trojans. But we think it could be related to the fact that it had a somewhat close encounter with Jupiter."
The team's paper appears in the February 11, 2021 issue of The Astronomical Journal.
The research team's computer simulations show that the icy object, called P/2019 LD2 (LD2), probably swung close to Jupiter about two years ago. The planet then gravitationally punted the wayward visitor to the Trojan asteroid group's co-orbital location, leading Jupiter by about 437 million miles.
Bucket Brigade
The nomadic object was discovered in early June 2019 by the University of Hawaii's Asteroid Terrestrial-impact Last Alert System (ATLAS) telescopes located on the extinct volcanoes, one on Mauna Kea and one on Haleakala. Japanese amateur astronomer Seiichi Yoshida tipped off the Hubble team to possible comet activity. The astronomers then scanned archival data from the Zwicky Transient Facility, a wide-field survey conducted at Palomar Observatory in California, and realized that the object was clearly active in images from April 2019.
They followed up with observations from the Apache Point Observatory in New Mexico, which also hinted at the activity. The team observed the comet using Spitzer just days before the observatory's retirement in January 2020, and identified gas and dust around the comet nucleus. These observations convinced the team to use Hubble to take a closer look. Aided by Hubble's sharp vision, the researchers identified the tail, coma structure and the size of the dust particles and their ejection velocity. These images helped them confirm that the features are due to relatively new comet-like activity.
Although LD2's location is surprising, Bolin wonders whether this pit stop could be a common pull-off for some sunward-bound comets. "This could be part of the pathway from our solar system through the Jupiter Trojans to the inner solar system," he said.
The unexpected guest probably will not stay among the asteroids for very long. Computer simulations show that it will have another close encounter with Jupiter in about another two years. The hefty planet will boot the comet from the system, and it will continue its journey to the inner solar system.
"The cool thing is that you're actually catching Jupiter flinging this object around and changing its orbital behavior and bringing it into the inner system," said team member Carey Lisse of the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland. "Jupiter controls what's going on with comets once they get into the inner system by altering their orbits."
The icy interloper is most likely one of the latest members of the so-called "bucket brigade" of comets to get kicked out of its frigid home in the Kuiper belt and into the giant planet region through interactions with another Kuiper belt object. Located beyond Neptune's orbit, the Kuiper belt is a haven of icy, leftover debris from our planets' construction 4.6 billion years ago, containing millions of objects, and occasionally these objects have near misses or collisions that drastically alter their orbits from the Kuiper belt inward into the giant planet region.
The bucket brigade of icy relics endure a bumpy ride during their journey sunward. They bounce gravitationally from one outer planet to the next in a game of celestial pinball before reaching the inner solar system, warming up as they come closer to the Sun. The researchers say the objects spend as much or even more time around the giant planets, gravitationally pulling on them--about 5 million years--than they do crossing into the inner system where we live.
"Inner system, 'short-period' comets break up about once a century," Lisse explained. "So, in order to maintain the number of local comets we see today, we think the bucket brigade has to deliver a new short-period comet about once every 100 years."
An Early Bloomer
Seeing outgassing activity on a comet 465 million miles away from the Sun (where the intensity of sunlight is 1/25th as strong as on Earth) surprised the researchers. "We were intrigued to see that the comet had just started to become active for the first time so far away from the Sun at distances where water ice is barely starting to sublimate," said Bolin.
Water remains frozen on a comet until it reaches about 200 million miles from the Sun, where heat from sunlight converts water ice to gas that escapes from the nucleus in the form of jets. So the activity signals that the tail might not be made of water. In fact, observations by Spitzer indicated the presence of carbon monoxide and carbon dioxide gas, which could be driving the creation of the tail and jets seen on the Jupiter-orbiting comet. These volatiles do not need much sunlight to heat their frozen form and convert them to gas.
Once the comet gets kicked out of Jupiter's orbit and continues its journey, it may meet up with the giant planet again. "Short-period comets like LD2 meet their fate by being thrown into the Sun and totally disintegrating, hitting a planet, or venturing too close to Jupiter once again and getting thrown out of the solar system, which is the usual fate," Lisse said. "Simulations show that in about 500,000 years, there's a 90% probability that this object will be ejected from the solar system and become an interstellar comet."
