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

MEDICAL UNIVERSITY OF SOUTH CAROLINA

Research News

 

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.

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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.

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Comet makes a pit stop near Jupiter's asteroids

NASA/GODDARD SPACE FLIGHT CENTER

Research News

 

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."

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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

Research News

 

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.

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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)

Research News

 

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.

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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/.

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A cat of all trades

UNIVERSITY OF COPENHAGEN - FACULTY OF SCIENCE

Research News

 

IMAGE: LEOPARD view more 

CREDIT: PHOTO BY BRUTUS ÖSTLING

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

SOCIETY OF ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY

Research News

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.

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Indian agriculture: Groundwater depletion could reduce winter cropped acreage significantly in years

UNIVERSITY OF MICHIGAN

Research News

 

Map and photo

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.

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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.

Study: Groundwater depletion will reduce cropping intensity in India

Meha Jain

 

A tangled food web

Trophic levels are an 'insufficient' measure of sustainability for today's aquaculture policy

UNIVERSITY OF CALIFORNIA - SANTA BARBARA

Research News

 

Born in food web ecology, the concept of trophic levels -- the hierarchy of who eats who in the natural world -- is an elegant way to understand how biomass and energy move through a natural system. It's only natural that the idea found its way into the realm of aquaculture, where marine and freshwater farmers try to maximize their product with efficient inputs.

"It's often used as a measure of how sustainable it is to harvest or consume that species," said Rich Cottrell(link is external), a postdoctoral researcher at UC Santa Barbara's National Center for Ecological Analysis & Synthesis (NCEAS). As plants (level 1) become food to plant eaters (level 2), who in turn are consumed by carnivores (level 3) and so on, the amount of energy required to support the same weight of organisms increases, he explained. As a result, species at levels 4 or 5, such as tuna, require far more energy per pound than would species in the lower trophic levels. It's the same reason vegetarian diets are often considered to be more sustainable than meat-eating ones.

"In the same manner, trophic level measures are now being recommended in policy settings for use as an indicator of the sustainability of fish farming, or aquaculture," Cottrell said. The lower the trophic level, the more sustainable the species is considered to be, and so policy often calls for more farming of low-trophic species.

However, argue Cottrell and fellow aquaculture experts in a paper(link is external) published in the journal Reviews in Aquaculture, at this time of increasing complexity and sophistication in the aquaculture sector, the same simplicity that makes trophic levels attractive as a measure of sustainability also makes them insufficient.

The causes for that have largely to do with how today's farmed fish are fed.

"Most of the fish and invertebrates that we farm for food are produced using human-made feeds," Cottrell explained. "But these feeds are constantly changing, and so the meaning of farmed trophic levels is changing through time." For instance, he pointed out, salmon are considered to be at a higher trophic level because their naturally carnivorous diets would require large amounts of fishmeal and oil, but advances in feed and manufacturing have reduced the proportion of fish-based ingredients to 10-15% in modern salmon diets. Meanwhile, herbivorous species such as carp and tilapia have been found to respond favorably to small amounts of fishmeal in their feed.

"In reality, they're now farmed at similar trophic levels," Cottrell said. "The line between 'low' and 'high' trophic levels will continue to blur with innovation."

The trophic level concept misses still another important aspect of aquaculture sustainability in the realm of feed and resource efficiency, or how efficiently the farmed animals convert what they are fed into edible food.

"This is not well explained by trophic level," Cottrell said, adding that despite their high trophic placement, many carnivorous farmed fish could be more feed-efficient than their naturally carnivorous counterparts. And because aquaculture is increasingly turning to agriculture to provide replacements for fishmeal and oil, the promise of sustainability might be an empty one.

"Replacing fish-based ingredients with crops has led to a dramatic reduction in the trophic level of fed aquaculture species, but we know very little about how sustainable it is to increase pressure on global agricultural systems," he said.

As the global aquaculture sector strives to meet the growing demand for farmed seafood, the researchers say it's time to rethink the use of trophic levels as a rule for and measure of sustainability. Stipulating low trophic level aquaculture recommendations may not be successful in promoting greater sustainability, Cottrell said. Boosting the supply of mussels, for instance, may not fulfill increasing demand for shrimp or salmon.

