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Open access publications related to sustainability research.

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Sea-ice loss accelerates carbon cycling and enhances seasonal extremes of acidification in the Arctic Chukchi Sea
(Limnology and Oceanography Letters, 2024-02-05) Zhang, Yixing; Wu, Yingxu; Cai, Wei-Jun; Yi, Xiangqi; Gao, Xiang; Bi, Haibo; Zhuang, Yanpei; Chen, Liqi; Qi, Di
The Chukchi Sea shelf (CSS) is a highly productive region in the Arctic Ocean and it is highly efficient for absorbing atmospheric carbon dioxide and exporting and retaining carbon in the deep sea. However, with global warming, the carbon retention time in CSS may decrease, leading to less efficient carbon export. Here, we investigate the seasonal variability of carbonate chemistry in CSS using three sets of late- vs. early-summer reoccupations of the same transect. Our findings demonstrate substantially increased and rapid degradation of biologically produced organic matter and therefore acidification over time in the southern CSS due to earlier sea-ice retreat, resulting in significantly shorter carbon retention time. In sharp contrast, no increased degradation has been observed in the northern CSS where photosynthesis has just commenced. In the future, climate change would further diminish the carbon export capacity and exacerbate seasonal acidification not only within CSS but also across other polar coastal oceans. Scientific Significance Statement The Arctic Chukchi Sea shelf (CSS) is a prominent site for the biological drawdown of atmospheric carbon dioxide, which can subsequently be transported to the deep sea in the Arctic Ocean. The efficiency of carbon export is influenced by seasonal sea-ice formation and retreat: longer period of sea-ice opening results in shorter carbon retention time and reduced carbon export due to rapid recycling of organic matter. However, this process is poorly understood due to lack of observations. Here, we present three sets of late- vs. early-summer reoccupations along the same transect in the CSS. We unveil distinct spatial patterns of carbonate chemistry and subsurface acidification between the southern CSS and northern CSS. In the sCSS, degradation of biologically produced organic matter has occurred rapidly and caused subsurface acidification since early summer due to earlier sea-ice retreat; however, no such phenomenon is observed in the northern region. As Arctic warming continues in the future, these conditions are expected to persist, further diminishing carbon export capacity and exacerbating seasonal acidification.
The Impact of Sea Level Rise on Roadway Design and Evacuation Routes in Delaware
(American Journal of Climate Change, 2024-03-29) Palevich, Jack; Faghri, Ardeshir; Karakurt, Ahmet
As the global temperature continues to increase, the sea level continues to rise at a rapid rate that has never been seen before. This becomes an issue for many facets of life but one of the most impacted is the transportation infrastructure. Many people living in low elevation coastal areas can become trapped by flooding with no way in or out. With Delaware being a coastal state, this would affect a large portion of the population and will have detrimental effects over time if nothing is done to combat sea level rise. The issue with sea level rise in transportation is that once the roads become flooded, they become virtually unusable and detour routes would be needed. If all the roads in a coastal area were to be affected by sea level rise, the options for detours would become limited. This article looks at direct solutions to combat sea level rise and indirect solutions that would specifically help transportation infrastructure and evacuation routes in Delaware. There is not one solution that can fix every problem, so many solutions are laid out to see what is applicable to each affected area. Some solutions include defense structures that would be put close to the coast, raising the elevation of vulnerable roads throughout the state and including pumping stations to drain the water on the surface of the road. With an understanding of all these solutions around the world, the ultimate conclusion came in the form of a six-step plan that Delaware should take in order to best design against sea level rise in these coastal areas.
Knowledge gaps about micronutrient deficiencies in Tanzania and the effect of information interventions
(Global Food Security, 2024-02-02) Kilasy, Pius; McFadden, Brandon R.; Davidson, Kelly A.; Palm-Forster, Leah H.