###
The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, in Washington, D.C. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, managed the Spitzer mission for NASA's Science Mission Directorate in Washington, D.C. Science operations were conducted at the Spitzer Science Center at IPAC at Caltech. Spitzer's entire science catalogue is available via the Spitzer data archive, housed at the Infrared Science Archive at IPAC. Spacecraft operations were based at Lockheed Martin Space in Littleton, Colorado.
Credits: NASA, ESA, and B. Bolin (Caltech)
Smaller plates help reduce food waste in campus dining halls
UNIVERSITY OF ILLINOIS COLLEGE OF AGRICULTURAL, CONSUMER AND ENVIRONMENTAL SCIENCES
IMAGE: STUDENTS IN A UNIVERSITY DINING HALL. view more
CREDIT: UNIVERSITY OF ILLINOIS.
URBANA, Ill. - Food waste is a major problem in the U.S., and young adults are among the worst culprits. Many of them attend college or university and live on campus, making dining halls a prime target for waste reduction efforts. And a simple intervention can make a big difference, a University of Illinois study shows.
Shifting from round to oval plates with a smaller surface area can significantly reduce food waste in dining halls, says Brenna Ellison, associate professor in the Department of Agricultural and Consumer Economics (ACE) and co-author on the study.
"Americans waste about 31% of the food that is available at the retail and consumer levels," Ellison says. "All-you-can-eat settings [common in dining halls] are extra challenging, because there's not the normal incentives to try to reduce waste on your own. When you pay a fixed amount of money to go and eat, you want to get your money's worth."
Ellison's research team previously worked with University Housing at Illinois on an educational campaign to reduce waste.
"It wasn't as successful as we expected it to be," she says. "So University Housing wanted to see if changing the plates would be a more successful way to reduce waste."
Thurman Etchison, assistant director of dining¬-facilities and equipment operations at U of I, says a 2016 waste study in campus dining halls showed about 3.3 ounces (93.5 grams) of wasted food per meal served. That amounted to 14,875 pounds (6,747 kilograms) per week across six residential dining hall locations.
"When we think about food waste in our setting, it is important to note it is not just the resources to produce the food that are wasted," Etchison says. "There is a great deal of energy, water and labor that go into the refrigeration, preparation, transportation, and serving of this food that is wasted as well. If that were not enough, there is also the wasted energy, labor, and water that go into disposing of that food. The food we waste costs us more per pound than the food that is eaten."
Ellison and co-authors Rachel Richardson, former graduate student in ACE, and Melissa Pflugh Prescott, assistant professor in the Department of Food Science and Human Nutrition, conducted the plate study in two University Housing dining halls on the U of I campus; both the round and oval plates were tested in each location, making sure to use the same menu for both plate types.
The researchers approached diners after they selected their food, and asked to take a picture of the plate and weigh the food. Diners then filled out a short survey, and when they were done eating and brought their tray to the dish return, the researchers again took a picture and weighed the remaining food.
The study included more than 1200 observations, and the researchers found significant reductions in food selection, consumption, and waste when diners used the oval plates. Overall, food waste went down from 15.8% of food selected for round plates to 11.8% for oval plates. That amounts to nearly 20 grams (0.7 oz) less food waste per plate, which adds up to a lot for a dining hall that serves thousands of meals, Ellison notes.
The researchers did not weigh plates for any diners who went back for seconds, Ellison says. They did ask diners if they went back for seconds on the survey. Using this information, they estimated the potential effects of seconds and found it would not significantly change the results.
Ellison concludes that changing plate type is a viable strategy to reduce food waste, though dining hall managers need to weigh the cost of purchasing new plates against the potential savings. Combining the direct-nudge approach of smaller plates with an education campaign may be even more effective, she notes.
###
The Department of Agricultural and Consumer Economics and the Department of Food Science and Human Nutrition are in the College of Agricultural, Consumer and Environmental Sciences, University of Illinois.
The paper, "Impact of plate shape and size on individual food waste in a university dining hall," is published in Resources, Conservation & Recycling. Authors include Rachel Richardson, Melissa Pflugh Prescott, and Brenna Ellison. [https://doi.org/10.1016/j.resconrec.2020.105293]
This research was supported by funding from the National Institute of Food and Agriculture, U.S. Department of Agriculture, under award number ILLU-470-334.
