Browsing by Author "Ulrich, Rachel"

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Diarrhea prevalence in a randomized, controlled prospective trial of point-of-use water filters in homes and schools in the Dominican Republic
(Springer Science and Business Media LLC, 2021-01) Tintle, Nathan; Van De Griend, Kristin; Ulrich, Rachel; Wade, Randall D.; Baar, Tena M.; Boven, Emma; Cooper, Carolyn E. A.; Couch, Olivia; Eekhoff, Lauren; Fry, Benjamin; Goszkowicz, Grace K.; Hecksel, Maya A.; Heynen, Adam; Laughlin, Jade A.; Les, Sydney M.; Lombard, Taylor R.; Munson, B. Daniel; Peterson, Jonas M.; Schumann, Eric; Settecerri, Daniel J.; Spry, Jacob E.; Summerfield, Matthew J.; Sunder, Meghana; Wade, Daniel R.; Zonnefeld, Caden G.; Brokus, Sarah A.; Moen, Francesco S.; Slater, Adam D.; Peterson, Jonathan W.; Pikaart, Michael J.; Krueger, Brent P.; Best, Aaron A.
Background. Lack of sustainable access to clean drinking water continues to be an issue of paramount global importance, leading to millions of preventable deaths annually. Best practices for providing sustainable access to clean drinking water, however, remain unclear. Widespread installation of low-cost, in-home, point of use water filtration systems is a promising strategy. Methods. We conducted a prospective, randomized, controlled trial whereby 16 villages were selected and randomly assigned to one of four treatment arms based on the installation location of Sawyer® PointONE™ filters (filter in both home and school; filter in home only; filter in school only; control group). Water samples and self-reported information on diarrhea were collected at multiple times throughout the study. Results. Self-reported household prevalence of diarrhea decreased from 25.6 to 9.76% from installation to follow-up (at least 7 days, and up to 200 days post-filter installation). These declines were also observed in diarrhea with economic or educational consequences (diarrhea which led to medical treatment and/or missing school or work) with baseline prevalence of 9.64% declining to 1.57%. Decreases in diarrhea prevalence were observed across age groups. There was no evidence of a loss of efficacy of filters up to 200 days post-filter installation. Installation of filters in schools was not associated with decreases in diarrhea prevalence in school-aged children or family members. Unfiltered water samples both at schools and homes contained potential waterborne bacterial pathogens, dissolved heavy metals and metals associated with particulates. All dissolved metals were detected at levels below World Health Organization action guidelines. Conclusions. This controlled trial provides strong evidence of the effectiveness of point-of-use, hollow fiber membrane filters at reducing diarrhea from bacterial sources up to 200 days post-installation when installed in homes. No statistically significant reduction in diarrhea was found when filters were installed in schools. Further research is needed in order to explore filter efficacy and utilization after 200 days post-installation. Trial registration. ClinicalTrials.gov, NCT03972618. Registered 3 June 2019—retrospectively registered.
Net Primary Production of Ecoregions Across North America in Response to Drought and Wildfires From 2015 to 2022
(American Geophysical Union, 2024-04) Potter, Christopher; Pass, Stephanie; Ulrich, Rachel
Ecosystem models are valuable tools to make climate-related assessments of change when ground-based measurements of water and carbon fluxes are not adequate to realistically capture regional variability. The Carnegie-Ames-Stanford Approach (CASA) is one such model based on satellite observations of monthly vegetation cover to estimate net primary production (NPP) of terrestrial ecosystems. CASA model predictions from 2015 to 2022 revealed several notable high and low periods in growing season NPP totals in certain biomes. Both Temperate Broadleaf and Boreal Forest production shifted from relatively high average NPP values in 2015 through 2019 to lower levels in 2020, typically representing a loss of 10%–14% of growing season NPP flux. This rapid decline in growing season NPP from 2019 to 2020–2021 was also estimated for the Temperate Grasslands and Savanna, Temperate Conifer Forest, and Tundra biomes. In contrast to the climate patterns in the temperate biomes that developed into severe widespread drought in 2020 and 2021 due to low precipitation totals and extreme hot temperatures, growing season NPP in the Tundra biome was depressed in these same years by colder temperature induced drought conditions at the high latitudes of North America. Drought severity classes were closely associated with different levels of decline in NPP in most biomes. Trends in NPP in areas of the largest wildfires in North America that burned between 2012 and 2021 were examined to assess recovery of vegetation and the resiliency of ecosystems during extreme drought periods.
Physical and chemical mechanisms that influence the electrical conductivity of lignin-derived biochar
(2021-10) Kane, Seth; Ulrich, Rachel; Harrington, Abigail; Stadie, Nicholas P.; Ryan, Cecily A.
Lignin-derived biochar is a promising, sustainable alternative to petroleum-based carbon powders (e.g., carbon black) for polymer composite and energy storage applications. Prior studies of these biochars demonstrate that high electrical conductivity and good capacitive behavior are achievable. However, these studies also show high variability in electrical conductivity between biochars (– S/cm). The underlying mechanisms that lead to desirable electrical properties in these lignin-derived biochars are poorly understood. In this work, we examine the causes of the variation in conductivity of lignin-derived biochar to optimize the electrical conductivity of lignin-derived biochars. To this end, we produced biochar from three different lignins, a whole biomass source (wheat stem), and cellulose at two pyrolysis temperatures (900 °C, 1100 °C). These biochars have a similar range of conductivities (0.002 to 18.51 S/cm) to what has been reported in the literature. Results from examining the relationship between chemical and physical biochar properties and electrical conductivity indicate that decreases in oxygen content and changes in particle size are associated with increases in electrical conductivity. Importantly, high variation in electrical conductivity is seen between biochars produced from lignins isolated with similar processes, demonstrating the importance of the lignin’s properties on biochar electrical conductivity. These findings indicate how lignin composition and processing may be further selected and optimized to target specific applications of lignin-derived biochars.
Reconstructing suicide vs. elevation datasets and related analyses
(Montana State Univeristy, 2017-04) Ulrich, Rachel
Dr. Mark Greenwood has authored a locally published textbook for STAT 217 – an intermediate statistics course offered at MSU – and is interested in incorporating an exploration of data on county suicide rates and a possible connection to elevation. Both elevation and suicide rate information are publicly available, but researchers using these data sets have not published a holistic dataset incorporating the multiple sources from which this information stems. I plan to recreate a dataset focusing on the potential relationship between altitude and suicide rates in the contiguous United States based upon two well-publicized articles. In addition to providing a thought-provoking textbook example, this dataset and exact methods for reconstruction will be submitted to MSU’s Scholarworks and made available as a public geospatial dataset on ArcGIS Online, allowing other researchers interested in these data access to an easily analyzed version. A comparison of results will serve as a verification of methods, possibly allowing me to improve upon these methods in future research.