Researcher Paul Patterson, professor of poultry science, College of Agricultural Sciences, suggests the technology has merit for commercial application in the egg industry.

“This study is unique because it scaled-up and applied components of standard egg processing to a conveyor and sanitizing eggs in a commercial setting,” he said. “In the absence of water or other chemical sanitizers, this technology has the potential to achieve significant — equal or greater — microbial reductions than some currently available technologies.”

Every year in the United States, an average of 287 eggs are consumed per person, and more than 14.1 billion eggs are set in hatchery incubators to produce chicks destined for the egg and meat bird industries. By reducing the microbial load on eggs, foodborne illness outbreaks associated with eggs and poultry meat can be reduced while chick health is maintained.

The egg industry currently uses sanitizers and detergents to decontaminate eggs and wash off any physical debris, while low-intensity ultraviolet light has been used as an additional antimicrobial step. However, pulsed ultraviolet light is more effective, explained lead researcher Josh Casser, doctoral candidate in animal science, because it delivers a higher intensity of ultraviolet light to the surface of the eggshell. That results in a greater microbial reduction in a shorter period of time than conventional ultraviolet light treatment.

In this study, the surfaces of shell eggs were inoculated with nonpathogenic bacteria strains used for research and were treated with pulsed ultraviolet light derived from a xenon flashlamp. Eggs were exposed on a modified egg-carrying conveyor that provided complete rotation of eggs under the flashlamp.

The novel conveyor devised for the experiment was instrumental in achieving acceptable decontamination, Casser noted, adding that the xenon flashlamps could be scaled up and customized for any commercial installation.

“As the egg rotates on its long axis along the way, the entire surface of the eggshell is exposed to the pulsed ultraviolet light energy, and the 27 seconds of exposure in our experiment resulted in an acceptable germicidal response,” he said. “At three pulses per second, each egg is exposed to nearly 90 pulses, and each pulse has a duration of 360 microseconds — an extremely short duration pulse.”

The researchers, who recently published their results in Poultry Science, found that pulsed ultraviolet light treatment inactivated two different microbial strains, with greater energy resulting in a greater germicidal response.

The study also evaluated the effects of pulsed ultraviolet light treatment of hatching eggs on both embryo and chick growth. Using the same system, four batches of 125 fertile eggs were treated with the same and greater intensities of pulsed ultraviolet light. After processing, eggs were placed in a commercial incubator under normal incubation conditions.

There was no significant effect of the pulsed ultraviolet light treatment on percent fertility, hatchability or hatch. Also, there were no significant effects on post-hatch observations, including chick livability and average bird weight at hatch or at 42 days of age.

“Our research supports the application of pulsed ultraviolet light as an effective antimicrobial intervention for both table and hatching eggs,” Cassar said. “If the egg industry embraces pulsed ultraviolet light technology and applies it in its processing operations, food safety would be improved because of the reduced pathogen presence on the surface of the eggs. And that matters because 9% of all foodborne illness in the U.S. is associated with eggs.”

The technology is especially promising because it appears to have no negative consequences for the vital hatching-eggs component of the business, even at 10 times the UV-light intensity used in the table egg study, Patterson pointed out. Hatcheries produce the replacement stock for both the egg and broiler flocks of the poultry industry, including turkeys.

“Our research showed that there are no negative effects on hatching eggs and the embryos and chicks that are derived from those treated eggs,” he said. “Using pulsed ultraviolet light before incubation in a hatchery setting would improve chick health, would avoid some of the financial constraints caused by poor chick quality resulting from chicks getting sick from early exposure to microbial pathogens, and potentially would improve the food safety of poultry meat.”

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“While we knew that the memories of people with primary progressive aphasia were not affected at first, we did not know if they maintained their memory functioning over years,” said study author M. Marsel Mesulam, M.D., of Northwestern University Feinberg School of Medicine in Chicago and a Fellow of the American Academy of Neurology. “This has been difficult to determine because most memory tests rely on verbal skills that these people have lost or are losing.”

The study included 17 people with primary progressive aphasia associated with Alzheimer’s disease. They were compared to 14 people who had typical Alzheimer’s disease with memory loss.

Researchers tested memory skills of the people with primary progressive aphasia by showing them pictures of common objects. After waiting 10 minutes, they were shown the same pictures along with others and had to indicate whether they had seen the picture before. This test was given once and then again an average of 2.4 years later. The people with typical Alzheimer’s disease listened to a list of common words and were later given the same words along with others and asked to choose the ones they had heard before. They were tested once and then again an average of 1.7 years later.

Both groups also had tests of their language skills. Brain scans were taken of the people with primary progressive aphasia to look at how the disease was affecting their brains, especially in the areas related to memory.

