Tuesday, August 03, 2021

Closeness with dads may play special role in how kids weather adolescence

by Katie Bohn, Pennsylvania State University

parent and teenager — Credit: Unsplash/CC0 Public Domain

Adolescence can be an emotionally turbulent time, but new research at Penn State found that close, supportive relationships with parents—especially dads—at key points during adolescence can help stave off certain adjustment problems.

The researchers examined how emotionally close and supportive relationships with parents—referred to in the research as "parental intimacy"—in families with mothers and fathers affected their children's self-esteem, weight concerns, and depressive symptoms at different points across adolescence.

They found that closeness with fathers had broad, positive effects across adolescence for both daughters and sons. But while close relationships with mothers also had benefits, they were more limited by their children's age, and weren't protective against all the adjustment issues measured in the study for both girls and boys.

Anna Hochgraf, doctoral candidate in human development and family studies, said the findings suggest that while close relationships with moms are certainly important, fathers may play an important, distinct role in fostering healthy adjustment in adolescents.

"Adolescents tend to feel emotionally closer to their mothers than to their fathers and mothers tend to have supportive conversations with their children more frequently than fathers do," Hochgraf said. "This may make emotional closeness with fathers more salient, and in turn, protective against these common adjustment problems experienced during adolescence."

According to the researchers, adolescence is a period of development that includes many biological, cognitive, emotional and social changes that can lead to certain adjustment issues, with weight concerns, low self-esteem, and symptoms of depression being some of the most common, especially for girls.

But, previous research has also shown that close relationships with parents have the potential to help protect against the development of some of these problems. Hochgraf said she and the other researchers wanted to explore the topic further, breaking the results down by participants' age, gender, and relationship with each parent.

"We wanted to investigate when during the course of adolescence intimacy with mothers and fathers becomes a protective factor for body image concerns, depressive symptoms, and low self-esteem, and whether intimacy is more strongly associated with positive adjustment at some ages than at others," Hochgraf said. "We also wanted to see if patterns differed for girls and boys."

The researchers recruited 388 adolescents from 202 two-parent families with both fathers and mothers for the study. Data was gathered at three checkpoints when the participants were between the ages of 12 and 20, and included information on participants' weight concerns, symptoms of depression, and self-esteem, as well as measurements of intimacy between parents and their kids.

Intimacy was measured by the participants answering questions such as how much they go to their mother or father for advice or support and how much they share inner feelings or secrets with them, to which the adolescents responded with a score ranging from one to five.

Hochgraf said it was important to gather data at several points in time because problems with adjustment, as well as relationships with parents, can change and develop swiftly throughout adolescence.

"Rather than assume that the associations between parent-adolescent intimacy and adolescent adjustment problems are static across adolescence, we studied changes in these links as a function of age," Hochgraf said. "This approach enabled us to determine at which ages parent-youth intimacy may be most protective against body image concerns, depressive symptoms and self-esteem."

After analyzing the data, the researchers found several different effects of parental intimacy on their sons and daughters at different times throughout adolescence. These effects were also different between mothers and fathers.

"For example, while father-adolescent intimacy was associated with fewer depressive symptoms across adolescence, mother-adolescent intimacy was associated with fewer depressive symptoms during mid-adolescence, around age 15," Hochgraf said.

They also found that father-youth intimacy was associated with fewer weight concerns for both girls and boys throughout most of adolescence, with the greatest effects in mid-adolescence for girls and late adolescence for boys. In contrast, mother-youth intimacy was only associated with fewer weight concerns for boys, and only in early adolescence.

Additionally, father-youth intimacy was associated with higher self-esteem from early through mid-adolescence for both boys and girls. Mother-youth intimacy was associated with higher self-esteem across most of adolescence for girls, and during early and late adolescence for boys.

Hochgraf said the study—recently published in the Journal of Family Psychology—underscores the importance of parents being close, open and supportive with their children.

