Physical Sciences and Mathematics Commons^™

Source Apportionment And Health Risk Assessment Of Nitrate In Foothill Aquifers Of Western Ghats, South India, Banajarani Panda, S. Chidambaram, Daniel D. Snow, Arindam Malakar, Dhiraj Kr Singh, L. Ramanathan

Nebraska Water Center: Faculty Publications

The present research reports the level of nitrate (NO₃^-), associated health risks and possible sources of contamination in groundwater from south India. Many samples (32%) are above or approaching the recommended level of NO₃^- for safe drinking water. The correlation analysis indicates different sources of NO₃^- contamination in different regions rather than a common origin. The isotopic measurements provide information about potential nitrogen sources contributing NO₃^- to the groundwater. Based on isotope analysis, the sources of NO₃^- in the groundwater of this region are likely to be from (a) …

Continuous Turbidity Data Used To Compute Constituent Concentrations In The South Loup River, Nebraska, 2017–18, David L. Rus, Brenda K. Densmore

United States Geological Survey: Water Reports and Publications

The South Loup River in central Nebraska has been impaired by bacteria since at least 2004, which has resulted in the river not meeting its intended use as a recreational waterway. As part of a strategy for reducing the bacterial load in the river, the United States Geological Survey (USGS), in cooperation with the Lower Loup Natural Resources District, made continuous estimates of Escherichia coli (E. coli) and nutrient concentrations during seasonal monitoring at the South Loup River at Saint Michael, Nebraska, during 2017–18. Continuous turbidity data were collected from mid-April through October in 2017 and 2018 …

Recharge Assessment In The Context Of Expanding Agricultural Activity: Urucuia Aquifer System, Western State Of Bahia, Brazil, Glauco Z.S. Eger, Gerson C. Silva Junior, Eduardo A.G. Marques, Bernardo R.C. Leão, Diana G.T.B. Da Rocha, Troy E. Gilmore, Luís G.H. Do Amaral, Juremá A.O. Silva, Christopher Neale

Conservation and Survey Division

Groundwater recharge rate estimation is crucial to sustainable development of aquifers in intensely pumped regions, such as the Urucuia Aquifer System (UAS). A sedimentary aquifer in Western Bahia, Brazil, that underlies one of the major agricultural areas of the country where there has been major growth of irrigated areas. This study seeks to evaluate the recharge component of the water budget in the UAS area, based on three complementary techniques. The double-ring infiltrometer test was used to evaluate surface infiltration capacity, an important control on recharge. Water level data from wells (2011–2019 period, 19 wells) in the Brazilian Geological Survey’s …

Assessing The Vegetation Condition Impacts Of The 2011 Drought Across The U.S. Southern Great Plains Using The Vegetation Drought Response Index (Vegdri), Tsegaye Tadesse, Brian D. Wardlow, Jesslyn F. Brown, Mark D. Svoboda, Michael J. Hayes, Brian Fuchs, Denise Gutzmer

Drought Mitigation Center: Faculty Publications

The vegetation drought response index (VegDRI), which combines traditional climate- and satellite-based approaches for assessing vegetation conditions, offers new insights into assessing the impacts of drought from local to regional scales. In 2011, the U.S. southern Great Plains, which includes Texas, Oklahoma, and New Mexico, was plagued by moderate to extreme drought that was intensified by an extended period of recordbreaking heat. The 2011 drought presented an ideal case study to evaluate the performance of VegDRI in characterizing developing drought conditions. Assessment of the spatiotemporal drought patterns represented in the VegDRI maps showed that the severity and patterns of the …

Geology And Hydrogeology Of Northeastern Nebraska: Geology, Water Management And Geological Hazards, Nebraska Geological Society Field Trip 2021, Robert F. Diffendal Jr., Sue Olafsen Lackey, Douglas R. Hallum

Conservation and Survey Division

The 2021 Nebraska Geological Society field trip will provide an overview of the geology and hydrogeology of northeast Nebraska, the groundwater quality and quantity issues unique to the region, water management issues and decision-making, and ongoing work relating to water quality and geologic (hydrostratigraphic) framework, along the lower Niobrara and Missouri rivers Between Spencer Dam and Homer Nebraska. This program will be comprised of an auto tour with multiple stops on Saturday October 16 through Monday October 18 as illustrated in Map 1. The tour will begin with an examination of the Spencer Dam site and several locations in and …