"It behooves us to find a way to ensure that for high-demand products, we produce these in the most environmentally efficient and socially responsible way possible," he said. "Trophic levels will not get us there."

Fortunately, there are efforts at more nuanced sustainability assessments, such as voluntary certifications through the Aquaculture Stewardship Council or Best Aquaculture Practices, which examine the impacts of aquaculture at the farm level and through supply chains.

"Greater support for these programs and incentives for producers from various regions and production systems to join them would be a far more robust way to strengthen the sustainability of the aquaculture sector going forward," Cottrell said.

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Research for this paper was conducted also by Halley E. Froehlich, Caitlin D. Kuempel, Benjamin S. Halpern and David R. Williams at UCSB; Marc Metian at the International Atomic Agency, Monaco; Julia Blanchard and Kirsty L. Nash at the University of Tasmania; Nis Sand Jacobsen at the Technical University of Denmark; Peter B. McIntyre at Cornell University; Lex Bouwman at Utrecht University; Jessica Gephart at American University; Daniel D. Moran at the Norwegian University of Science and Technology and Max Troell at the Royal Swedish Academy of Sciences.

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What might sheep and driverless cars have in common? Following the herd

Researchers show how social component of moral decision-making can influence programming of autonomous vehicles and other technologies

UNIVERSITY OF SOUTHERN CALIFORNIA

Research News

 

Psychologists have long found that people behave differently than when they learn of peers' actions. A new study by computer scientists found that when individuals in an experiment about autonomous vehicles were informed that their peers were more likely to sacrifice their own safety to program their vehicle to hit a wall rather than hit pedestrians who were at risk, the percentage of individuals willing to sacrifice their own safety increased by approximately two-thirds.

As computer scientists train machines to act as people's agents in all sorts of situations, the study's authors indicate that the social component of decision-making is often overlooked. This could be of great consequence, note the paper's authors who show that the trolly problem -long shown to be the scenario moral psychologists turn to--is problematic. The problem, the authors indicate, fails to show the complexity of how humans make decisions.

Jonathan Gratch, one of the paper's author, the principal investigator for this project, and a computer scientist at the USC Institute for Creative Technologies, says existing models assume that in high stakes life and death decisions, people think differently than they actually do. He indicates that there are not moral absolutes for human decision-making but rather "it is more nuanced," says Gratch.

The researchers conducted four separate simulation experiments to understand how people might process and act on the moral dilemmas they would face as an operator of a driverless car. The first three experiments focused on human behavior when faced with risk to themselves and others in the event of negative scenario in which the vehicle would have to be programmed to either the car to hit the wall or hit five pedestrians. The authors prove that participants would use severity of injury to self and the risk to others as guideposts for decision-making. They found that the higher the risk to pedestrians; the more likely people were likely to self -sacrifice their own health. In addition, the level of risk to pedestrians did not to have to be as high as for the operator of the autonomous vehicle to sacrifice their own well-being.

In the fourth experiment, the researchers added a social dimension telling participants what peers had opted to do in the same situation. In one simulation, the knowledge that peers chose to risk their own health changed the participants' responses, rising from 30 percent who were willing to risk their health to 50 percent. But this can go both ways cautions Gratch. "Technically there are two forces at work. When people realize their peers don't care, this pulls people down to selfishness. When they realize they care, this pulls them up."

The research has implications for autonomous vehicles including drones and boats, as well as robots that are programmed by humans. The authors suggest that it is important for manufacturers to have an awareness of how humans actually make decisions in life or death situations. In addition, the authors imply that transparency in how machines are programmed as well as relinquishing controls to the human drivers so that they might change settings prior to these life and death situations are important for the public. They also suggest it is important for legislators to be aware of how vehicles might be programmed. Lastly, given the human susceptibility to conform to social norms, the authors believe that public health campaigns related to how peers programmed their autonomous vehicles for self-sacrifice might influence future owners to change their vehicle settings to be more oriented to protecting others from injury and choose self-sacrifice.

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The authors of this study are Celso M. de Melo of the US Army Research Laboratory, Stacy Marsella of Northeastern University, and Jonathan Gratch of the USC Institute for Creative Studies.