"Parents can promote their adolescents' healthy development by fostering emotionally warm, accepting, and supportive relationships with them," Hochgraf said. "There are a number of evidence-based, family-centered prevention programs that can help parents improve or maintain positive relationship quality and communication with their children throughout adolescence and that have been shown to prevent multiple adolescent adjustment problems."

Gregory Fosco, associate professor of human development and family studies; Stephanie Lanza, professor of biobehavioral health and human development and family studies; and Susan McHale, distinguished professor of human development and family studies, also participated in this work.

The National Institute of Child Health and Human Development, National Institute on Drug Abuse of the National Institutes of Health, and the Prevention and Methodology Training Program helped support this researc

Concerns about child's weight increase risk for family weight teasing

Journal information: Journal of Family Psychology

Provided by Pennsylvania State University

How people prefer to receive life-changing news, be it good or bad

by Brittney Wheeler, Washington University in St. Louis

How people prefer to receive life-changing news, good or bad — Credit: Shutterstock

When finding out life-changing news, whether good or bad, some people prefer to receive information as soon as possible. Others wish to receive and process bits of information over time or wait until the last minute to hear the news. Economists have tended to ignore consumers' attitudes toward how information is disclosed.

A team including a Washington University in St. Louis economist lays the theoretical foundations that allow economists to take into account consumers' preferences over how and when information is disclosed. The researchers, including two from Princeton University, created a model in which people react better when the news is revealed in the manner they are most comfortable.

The consumers that populate standard economic models only care about the likelihood of each outcome when making choices. "In practice, however, people exhibit strong preferences over the way in which information is revealed, even when the probabilities of each outcome remain fixed," said Paulo Natenzon, assistant professor of economics at Olin Business School at Washington University.

Natenzon partnered with Faruk Gul and Wolfgang Pesendorfer, both professors of economics at Princeton, in a new study in the journal Econometrica, titled "Random Evolving Lotteries and Intrinsic Preference for Information."

"In our paper, we model agents' preferences over random evolving lotteries (RELs), which describe, in probabilistic terms, how the beliefs of the agent change over time as the agent gathers more information about the likelihood of each outcome," Natenzon said.

The researchers provide a new framework to analyze how people prefer to receive news in instances of possible risk, such as a health condition or a hoped-for promotion. "In organizations, leaving workers in the dark with too little feedback can be bad for morale. But overwhelming them with too much feedback too often can be just as bad," Natenzon said. "Our work provides an analytic toolkit to precisely quantify the tradeoffs involved and find the sweet spot."

The study addresses the difference between information-seeking and information-aversion behaviors. Some people are naturally bent to prefer surprise while others may be apprehensive when it comes to receiving news. Their model also can help explain the puzzling "ostrich effect," which describes the tendency people have to become information seeking after learning good news, but information adverse when learning bad news.

"Many people bury their heads in the sand after receiving some bad news. The behavioral literature has shown that people's preferences over information disclosure can be nuanced," Natenzon said.

Natenzon believes that a study such as this one can help future research to try to map predictable patterns as a starting point in further exploration of potential attitudes toward receiving information. In the real world, people are more complex than what a model can predict on its own.

"This is a very active area of research, and having the right theoretical framework to guide our thinking about these issues can be the key to advance our understanding. The theoretical results we obtained in this study have allowed us to formulate new questions about information demand, and we are starting to test them experimentally in the lab, which is incredibly exciting."The desire for information: Blissful ignorance or painful truth?

More information: Random Evolving Lotteries and Intrinsic Preference for Information: www.econometricsociety.org/sys … em/files/16190-4.pdf

Provided by Washington University in St. Louis

#SPECIESISM

Giraffes are as socially complex as elephants: study

by University of Bristol

Scientists at the University of Bristol have discovered evidence that giraffes are a highly socially complex species.

Traditionally, giraffes were thought to have little or no social structure, and only fleeting, weak relationships. However in the last ten years, research has shown that giraffe social organization is much more advanced than once thought.