Groundwater Quality And Age Of Secondary Bedrock Aquifers In The Glaciated Portion Of Eastern Nebraska, 2016–18, Christopher M. Hobza, Amanda T. Flynn

United States Geological Survey: Water Reports and Publications

The Eastern Nebraska Water Resources Assessment (ENWRA) project was initiated in 2006 to assist water managers by developing a hydrogeologic framework and water budget for the glaciated portion of eastern Nebraska. Within the ENWRA area, the primary groundwater sources for municipal, domestic, and irrigation water needs are provided by withdrawals from alluvial, buried paleovalley, and the High Plains aquifer (where present). Generally, other bedrock aquifers are considered a secondary water source. However, in some areas, such as parts of Sarpy and Nemaha Counties, these secondary bedrock aquifers are the only source of water within glaciated upland areas. To improve the …

A Typology Of Drought Decision Making: Synthesizing Across Cases To Understand Drought Preparedness And Response Actions, Amanda E. Cravens, Jen Henderson, Jack Friedman, Nina Burkardt, Ashley E. Cooper, Tonya Haigh, Michael Hayes, Jamie Mcenvoy, Stephanie Paladino, Adam K. Wilke, Hailey Wilmer

Drought Mitigation Center: Faculty Publications

Drought is an inescapable reality in many regions, including much of the western United States. With climate change, droughts are predicted to intensify and occur more frequently, making the imperative for drought management even greater. Many diverse actors – including private landowners, business owners, scientists, non-governmental organizations (NGOs), and managers and policymakers within tribal, local, state, and federal government agencies – play multiple, often overlapping roles in preparing for and responding to drought. Managing water is, of course, one of the most important roles that humans play in both mitigating and responding to droughts; but, focusing only on “water managers” …

Right Side Up: Payment For Ecosystem Services On Privately Owned Grasslands In Nebraska, Kyle Martens

School of Natural Resources: Dissertations, Theses, and Student Research

Grasslands are an important ecological and economic resource in the United States. As part of a natural system, these landscapes can provide income for ranching operations and employment in rural communities; habitat for grassland plants, animals, and migratory species; and offer other services not always readily observed such as improved soil health, clean water, and carbon sequestration. Despite the overarching benefits, the conversion of grasslands to other uses remains widespread throughout much of the remaining Great Plains ecosystem.

Shifting from livestock ranching to another land use often reflects a tipping point. This occurs when the alternative land use is perceived …

U.S. Geological Survey Science For The Wyoming Landscape Conservation Initiative—2018 Annual Report, Patrick J. Anderson, Cameron L. Aldridge, Jason S. Alexander, Timothy J.` Assal, Steven Aulenbach, Zachary H. Bowen, Anna D. Chalfoun, Geneva W. Chong, Holly Copeland, David R. Edmunds, Steve Germaine, Tabitha Graves, Julie A. Heinrichs, Collin G. Homer, Christopher G. Huber, Aaron N. Johnston, Matthew J. Kauffman, Daniel J. Manier, Ryan R. Mcshane, Cheryl A. Eddy-Miller, Kirk A. Miller, Adrian P. Monroe, Michael S. O'Donnell, Anna Ortega, Annika W. Walters, Daniel J. Wieferich, Teal B. Wyckoff, Linda Zeigenfuss

United States Geological Survey: Water Reports and Publications

The Wyoming Landscape Conservation Initiative (WLCI) was established in 2007 as a collaborative interagency partnership to develop and implement science-based conservation actions. During the past 11 years, partners from U.S. Geological Survey (USGS), State and Federal land management agencies, universities, and the public have collaborated to implement a long-term (more than 10 years) science-based program that assesses and enhances the quality and quantity of wildlife habitats in the southwest Wyoming region while facilitating responsible development. The USGS WLCI Science Team completes scientific research and develops tools that inform and support WLCI partner planning, decision making, and on-the-ground management actions.