There were knowledge gaps about the severity of deficiencies and biofortified foods.Reducing micronutrient malnutrition (“hidden hunger”) in low-income countries is a global challenge, particularly among women, children, and high-poverty households. Countries like Tanzania have developed diverse strategies to combat malnutrition, including the biofortification of staple foods. However, broad awareness and knowledge of micronutrient deficiencies and beneficial foods are needed for these strategies to be effective. The objectives of this study were to (i) examine Tanzanian consumers' initial awareness and knowledge of deficiencies for four micronutrients and associated biofortified foods, and (ii) to examine the effectiveness of targeted communication approaches (i.e., information and branding) to improve knowledge. Data were collected from 1029 respondents in Tanzania using an online survey. Respondents were randomly assigned to treatments across two experiments in the survey. One experiment examined the effect of information about susceptibility and severity of micronutrient deficiencies and foods that reduce the risk of deficiency, and the other experiment examined the impact of ‘branding’ biofortified foods. The combination of providing information and branded biofortified crops most effectively reduced knowledge gaps about negative health outcomes and risk-reducing foods. Results suggest a need for evidence-based interventions that provide broad nutrition education and financial assistance for purchasing food. Highlights • Knowledge gaps were identified for deficiency in iron, vitamin A, and zinc. • Information interventions were used to identify knowledge gaps. • No information was provided for iodine to determine internal validity of results. • The at-risk subpopulation, women of reproductive age, were oversampled. • There were knowledge gaps about the severity of deficiencies and biofortified foods.
Blue Photons from Broad-Spectrum LEDs Control Growth, Morphology, and Coloration of Indoor Hydroponic Red-Leaf Lettuce
(Plants, 2023-03-02) Meng, Qingwu; Runkle, Erik S.
For indoor crop production, blue + red light-emitting diodes (LEDs) have high photosynthetic efficacy but create pink or purple hues unsuitable for workers to inspect crops. Adding green light to blue + red light forms a broad spectrum (white light), which is created by: phosphor-converted blue LEDs that cast photons with longer wavelengths, or a combination of blue, green, and red LEDs. A broad spectrum typically has a lower energy efficiency than dichromatic blue + red light but increases color rendering and creates a visually pleasing work environment. Lettuce growth depends on the interactions of blue and green light, but it is not clear how phosphor-converted broad spectra, with or without supplemental blue and red light, influence crop growth and quality. We grew red-leaf lettuce ‘Rouxai’ in an indoor deep-flow hydroponic system at 22 °C air temperature and ambient CO2. Upon germination, plants received six LED treatments delivering different blue fractions (from 7% to 35%) but the same total photon flux density (400 to 799 nm) of 180 μmol·m−2·s−1 under a 20 h photoperiod. The six LED treatments were: (1) warm white (WW180); (2) mint white (MW180); (3) MW100 + blue10 + red70; (4) blue20 + green60 + red100; (5) MW100 + blue50 + red30; and (6) blue60 + green60 + red60. Subscripts denote photon flux densities in μmol·m−2·s−1. Treatments 3 and 4 had similar blue, green, and red photon flux densities, as did treatments 5 and 6. At the harvest of mature plants, lettuce biomass, morphology, and color were similar under WW180 and MW180, which had different green and red fractions but similar blue fractions. As the blue fraction in broad spectra increased, shoot fresh mass, shoot dry mass, leaf number, leaf size, and plant diameter generally decreased and red leaf coloration intensified. Compared to blue + green + red LEDs, white LEDs supplemented with blue + red LEDs had similar effects on lettuce when they delivered similar blue, green, and red photon flux densities. We conclude that the blue photon flux density in broad spectra predominantly controls lettuce biomass, morphology, and coloration.
Half of twenty-first century global irrigation expansion has been in water-stressed regions
(Nature Water, 2024-03-08) Mehta, Piyush; Siebert, Stefan; Kummu, Matti; Deng, Qinyu; Ali, Tariq; Marston, Landon; Xie, Wei; Davis, Kyle Frankel
The expansion of irrigated agriculture has increased global crop production but resulted in widespread stress on freshwater resources. Ensuring that increases in irrigated production occur only in places where water is relatively abundant is a key objective of sustainable agriculture and knowledge of how irrigated land has evolved is important for measuring progress towards water sustainability. Yet, a spatially detailed understanding of the evolution of the global area equipped for irrigation (AEI) is missing. In this study, we used the latest subnational irrigation statistics (covering 17,298 administrative units) from various official sources to develop a gridded (5 arcmin resolution) global product of AEI for the years 2000, 2005, 2010 and 2015. We found that AEI increased by 11% from 2000 (297 Mha) to 2015 (330 Mha), with areas of both substantial expansion, such as northwest India and northeast China, and decline, such as Russia. Combining these outputs with information on green (that is, rainfall) and blue (that is, surface and ground) water stress, we also examined to what extent irrigation has expanded unsustainably in places already experiencing water stress. We found that more than half (52%) of the irrigation expansion has taken place in areas that were already water-stressed in the year 2000, with India alone accounting for 36% of global unsustainable expansion. These findings provide new insights into the evolving patterns of global irrigation with important implications for global water sustainability and food security.