In a paper published in today in the journal Mammal Review, Zoe Muller, of Bristol's School of Biological Sciences, has demonstrated that giraffes spend up to 30% of their lives in a post-reproductive state. This is comparable to other species with highly complex social structures and cooperative care, such as elephants and killer-whales which spend 23% and 35% of their lives in a post-reproductive state respectively. In these species, it has been demonstrated that the presence of post-menopausal females offers survival benefits for related offspring. In mammals—and –ncluding humans—this is known as the 'Grandmother hypothesis' which suggests that females live long past menopause so that they can help raise successive generations of offspring, thereby ensuring the preservation of their genes. Researchers propose that the presence of post-reproductive adult female giraffes could also function in the same way, and supports the author's assertion that giraffes are likely to engage in cooperative parenting, along matrilines, and contribute to the shared parental care of related kin.

Zoe said: "It is baffling to me that such a large, iconic and charismatic African species has been understudied for so long. This paper collates all the evidence to suggest that giraffes are actually a highly complex social species, with intricate and high-functioning social systems, potentially comparable to elephants, cetaceans and chimpanzees.

"I hope that this study draws a line in the sand, from which point forwards, giraffes will be regarded as intelligent, group-living mammals which have evolved highly successful and complex societies, which have facilitated their survival in tough, predator-filled ecosystems."

For scientists to recognize giraffes as a socially complex species, Zoe has suggested eight key areas for future research, including the need to understand the role that older, post-reproductive adults play in society and what fitness benefits they bring for group survival.

Zoe added: "Recognizing that giraffes have a complex cooperative social system and live in matrilineal societies will further our understanding of their behavioral ecology and conservation needs.

"Conservation measures will be more successful if we have an accurate understanding of the species' behavioral ecology. If we view giraffes as a highly socially complex species, this also raises their 'status' towards being a more complex and intelligent mammal that is increasingly worthy of protection."

Just like humans, giraffes prefer to dine with friends, study finds

More information: A review of the social behaviour of the giraffe Giraffa camelopardalis: a misunderstood but socially complex species, Mammal Review (2021).

Provided by University of Bristol

Skull of 340 million year old animal digitally recreated, revealing secrets of ancient amphibian

by University of Bristol

Researchers from the University of Bristol and University College London have used cutting-edge techniques to digitally reconstruct the skull of one of the earliest limbed animals.

Tetrapods include mammals, reptiles and amphibians—everything from salamanders to humans. Their origin represents a crucial time in animal evolution, from the development of limbs with digits and the shift from water on to land. The study, which was recently published in the Journal of Vertebrate Paleontology, depicts the reconstructed skull of a prehistoric amphibian, the 340-million year old Whatcheeria deltae, to reveal what this animal looked like and how it may have fed.

First discovered in Iowa in 1995, the fossils of Whatcheeria were originally squashed flat after being buried by mud at the bottom of an ancient swamp, but paleontologists were able to use computational methods to restore the bones to their original arrangement. The fossils were put through a CT scanner to create exact digital copies, and software was used to separate each bone from the surrounding rock. These digital bones were then repaired and reassembled to produce a 3D model of the skull as it would have appeared while the animal was alive.

The authors found that Whatcheeria possessed a tall and narrow skull quite unlike many other early tetrapods that were alive at the time. Lead author James Rawson, who worked on this project alongside his undergraduate degree in paleontology and evolution, said: "Most early tetrapods had very flat heads which might hint that Whatcheeria was feeding in a slightly different way to its relatives, so we decided to look at the way the skull bones were connected to investigate further."

By tracing the connecting edges of the skull bones, known as sutures, the authors were able to figure out how this animal tackled its prey. Professor Emily Rayfield, of the University of Bristol's School of Earth Sciences, who also worked on the study, said: "We found that the skull of Whatcheeria would have made it well-adapted to delivering powerful bites using its large fangs."

Co-author Dr. Laura Porro said: "There are a few types of sutures that connect skull bones together and they all respond differently to various types of force. Some are better at dealing with compression, some can handle more tension, twisting and so on. By mapping these suture types across the skull, we can predict what forces were acting on it and what type of feeding may have caused those forces."

The authors found that the snout had lots of overlapping sutures to resist twisting forces from struggling prey, while the back of the skull was more solidly connected to resist compression during biting.