New model describes wave behavior in straits, predicts killer waves
SKOLKOVO INSTITUTE OF SCIENCE AND TECHNOLOGY (SKOLTECH)
A Skoltech researcher has developed a theoretical model of wave formation in straits and channels that accounts for nonlinear effects in the presence of a coastline. This research can improve wave prediction, making maritime travel safer and protecting coastline infrastructure. The paper was published in the journal Ocean Dynamics.
Predicting surface weather at sea has always been a challenging task with very high stakes; for instance, over 4,000 people died due to rough seas during Operation Overlord at Normandy in June 1944, an allied incursion where poor forecasting altered the course of the operation quite significantly. Current wave forecasting models used, for example, by NOAA in the US, are imperfect, but they have many tunable parameters to ensure a reasonably good prediction.
However, as Andrei Pushkarev, senior research scientist at Skoltech and Lebedev Physical Institute of the Russian Academy of Sciences notes in his paper, coastlines complicate the situation: he writes that, "wave forecasting in the English Channel nowadays is still almost as hard as it was in 1944." His research suggests that the wave behavior in channels or straits will differ quite significantly from that in open seas.
"Coastlines create inhomogeneity - a gradient of the wave energy distribution between its zero value at the boundary and non-zero value off-shore. This gradient launches wave advection, and its mutual interplay with nonlinear wave interaction creates peculiar effects of generating waves orthogonal to the wind," Pushkarev says.
The specific conditions of the channels allow for a precise solution of the Hasselmann equation describing wave behavior, the one current models approximate because it is still impossible to solve with modern computers. Pushkarev's theoretical modeling of wave formation in an English Channel-like strait showed that the development of turbulence did not match predictions from conventional models, as turbulence structure was significantly different due to nonlinear interactions and wave advection. Since the phenomenon researchers observed has some similarities to laser radiation, they call it the Nonlinear Ocean Wave Amplifier, or NOWA.
"The strait shores play the role of the semi-reflecting mirrors for generated waves, which makes the situation similar to conventional lasers, with the nonlinear wave media playing the role of active resonator, in some sense similar to the conventional lasers. The power of the radiation excited orthogonally to the wind grows significantly with the growth of the reflection coefficient of the strait boundaries. In a sense, we are dealing with some sort of nonlinear laser," Pushkarev notes.
"This model, exploiting the exact version of the Hasselmann Equation, shows that existing operational wave weather forecasting models miss the described effect, considering it rather a numerical artifact," he adds.
The researcher says that this laser-like effect of wave generation orthogonally to the wind can be observed not only in straits, but also in the open seas with specific inhomogeneous winds, where spatial wind turning points create conditions similar to those observed in presence of shores.
The new research holds promise in explaining the nature of seiches, peculiar standing waves in semi-enclosed bodies of water that present a big problem for ships in ports. But it also suggests that a correct description of turbulence in the presence of coastlines will allow for rogue waves, seemingly unpredictable surface waves that are extremely dangerous even to large vessels.
###
Skoltech is a private international university located in Russia. Established in 2011 in collaboration with the Massachusetts Institute of Technology (MIT), Skoltech is cultivating a new generation of leaders in the fields of science, technology and business, is conducting research in breakthrough fields, and is promoting technological innovation with the goal of solving critical problems that face Russia and the world. Skoltech is focusing on six priority areas: data science and artificial intelligence, life sciences, advanced materials and modern design methods, energy efficiency, photonics and quantum technologies, and advanced research. Web: https://www.skoltech.ru/.
Large carnivores are generally sensitive to ecosystem changes because their specialized diet and position at the top of the trophic pyramid is associated with small population sizes. This in turn leads to lower genetic diversity in top predators compared to animals lower down the food chain. Genetic diversity is very important for a species' ability to survive and adapt to future changes.
Extraordinary genetic diversity in an extraordinary cat
In this study, the researchers sequenced the complete genome of 53 African leopards and compared them to the Amur leopards and other big cat species. To their surprise, the researchers found that the genetic diversity of African leopards is extremely high: Almost four times higher than the Amur leopard's, twice as high as the lion's and almost five times higher than the cheetah's.
Patrícia Pečnerová, postdoc at the Department of Biology and one of the shared first authors, explains:
- "The exceptional genetic diversity is likely a result of the leopard's ability to avoid population crashes and reductions. We found that during hundreds of thousands of years, African leopard populations remained large. We think that this reflects the versatility of the species, feeding on a wider variety of prey than any of the other large predators."