Assessing and addressing the global state of food production data scarcity
(Nature Reviews Earth & Environment, 2024-02-20) Kebede, Endalkachew Abebe; Abou Ali, Hanan; Clavelle, Tyler; Froehlich, Halley E.; Gephart, Jessica A.; Hartman, Sarah; Herrero, Mario; Kerner, Hannah; Mehta, Piyush; Nakalembe, Catherine; Ray, Deepak K.; Siebert, Stefan; Thornton, Philip; Davis, Kyle Frankel
Food production data — such as crop, livestock, aquaculture and fisheries statistics — are critical to achieving multiple sustainable development goals. However, the lack of reliable, regularly collected, accessible, usable and spatially disaggregated statistics limits an accurate picture of the state of food production in many countries and prevents the implementation of effective food system interventions. In this Review, we take stock of national and international food production data to understand its availability and limitations. Across databases, there is substantial global variation in data timeliness, granularity (both spatially and by food category) and transparency. Data scarcity challenges are most pronounced for livestock and aquatic food production. These challenges are largely concentrated in Central America, the Middle East and Africa owing to a combination of inconsistent census implementation and a global reliance on self-reporting. Because data scarcity is the result of technical, institutional and political obstacles, solutions must include technological and policy innovations. Fusing traditional and emerging data-gathering techniques with coordinated governance and dedicated long-term financing will be key to overcoming current obstacles to sustained, up-to-date and accurate food production data collection, foundational in promoting and monitoring progress towards healthier and more sustainable food systems worldwide.
Dynamics of short-term ecosystem carbon fluxes induced by precipitation events in a semiarid grassland
(Biogeosciences, 2023-06-22) Delgado-Balbuena, Josué; Loescher, Henry W.; Aguirre-Gutiérrez, Carlos A.; Alfaro-Reyna, Teresa; Pineda-Martínez, Luis F.; Vargas, Rodrigo; Arredondo, Tulio
Infrequent and small precipitation (PPT) events characterize PPT patterns in semiarid grasslands; however, plants and soil microorganisms are adapted to use the unpredictable small pulses of water. Several studies have shown short-term responses of carbon and nitrogen mineralization rates (called the “priming effect” or the Birch effect) stimulated by wet–dry cycles; however, dynamics, drivers, and the contribution of the priming effect to the annual C balance are poorly understood. Thus, we analyzed 6 years of continuous net ecosystem exchange measurements to evaluate the effect of the PPT periodicity and magnitude of individual PPT events on the daily/annual net ecosystem C exchange (NEE) in a semiarid grassland. We included the period between PPT events, previous daytime NEE rate, and previous soil moisture content as the main drivers of the priming effect. Ecosystem respiration (ER) responded within a few hours following a PPT event, whereas it took 5–9 d for gross ecosystem exchange (GEE; where −NEE = GEE + ER) to respond. Precipitation events as low as 0.25 mm increased ER, but cumulative PPT > 40 mm infiltrating deep into the soil profile stimulated GEE. Overall, ER fluxes following PPT events were related to the change in soil water content at shallow depth and previous soil conditions (e.g., previous NEE rate, previous soil water content) and the size of the stimulus (e.g., PPT event size). Carbon effluxes from the priming effect accounted for less than 5 % of ecosystem respiration but were significantly high with respect to the carbon balance. In the long term, changes in PPT regimes to more intense and less frequent PPT events, as expected due to the effects of climate change, could convert the semiarid grassland from a small C sink to a C source.
Projected increase in carbon dioxide drawdown and acidification in large estuaries under climate change
(Communications Earth & Environment, 2023-03-13) Li, Ming; Guo, Yijun; Cai, Wei-Jun; Testa, Jeremy M.; Shen, Chunqi; Li, Renjian; Su, Jianzhong
Most estuaries are substantial sources of carbon dioxide (CO2) to the atmosphere. The estimated estuarine CO2 degassing is about 17% of the total oceanic uptake, but the effect of rising atmospheric CO2 on estuarine carbon balance remains unclear. Here we use 3D hydrodynamic-biogeochemical models of a large eutrophic estuary and a box model of two generic, but contrasting estuaries to generalize how climate change affects estuarine carbonate chemistry and CO2 fluxes. We found that small estuaries with short flushing times remain a CO2 source to the atmosphere, but large estuaries with long flushing times may become a greater carbon sink and acidify. In particular, climate downscaling projections for Chesapeake Bay in the mid-21st century showed a near-doubling of CO2 uptake, a pH decline of 0.1–0.3, and >90% expansion of the acidic volume. Our findings suggest that large eutrophic estuaries will become carbon sinks and suffer from accelerated acidification in a changing climate.