Mr Rawson added: "Although this animal was still probably doing most of its hunting in the water, a bit like a modern crocodilian, we're starting to see the sorts of adaptations that enabled later tetrapods to feed more efficiently on land."

Fossil skull sheds new light on transition from water to land

More information: James R. G. Rawson et al, Osteology and digital reconstruction of the skull of the early tetrapod Whatcheeria deltae, Journal of Vertebrate Paleontology (2021). DOI: 10.1080/02724634.2021.1927749

Journal information: Journal of Vertebrate Paleontology

Provided by University of Bristol

Why is this weird, metallic star hurtling out of the Milky Way?

by Boston University

supernova — Credit: Pixabay/CC0 Public Domain

About 2,000 light-years away from Earth, there is a star catapulting toward the edge of the Milky Way. This particular star, known as LP 40−365, is one of a unique breed of fast-moving stars—remnant pieces of massive white dwarf stars—that have survived in chunks after a gigantic stellar explosion.

"This star is moving so fast that it's almost certainly leaving the galaxy…[it's] moving almost two million miles an hour," says JJ Hermes, Boston University College of Arts & Sciences assistant professor of astronomy. But why is this flying object speeding out of the Milky Way? Because it's a piece of shrapnel from a past explosion—a cosmic event known as a supernova—that's still being propelled forward.

"To have gone through partial detonation and still survive is very cool and unique, and it's only in the last few years that we've started to think this kind of star could exist," says Odelia Putterman, a former BU student who has worked in Hermes' lab.

In a new paper published in The Astrophysical Journal Letters, Hermes and Putterman uncover new observations about this leftover "star shrapnel" that gives insight to other stars with similar catastrophic pasts.

Putterman and Hermes analyzed data from NASA's Hubble Space Telescope and Transiting Exoplanet Survey Satellite (TESS), which surveys the sky and collects light information on stars near and far. By looking at various kinds of light data from both telescopes, the researchers and their collaborators found that LP 40−365 is not only being hurled out of the galaxy, but based on the brightness patterns in the data, is also rotating on its way out.

"The star is basically being slingshotted from the explosion, and we're [observing] its rotation on its way out," says Putterman, who is second author on the paper.

"We dug a little deeper to figure out why that star [was repeatedly] getting brighter and fainter, and the simplest explanation is that we're seeing something at [its] surface rotate in and out of view every nine hours," suggesting its rotation rate, Hermes says. All stars rotate—even our sun slowly rotates on its axis every 27 days. But for a star fragment that's survived a supernova, nine hours is considered relatively slow.

Supernovas occur when a white dwarf gets too massive to support itself, eventually triggering a cosmic detonation of energy. Finding the rotation rate of a star like LP 40−365 after a supernova can lend clues into the original two-star system it came from. It's common in the universe for stars to come in close pairs, including white dwarfs, which are highly dense stars that form toward the end of a star's life. If one white dwarf gives too much mass to the other, the star being dumped on can self-destruct, resulting in a supernova. Supernovas are commonplace in the galaxy and can happen in many different ways, according to the researchers, but they are usually very hard to see. This makes it hard to know which star did the imploding and which star dumped too much mass onto its star partner.

Based on LP 40−365's relatively slow rotation rate, Hermes and Putterman feel more confident that it is shrapnel from the star that self-destructed after being fed too much mass by its partner, when they were once orbiting each other at high speed. Because the stars were orbiting each other so quickly and closely, the explosion slingshotted both stars, and now we only see LP 40–365.

"This [paper] adds one more layer of knowledge into what role these stars played when the supernova occurred," and what can happen after the explosion, Putterman says. "By understanding what's happening with this particular star, we can start to understand what's happening with many other similar stars that came from a similar situation."