Roaming every habitat in Africa - but for how long?
The high genetic diversity of the African leopards is not the only surprise hidden in the leopard genomes. They also show fewer genetic barriers within the continent of Africa than other mammal species.
Kristian Hanghøj, one of the corresponding authors of the study explains:
- "We believe that during evolutionary history the leopard roamed the African continent more freely than almost any other mammal species, exchanging genetic material throughout. It has a unique ability to succeed in almost any habitat and climate and neither rain forests, nor deserts seem to have blocked the movements of leopards over the millennia."
The surprising findings demonstrate how the ecology of a species - such as how 'picky' it is about habitat and prey, can influence its genomic variation. The exceptionally high genetic diversity could give the African leopard an advantage in coping with environmental challenges, including climate change and habitat destruction.
However, habitat fragmentation is a severe threat to all large animals, even those as adept at coping with human presence as the leopard. The human-made changes to natural habitats are occurring at a pace that is likely too fast for almost any wild animal species to adapt to, and previous studies have shown that African leopards have lost 48-67% of their natural habitat over the last 300 years.
- "To place our results into a greater context, we emphasize that the African leopard is also facing severe threats to its survival, despite being sort of an evolutionary success", finishes Patrícia Pečnerová.
FOREVER CHEMICALS
Just published: Compilation of research on PFAS in the environment
Per- and polyfluoroalkyl substances (PFAS) are a class of man-made chemical compounds and a current, emerging concern to environmental health. PFAS substances have unique characteristics-resistance to heat, water, oil and stains-that make them useful in a variety of industrial applications and popular in consumer goods. Many PFAS are stable and long-lasting in the environment, acquiring the name "forever chemicals." Industrial use of some of these compounds has been halted; however, many derivatives are still in commerce and more are under development. PFAS are now found in many compartments of the environment.
In order to manage PFAs in the environment, a lot of research has been directed at understanding their sources, fate and transport in the environment, and their potential effects on humans and wildlife. Recently, Environmental Toxicology and Chemistry (ET&C) published a special issue dedicated to PFAS with 32 articles, providing a valuable summarization of risk assessment approaches for PFAS, which are needed for environmental managers and regulatory bodies to set appropriate drinking water standards and health advisory guidelines.
The published research illustrates that PFAS are ubiquitous and raise more questions than answers about their potential toxicity to humans and wildlife. The articles in the issue report that PFAS were found near defense bases, urban environments, treatment plants and waste disposal sites but also in remote, less inhabited areas. PFAS were detected in breeding kittiwakes in Svalbard, Norway, and ducks in Australian estuaries. They were found in hens' eggs, soil, tadpoles, zebrafish, house crickets; the list goes on. The breadth of the published research illustrates that PFAS have dispersed in every medium in the environment (soil, water and wildlife).
In some of the studies, the presence of PFAS was related to a nearby source while in others it was not determined. For example, the authors of the article that investigated PFAS in Australian ducks did find a correlation between local sources of PFAS and bioaccumulation in ducks and noted that "Human health risk assessment showed that only ducks inhabiting wetlands near local sources of PFAS were likely to pose a risk to consumers," and continued, "Management of food consumption from these locations is an effective measure to limit exposure." In another study published in this same issue, long-chain PFAS were found in eight fish species across ten European glacial lakes in the Alps region, and while correlated to urban areas, could not be attributed to a specific, nearby industry source.
The issue illustrates that there are a tremendous number of PFAS substances, and it is a challenge for environmental managers and regulatory bodies to devise an approach to identify, understand and manage them all. The series provided a great review of the state of the science of PFAs risk assessment and also identified data gaps and the work needed to fill them in order to devise an effective approach to manage PFAS.
###
Indian agriculture: Groundwater depletion could reduce winter cropped acreage significantly in years
India is the world's second-largest producer of wheat and rice and is home to more than 600 million farmers.
The country has achieved impressive food-production gains since the 1960s, due in part to an increased reliance on irrigation wells, which allowed Indian farmers to expand production into the mostly dry winter and summer seasons.
But those gains have come at a cost: The country that produces 10% of the world's crops is now the world's largest consumer of groundwater, and aquifers are rapidly becoming depleted across much of India.
Indian government officials have suggested that switching from groundwater-depleting wells to irrigation canals, which divert surface water from lakes and rivers, is one way to overcome projected shortfalls.