High soil carbon sequestration rates persist several decades in turfgrass systems: A meta-analysis
(Science of The Total Environment, 2023-02-01) Phillips, Claire L.; Wang, Ruying; Mattox, Clint; Trammell, Tara L.E.; Young, Joseph; Kowalewski, Alec
Highlights • Turfgrass can sequester C and may influence emissions stemming from urbanization. • We summarized soil C sequestration rates from 63 datasets, most in the U.S. • Initial C sequestration exceeded rates for many soil conservation practices. • On average turfgrass stopped accruing soil C by 50 years after establishment. Abstract Managed turfgrass is a common component of urban landscapes that is expanding under current land use trends. Previous studies have reported high rates of soil carbon sequestration in turfgrass, but no systematic review has summarized these rates nor evaluated how they change as turfgrass ages. Here we conducted a meta-analysis of soil carbon sequestration rates from 63 studies globally, comprised mostly of C3 grass species in the U.S., including 24 chronosequence studies that evaluated carbon changes over 75 years or longer. We showed that turfgrass established within the last ten years had a positive mean soil C sequestration rate of 5.3 Mg CO2 ha−1 yr−1 (95% CI = 3.7–6.2), which is higher than rates reported for several soil conservation practices. Areas converted to turfgrass from forests were an exception, sometimes lost soil carbon, and had a cross-study mean sequestration rate that did not differ from 0. In some locations, soil C accumulated linearly with turfgrass age over several decades, but the major trend was for soil C accumulation rates to decline through time, reaching a cross-study mean sequestration rate that was not different from 0 at 50 years. We show that fitting soil C timeseries with a mechanistically derived function rather than purely empirical functions did not alter these conclusions, nor did employing equivalent soil mass versus fixed-depth carbon stock accounting. We conducted a partial greenhouse gas budget that estimated emissions from mowing, N-fertilizer production, and soil N2O emissions. When N fertilizer was applied, average maintenance emissions offset 32% of C sequestration in recently established turfgrass. Potential emission removals by turfgrass can be maximized with reduced-input management. Management decisions that avoid losing accrued soil C—both when turfgrass is first established and when it is eventually replaced with other land-uses—will also help maximize turfgrass C sequestration potential. Graphical abstract available at: https://doi.org/10.1016/j.scitotenv.2022.159974
Conformations of polyolefins on platinum catalysts control product distribution in plastics recycling
(Chemical Science, 2023-01-03) Zare, Mehdi; Kots, Pavel A.; Caratzoulas, Stavros; Vlachos, Dionisios G.
The design of catalysts for the chemical recycling of plastic waste will benefit greatly from an intimate knowledge of the interfacial polymer–catalyst interactions that determine reactant and product distributions. Here, we investigate backbone chain length, side chain length, and concentration effects on the density and conformation of polyethylene surrogates at the interface with Pt(111) and relate them to experimental product distributions resulting from carbon–carbon bond cleavage. Using replica-exchange molecular dynamics simulations, we characterize the polymer conformations at the interface by the distributions of trains, loops, and tails and their first moments. We find that the preponderance of short chains, in the range of 20 carbon atoms, lies entirely on the Pt surface, whereas longer chains exhibit much broader distributions of conformational features. Remarkably, the average length of trains is independent of the chain length but can be tuned via the polymer–surface interaction. Branching profoundly impacts the conformations of long chains at the interface as the distributions of trains become less dispersed and more structured, localized around short trains, with the immediate implication of a wider carbon product distribution upon C–C bond cleavage. The degree of localization increases with the number and size of the side chains. Long chains can adsorb from the melt onto the Pt surface even in melt mixtures containing shorter polymer chains at high concentrations. We confirm experimentally key computational findings and demonstrate that blends may provide a strategy to reduce the selectivity for undesired light gases.