The people with primary progressive aphasia had no decline in their memory skills when they took the tests a second time. At that point, they had been showing symptoms of the disorder for an average of six years. In contrast, their language skills declined significantly during the same period. For the people with typical Alzheimer’s disease, their verbal memory and language skills declined with equal severity during the study.

Researchers had brain autopsies from eight of the people with primary progressive aphasia and all of the people with typical Alzheimer’s disease. The people with primary progressive aphasia had similar amounts of the plaques and tangles that are signs of Alzheimer’s disease as the people with typical Alzheimer’s, Mesulam said. Left sided asymmetry of brain shrinkage and a lower incidence of brain proteins known as ApoE4 and TDP-43 were identified as potential contributors to the preservation of memory in this rare type of Alzheimer’s disease.

“More research is needed to help us determine what factors allow these people to show this resilience of memory skills even in the face of considerable Alzheimer’s disease pathology in the brain,” Mesulam said.

Limitations of the study are the relatively small sample size and that autopsies were not available for all of the primary progressive aphasia cases.

The study was supported by the National Institute on Deafness and Other Communication Disorders, National Institute of Neurological Disorders and Stroke, The Davee Foundation and The Jeanine Jones Fund.

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Some previous research has found that typical familial patterns may get upended during crises, but that’s not what Shockley and her colleagues found in the early months of the COVID-19 shutdown.

“Most people have never undergone anything like this before, where all of a sudden they can’t rely on their normal child care, and most people’s work situation has changed too,” said Shockley, associate professor of psychology in the Franklin College of Arts and Sciences. “We thought this would be a chance for men to step in and partake equally in child care, but for many couples we didn’t see that happen.”

In mid-March, as schools and day cares closed and many shifted to remote work, Shockley and her colleagues quickly created a survey targeting dual-earner couples with at least one child under age 6.

“My son was 15 months old when this all started, and I know firsthand that you can’t just plop younger kids in front of a TV or expect them to do their schoolwork,” she said. “We were particularly interested in people who really had to provide active child care.”

The team initially surveyed 274 couples, conducting a follow-up survey with 133 of the same couples in May. The study, which will appear Journal of Applied Psychology, assessed marital tension, health and job performance in addition to child care strategies.

“When the wife does it all, not surprisingly, the outcomes are bad for the couple,” Shockley said. “It’s not just bad for the wife, it’s also bad for the husband, including in terms of job performance although his work role presumably hasn’t changed. When one person’s doing it all, there’s a lot of tension in the relationship, and it’s probably spilling over into the husband’s ability to focus at work.”

Though 36.6% of couples relied on the wife to provide most or all child care, 44.5% used more egalitarian strategies, and 18.9% used strategies that were not clearly gendered or egalitarian.

Egalitarian strategies included alternating work days, planning daily mini shifts that included both work and child care for husband and wife, and alternating shifts that changed day to day based on the couple’s work needs.

“When you look at the more egalitarian strategies, we found the best outcomes for people who were able to alternate working days,” Shockley said. “The boundaries are clear. When you’re working, you can really focus on work, and when you’re taking care of the kids, you can really focus on the kids. But not everybody has jobs amenable to that.”

When both people were working at home, planned mini shifts and needs-based alternation had similar well-being outcomes for the couple, but job performance was higher for couples who used needs-based alternation, according to Shockley.

“I think that’s due to the communication that comes with it, and the flexibility within your dyad at home,” she said. “For couples who are continuing to work remotely, I would say needs-based alternation with night-before communication about work needs is probably better than having fixed shifts.”

Although the paper doesn’t include qualitative quotes, Shockley remembers the participants’ comments quite clearly.

“People were saying, ‘I’m at my breaking point,’ and this was just two weeks in. A lot of people said, ‘I’m just not sleeping.’ You could feel people’s struggle, and there was a lot of resentment, particularly when the wife was doing it all,” she said.

“This really highlights some infrastructure issues we have with the way we think about child care in this country. The default becomes, ‘Oh well, the wife is going to pick up the slack.’ It’s not a long-term solution.”

Shockley also noted that the couples surveyed have relatively high incomes.

“Compared to the country, the household income of our study is pretty high,” she said. “This might look different in lower-income samples. We might see totally different strategies emerging, particularly if there’s less possibility for remote work.”

Co-authors include Malissa A. Clark and Hope Dodd at UGA and Eden B. King at Rice University.

Completely shifting to no-till would reduce soil loss and sediment yield by more than 70%, says Sanghyun Lee, doctoral student in the Department of Agricultural and Biological Engineering at U of I and lead author on the study, published in Journal of Environmental Management.

But even a partial change in tilling practices could have significant results, he adds.

“If we focus on the most vulnerable area in terms of soil erosion, then only 40% no-till shows almost the same reduction as 100% no-till implementation,” Lee says.

