Tracking ticks in Georgia to help monitor emerging diseases

Tickborne diseases are on the rise

Peer-Reviewed Publication

EMORY UNIVERSITY

 

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MAPPING THE LONE STAR TICK IS ANOTHER STEP IN A COMPREHENSIVE EMORY UNIVERSITY PROJECT TO TRACK AND MONITOR THE ARRAY OF TICK SPECIES IN GEORGIA AND THE DISEASES THAT THEY CAN SPREAD — INCLUDING THOSE CAUSED BY EMERGING PATHOGENS.

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CREDIT: EMORY UNIVERSITY

The most common tick found on humans in Georgia is the lone star tick — an aggressive seeker of blood that can spread dangerous pathogens through its bites.

Emory University researchers combined field data with spatial-analysis techniques to map the distribution of the lone star tick across the state. The journal Parasites & Vectors published the research, which identifies specific environmental conditions associated with this tick species, Amblyomma americanum, in Georgia.

The areas with the highest probability for the presence of lone star ticks include parts of the Southeastern Plains and Piedmont ecoregions of the state, including metro Atlanta.

“We found that these regions contain sweet spots for the lone star tick,” says Stephanie Bellman, first author of the study and an MD/PhD student in Emory’s School of Medicine and Rollins School of Public Health. “They tend to be more prevalent in forested areas of mid-elevation — not too high or too low — and in soils that retain moisture but are not swampy.”

The study maps the distribution at the scale of one square kilometer. That resolution is far finer than the currently available information, which is limited to the county level and does not encompass the state.

“As the weather warms and people start getting into the outdoors more, we hope our data can be used to target areas for tick-bite prevention messaging,” says Gonzalo Vazquez-Prokopec, professor in Emory’s Department of Environmental Sciences and senior author of the study.

Vazquez-Prokopec is a leading expert in vector-borne diseases — infections transmitted among humans and animals by the bite of a living organism, such as a tick or a mosquito.

Diseases the lone star tick is known to transmit include ehrlichiosis, southern tick-associated rash illness (STARI) and Heartland virus disease — which was first identified in the United States in 2009. The bite of the lone star tick is also associated with a potentially life-threatening allergy to red meat and dairy products known as alpha-gal syndrome.

Mapping the lone star tick is another step in a comprehensive Emory project to track and monitor the array of tick species in Georgia and the diseases that they can spread — including those caused by emerging pathogens.

Tickborne diseases are on the rise, far surpassing the incidence of diseases spread by mosquitos in the United States. While Lyme disease is the most common, the Centers for Disease Control and Prevention (CDC) currently recognizes 18 tickborne diseases in the country.

“We need to educate people that the environment that they grew up in is likely very different in terms of the number and types of ticks and the pathogens that they are carrying,” Vazquez-Prokopec says.

Climate change is fueling warmer and shorter winters, increasing opportunities for some species of ticks to breed more frequently and expand their ranges. Land-use changes are also strongly associated with tickborne diseases, as more human habitats encroach on wooded areas and the loss of natural habitat forces wildlife to live in denser populations.

“Georgia is a tick haven in general,” Bellman says, “since we have a long warm season and such a diversity of habitats.”

The researchers decided to focus first on mapping the distribution of the lone star tick because it is the dominant tick species in Georgia and can spread an array of pathogens. In 2019, the Emory researchers found that Heartland virus is circulating in lone star ticks in Georgia, an emerging pathogen that is not well understood.

Named for a bright, yellowish-white spot on its back, the lone star tick is widely distributed in wooded areas across the Southeast, Eastern and Midwest United States. It is tiny —in the nymph stage it is about the size of a sesame seed and as an adult it is barely a quarter-of-an-inch in diameter as an adult.

Despite its tiny size, the lone star tick is aggressive in its quest for blood meals. “They can sense carbon dioxide from your exhaled breath and the vibrations from your movement in a forest,” Bellman says. “They climb up onto vegetation and reach out their legs to grab onto you as you pass by.”

For the current study, Bellman led crews of Emory students, known as “the tick team,” in field surveys. They used “flagging” as a tick-collection technique. A white flannel cloth attached to a pole is swished in a figure-eight motion through the underbrush. Tweezers are used to transfer any ticks found on the flannel into a vial.

Tick team members surveyed 198 locations at 43 state parks and wildlife management areas across the state, from March to July 2022. Analyses combined the site-sampling data with environmental variables — including type of vegetation, land use, climate, elevation and other factors — characteristic for six different ecoregions of Georgia.