Hydrodynamics and Sediment-Transport Pathways along a Mixed-Energy Spit-Inlet System: A Modeling Study at Chincoteague Inlet (Virginia, USA)
(Journal of Marine Science and Engineering, 2023-05-18) Georgiou, Ioannis Y.; Messina, Francesca; Sakib, Md Mohiuddin; Zou, Shan; Foster-Martinez, Madeline; Bregman, Martijn; Hein, Christopher J.; Fenster, Michael S.; Shawler, Justin L.; McPherran, Kaitlyn; Trembanis, Arthur C.
Tidal-inlet systems are dynamic features that respond to short-term (e.g., storms) and longer-term processes (e.g., sea-level rise, changes in tidal prism). The Chincoteague Inlet system, located along the northern Eastern Shore of Virginia (USA), is a dynamic coastal complex that experiences rapid change associated with sediment redistribution and a shifting inlet throat due to the southern elongation of adjacent Assateague Island. In this study, a numerical model based on Delft3D with coupled flow–waves, multiclass sediment transport, and morphologic feedback was developed to quantify the hydrodynamic and geomorphic controls within this rapidly evolving inlet–spit system and to develop a more comprehensive understanding of regional to local controls on sediment-transport pathways. Model results show that most of the sand transport along southern Assateague Island is sequestered nearshore and proximally in deeper sinks within Fishing Point, and, of that, only finer sand sizes are transported around the spit, confirming previous analysis and hypothesis. The model also showed that sand transport toward the south increases along Wallops Island and quantified spatially explicit transport trends for selected sediment classes, revealing that coarser sediment bypassing is a punctuated process that is proportional to storms.
‘I’m Scared to Death to Try It on My Own’: I-Poems and the complexities of religious housing support for people on the US sex offender registry
(Anti-Trafficking Review, 2023-04-26) Leon, Chrysanthi S.; Buckridge, Maggie; Herdoíza, Michaela
In the US, street-based sex workers and people convicted of sex offences are both ‘special populations’, often with additional conditions of community supervision. People convicted of sex offences experience a complicated mix of assistance and surveillance as they re-enter society post-conviction, including numerous restrictions on housing and employment. As a result, they are especially likely to experience homelessness upon release. This article uses I-Poems drawn from interviews with volunteers and professionals who navigate the obstacles to re-entry that govern people on the sex offender registry. We focus on people with religious affiliations (n=38) who provide urgent support during the re-entry process. I-poems are a feminist technique for analysing qualitative data that forefronts the voices of people not often heard and distils complex experiences into accessible narratives. While few in our study overtly exploited re-entering persons on the registry, most support was problematic in subtler ways: we found that re-entering registrants are asked to accept constrained choices involving labour, religious participation, and romantic and other personal relationships in order to receive assistance. Given the secondary stigma attached to work with people convicted of sex offences, and the obscurity within in which many of these religiously-affiliated programmes operate, I-Poems both humanise and reveal the complexities of coercion, religious calling, and supportive housing.
Calculating the Environmental Impacts of Low-Impact Development Using Long-Term Hydrologic Impact Assessment: A Review of Model Applications
(Land, 2023-03-04) Cai, Zhenhang; Zhu, Rui; Ruggiero, Emma; Newman, Galen; Horney, Jennifer A.
Low-impact development (LID) is a planning and design strategy that addresses water quality and quantity while providing co-benefits in the urban and suburban landscape. The Long-Term Hydrologic Impact Assessment (L-THIA) model estimates runoff and pollutant loadings using simple inputs of land use, soil type, and climatic data for the watershed-scale analysis of average annual runoff based on curve number analysis. Using Scopus, Web of Science, and Google Scholar, we screened 303 articles that included the search term “L-THIA”, identifying 47 where L-THIA was used as the primary research method. After review, articles were categorized on the basis of the primary purpose of the use of L-THIA, including site screening, future scenarios and long-term impacts, site planning and design, economic impacts, model verification and calibration, and broader applications including policy development or flood mitigation. A growing body of research documents the use of L-THIA models across landscapes in applications such as the simulations of pollutant loadings for land use change scenarios and the evaluation of designs and cost-effectiveness. While the existing literature demonstrates that L-THIA models are a useful tool, future directions should include more innovative applications such as intentional community engagement and a focus on equity, climate change impacts, and the return on investment and performance of LID practices to address gaps in knowledge.