"These are very weird stars," Hermes says. Stars like LP 40–365 are not only some of the fastest stars known to astronomers, but also the most metal-rich stars ever detected. Stars like our sun are composed of helium and hydrogen, but a star that has survived a supernova is primarily composed of metal material, because "what we're seeing are the by-products of violent nuclear reactions that happen when a star blows itself up," Hermes says, making star shrapnel like this especially fascinating to studyBlistering stars in the Universe: Rare insights into the evolution of stars

More information: J. J. Hermes et al, 8.9 hr Rotation in the Partly Burnt Runaway Stellar Remnant LP 40-365 (GD 492), The Astrophysical Journal Letters (2021). DOI: 10.3847/2041-8213/ac00a8

Journal information: Astrophysical Journal Letters

Provided by Boston University

ONE WORD;CHINA

The chips are down: why there's a semiconductor shortage

by Katy Lee

Thousands of unfinished cars are seen parked at a Volkswagen factory in Pamplona, Spain, in May due to the lack of semiconductor supplies.

A shortage of semiconductors has sent shockwaves through the global economy, squeezing supplies of everything from cars to headphones.

The dearth of chips has exposed the modern world's reliance on these miniscule components, the basic building blocks of computers which allow electronic devices to process data. Why is the shortage happening, and what can be done about it?

How is the shortage linked to the pandemic?

The start of the Covid-19 crisis in early 2020 prompted a global spending spree on electronic items—from extra monitors as people rushed to set up home offices, to televisions and games consoles for beating lockdown boredom.

Temporary factory closures due to the pandemic also put pressure on supplies.

And as plants reopened, electronic goods producers continued to place orders—creating an ever-increasing backlog for the chips, which can be just a fraction of a millimetre long.

The pandemic isn't the only factor. A storm briefly halted production at several plants in Texas in February, and a fire ripped through a Japanese factory in March.

US-China tensions are also part of the story. Last August, the US banned foreign companies whose chips use American technology from selling to Chinese tech giant Huawei, over espionage allegations.

Huawei began stockpiling semiconductors ahead of the sanctions coming into effect, and other companies followed their lead, further straining supplies.

Which industries have been hit?

Making semiconductors is a delicate process that involves pressing layers of chemicals into silicon.

The car industry has been the most visible victim so far, with many brands forced to slow their output in recent months.

As automakers slashed production early in the pandemic, their chip suppliers turned to clients from other sectors—namely the makers of electronic goods in high demand due to the pandemic.

That has left car brands, from Volkswagen to Volvo, scrambling to get hold of semiconductors now that sales are revving up again.

Smartphone makers had been relatively protected so far as they had existing stockpiles of chips, but they too are starting to suffer.

Apple CEO Tim Cook warned this week that the shortages are set to hit the production of iPhones and iPads. Smaller phone-makers are likely to be worse affected, analysts say.

Games consoles like the PlayStation 5 and Xbox Series X have also been in short supply.

So great is the clamour among gamers to get hold of chip-powered graphic cards needed for their playing, that they have been resorting to increasingly unusual strategies.

The die-hards are tuning into live-streams on YouTube and Twitch, which ring an alarm every time a card is listed for sale online.

When will this end?

Governments are hurrying to boost their chip-making capacities, meanwhile.

The pandemic has revealed our dependence on semiconductors, tiny components essential to many electronic goods.

In May, South Korea announced a whopping $451 billion investment in its bid to become a semiconductor giant, while the US Senate last month voted through $52 billion in subsidies for chip plants, known as "fabs".

The European Union is seeking to double its share of global chip-manufacturing capacity to 20 percent of the market by 2030.

But factories cannot open overnight—particularly those that make semiconductors, a delicate process that involves pressing layers of chemicals into silicon.

"Building new capacity takes time—for a new fab, more than 2.5 years—so most expansions that are starting now will not increase the available capacity until 2023," said Ondrej Burkacky, senior partner and co-leader of the global semiconductors practice at consultancy McKinsey.

He added that long-term factors also meant global demand was in "hyper growth", such as the trend towards companies storing their data in the cloud, requiring more and more data centres to be built—sites that use huge quantities of chips.

Jean-Marc Chery, CEO of Franco-Italian chip-maker STMicroelectronics, said orders for next year have already outstripped his company's manufacturing capacities.