Lone star ticks were found in all of the ecoregions except for the mountainous Blue Ridge ecoregion in the northeast corner of the state. The majority of the ticks were found in forested areas of the Piedmont, Southeastern Plains and Southern Coastal Plains ecoregions.

The researchers encourage people to follow the recommendations of the CDC for preventing tick bites. And while the map for the lone star tick provides guidance on the likelihood of encountering the most prevalent human-biting tick in the state, there are other tick species that the researchers have yet to map.

The black-legged tick (Ixodes scapularis), which can transmit the bacterium that causes Lyme disease, for instance, is also established in Georgia. Lyme disease, however, is relatively uncommon in in the state for reasons that are not yet well-understood.

The researchers are also investigating the Asian longhorned tick (Haemaphysalis longicornis) in Georgia. Long established in China, Japan, Russia and parts of the Pacific, the Asian longhorned tick was first detected in the United States in 2017, in New Jersey, and has since spread to 19 states. It was found on farm animals in Pickens County, Georgia in 2021.

The Asian longhorned tick reproduces asexually and a single female can generate as many as 100,000 eggs, rapidly producing massive amounts of offspring that feed on livestock. So many ticks can be covering a single sheep or cow that the loss of blood physically weakens or, in extreme cases, kills the animal.

While it is often associated with livestock, the Emory research team recently found Asian longhorned ticks in the Buck Shoals Wildlife Management Area in White County, Georgia.

The Asian longhorned tick carries bacterial and viral pathogens that can infect humans, including severe fever with thrombocytopenia syndrome virus (SFTSV), also known as Dabie bandavirus. Human cases of SFTS, a hemorrhagic fever, emerged in China in 2009 and have since been identified in other parts of Asia, although not in the United States.

Also of concern is the fact that the Heartland virus shares genomic similarities with SFTS, which suggests the Asian longhorn tick could potentially transmit this emerging pathogen.

The Emory team has been finding the Heartland virus in lone star ticks collected from central Georgia starting in 2019. They have continued to find Heartland virus in at least some of the ticks collected from that area nearly annually through 2023. (They did not perform collections in 2020 due to the COVID-19 pandemic.)

More than 60 cases of Heartland virus disease have been reported in the United States, according to the latest CDC statistics. Many of the identified cases were severe enough to require hospitalization, and a few individuals with co-morbidities have died.

The actual number of people who may have been infected with Heartland virus is believed to be higher, however, since the virus is not well known and tests are rarely ordered for it. Complicating the issue is the fact that symptoms of Heartland virus are akin to those of many tickborne illnesses: fever, fatigue, headache, nausea, diarrhea and muscle or joint pain.

“Human cases of Heartland virus are rare now, but we don’t know whether that could change,” Bellman says. “We need to gather more baseline data and learn how it spreads in the environment so that we have the evidence we need to potentially prevent, or limit, its spread.”

Anne Piantadosi, assistant professor in Emory School of Medicine’s Department of Pathology and Laboratory Medicine, is co-author of the study.

Co-authors also include five Emory students who conducted fieldwork: Ellie Fausett (who has since graduated with a joint environmental sciences/MPH degree); Leah Aeschleman and Audrey Long (who have since received master’s of public health degrees from Rollins School of Public Health); Josie Pilchik, (who graduated with a bachelor’s in biology) and Isabella Roeske (an Emory senior majoring in environmental sciences).

Work on the current paper was funded by grants from the U.S. Department of Agriculture, National Institutes of Health, Emory University and the Emory MP3 Initiative and Infectious Disease Across Scales Training Program.

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JOURNAL

Parasites & Vectors

DOI

10.1186/s13071-024-06142-7 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

sMapping the distribution of Amblyomma americanum in Georgia, USA

With inspiration from “Tetris,” MIT researchers develop a better radiation detector

The device, based on simple tetromino shapes, could determine the direction and distance of a radiation source, with fewer detector pixels

MASSACHUSETTS INSTITUTE OF TECHNOLOGY

The spread of radioactive isotopes from the Fukushima Daiichi Nuclear Power Plant in Japan in 2011 and the ongoing threat of a possible release of radiation from the Zaporizhzhia nuclear complex in the Ukrainian war zone have underscored the need for effective and reliable ways of detecting and monitoring radioactive isotopes. Less dramatically, everyday operations of nuclear reactors, mining and processing of uranium into fuel rods, and the disposal of spent nuclear fuel also require monitoring of radioisotope release. 