Impact of Marine Heatwaves on Air-Sea CO2 Flux Along the US East Coast
(Geophysical Research Letters, 2024-01-02) Edwing, Kelsea; Wu, Zelun; Lu, Wenfang; Li, Xinyu; Cai, Wei-Jun; Yan, Xiao-Hai
Marine heatwaves (MHWs) are extremely warm ocean temperature events that significantly affect marine environments, but their effects on the coastal carbonate system are still uncertain. In this study, we systematically quantify MHWs' impacts on air-sea carbon dioxide (CO2) flux anomalies (FCO2′) in the Mid-Atlantic Bight (MAB) and South Atlantic Bight (SAB) from 1992 to 2020. During the longest MHW in both regions, oceanic CO2 uptake capabilities substantially decreased, primarily due to significant increases in the seawater partial pressure of CO2 (pCO2sea). For all cases, MHWs played a more significant role in driving pCO2sea changes in the MAB than the SAB, where non-thermal drivers dominated pCO2sea variability. In the MAB, weakened wind speeds related to wintertime atmospheric perturbations increase ocean temperatures and pCO2sea, further reducing CO2 uptake during winter MHWs. This work is the first to connect extreme temperatures to coastal air-sea CO2 fluxes. The reduction in CO2 absorption noted during MHWs in this study has important implications for coastal regions to act as continued sinks for excess CO2 emissions in the atmosphere. Key Points - Marine heatwaves (MHWs) primarily generated positive sea surface pCO2 (pCO2sea) anomalies in the Mid-Atlantic Bight (MAB) and South Atlantic Bight (SAB) but had a larger impact on air-sea CO2 flux anomalies in the MAB - Reduced wind speeds amplified MHW contributions during CO2 sink months and counteracted them during CO2 source months - In the MAB, wintertime atmospheric perturbations related to zonal shifts in the jet stream produce slower wind speeds which aid in generating air-sea heat flux type MHW events that ultimately reduce oceanic CO2 uptake Plain Language Summary The transfer of carbon dioxide (CO2) between the atmosphere and ocean is sensitive to sea surface temperature (SST) changes because warmer SSTs increase the sea surface partial pressure of CO2 and reduce the ocean's ability to absorb CO2 from the atmosphere. It is, therefore, conceivable that marine heatwaves (MHWs), which are extremely warm ocean temperature events, could modify how carbon moves between the ocean and the atmosphere. This study provides the first attempt to evaluate the impacts of MHWs on the air-sea CO2 flux (FCO2) anomalies along the US East Coast, encompassing the Mid-Atlantic Bight (MAB) and South Atlantic Bight (SAB) during 1992–2020. Both regions experienced reduced CO2 absorption in response to the longest MHWs in each region. These extreme temperatures had a larger impact on CO2 absorption in the MAB compared to the SAB, where non-temperature factors were more influential. The coastal ocean plays an important role in helping to mitigate human-induced climate change by absorbing excess CO2 from the atmosphere. As such, the demonstrated reduced absorption of the ocean associated with MHWs in this study, which might also apply to other coastal locations, has vital implications for the efficiency of the ocean in offsetting global warming impacts.
Predicting road flooding risk with crowdsourced reports and fine-grained traffic data
(Computational Urban Science, 2023-03-21) Yuan, Faxi; Lee, Cheng-Chun; Mobley, William; Farahmand, Hamed; Xu, Yuanchang; Blessing, Russell; Dong, Shangjia; Mostafavi, Ali; Brody, Samuel D.
The objective of this study is to predict road flooding risks based on topographic, hydrologic, and temporal precipitation features using machine learning models. Existing road inundation studies either lack empirical data for model validations or focus mainly on road inundation exposure assessment based on flood maps. This study addresses this limitation by using crowdsourced and fine-grained traffic data as an indicator of road inundation, and topographic, hydrologic, and temporal precipitation features as predictor variables. Two tree-based machine learning models (random forest and AdaBoost) were then tested and trained for predicting road inundations in the contexts of 2017 Hurricane Harvey and 2019 Tropical Storm Imelda in Harris County, Texas. The findings from Hurricane Harvey indicate that precipitation is the most important feature for predicting road inundation susceptibility, and that topographic features are more critical than hydrologic features for predicting road inundations in both storm cases. The random forest and AdaBoost models had relatively high AUC scores (0.860 and 0.810 for Harvey respectively and 0.790 and 0.720 for Imelda respectively) with the random forest model performing better in both cases. The random forest model showed stable performance for Harvey, while varying significantly for Imelda. This study advances the emerging field of smart flood resilience in terms of predictive flood risk mapping at the road level. In particular, such models could help impacted communities and emergency management agencies develop better preparedness and response strategies with improved situational awareness of road inundation likelihood as an extreme weather event unfolds.