There is a broad acknowledgement within the industry that the shortage "will last up to next year minimum," he said.

Analysts say the continuing squeeze could lead to higher prices for consumers.

SEB, a French maker of kitchen equipment such as blenders, has already warned that it is being forced to hike its prices

'Perfect storm': phones, consoles could get pricier as chip crisis bites

NAUGHTY TECHNO CRIMINAL CAPITALI$M

Zoom to settle US privacy lawsuit for $85 mn

Zoom, the videoconferencing firm, has agreed to settle a class-action US privacy lawsuit for $85 million, it said Sunday.

The suit charged that Zoom's sharing of users' personal data with Facebook, Google and LinkedIn was a breach of privacy for millions.

While Zoom denied wrongdoing, it did agree to improve its security practices.

The settlement needs to be approved by US District Judge Lucy Koh in San Jose, California.

A Zoom spokesman told AFP: "The privacy and security of our users are top priorities for Zoom, and we take seriously the trust our users place in us.

"We are proud of the advancements we have made to our platform, and look forward to continuing to innovate with privacy and security at the forefront."

The settlement will set up a "non-reversionary cash fund of $85 million to pay valid claims, notice and administration costs, Service Payments to Class Representatives, and any attorneys' fees and costs awarded by the Court," according to the preliminary settlement.

All class members are eligible for payment, it said.

Those who paid for an account can receive 15 percent of the money they paid to Zoom for their core subscription during that time or $25, whichever is greater; while those who did not pay for a subscription can make a claim for $15.

As the coronavirus pandemic closed offices due to health risks and companies shifted to working online, use of video and collaboration platforms hosted by companies including Zoom, Slack, Microsoft, and Google rocketed.

But Zoom's rapid growth came with pressure to deal with security and privacy as the platform faced scrutiny from rising usage.

Zoom buys security firm Keybase

CRIMINAL CRYPTO CAPITALI$M

'Vultur' malware uses new technique to steal banking credentials

A team of researchers at the security firm ThreatFabric is reporting on their website blog page that they have found instances of a new kind of malware in Android apps downloaded from Google Play that attempt to steal banking login information. They have named the new malware Vultur, after the birds that prey on wounded or dead targets.

The team at ThreatFabric note that prior efforts to steal banking login and password information from users of Android-based devices have used overlays; where an image is pasted over the top of an application's login page and data from it is then routed to the hackers. In this new threat, the Vultur software instead uses code to recognize when a data entry form is being used, takes a screen grab, and then begins keylogging. All of the data captured by the malware is then routed to a site specified by its creators.

The team at ThreatFabric notes that thus far, Vultur has mostly affected people living in Italy, Australia, the U.K and the Netherlands—and while its prime mission appears to be capturing banking login information, instances of keylogging have also been found for social media apps, such as TikTok, Facebook and WhatsApp—they have also seen a few instances of cryptocurrency apps being targeted as well.

The malware can make its way onto user devices via a "dropper" called Brunhilda, which has been found in several phone-security, fitness and authentication apps—all on Google Play. The team at ThreatFabric is estimating that approximately 30,000 Android-based devices have been infected with Brunhilda to date, which suggests that thousands of users have likely been infected with Vultur. They also note that Vultur makes use of Accessibility Services on infected devices to prevent users from removing it from their device—it instigates a Back button press if such an attempt is made.

Users can prevent the malware from stealing their data by denying access when notified by Accessibility Services. Also, the malware can be detected by a casting icon appearing when users are not casting something. ThreatFabric also suggests installing Android antivirus apps.

New malware detection for Android at the source code level

More information: threatfabric.com/blogs/vultur-v-for-vnc.html

Nitrous oxide emissions coming from legume cover crops, manure, can be reduced

by Jeff Mulhollem, Pennsylvania State University

The application of manure after the growth and demise of legume cover crops in rotations is a recipe to increase nitrous oxide releases during ensuing corn growth, according to a team of Penn State researchers who conducted a new study. They suggest that innovative management strategies are needed to reduce these emissions.