Now, researchers at MIT and the Lawrence Berkeley National Laboratory (LBNL) have come up with a computational basis for designing very simple, streamlined versions of sensor setups that can pinpoint the direction of a distributed source of radiation. They also demonstrated that by moving that sensor around to get multiple readings, they can pinpoint the physical location of the source. The inspiration for their clever innovation came from a surprising source: the popular computer game “Tetris.”

The team’s findings, which could likely be generalized to detectors for other kinds of radiation, are described in a paper published in Nature Communications, by MIT professors Mingda Li, Lin-Wen Hu, Benoit Forget, and Gordon Kohse; graduate students Ryotaro Okabe and Shangjie Xue; research scientist Jayson Vavrek SM ’16, PhD ’19 at LBNL; and a number of others at MIT and Lawrence Berkeley. 

Radiation is usually detected using semiconductor materials, such as cadmium zinc telluride, that produce an electrical response when struck by high-energy radiation such as gamma rays. But because radiation penetrates so readily through matter, it’s difficult to determine the direction that signal came from with simple counting. Geiger counters, for example, simply provide a click sound when receiving radiation, without resolving the energy or type, so finding a source requires moving around to try to find the maximum sound, similarly to how handheld metal detectors work. The process requires the user to move closer to the source of radiation, which can add risk. 

To provide directional information from a stationary device without getting too close, researchers use an array of detector grids along with another grid called a mask, which imprints a pattern on the array that differs depending on the direction of the source. An algorithm interprets the different timings and intensities of signals received by each separate detector or pixel. This often leads to a complex design of detectors.  

Typical detector arrays for sensing the direction of radiation sources are large and expensive and include at least 100 pixels in a 10 by 10 array. However, the group found that using as few as four pixels arranged in the tetromino shapes of the figures in the “Tetris” game can come close to matching the accuracy of the large, expensive systems. The key is proper computerized reconstruction of the angles of arrival of the rays, based on the times each sensor detects the signal and the relative intensity each one detects, as reconstructed through an AI-guided study of simulated systems.

Of the different configurations of four pixels the researchers tried — square, or S-, J- or T-shaped — they found through repeated experiments that the most precise results were provided by the S-shaped array. This array gave directional readings that were accurate to within about 1 degree, but all three of the irregular shapes performed better than the square. This approach, Li says, “was literally inspired by ‘Tetris.’”

Key to making the system work is placing an insulating material such as a lead sheet between the pixels to increase the contrast between radiation readings coming into the detector from different directions. The lead between the pixels in these simplified arrays serves the same function as the more elaborate shadow masks used in the larger-array systems. Less symmetrical arrangements, the team found, provide more useful information from a small array, explains Okabe, who is the lead author of the work. 

“The merit of using a small detector is in terms of engineering costs,” he says. Not only are the individual detector elements expensive, typically made of cadmium-zinc-telluride, or CZT, but all of the interconnections carrying information from those pixels also become much more complex. “The smaller and simpler the detector is, the better it is in terms of applications,” adds Li. 

While there have been other versions of simplified arrays for radiation detection, many are only effective if the radiation is coming from a single localized source. They can be confused by multiple sources or those that are spread out in space, while the “Tetris”-based version can handle these situations well, adds Xue, co-lead author of the work.

In a single-blind field test at the Berkeley Lab with a real cesium radiation source, led by Vavrek, where the researchers at MIT did not know the ground-truth source location, a test device was performed with high accuracy in finding the direction and distance to the source.  

“Radiation mapping is of utmost importance to the nuclear industry, as it can help rapidly locate sources of radiation and keep everyone safe,” says co-author Forget, an MIT professor of nuclear engineering and head of the Department of Nuclear Science and Engineering.

Vavrek, another co-lead-author, says that while in their study they focused on gamma-ray sources, he believes the computational tools they developed to extract directional information from the limited number of pixels are “much, much more general.” It isn’t restricted to certain wavelengths, it can also be used for neutrons, or even other forms of light, ultraviolet light, adds Hu, a senior scientist at MIT Nuclear Reactor Lab. 

Additional research team members include Ryan Pavlovsky, Victor Negut, Brian Quiter, and Joshua Cates at Lawrence Berkely National Laboratory, and Jiankai Yu, Tongtong Liu, Stephanie Jegelka at MIT. The work was supported by the U.S. Department of Energy.