Roadmap on energy harvesting materials
(Journal of Physics: Materials, 2023-08-07) Pecunia, Vincenzo; Silva, S. Ravi; Phillips, Jamie D.; Artegiani, Elisa; et al.
Ambient energy harvesting has great potential to contribute to sustainable development and address growing environmental challenges. Converting waste energy from energy-intensive processes and systems (e.g. combustion engines and furnaces) is crucial to reducing their environmental impact and achieving net-zero emissions. Compact energy harvesters will also be key to powering the exponentially growing smart devices ecosystem that is part of the Internet of Things, thus enabling futuristic applications that can improve our quality of life (e.g. smart homes, smart cities, smart manufacturing, and smart healthcare). To achieve these goals, innovative materials are needed to efficiently convert ambient energy into electricity through various physical mechanisms, such as the photovoltaic effect, thermoelectricity, piezoelectricity, triboelectricity, and radiofrequency wireless power transfer. By bringing together the perspectives of experts in various types of energy harvesting materials, this Roadmap provides extensive insights into recent advances and present challenges in the field. Additionally, the Roadmap analyses the key performance metrics of these technologies in relation to their ultimate energy conversion limits. Building on these insights, the Roadmap outlines promising directions for future research to fully harness the potential of energy harvesting materials for green energy anytime, anywhere.
Fluoroalkyl phosphonic acid radical scavengers for proton exchange membrane fuel cells
(Journal of Materials Chemistry A, 2023-04-06) Agarwal, Tanya; Adhikari, Santosh; Kim, Yu Seung; Babu, Siddharth Komini; Tian, Ding; Bae, Chulsung; Pham, Nguyet N. T.; Lee, Seung Geol; Prasad, Ajay K.; Advani, Suresh G.; Sievert, Allen; Rasika, Wipula Priya Liyanage; Hopkins, Timothy E.; Park, Andrew; Borup, Rod
Radical-induced degradation of proton exchange membranes limits the durability of proton-exchange membrane fuel cells. Cerium is widely used as a radical scavenger, but the migration of cerium ions to the catalyst layer has been an unresolved issue, reducing its effectiveness over time. Here, we report phosphonic acids as a promising class of radical scavengers, showing competent radical scavenging activity compared to cerium without the migration issue. The ex situ Fenton test shows that the fluoride emission rate for Nafion membrane incorporated with fluoroalkyl phosphonic acid ranged from 0.22 to 0.37 μg F cm−2 h−1, lower than that of the cerium-incorporated Nafion™ membrane (0.39 μg F cm−2 h−1). The in situ open circuit voltage hold test confirmed that a phosphonic acid-incorporated Nafion™ membrane has a 58% lower fluoride emission rate compared to the baseline. Density functional theory calculations indicate that the activation energy of the hydroxyl radical scavenging reaction of an alkyl phosphonic acid is only 0.68 eV, suggesting an effective radical scavenging pathway.
A qualitative study of healthcare providers’ attitudes toward assisted partner notification for people with HIV in Indonesia
(BMC Health Services Research, 2023-01-24) Levy, Judith A.; Earnshaw, Valerie A.; Milanti, Ariesta; Waluyo, Agung; Culbert, Gabriel J.
Background Assisted partner notification (APN) is recommended as a public health strategy to increase HIV testing in people exposed to HIV. Yet its adoption in many countries remains at an early stage. This qualitative study sought the opinions of HIV health service providers regarding the appropriateness and feasibility of implementing APN in Indonesia where such services are on the cusp of adoption. Methods Four focus group discussions totaling 40 health service providers were held in Jakarta, Indonesia to consider APN as an innovative concept and to share their reactions regarding its potential implementation in Indonesia. Voice-recorded discussions were conducted in Bahasa, transcribed verbatim, and analyzed. Results Participants recognized APN’s potential in contacting and informing the partners of HIV-positive clients of possible viral exposure. They also perceived APN’s value as a client-driven service permitting clients to select which of three partner notification methods would work best for them across differing partner relationships and settings. Nonetheless, participants also identified personal and health system challenges that could impede successful APN adoption including medical and human resource limitations, the need for specialized APN training, ethical and equity considerations, and lack of sufficient clarity concerning laws and government policies regulating 3rd party disclosures. They also pointed to the job-overload, stress, personal discomfort, and the ethical uncertainty that providers might experience in delivering APN. Conclusion Overall, providers of HIV services embraced the concept of APN but forecast practical difficulties in key service areas where investments in resources and system change appeared necessary to ensure effective and equitable implementation.