Study uncovers flaws in process for maintaining state voter rolls

YALE UNIVERSITY

Research News

 

States regularly use administrative records, such as motor-vehicle data, in determining whether people have moved to prune their voter rolls. A Yale-led study of this process in Wisconsin shows that a significant percentage of registered voters are incorrectly identified as having changed addresses, potentially endangering their right to vote.

The study, published in the journal Science Advances, found that at least 4% of people listed as suspected "movers" cast ballots in 2018 elections using addresses that were wrongly flagged as out of date. Minority voters were twice as likely as white voters to cast their ballot with their original address of registration after the state marked them as having moved, the study showed.

The findings suggest that states should more clearly communicate the processes they use to update voter-registration files and that a more robust effort is required to confirm whether individuals have moved before they are removed from the voter rolls, said Yale political scientist Gregory A. Huber, the study's lead author.

"The process of maintaining states' voter-registration files cries out for greater transparency," said Huber, the Forst Family Professor of Political Science in the Faculty of Arts & Sciences. "Our work shows that significant numbers of people are at risk of being disenfranchised, particularly those from minority groups.

"Unfortunately, we don't know enough about the process used to prune voter rolls nationwide to understand why mistakes occur and how to prevent them."

Regularly updating voter rolls prevents registration files from becoming bloated with individuals who have died, moved away, or are otherwise no longer eligible to vote. When these rolls swell with ineligible voters, it raises concerns about potential fraud (although there is little evidence it causes unlawful voting, Huber says) and creates headaches for political campaigns, which rely on accurate registration records to reach potential voters.

Americans are not obligated to inform local election officials when they move to a new address, but federal law mandates that states identify changes in residence among registered voters. To better accomplish this task, 30 states, including Wisconsin, and the District of Columbia have formed the Electronic Registration Information Center (ERIC), a non-profit organization that assists them in improving the accuracy of their voter rolls.

ERIC uses various administrative records, including motor vehicle data, change of address information from the U.S. Postal Service, and the Social Security Administration's master death file, to flag registrations that are potentially out of date. It provides states a "movers list" of people who likely have changed residences. The states contact listed individuals, often by sending them postcards they can use to confirm their address. If people do not return the postcards, their registration can be inactivated, starting the process for removal.

Federal privacy protections and ERIC's agreements with member states prohibit the organization from disclosing who is marked as having moved and on what basis they were flagged as such, making it difficult to examine its process. However, after submitting a Wisconsin Freedom of Information Act request, Huber and his co-authors obtained special "movers poll books" from the state which list all people who were marked as suspected movers and who did not respond to the postcard notification. Individuals in the books who showed up to vote in 2018 signed their names in these books, providing evidence that they voted at addresses that had been flagged as invalid.

The researchers collected movers poll books from a representative sample of election wards and matched their contents against voting records for 2018 local, state, and federal elections. They found that at least 9,000 people -- about 4% of those listed in the poll books -- voted in 2018 using the address of registration that ERIC had marked as invalid. Minority voters were twice as likely to be incorrectly identified as having moved.

The study likely undercounts the number of registered voters incorrectly listed as having moved, the researchers said, explaining that a significant number of people who did not respond to the postcard might have nonetheless renewed their voting registration before the poll books were published. In addition, the study examined low-turnout elections, making it likely that many people wrongly listed in the poll books weren't covered in the analysis because they didn't vote, Huber said.

The researchers are not suggesting that ERIC intentionally targeted minorities.

"There's no malice here," Huber said. "ERIC wants to help states, but relying on administrative records inevitably produces mistakes for any number of reasons. This makes the process used to validate having moved, such as mailed postcards, even more important. Without more information, we can't be certain why the process disparately affects minorities."

A potential reason for the disparity is that minorities are more likely than whites to live in apartment buildings and large households, which may increase the risk of errors in administrative records, the researchers suggest. In addition, residents of apartment buildings also may be less likely to confirm their address using the postcard since mail service can be spottier in multi-unit buildings than single-family homes.

Huber credits Wisconsin for taking steps to protect people's voting rights.

"The poll books are a great way to identify mistakes and prevent people from being disenfranchised," he said. "The state also has same day voter registration, which is another safety valve that doesn't exist in many states. We suggest that states expend more effort on contacting people at risk of losing their registration."

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The study's co-authors are Marc Meredith of the University of Pennsylvania, Yale Law School graduate Michael Morse, and Katie Steele of the University of Pennsylvania.