The study used physical data and computer modeling to estimate soil erosion in the Drummer Creek watershed, which is part of the Upper Sangamon River watershed in Central Illinois. The area’s main crops are corn and soybeans, and tillage is a predominant agricultural practice.

“The rate of soil erosion is increased and accelerated by unsustainable agricultural production. One of the main reasons is conventional tillage in the field,” Lee says. “Our model provides a tool to estimate the impacts of tilling on soil erosion across the watershed.”

Lee and co-authors Maria Chu, Jorge Guzman, and Alejandra Botero-Acosta developed the modeling framework, coupling a hydrological model (MIKE SHE) with the Water Erosion Prediction Project (WEPP) to examine the impacts of no-till practice in the watershed. The WEPP model provided the sediment sources from the agricultural fields under different tillage practices and the hydrologic model simulated sediment transport across the watershed.

The researchers included historical data on climate, soil properties, sediment sample data, and other relevant measures, then used the coupled model to predict how different management practices affect soil erosion rates.

“Farmers may prefer tilling because wet climate conditions cause compacted soil,” Lee says. “However, soil erosion removes topsoil, which contains lots of nutrients, and this may reduce yield in the long term. Soil erosion also affects water quality, both locally over time and at a distance.

“Therefore, farmers need to weigh the benefits of tilling with the consequences of soil erosion and choose the best management strategies.”

The modeling framework can help identify the most vulnerable areas, so producers can implement sustainable management practices where it matters most, Lee notes.

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“The study addresses the impact of wildfires on global climate, and we extensively used the NCAR-Wyoming supercomputer (Cheyenne),” says Shane Murphy, a UW associate professor of atmospheric science. “Also, the paper used observations from UW and other teams around the world to compare to the climate model results. The main conclusion of the work is that wildfire smoke is more cooling than current models assume.”

Murphy was a contributing author of a paper, titled “Biomass Burning Aerosols in Most Climate Models Are Too Absorbing,” that was published Jan. 12 (today) in Nature Communications, an open-access journal that publishes high-quality research from all areas of the natural sciences. Papers published by the journal represent important advances of significance to specialists within each field.

Hunter Brown, who graduated from UW in fall 2020 with a Ph.D. in atmospheric science, was the paper’s lead author. Other contributors to the paper included researchers from Texas A&M University; North Carolina A&T State University; the University of Georgia; the Finnish Meteorological Institute; the Center for International Climate and Environmental Science, and Norwegian Meteorological Institute, both in Oslo, Norway; the University of Reading in the United Kingdom; North-West University in South Africa; the University of Science and Technology of China in Hefei, China; and Pacific Northwest National Laboratory in Richland, Wash.

The composition, size and mixing state of biomass burning aerosols determine the optical properties of smoke plumes in the atmosphere which, in turn, are a major factor in dictating how these aerosols perturb the energy balance in the atmosphere.

“We found that many of the most advanced climate models simulate biomass burning aerosols or smoke that is darker, or more light absorbing, than what we see in observations,” says Brown, of Juneau, Alaska. “This has implications for the climate predictions made by these models.”

Observations and models used in the study covered a wide temporal range. Africa, South America and Southeastern Asia, in addition to boreal fire regions, were chosen because these are the largest contributors to biomass burning smoke emissions in the world, Brown says.

The National Center for Atmospheric Research (NCAR)-Wyoming Supercomputing Center (NWSC) in Cheyenne was used for all of the data processing and the model sensitivity simulations, Brown says. Some of the other model data used for comparison in this study were generated elsewhere.

“When we compare global observations of wildfire smoke to simulated wildfire smoke from a collection of climate models, the vast majority of the models have smoke that is more light absorbing than the observations,” Brown explains. “This means that more energy from the sun is going toward warming the atmosphere in these models, as opposed to what we see in these field campaigns and laboratory studies, which report less absorbing smoke that has more of a cooling effect by scattering light away from the Earth and back to space.”

How absorbing these aerosols are in the atmosphere depends on the type of fuel that is burning, as well as the climate of the fire region. Generally, hot, dry grassland fires in Africa and Australia tend to have much darker smoke, which is more absorbing, while cooler, wetter boreal forest fires in North America and Northern Asia tend to have much brighter smoke, which is less absorbing.

After researchers made aerosol improvements to the model, African wildfire smoke still tended to be more absorbing than observations. This might be explained by simplifications in how aerosols evolve over time in the model, or it may be due to a lack of observations from this part of the world biasing the results toward the boreal fire regime, Brown explains.

“We were able to trace the disagreement between the model and observations to how the models represented the individual smoke particles, or aerosols, in the model,” Brown says. “This came down to how the model characterized their makeup, their size and the mixtures of different types of biomass burning aerosol. When we changed these variables in one of the models, we saw considerable improvement in the simulated smoke.”