In …

Soil Morphology And Carbon Stocks Of Deflation Basin Wetlands In Eastern Nebraska, Usa, Aubrey Grace Kemper

School of Natural Resources: Dissertations, Theses, and Student Research

Wetlands contribute important ecosystem services such as water filtration and storage, wildlife habitat, and carbon sequestration. The objective of this study is to compare the soil morphology and the carbon and nitrogen stocks between the upland, basin edge, and basin floor in playa wetlands of eastern Nebraska. This work was conducted in three deflation basin wetlands in the Todd Valley, a loess-mantled, former course of the Platte River, in eastern Nebraska. Soil morphological descriptions were evaluated to two meters’ depth using cores collected along three transects from the upland to the basin floor in three basins, carbon and nitrogen stocks …

Development Of A Flash Drought Intensity Index, Jason A. Otkin, Yafang Zhong, Eric D. Hunt, Jordan I. Christian, Jeffrey B. Basara, Hanh Nguyen, Matthew C. Wheeler, Trent W. Ford, Andrew Hoell, Mark Svoboda, Martha C. Anderson

Drought Mitigation Center: Faculty Publications

Flash droughts are characterized by a period of rapid intensification over sub-seasonal time scales that culminates in the rapid emergence of new or worsening drought impacts. This study presents a new flash drought intensity index (FDII) that accounts for both the unusually rapid rate of drought intensification and its resultant severity. The FDII framework advances our ability to characterize flash drought because it provides a more complete measure of flash drought intensity than existing classification methods that only consider the rate of intensification. The FDII is computed using two terms measuring the maximum rate of intensification (FD_INT) and average drought …

Water Quality Threats, Perceptions Of Climate Change And Behavioral Responses Among Farmers In The Ethiopian Rift Valley, Tewodros R. Godebo, Marc A. Jeuland, Christopher J. Paul, Dagnachew L. Belachew, Peter G. Mccornick

Drought Mitigation Center: Faculty Publications

This work aims to assess water quality for irrigated agriculture, alongside perceptions and adaptations of farmers to climate change in the Main Ethiopian Rift (MER). Climate change is expected to cause a rise in temperature and variability in rainfall in the region, reducing surface water availability and raising dependence on groundwater. The study data come from surveys with 147 farmers living in the Ziway–Shala basin and water quality assessments of 162 samples from groundwater wells and surface water. Most groundwater samples were found to be unsuitable for long term agricultural use due to their high salinity and sodium adsorption ratio, …

Biotransformation Of Doxycycline By Brevundimonas Naejangsanensis And Sphingobacterium Mizutaii Strains, Ting He, Jianguo Bao, Yifei Leng, Daniel D. Snow, Shuqiong Kong, Tong Wang, Xu Li

Nebraska Water Center: Faculty Publications

The fate of doxycycline (DC), a second generation tetracycline antibiotic, in the environment has drawn increasing attention in recent years due to its wide usage. Little is known about the biodegradability of DC in the environment. The objective of this study was to characterize the biotransformation of DC by pure bacterial strains with respect to reaction kinetics under different environmental conditions and biotransformation products. Two bacterial strains, Brevundimonas naejangsanensis DD1 and Sphingobacterium mizutaii DD2, were isolated from chicken litter and characterized for their biotransformation capability of DC. Results show both strains rely on cometabolism to biotransform DC with tryptone as …

Modeling Vadose Zone Hydrology: Lecture Notes, Derek M. Heeren, Dean Eisenhauer

Open Educational Resources for Engineering

Modeling Vadose Zone Hydrology is a graduate-level course offered biennially in the Department of Biological Systems Engineering. Topics included hydraulic properties of porous media, application of Darcy's Law in variably saturated media, hydrologic and transport processes in the vadose zone, and solution of steady and unsteady flow problems using numerical techniques. A graphical approach for characterizing vertical one-dimensional problems with energy head profiles was emphasized. Common one-dimensional flow and transport problems were solved analytically. The course was taught using a combination of lecture notes and PowerPoint presentations. The lecture notes from 2021, captured using the Microsoft Whiteboard app with a …

Multi-Dimensional Drought Assessment In Abbay/Upper Blue Nile Basin: The Importance Of Shared Management And Regional Coordination Efforts For Mitigation, Yared Bayissa, Semu Moges, Assefa Melesse, Tsegaye Tadesse, Anteneh Z. Abiy, Abeyou Worqlul

Drought Mitigation Center: Faculty Publications

Drought is one of the least understood and complex natural hazards often characterized by a significant decrease in water availability for a prolonged period. It can be manifested in one or more forms as meteorological, agricultural, hydrological, and/or socio-economic drought. The overarching objective of this study is to demonstrate and characterize the different forms of droughts and to assess the multidimensional nature of drought in the Abbay/ Upper Blue Nile River (UBN) basin and its national and regional scale implications. In this study, multiple drought indices derived from in situ and earth observation-based hydro-climatic variables were used. The meteorological drought …