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Written by David L. Chandler, MIT News

Paper: “Tetris-inspired detector with neural network for radiation mapping” 

https://www.nature.com/articles/s41467-024-47338-w

 

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JOURNAL

Nature Communications

DOI

10.1038/s41467-024-47338-w 

ARTICLE TITLE

“Tetris-inspired detector with neural network for radiation mapping”

 

Study helps explain why childhood maltreatment continues to impact on mental and physical health into adulthood

UNIVERSITY OF CAMBRIDGE

Childhood maltreatment can continue to have an impact long into adulthood because of how it effects an individual’s risk of poor physical health and traumatic experiences many years later, a new study has found.

Individuals who experienced maltreatment in childhood – such as emotional, physical and sexual abuse, or emotional and physical neglect – are more likely to develop mental illness throughout their entire life, but it is not yet well understood why this risk persists many decades after maltreatment first took place.

In a study published in Proceedings of the National Academy of Sciences, scientists from the University of Cambridge and Leiden University found that adult brains continue to be affected by childhood maltreatment in adulthood because these experiences make individuals more likely to experience obesity, inflammation and traumatic events, all of which are risk factors for poor health and wellbeing, which in turn also affect brain structure and therefore brain health.

The researchers examined MRI brain scans from approximately 21,000 adult participants aged 40 to 70 years in UK Biobank, as well as information on body mass index (an indicator of metabolic health), CRP (a blood marker of inflammation) and experiences of childhood maltreatment and adult trauma.

Sofia Orellana, a PhD student at the Department of Psychiatry and Darwin College, University of Cambridge, said: “We’ve known for some time that people who experience abuse or neglect as a child can continue to experience mental health problems long into adulthood and that their experiences can also cause long term problems for the brain, the immune system and the metabolic system, which ultimately controls the health of your heart or your propensity to diabetes for instance. What hasn’t been clear is how all these effects interact or reinforce each other.”

Using a type of statistical modelling that allowed them to determine how these interactions work, the researchers confirmed that experiencing childhood maltreatment made individuals more likely to have an increased body mass index (or obesity) and experience greater rates of trauma in adulthood. Individuals with a history of maltreatment tended to show signs of dysfunction in their immune systems, and the researchers showed that this dysfunction is the product of obesity and repeated exposure to traumatic events.

Next, the researchers expanded their models to include MRI measures of the adult’s brains and were able to show that widespread increases and decreases in brain thickness and volume associated with greater body mass index, inflammation and trauma were attributable to childhood maltreatment having made these factors more likely in the first place. These changes in brain structure likely mean that some form of physical damage is occurring to brain cells, affecting how they work and function.

Although there is more to do to understand how these effects operate at a cellular level in the brain, the researchers believe that their findings advance our understanding of how adverse events in childhood can contribute to life-long increased risk of brain and mind health disorders.

Professor Ed Bullmore from the Department of Psychiatry and an Honorary Fellow at Downing College, Cambridge, said: “Now that we have a better understanding of why childhood maltreatment has long term effects, we can potentially look for biomarkers – biological red flags – that indicate whether an individual is at increased risk of continuing problems. This could help us target early on those who most need help, and hopefully aid them in breaking this chain of ill health.”

The research was supported by MQ: Transforming Mental Health, the Royal Society, Medical Research Council, National Institute for Health and Care Research (NIHR) Cambridge Biomedical Research Centre, the NIHR Applied Research Collaboration East of England, Girton College and Darwin College.

Reference

Orellana, SC et al. Childhood maltreatment influences adult brain structure through its effects on immune, metabolic and psychosocial factors. PNAS; 9 Apr 2024 ; DOI: 10.1073/pnas.230470412

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JOURNAL

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.230470412 

ARTICLE TITLE

Childhood maltreatment influences adult brain structure through its effects on immune, metabolic and psychosocial factors

ARTICLE PUBLICATION DATE

9-Apr-2024

 

A new spin on organic shampoo makes it sudsier, longer lasting

AMERICAN CHEMICAL SOCIETY

 

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XUEJIAO CAOA COMMERCIAL ORGANIC SHAMPOO STORED FOR 30 DAYS YELLOWED AND SEPARATES (LEFT) WHILE THE SAME SHAMPOO SPUN IN A VORTEX FLUIDIC DEVICE MAINTAINS ITS COLOR AND TEXTURE (RIGHT).