"In the United States, agriculture accounts for approximately 10% of all greenhouse gas emissions but contributes about 80% of all nitrous oxide emissions linked to human activity," he said. "Of the three major greenhouse gases emitted naturally—carbon dioxide, methane and nitrous oxide—nitrous oxide is the most important in field crops. We have an obligation, I believe, to develop climate-friendly farming practices and reduce nitrous oxide emissions."The greenhouse gas—nitrous oxide—is important because it is about 300 times better at trapping heat than is carbon dioxide, so even small emissions of nitrous oxide affect the climate, explained team leader Armen Kemanian, professor of production systems and modeling in the College of Agricultural Sciences.

With organic agriculture growing in significance, nitrous oxide emissions are undergoing added scrutiny because soil fertility in organic agriculture relies on microbial cycling of nutrient inputs from legume cover crops and animal manure. However, large quantities of carbon and nitrogen in these amendments may promote the production and emission of nitrous oxide from soils, Kemanian pointed out.

"A better understanding of the nitrous oxide emission controls may lead to new management strategies to reduce these emissions," he said. "Agriculture is the science of interventions."

Nitrous oxide emissions related to cover crops are an unexpected complication from an ecologically smart, best-management practice, but one that the researchers expect can be managed. The wide adoption of cover cropping has been a conservation boon for agriculture in the Chesapeake Bay Watershed and much of the Northeast. Cover crops grown in rotations with corn and soybeans curtail nutrient runoff and soil erosion.

But the nitrogen in the decaying biomass from the cover crops, combined with the nitrogen in applied manure, is often too much for the soil to hold.

As with any agricultural practice, there are trade-offs with cover cropping, noted Debasish Saha, assistant professor of sustainable soil management, University of Tennessee. Formerly a postdoctoral scholar in Penn State's Department of Plant Science, he spearheaded the research.

"Cover crops bring a lot of benefits, but not everything that comes with a cover crop is a benefit—they need to be managed," Saha said. "For example, we know that certain cover crops will boost nitrogen retention. You plant a grassy cover crop, it takes up nitrogen that is not lost to water, but the type of residue left by these grasses makes for lazy release of nitrogen for the following crop. That trade-off is well-known."

To reach their conclusions, researchers measured soil nitrous oxide emissions for two growing seasons in four corn-soybean-winter grain rotations, with tillage, cover crop and manure-management variations typical of organic agriculture in temperate and humid North America. The study was established within the Reduced-Tillage Organic Systems Experiment at Penn State's Russell E. Larson Agricultural Research Center at Rock Springs.

To identify nitrous oxide-production pathways and mitigation opportunities, the researchers measured fluctuating nitrous oxide emissions in microplots where they manipulated cover crops and manure additions. The researchers suggest that high levels of nitrous oxide emissions came after fast oxygen consumption in the soil resulting from the burial of cover crop residues and manure.

Low oxygen in the soil, a condition called hypoxia, favors the metabolism of denitrifying bacteria and the release of nitrous oxide. "The process is invisible to us, but swift and brusque for the microbes," Kemanian said. "We knew that cover crops needed to be managed, but we weren't aware that they needed to be managed for nitrous oxide emissions. We just found a big leak."

In findings recently published in Ecological Applications, the researchers reported that the nitrogen input from legume cover crops and manure prior to corn planting made the corn phase of rotations the main source of nitrous oxide emissions, with emissions averaging about 10 pounds per acre of nitrogen escaping as nitrous oxide.

"That is a very large rate, any way you look at it," Kemanian said. "That represents 80% of the three-year rotations' total emissions. Nitrous oxide emissions rose sharply when both legume and manure inputs increased simultaneously."

The researchers proposed several strategies to reduce those emissions. One is to remove a fraction of the legume aboveground biomass before corn planting. In the study, preventing the "co-location" of fresh biomass and manure decreased nitrous oxide emissions by 60% during the corn phase.