But in a study scheduled for publication Feb. 24 in the journal Science Advances, a University of Michigan researcher and her colleagues conclude that a switch to canal irrigation will not fully compensate for the expected loss of groundwater in Indian agriculture.
The authors estimate that if Indian farmers lose all access to groundwater in overexploited regions, and if that irrigation water is not replaced with water from other sources, then winter cropped acreage could be reduced by up to 20% nationwide. However, that scenario seems highly unlikely and was included in the study only as an upper-bound estimate.
It seems more likely that any future groundwater shortfalls would be at least partially offset by increases in canal irrigation. But even if all Indian regions currently using depleted groundwater switch to canal irrigation, winter cropped acreage could still decline by 7% nationwide and by 24% in the most severely affected locations, according to the researchers.
"Our results highlight the critical importance of groundwater for Indian agriculture and rural livelihoods, and we were able to show that simply providing canal irrigation as a substitute irrigation source will likely not be enough to maintain current production levels in the face of groundwater depletion," said study lead author Meha Jain of the University of Michigan.
The study analyzed high-resolution satellite imagery and village-level census data and focused on winter cropped acreage. While nearly all Indian farmers plant crops during the monsoon to take advantage of seasonal rains, winter agriculture is mainly reliant on groundwater irrigation and now accounts for 44% of the country's annual cropped acreage for food grains.
"These findings suggest that other adaptation strategies, in addition to canal expansion, are needed to cope with ongoing groundwater losses," said Jain, an assistant professor at the U-M School for Environment and Sustainability.
The possibilities include switching from winter rice to less water-intensive cereals, increased adoption of sprinklers and drip irrigation to conserve water in the fields, and policies to increase the efficiency of irrigation canals.
While groundwater depletion is becoming a global threat to food security, and the extent of current and projected groundwater depletion are well documented, the potential impacts on food production remain poorly quantified.
The study by Jain and colleagues is the first to use high-resolution empirical data, including census data about the irrigation methods used in more than 500,000 Indian villages, to estimate the crop production losses that may occur when overexploited groundwater is lost.
The proliferation of deep (>100 feet) irrigation wells called tube wells since the 1960s has enabled Indian farmers to increase the number of seasons when crops are planted in a given year. This increase in "cropping intensity" is credited for much of the country's food-production gains.
The researchers used satellite data to measure Indian winter cropped area, a key determinant of cropping intensity. They then linked the satellite data to census information about the three main types of irrigation infrastructure in India: shallow "dug wells," deeper tube wells and canals that divert surface water.
Linking the two datasets allowed them to determine the relative efficacy of each irrigation method. That, in turn, enabled them to estimate potential future acreage losses and the ability of canal expansion to fill the gap.
The study's worst-case scenario found that winter cropped area could decrease by up to 20% nationwide and by 68% in the most severely affected regions, if farmers lose all access to groundwater and if that irrigation water is not replaced from another source. The expected losses would largely occur in northwest and central India, according to the study.
The researchers also found that increased distance from existing irrigation canals is strongly associated with decreased acreage planted with winter crops. In the future, a greater reliance on canals could increase inequities related to irrigation access, according to the authors.
"This suggests that while canals may be a viable form of irrigation for those who live near canals, they may lead to more unequal access to irrigation across villages compared to wells, with negative impacts for those who live farther from canals," the authors wrote.
In addition, the lakes and rivers that feed irrigation canals rise and fall in response to rainfall variability, unlike deep groundwater wells. So, a greater reliance on canal irrigation in the future would result in increased sensitivity to year-to-year precipitation fluctuations, as well as any long-term trends due to human-caused climate change.
"Understanding the complex relationship between food security and water availability is crucial as we prepare for future rainfall variability due to global climate change," said co-author Gillian Galford of the University of Vermont.
###
The authors of the Science Advances study, in addition to Jain and Galford, are Ram Fishman of Tel Aviv University; Pinki Mondal of the University of Delaware; Nishan Bhattarai of the U-M School for Environment and Sustainability; Shahid Naeem, Upmanu Lall and Ruth DeFries of Columbia University; and Balwinder-Singh of the International Maize and Wheat Improvement Center in New Delhi.
The work was funded by a NASA New Investigator Award to Jain and two NASA Land Cover and Land Use Change grants, one awarded to R.S. DeFries and one to Jain.