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CREDIT: XUEJIAO CAO

While there’s no regulation in the U.S. for what’s in organic shampoos, they tend to contain ingredients perceived as safe or environmentally friendly. However, these “clean” shampoos separate and spoil faster than those made with synthetic stabilizers and preservatives. Now, researchers in ACS Sustainable Chemistry & Engineering demonstrate that a simple process — spinning organic shampoo at high speeds — improved the final products’ shelf lives and ability to clean hair.

Natural emulsifiers, such as xanthan gum and cetyl alcohol, are sometimes used to prevent organic shampoo from separating and enhance its soapy lather. But they don’t remain effective for as long as synthetic emulsifiers used in conventional haircare products. So, Youhong Tang, Colin Raston and colleagues looked to a technology invented by Raston —a vortex fluidic device (VFD). The team wanted to see if the high-speed spinning platform could work as well as a chemical to improve the lather and shelf stability of organic shampoo without adding to the list of ingredients on the back of the bottle.

Previously, the researchers determined that VFD’s intense micromixing could produce clean biodiesel from used cooking oil and homogenize raw milk, but they hadn’t used the platform to process more goopy liquids, such as shampoos. They guessed that it could also minimize aggregation of oil droplets and glass microspheres, components in some organic shampoo formulations, thereby maximizing the stability of these personal care products. To test the theory, the researchers added fresh store-bought organic shampoo to a glass tube tilted 45 degrees and spun it for 15 minutes at 4,500 revolutions per minute. (Their previous work determined this angle and spinning speed were the optimal conditions for processing.)

After 30 days of storage, an unprocessed organic shampoo sample turned from white to yellow and separated into two layers, whereas the spun shampoo didn’t change color and remained homogenized. In tests comparing the products’ foaming and cleansing abilities, the researchers found that the spun shampoo’s lather lasted longer and cleaned human hair more thoroughly. And on a microscopic level, the spun shampoo contained more evenly dispersed oil droplets and glass microspheres compared to the original product. The team says that result confirmed the hypothesis that VFD processing could be a “green” one-step technique for more stable, emulsified viscous liquids.

Next, they plan to characterize how processing with VFD affects individual components in organic shampoos — like natural surfactants (soaps) and botanical extracts — so they can fine-tune the technique for a broader range of organic shampoos, other natural personal care products and cosmetics.

The authors acknowledge the Australian Research Council Industrial Transformation Training Centre for Green Chemistry in Manufacturing for funding, and Plantworx Pty Ltd for funding and materials.

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The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS’ mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and all its people. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.

To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.

Note: ACS does not conduct research, but publishes and publicizes peer-reviewed scientific studies.

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JOURNAL

ACS Sustainable Chemistry & Engineering

DOI

10.1021/acssuschemeng.3c08159 

ARTICLE TITLE

Stability and Cleansing Function Enhancement of Organic Shampoo by a Vortex Fluidic Device

Innovation linked to international exports for both rural and urban firms

PENN STATE

UNIVERSITY PARK, Pa. — U.S. firms actively engaged in creating innovative products or processes are more likely to expand into international markets, according to a new study led by Penn State researchers. The findings, which apply to both rural and urban companies, could inform efforts aimed at boosting U.S. exports.

The team — led by Luyi Han, a postdoctoral researcher in Penn State’s College of Agricultural Sciences — examined the effect of several factors on a firm’s decision to engage in international trade, including innovation activities, owner characteristics and firm characteristics. They found that firms, or for-profit commercial enterprises, that are more innovative are more likely to engage in exports, as are older and larger firms or those with multiple owners. The study is available online now and will publish in the April issue of Economics Letters.

“Our previous work identified key factors that appear to foster innovation within firms. In this study, we wanted to know whether innovation, in turn, might also foster export behavior after controlling for other factors that contribute to export decisions,” Han said. “Our study is the first to examine this question using firm-level data in the U.S., and it provides some much-needed context about the U.S. firms that are active in non-farm export markets.”

The U.S. currently imports more than it exports, resulting in what is known as an international trade deficit. According to the researchers, the U.S. trade deficit has been a perennial concern for the U.S. economy, which has some policy makers calling for ways to increase exports of goods and services.

Han and his colleagues utilized two confidential data sets from the Penn State Census Research Data Center. The 2018 Annual Business Survey, administered jointly by the National Center for Science and Engineering Statistics and the U.S. Census Bureau, collects firm-level information on innovation activities, firm ownership details and firm characteristics. The Longitudinal Firm Trade Transactions Database contains import-export transaction records that can be linked to individual firms by unique firm identifiers. The researchers merged the two, identifying roughly 30,000 U.S. exporting firms, and then conducted statistical analyses aimed at how these firms differed from the 430,000 non-exporting firms in the dataset.