The Drug-Induced Interface That Drives HIV-1 Integrase Hypermultimerization and Loss of Function
(mBio, 2023-02-06) Singer, Matthew R.; Dinh, Tung; Levintov, Lev; Annamalai, Arun S.; Rey, Juan S.; Briganti, Lorenzo; Cook, Nicola J.; Pye, Valerie E.; Taylor, Ian A.; Kim, Kyungjin; Engelman, Alan N.; Kim, Baek; Perilla, Juan R.; Kvaratskhelia, Mamuka; Cherepanov, Peter
Allosteric HIV-1 integrase (IN) inhibitors (ALLINIs) are an emerging class of small molecules that disrupt viral maturation by inducing the aberrant multimerization of IN. Here, we present cocrystal structures of HIV-1 IN with two potent ALLINIs, namely, BI-D and the drug candidate Pirmitegravir. The structures reveal atomistic details of the ALLINI-induced interface between the HIV-1 IN catalytic core and carboxyl-terminal domains (CCD and CTD). Projecting from their principal binding pocket on the IN CCD dimer, the compounds act as molecular glue by engaging a triad of invariant HIV-1 IN CTD residues, namely, Tyr226, Trp235, and Lys266, to nucleate the CTD-CCD interaction. The drug-induced interface involves the CTD SH3-like fold and extends to the beginning of the IN carboxyl-terminal tail region. We show that mutations of HIV-1 IN CTD residues that participate in the interface with the CCD greatly reduce the IN-aggregation properties of Pirmitegravir. Our results explain the mechanism of the ALLINI-induced condensation of HIV-1 IN and provide a reliable template for the rational development of this series of antiretrovirals through the optimization of their key contacts with the viral target. IMPORTANCE Despite the remarkable success of combination antiretroviral therapy, HIV-1 remains among the major causes of human suffering and loss of life in poor and developing nations. To prevail in this drawn-out battle with the pandemic, it is essential to continue developing advanced antiviral agents to fight drug resistant HIV-1 variants. Allosteric integrase inhibitors (ALLINIs) are an emerging class of HIV-1 antagonists that are orthogonal to the current antiretroviral drugs. These small molecules act as highly specific molecular glue, which triggers the aggregation of HIV-1 integrase. In this work, we present high-resolution crystal structures that reveal the crucial interactions made by two potent ALLINIs, namely, BI-D and Pirmitegravir, with HIV-1 integrase. Our results explain the mechanism of drug action and will inform the development of this promising class of small molecules for future use in antiretroviral regimens.
The motivations, challenges and needs of small- and medium-scale beginning farmers in the midwestern United States
(Journal of Agriculture, Food Systems, and Community Development, 2023-04-27) Iles, Keri; Nixon, Rebecca; Ma, Zhao; Gibson, Kevin; Benjamin, Tamara
Beginning farmers are increasingly recognized as important agricultural actors in the United States. Efforts to help interested individuals enter agriculture have increased; however, there is still a substantial knowledge gap regarding beginning farmers’ characteristics, motivations to farm, challenges, and information and resource needs, particularly among those who operate small or medium-sized farms. In this research, we collected and analyzed survey data in Indiana to gain a better understanding of small- and medium-scale beginning farmers in the midwestern United States. We found that small- and medium-scale beginning farmers were motivated by their desire for a farming lifestyle and to support local food and agroecological farming systems on a landscape dominated by commodity crops. They relied substantially on off-farm income and faced related challenges including limited access to labor and difficulty balancing their on-farm and off-farm responsibilities. Finding effective marketing strategies also challenged this group of farmers, as they were not well-integrated into existing agricultural programs, and many had limited interactions with agricultural agencies and organizations. Instead, the majority of small- and medium-scale beginning farmers relied heavily on their own internet research and informal interactions with other farmers to learn and obtain help for their farms. Together, our results contribute to a better understanding of small- and medium-scale beginning farmers’ characteristics, motivations, and farming practices, as well as the challenges they face and the support they need to address these challenges. Because beginning farmers often differ from their more established counterparts who operate larger farms, the results of this research can be used to inform tailored agricultural programs and technical assistance that address small- and medium-scale beginning farmers’ specific needs and challenges in order to increase their likelihood of success to not only start but also sustain a small- or medium-scale farm over time.

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