Climate-smart ag strategies may cut nitrous oxide emissions from corn production

More information: Debasish Saha et al, Organic fertility inputs synergistically increase denitrification‐derived nitrous oxide emissions in agroecosystems, Ecological Applications (2021). DOI: 10.1002/eap.2403

Journal information: Ecological Applications

Provided by Pennsylvania State University

Stinkweed could make a cleaner bio-jet fuel, study finds

by Laura Arenschield, The Ohio State University

A common farm weed could make a 'greener' jet fuel with fewer production-related environmental impacts than other biofuels, a new study indicates.

Growing the weed, pennycress—often called stinkweed—as a crop requires less fertilizer and fewer pesticides than other plants that can be used to make renewable jet fuel, according to the study. Pennycress also requires fewer farm operations, such as soil tilling, than other potential biofuel crops, reducing the associated environmental costs. Those costs include carbon dioxide emissions that cause the climate to change, as well as other emissions that pollute the air.

Environmental impacts could be further mitigated through farm management techniques that keep fertilizer on fields, rather than allowing it to run off into nearby watersheds, the study suggests. Such techniques can add to the financial cost of growing crops, but reduce their environmental footprints.

"Reducing greenhouse gas emissions from air travel will mean not just incremental changes, but a fundamental change in how we have been producing fuel and where that fuel comes from," said Ajay Shah, senior author of the study and associate professor of food, agricultural and biological engineering at The Ohio State University in Wooster. "And what we found is that pennycress might make a very good alternative fuel, especially when you consider the environmental costs of producing it."

The study was published recently online in the journal Applied Energy.

For this study, the researchers estimated the environmental impacts of growing pennycress, transporting it to a biorefinery and converting it to a usable jet fuel. They also accounted for the environmental costs of burning leftover byproducts of refining the pennycress seed into fuel.

Those environmental costs include fertilizer and pesticide use, water consumption and the energy required to harvest and transport pennycress seeds from a farm to a biorefinery and process them into usable fuel.

The researchers built computer models to determine how much total energy it would take to produce jet fuel from pennycress seeds and compared those estimates with the energy needed for producing biofuels from other crops. The data for the models came from existing studies about biofuel production.

Their models showed that it took about half as much energy to produce jet fuel from pennycress as it did to produce jet fuel from canola or sunflowers, two other potential bio-jet fuel crops. Pennycress oil production used about a third as much energy as soybean oil production, the researchers found, and the energy needed for turning pennycress into jet fuel was about the same as that used to produce fuel from the flowering plant camelina, another biofuel crop.

Renewable jetfuels are not yet financially competitive with fossil fuel-based fuels, Shah said. But calculating the environmental impacts of alternative bio-based fuels should help both farmers and policymakers as they try to limit carbon dioxide in the Earth's atmosphere and, hopefully, to slow or stop climate change.

"Pennycress also makes an appealing alternative jet fuel because of its growing season," Shah said. "It is a winter cover crop that can be grown between corn season and soybean season, giving the same body of farmland an extra production cycle each year."

"Pennycress can be planted when corn is still standing in the field, before the corn harvest," he said. "And it can be harvested before the soybean crops are planted. The bottom line is it can be used as a cover crop, it doesn't divert any agricultural production land, and it has suitable properties for renewable jet fuel production."

Greenhouse gas emissions from air travel contribute to climate change, accounting for about 2% of all human-induced carbon-dioxide emissions, according to various groups that study the effects of transportation on climate change.

"Reducing those emissions will almost certainly mean finding cleaner alternatives to jet fuels made from fossil fuels," Shah said. "Studies like this one can help determine the best alternative."

"When it comes to pennycress, production and logistics are the big contributors to both the environmental impacts and the costs, and those are the challenge areas—they have to be streamlined and solved to make it more efficient," he said. "If we could improve those areas, we could make production more energy-efficient and substantially lower the costs and environmental impacts."

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More information: Seyed Hashem Mousavi-Avval et al, Life cycle energy and environmental impacts of hydroprocessed renewable jet fuel production from pennycress, Applied Energy (2021). DOI: 10.1016/j.apenergy.2021.117098

Provided by The Ohio State University

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