The study examined the effects of four types of innovation activity: new-to-market innovation, which results in new products not yet seen on the market; new-to-business innovation, which results in a new or significantly improved product that was already available from competitors in the market; process innovation, which results in new or significantly improved methods of manufacturing, logistics or distribution; and marketing innovation, which results in new packaging, product promotion strategies, sales channels or pricing methods.

They found that all types of innovation activity exerted a strong influence on the likelihood of exporting, with new-to-market product innovation having the strongest effect.

“It stands to reason that innovative companies are more likely to participate in export markets, because being innovative typically puts companies at a competitive advantage,” said co-author Timothy Wojan, an Oak Ridge Institute for Science and Education fellow at the National Center for Science and Engineering Statistics (NCSES) within the U.S. National Science Foundation.

“For example, innovators might produce a unique or higher quality product than what’s already available, which would be more attractive to markets beyond the U.S., or they may develop economies of scale that allow them to increase production or lower costs, which would position them to expand their market more easily,” Wojan said.

Firms with manufacturing operations were also more likely to engage in exports, which is not unexpected as manufactured goods are highly exportable, whereas products from health care, personal services or real estate typically are not.

The findings have implications for the economic health of rural areas, according to co-author Stephan Goetz, professor of agricultural economics and regional economics at Penn State and director of the Northeast Regional Center for Rural Development.

“Being competitive in the global market is of national importance, but especially so for rural areas where manufacturing accounts for a much larger share of employment than in urban areas,” Goetz said. “We found that the influence of innovation was just as strong among rural firms as among their urban counterparts, which suggests that fostering innovation may be one way to enhance export activity among rural firms.”

Han emphasized that the study is exploratory in examining the association between innovation and exporting. The study does not establish causality — that promoting innovation will necessarily increase exports — but the strong association provides incentives to develop study designs that may more definitively establish that link.

Zheng Tian, assistant research professor at Penn State, also contributed to this research.

The U.S. Department of Agriculture’s National Institute of Food and Agriculture and Multistate/Regional Research and Extension Appropriations, the NSF NCSES and the Oak Ridge Institute for Science and Education supported this research in part.

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JOURNAL

Economics Letters

DOI

10.1016/j.econlet.2024.111657 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

How export performance is mediated by innovation, owner characteristics, and location

 

UC Santa Cruz researchers value salt marsh restoration as a crucial tool in flood risk reduction and climate resilience in the San Francisco Bay

UNIVERSITY OF CALIFORNIA - SANTA CRUZ

Salt marsh restoration can mitigate flood risk and bolster community resilience to climate change in our local waterways, according to a recent study published in Nature by a postdoctoral fellow with UC Santa Cruz’s Center for Coastal Climate Resilience (CCCR). 

The study, titled “The value of marsh restoration for flood risk reduction in an urban estuary,” explores the social and economic advantages of marsh restoration amidst the growing threats of sea level rise and storm-driven flooding. Climate change will put many communities at risk. In California, some of the study co-authors from the U.S. Geological Survey (USGS) have shown that 675,000 people and $250 billion in property are at risk of flooding in a scenario with 2 m of sea level rise combined with a 100-year storm. Flooding due to sea-level rise is amplified by storms, which drive higher coastal water levels via surges, waves, and increased river discharge, along with increasing coastal population density. 

To simulate marsh restoration, the research team used a hydrodynamic model of San Francisco Bay, focusing on San Mateo County, the county most vulnerable to future flooding in California. The team ran computer simulations of the county’s shoreline during storms, with and without marsh restoration, and worked closely with local flood managers and planners to incorporate their input into the model. 

“The Bay Area is low-lying and densely populated, thus at significant risk for future climate change impacts, and home to really large areas of degraded habitat. We have found compelling evidence that marsh restoration can reduce flood risk to people and property locally, providing both community and ecosystem co-benefits,” said CCCR fellow Rae Taylor-Burns, whose research also appears in a Springer Nature blog. 

Key findings from the study include:

• Identification of priority areas in San Mateo County for salt marsh restoration to maximize socio-economic impacts in reducing flood risk. 
• Development of a detailed flood model to evaluate the risk of flooding with and without salt marshes locally, aiding in the planning and design of restoration projects.
• The monetization of flood risk reduction benefits to identify cost-effective investments in marsh restoration, potentially attracting public and private funding.