Groundwater Education: An Investigation Of Students' Use Of A Groundwater Modeling Tool, Holly White

School of Natural Resources: Dissertations, Theses, and Student Research

Groundwater is a critical resource for life on Earth. However, our groundwater resources are at risk due to human activities, making this a topic of importance within K-12 and undergraduate environmental education. Yet, students hold alternative conceptions and may have limited awareness about groundwater systems. One way to support students’ learning is by incorporating computer-based modeling tools into classrooms. Here, we explore the use a groundwater modeling tool, the Hydrogeology Challenge (HGC), among two age groups of students: seventh grade students and undergraduate students. In the seventh-grade population, we investigated how students relate or map model components to their real-world …

Bioaccumulation And Partitioning Of Heavy Metals In Cicindelidia Haemorrhagica In Yellowstone National Park, Monica Gotschall

School of Natural Resources: Dissertations, Theses, and Student Research

The tiger beetle Cicindelidia haemorrhagica (Coleoptera: Cicindelidae) are widely distributed in Yellowstone National Park (YNP) and exclusively living on thermal areas. Heavy metals including arsenic, copper, lead, and selenium are present in these thermal springs, presenting an unique environment for C. haemorrhagica. Therefore, from 2018 – 2020 I sampled adult C. haemorrhagica from YNP and adult C. haemorrhagica from a known population in a salt flat in Idaho not associated with a hot spring and measured heavy metal concentrations. All populations of C. haemorrhagica bioaccumulated heavy metals. Cuticular waxes showed small concentrations of metals indicating that those metals are …

Removal Of Carbamazepine Onto Modified Zeolitic Tuff In Different Water Matrices: Batch And Continuous Flow Experiments, Othman A. Al-Mashaqbeh, Diya A. Alsafadi, Layal Z. Alsalhi, Shannon L. Bartelt-Hunt, Daniel D. Snow

Nebraska Water Center: Faculty Publications

Carbamazepine (CBZ) is the most frequently detected pharmaceutical residues in aquatic environments effluent by wastewater treatment plants. Batch and column experiments were conducted to evaluate the removal of CBZ from ultra-pure water and wastewater treatment plant (WWTP) effluent using raw zeolitic tuff (RZT) and surfactant modified zeolite (SMZ). Point zero net charge (pHpzc), X-ray diffraction (XRD), X-ray fluorescence (XRF), and Fourier Transform Infrared (FTIR) were investigated for adsorbents to evaluate the physiochemical changes resulted from the modification process using Hexadecyltrimethylammonium bromide (HDTMA-Br). XRD and FTIR showed that the surfactant modification of RZT has created an amorphous surface with new alkyl …

Occurrence And Potential Transformation Pathways Of Nitrogen Species In The Intermediate Vadose Zone, Jordan Shields

School of Natural Resources: Dissertations, Theses, and Student Research

Nebraska is a large agricultural producing state with a heavy reliance on groundwater resources and nitrogen fertilizer application to maintain output. Poor management, such as excessive fertilizer application, improper timing, and over irrigation can lead to contamination of groundwater. Nitrate is the leading groundwater contaminant in Nebraska and chronic consumption at medium to high concentrations leads to adverse health effects. Nitrate, a highly soluble anion, is present in the root zone in numerous forms and undergoes biogeochemical transformations before being leached through the profile. In order to predict the timing and quantity of nitrate contamination in groundwater, researchers study the …

Exploring Viirs Continuity With Modis In An Expedited Capability For Monitoring Drought-Related Vegetation Conditions, Trenton D. Benedict, Jesslyn F. Brown, Stephen P. Boyte, Daniel M. Howard, Brian A. Fuchs, Brian D. Wardlow, Tsegaye Tadesse, Kirk A. Evenson