This comparison of computer models and global observations is valuable for model development groups and may help reduce uncertainty in biomass burning aerosol climate impacts in models, Brown says.

The research, published Jan. 11 in the journal Proceedings of the National Academy of Sciences, helps to resolve a long-standing debate about the role of climate change in the rising costs of flooding and provides new insight into the financial costs of global warming overall.

“The fact that extreme precipitation has been increasing and will likely increase in the future is well known, but what effect that has had on financial damages has been uncertain,” said lead author Frances Davenport, a PhD student in Earth system science at Stanford’s School of Earth, Energy & Environmental Sciences (Stanford Earth). “Our analysis allows us to isolate how much of those changes in precipitation translate to changes in the cost of flooding, both now and in the future.”

The global insurance company Munich Re calls flooding “the number-one natural peril in the U.S.” However, although flooding is one of the most common, widespread and costly natural hazards, whether climate change has contributed to the rising financial costs of flooding — and if so, how much — has been a topic of debate, including in the most recent climate change assessments from the U.S. government and the Intergovernmental Panel on Climate Change.

At the crux of that debate is the question of whether or not the increasing trend in the cost of flooding in the U.S. has been driven primarily by socioeconomic factors like population growth, housing development and increasing property values. Most previous research has focused either on very detailed case studies (for example, of individual disasters or long-term changes in individual states) or on correlations between precipitation and flood damages for the U.S. overall.

In an effort to close this gap, the researchers started with higher resolution climate and socioeconomic data. They then applied advanced methods from economics to quantify the relationship between historical precipitation variations and historical flooding costs, along with methods from statistics and climate science to evaluate the impact of changes in precipitation on total flooding costs. Together, these analyses revealed that climate change has contributed substantially to the growing cost of flooding in the U.S., and that exceeding the levels of global warming agreed upon in the United Nations Paris Agreement is very likely to lead to greater intensification of the kinds of extreme precipitation events that have been most costly and devastating in recent decades.

“Previous studies have analyzed pieces of this puzzle, but this is the first study to combine rigorous economic analysis of the historical relationships between climate and flooding costs with really careful extreme event analyses in both historical observations and global climate models, across the whole United States,” said senior author and climate scientist Noah Diffenbaugh, the Kara J. Foundation Professor at Stanford Earth.

“By bringing all those pieces together, this framework provides a novel quantification not only of how much historical changes in precipitation have contributed to the costs of flooding, but also how greenhouse gases influence the kinds of precipitation events that cause the most damaging flooding events,” Diffenbaugh added.

The researchers liken isolating the role of changing precipitation to other questions of cause and effect, such as determining how much an increase in minimum wage will affect local employment, or how many wins an individual player contributes to the overall success of a basketball team. In this case, the research team started by developing an economic model based on observed precipitation and monthly reports of flood damage, controlling for other factors that might affect flooding costs like increases in home values. They then calculated the change in extreme precipitation in each state over the study period. Finally, they used the model to calculate what the economic damages would have been if those changes in extreme precipitation had not occurred.

“This counterfactual analysis is similar to computing how many games the Los Angeles Lakers would have won, with and without the addition of LeBron James, holding all other players constant,” said study co-author and economist Marshall Burke, an associate professor of Earth system science.

Applying this framework, the research team found that — when totaled across all the individual states — changes in precipitation accounted for 36 percent of the actual flooding costs that occurred in the U.S. from 1988 to 2017. The effect of changing precipitation was primarily driven by increases in extreme precipitation, which have been responsible for the largest share of flooding costs historically.

“What we find is that, even in states where the long-term mean precipitation hasn’t changed, in most cases the wettest events have intensified, increasing the financial damages relative to what would have occurred without the changes in precipitation,” said Davenport, who received a Stanford Interdisciplinary Graduate Fellowship in 2020.

The researchers emphasize that, by providing a new quantification of the scale of the financial costs of climate change, their findings have implications beyond flooding in the U.S.

“Accurately and comprehensively tallying the past and future costs of climate change is key to making good policy decisions,” said Burke. “This work shows that past climate change has already cost the U.S. economy billions of dollars, just due to flood damages alone.”

The authors envision their approach being applied to different natural hazards, to climate impacts in different sectors of the economy and to other regions of the globe to help understand the costs and benefits of climate adaptation and mitigation actions.

“That these results are as robust and definitive as they are really advances our understanding of the role of historical precipitation changes in the financial costs of flooding,” Diffenbaugh said. “But, more broadly, the framework that we developed provides an objective basis for estimating what it will cost to adapt to continued climate change and the economic value of avoiding higher levels of global warming in the future.”