The study underscores the broader implications of wetland restoration beyond flood protection, including carbon sequestration, habitat preservation, and recreational opportunities. It also makes the case for investments in nature-based solutions and community resilience that can help lessen future climate change impacts. 

Researchers show the benefits of integrating salt marsh restoration into comprehensive climate resilience strategies in San Mateo County and estuaries worldwide that are facing similar threats. This could include funding from FEMA grant programs or Regional Measure AA, which provides approximately $500 million for marsh restoration throughout the San Francisco Bay. This work also supports identifying CA coastal wetlands as critical national infrastructure, as the Center has helped support coral reefs in Guam, Hawai’i, Puerto Rico, and the U.S. Virgin Islands.

“As we confront the escalating challenges posed by climate change, it is imperative that we explore innovative solutions to enhance community resilience," said Michael W. Beck, director of the Center for Coastal Climate Resilience and a co-author of the study. “Salt marsh restoration represents a nature-based approach that can complement traditional infrastructure and safeguard our coastal communities."

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JOURNAL

Nature

METHOD OF RESEARCH

Meta-analysis

ARTICLE TITLE

The value of marsh restoration for flood risk reduction in an urban estuary

 

NSF grant awarded to manage salt contamination of tidal river water supplies

PENN STATE

UNIVERSITY PARK, Pa. — Salt contamination of water supplies in tidal rivers is a growing problem around the world, threatening the safe drinking water of billions of people, according to researchers at Penn State. Those researchers are part of a multi-institution team of scientists and engineers who were recently awarded $650,000 in funding from the U.S. National Science Foundation (NSF) to develop tools to help monitor and manage decision-making to address this critical issue.

Raymond Najjar, professor of oceanography and one of the co-principal investigators, said the team will develop a new coupled watershed-estuary model that simulates the transport and fate of major salt ions by leveraging recent advances in hydrological and estuarine modeling. They plan to use the Chesapeake Bay and its tidal rivers as a pilot study site to better understand the saltwater intrusion process.

“It's unusual to have watershed and estuary models coupled in real time,” Najjar said. “It's not unusual to simulate the conditions of the estuary, given the output of a hydrological model or using observed data like streamflow, but it is unusual to link and run the models together.”

The project was one of 15 multidisciplinary teams selected for Phase 1 of the NSF Convergence Accelerator program's Track K: Equitable Water Solutions. The Convergence Accelerator program builds upon NSF's investment in basic research and discovery to accelerate solutions toward societal and economic impact. The Penn State team also includes Alfonso Mejia, associate professor of civil and environmental engineering and co-principal investigator, and Antonia Hadjimichael, assistant professor of geosciences.

About 70% of the U.S. drinking water supply comes from surface waters, including tidal rivers, which are the tidal fresh region of estuaries. Drought and sea level rise, which lead to saltwater intrusion from the ocean, and changes in land-use, which lead to freshwater salinization, are putting water resources at risk. The risk extends to water uses for thermoelectric power, irrigation and industrial production, according to the researchers.

“Saltwater contamination has been discussed a lot in regard to groundwater but what’s novel about this project is that it is addressing surface water contamination,” Najjar said. “It is an issue that’s coming from two different directions. It can come from ocean saltwater making its way up the estuary, like it does under drought conditions when freshwater flow is low or from predicted sea level rise. It can also come from freshwater sources, like when road salt makes its way into streams and rivers. That is the reason for trying to couple these two modeling systems.”

Many water suppliers do not have the necessary planning and technical capacity to prepare for these changes. This project proposes to develop and prototype decision support and monitoring tools for salinity management through co-production with water resource managers, under-resourced rural communities and water suppliers.

“Both developed and developing countries are struggling with salt contamination of tidal river waters, and many rely on numerical models to manage salinity,” said Ming Li, project lead and professor at University of Maryland’s Center for Environmental Science. “These new tools will be applicable to numerous systems around the globe.”

The model will be used in combination with artificial intelligence algorithms to quantify the tradeoffs between competing needs for freshwater resources. This approach will also be used to search for long-term planning strategies to help communities adapt to increased salinization.

Najjar said another novelty is that the team is going to simulate individual ions as opposed to only bulk salinity.

“In ocean models, the salinity is just predicted as the total amount of dissolved ions,” Najjar said. “The model doesn't distinguish whether the ions are sodium, chlorine, potassium, sulfate and so forth. The mix of ions in seawater is relatively constant but those ratios are different than they are in the rivers. So, we're going to be looking at trying to model individual ions and that's something new as well.”