Drought Mitigation Center: Faculty Publications

Vegetation has been effectively monitored using remote sensing time-series vegetation index (VI) data for several decades. Drought monitoring has been a common application with algorithms tuned to capturing anomalous temporal and spatial vegetation patterns. Drought stress models, such as the Vegetation Drought Response Index (VegDRI), often use VIs like the Normalized Difference Vegetation Index (NDVI). The EROS expedited Moderate Resolution Imaging Spectrora-diometer (eMODIS)-based, 7-day NDVI composites are integral to the VegDRI. As MODIS satellite platforms (Terra and Aqua) approach mission end, the Visible Infrared Imaging Radiometer Suite (VIIRS) presents an alternate NDVI source, with daily collection, similar band passes, and …

Exploring Viirs Continuity With Modis In An Expedited Capability For Monitoring Drought-Related Vegetation Conditions, Trenton D. Benedict, Jesslyn F. Brown, Stephen P. Boyte, Daniel M. Howard, Brian A. Fuchs, Brian D. Wardlow, Tsegaye Tadesse, Kirk A. Evenson

Drought Mitigation Center: Faculty Publications

Vegetation has been effectively monitored using remote sensing time-series vegetation index (VI) data for several decades. Drought monitoring has been a common application with algorithms tuned to capturing anomalous temporal and spatial vegetation patterns. Drought stress models, such as the Vegetation Drought Response Index (VegDRI), often use VIs like the Normalized Difference Vegetation Index (NDVI). The EROS expedited Moderate Resolution Imaging Spectrora-diometer (eMODIS)-based, 7-day NDVI composites are integral to the VegDRI. As MODIS satellite platforms (Terra and Aqua) approach mission end, the Visible Infrared Imaging Radiometer Suite (VIIRS) presents an alternate NDVI source, with daily collection, similar band passes, and …

Assessment Of Water Availability In The Osage Nation Using An Integrated Hydrologic-Flow Model, Jonathan (Jp) Traylor, Shana L. Mashburn, Randall T. Hanson, Steven M. Peterson

United States Geological Survey: Water Reports and Publications

Document abstract

The Osage Nation of northeastern Oklahoma, conterminous with Osage County, covers about 2,900 square miles. The area is primarily rural with 62 percent of the land being native prairie grass, and much of the area is used for cattle ranching and extraction of petroleum and natural gas. Protection of water rights are important to the Osage Nation because of its reliance on cattle ranching and the potential for impairment of water quality by petroleum extraction. Additionally, the potential for future population increases, demands for water from neighboring areas such as the Tulsa metropolitan area, and expansion of petroleum …

The Drought Monitor Comes Of Age, Brad Rippey, Brian Fuchs, David Simeral, Deborah J. Bathke, Richard Heim, Mark Svoboda

Drought Mitigation Center: Faculty Publications

The 20th century featured immense scientific discoveries and advances. Astrophysics gained Einstein’s life-altering theory of relativity, opening the door to nuclear weaponry and the mind-bending Big Bang theory. The medical field achieved stunning success in suppressing or vanquishing a host of deadly diseases, including polio and smallpox. And through advances in computing technology, meteorological forecasting moved from backof- the-envelope calculations to supercomputers. However, drought monitoring fell behind the curve of scientific advancement. Not until 1965, when the U.S. Department of Commerce published Wayne C. Palmer’s “Research Paper No. 45: Meteorological Drought,” was there even a complex mathematical definition of drought. …

Rock Glen Wildlife Area: A Landscape History, Gerry Steinauer, Robert Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Nestled in the hills of southern Jefferson County, Rock Glen Wildlife Management Area, as its name implies, is a rocky land shaped by ancient geological forces, among them, meandering tropical rivers and grinding glacial ice. Euro-American settlers in the region arrived to a picturesque scene: rolling hills cloaked in tallgrass prairie fingered by glens, narrow valleys and canyons, filled with sprawling bur oaks. Too rocky to plow, southern Jefferson County has survived as an island of prairie amidst a sea of cropland. Settlement was not kind to the land. Fire suppression allowed eastern red cedars and other trees to spread, …

Flash Drought Onset Over The Contiguous United States: Sensitivity Of Inventories And Trends To Quantitative Definitions, Mahmoud Osman, Bejamin F. Zaitchik, Hamada S. Badr, Jordan I. Christian, Tsegaye Tadesse, Jason A. Otkin, Martha C. Anderson