Other co-principal investigators are Sujay Kaushal from the University of Maryland and Allison Lassiter from the University of Pennsylvania. Additional institutions contributing to this effort include the Salisbury University, Rutgers University, Izaak Walton League of America, Maryland Department of the Environment, Maryland Department of Planning, Maryland Geological Survey, Metropolitan Washington Council, Interstate Commission on the Potomac River Basin, Susquehanna River Basin Commission, Delaware River Basin Commission, EPA Chesapeake Bay Program and Maryland Sea Grant.

 

Nanoscale movies shed light on one barrier to a clean energy future

Research could dramatically extend the lifetime of the devices needed to turn hydrogen green

DUKE UNIVERSITY

DURHAM, N.C. -- Left unchecked, corrosion can rust out cars and pipes, take down buildings and bridges, and eat away at our monuments.

Corrosion can also damage devices that could be key to a clean energy future. And now, Duke University researchers have captured extreme close-ups of that process in action.

“By studying how and why renewable energy devices break down over time, we might be able to extend their lifetime,” said chemistry professor and senior author Ivan Moreno-Hernandez.

In his lab at Duke sits a miniature version of one such device. Called an electrolyzer, it separates hydrogen out of water, using electricity to power the reaction.

When the electricity to power electrolysis comes from renewable sources such as wind or solar, the hydrogen gas it churns out is considered a promising source of clean fuel, because it takes no fossil fuels to produce and it burns without creating any planet-warming carbon dioxide.

A number of countries have plans to scale up their production of so-called “green hydrogen” to help curb their dependence on fossil fuels, particularly in industries like steel- and cement-making.

But before hydrogen can go mainstream, some big obstacles need to be overcome.

Part of the trouble is electrolyzers require rare metal catalysts to function, and these are prone to corrosion. They’re not the same after a year of operation than they were in the beginning.

In a study published April 10 in the Journal of the American Chemical Society, Moreno-Hernandez and his Ph.D. student Avery Vigil used a technique called liquid phase transmission electron microscopy to study the complex chemical reactions that go on between these catalysts and their environment that cause them to decay.

You might remember from high school that to make hydrogen gas, an electrolyzer splits water into its constituent hydrogen and oxygen molecules. For the current study, the team focused on a catalyst called ruthenium dioxide that speeds up the oxygen half of the reaction, since that’s the bottleneck in the process.

“We essentially put these materials through a stress test,” Vigil said.

They zapped nanocrystals of ruthenium dioxide with high-energy radiation, and then watched the changes wrought by the acidic environment inside the cell.

To take pictures of such tiny objects, they used a transmission electron microscope, which shoots a beam of electrons through nanocrystals suspended inside a super-thin pocket of liquid to create time-lapse images of the chemistry taking place at 10 frames per second.

The result: desktop-worthy close-ups of virus-sized crystals, more than a thousand times finer than a human hair, as they get oxidized and dissolve into the acidic liquid around them.

“We're actually able to see the process of this catalyst breaking down with nanoscale resolution,” Moreno-Hernandez said.

Over the course of five minutes, the crystals broke down fast enough to “render a real device useless in a matter of hours,” Vigil said.

Zooming in hundreds of thousands of times, the videos reveal subtle defects in the crystals’ 3D shapes that create areas of strain, causing some to break down faster than others.

By minimizing such imperfections, the researchers say it could one day be possible to design renewable energy devices that last two to three times longer than they currently do.

“So instead of being stable for, say, two years, an electrolyzer could last six years. That could have a massive impact on renewable technologies,” Moreno-Hernandez said.

This research was supported by grants from the National Science Foundation (DGE-2139754, ECCS-2025064, ECCS-2025064).

CITATION: "Dissolution Heterogeneity Observed in Anisotropic Ruthenium Dioxide Nanocrystals via Liquid-Phase Transmission Electron Microscopy," S. Avery Vigil, Ivan A. Moreno-Hernandez. Journal of the American Chemical Society, April 10, 2024. https://doi.org/10.1021/jacs.3c13709

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DOI

10.1021/jacs.3c13709 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Dissolution Heterogeneity Observed in Anisotropic Ruthenium Dioxide Nanocrystals via Liquid-Phase Transmission Electron Microscopy

ARTICLE PUBLICATION DATE

10-Apr-2024