Drought Mitigation Center: Faculty Publications

The term “flash drought” is frequently invoked to describe droughts that develop rapidly over a relatively short timescale. Despite extensive and growing research on flash drought processes, predictability, and trends, there is still no standard quantitative definition that encompasses all flash drought characteristics and pathways. Instead, diverse definitions have been proposed, supporting wide-ranging studies of flash drought but creating the potential for confusion as to what the term means and how to characterize it. Use of different definitions might also lead to different conclusions regarding flash drought frequency, predictability, and trends under climate change. In this study, we compared five …

Nebraska Statewide Groundwater-Level Monitoring Report 2020, Aaron R. Young, Mark E. Burbach, Leslie M. Howard, Sue Olafsen Lackey, Robert Matthew Joeckel

Conservation and Survey Division

The term “groundwater” has come to be all but synonymous with Nebraska. Nearly three-quarters of the total volume of the High Plains Aquifer lies beneath the state. Groundwater maintains our streams, our ecosystems, our people, and our vitally important agricultural economy. Nebraska’s total groundwater resource is vast, yet it is also vulnerable to natural and anthropogenic changes, necessitating a long-term commitment to wise management through informed decision-making. Monitoring, studying, and reporting form the essential basis for such management and, ultimately, for meeting the myriad challenges presented by change.

Valuation Of Drought Information: Understanding The Value Of The Us Drought Monitor In Land Management, Tingting Liu, Richard Krop, Tonya Haigh, Kelly Helm Smith, Mark D. Svoboda

Drought Mitigation Center: Faculty Publications

Droughts affect recreation and tourism, grazing, forests, and timber, and can have important indirect effects for the ecosystems and species that rely on water. Despite its importance, the effect of drought in the land management sector is less understood than in other water-intensive sectors, such as agriculture and public water supplies. This study presents the first-ever estimates of the economic valuation of the information provided by the U.S. Drought Monitor using the avoided cost method. These estimates are based on the time and labor saved by using the U.S. Drought Monitor rather than compiling drought-related information from other sources, or …

Nanomaterials In The Environment, Human Exposure Pathway, And Health Effects: A Review, Arindam Malakar, Sushil R. Kanel, Chittaranjan Ray, Daniel D. Snow, Mallikarjuna N. Nadagouda

Daugherty Water for Food Global Institute: Faculty Publications

Nanomaterials (NMs), both natural and synthetic, are produced, transformed, and exported into our environment daily. Natural NMs annual flux to the environment is around 97% of the total and is significantly higher than synthetic NMs. However, synthetic NMs are considered to have a detrimental effect on the environment. The extensive usage of synthetic NMs in different fields, including chemical, engineering, electronics, and medicine, makes them susceptible to be discharged into the atmosphere, various water sources, soil, and landfill waste. As ever-larger quantities of NMs end up in our environment and start interacting with the biota, it is crucial to understand …

Moving Beyond ‘More Crop Per Drop’: Insights From Two Decades Of Research On Agricultural Water Productivity, Meredith Giordano, Susanne M. Scheierling, David O. Tréguer, Hugh Turral, Peter G. Mccornick

Daugherty Water for Food Global Institute: Faculty Publications

Concern over increasing water scarcity has led to the introduction of the concept of agricultural water productivity and an emphasis on interventions to achieve ‘more crop per drop’. Yet, a strong debate continues on how the concept is to be defined and used. Drawing largely from the irrigation literature, the origins of the concept and its methodological developments are reviewed, and its use in applied work over two decades is discussed. Based on this analysis of conceptual and applied research, key insights into the concept’s contributions and limitations are presented, as well as opportunities for further refinements.

Whose Ground Truth Is It? Harvesting Lessons From Missouri’S 2018 Bumper Crop Of Drought Observations, Kelly Helm Smith, Mark E. Burbach, Michael Hayes, Patrick Guinan, Andrew Tyre, Brian Fuchs, Tonya Haigh, Mark Svoboda

Drought Mitigation Center: Faculty Publications

Drought-related decision-making and policy should go beyond numeric hydrometeorological data to incorporate information on how drought affects people, livelihoods, and ecosystems. The effects of drought are nested within environmental and human systems, and relevant data may not exist in readily accessible form. For example, drought may reduce forage growth, compounded by both late-season freezes and management decisions. An effort to gather crowdsourced drought observations in Missouri in 2018 yielded a much higher number of observations than did previous related efforts. Here we examine 1) the interests, circumstances, history, and recruitment messaging that coincided to produce a high number of reports …