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The dual role of water: driver and reflector of socio-environmental changes
Get PDFUniversity of Minnesota Ph.D. dissertation. June 2025. Major: Applied Economics. Advisors: Stephen Polasky, Marc Bellemare. 1 computer file (PDF); v, 127 pages.Water is a fundamental resource, essential not only for ecosystems and biodiversity but also for human development. In the last years, the importance of water has gained broader recognition in the research arena of environmental economics. This dissertation aims to underscore the value of water by examining both its role as a driver of change for socio-economic activities (Chapter 1) and the ways in which various human activities are reflected on water quality (Chapters 2 and 3).Castillo Castillo, Adriana. (2025). The dual role of water: driver and reflector of socio-environmental changes. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/276740
Driving Better Governance: The Case for Institutionalizing Evidence-Based Policy
Get PDFBoth the public and civil servants want government to spend resources on policies that work. In new research Chengxin Xu, Patrick Carter, Yuan (Daniel) Cheng, Weston Merrick and Shuping Wang find that US state-level policymakers are more likely to support and fund programs that have proven outcomes. Decision-makers, they write, were more likely to prioritize programs with proven positive impacts over those that only reported outputs.Xu, Chengxin; Carter, Patrick; Cheng, Yuan; Merrick, Weston; Wang, Shuping. (2025). Driving Better Governance: The Case for Institutionalizing Evidence-Based Policy. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/277664
The implementation of chloramine disinfection halts Legionnaires disease outbreak in a community water system
Get PDFUniversity of Minnesota M.S. thesis. June 2025. Major: Civil Engineering. Advisors: Raymond Hozalski, Timothy LaPara. 1 computer file (PDF); ix, 66 pages.A Legionnaires’ disease outbreak occurred in a small city in northern Minnesota, USA from April 2023 to June 2024. The source of the Legionella bacteria was suggested to be the non-disinfected, groundwater supplied community water system. The goal of this investigation, therefore, was to assess the occurrence of Legionella pneumophila throughout the water distribution system and in selected public buildings (i.e., premise plumbing samples) and the effectiveness of chloramine disinfection at resolving the outbreak. L. pneumophila were quantified in two sets of water samples collected prior to and two sets collected after introducing chloramines in June 2024. Before disinfection, L. pneumophila was detected in only 1/16 (6.3%) of water distribution samples but frequently detected (5/10, 50%) in premise plumbing samples at concentrations ranging from 102.0 to 104.0 MPN per liter via the Legiolert assay and from 102.5 to 104.3 gene copies per liter via digital PCR (gene target = mip). Within 15 days of the initiation of disinfection, all water distribution system samples were negative for L. pneumophila via Legiolert and digital PCR while 3/6 (50%) of premise plumbing samples were positive for mip (concentrations =102.6, 103.9, and 108.2 gene copies per liter) by digital PCR. Most of the premise plumbing samples were negative via the Legiolert assay, except for the sample that had the highest concentration of mip genes (101.6 MPN per liter). After 168 days of chloramine disinfection, all water distribution system and premise plumbing samples were negative for L. pneumophila. These results show that the community water system supplied by groundwater supported the growth of substantial levels of L. pneumophila in premise plumbing but not within the water distribution system. Furthermore, the implementation of chloramine disinfection quickly (< 3 weeks) reduced the levels of L. pneumophila in tap water, which coincided with a cessation of new cases of Legionnaires’ disease.Bledsoe, Molly. (2025). The implementation of chloramine disinfection halts Legionnaires disease outbreak in a community water system. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/276725
A first-principles study of ferroelectricity via symmetry-mode couplings
Get PDFUniversity of Minnesota Ph.D. dissertation. July 2025. Major: Chemical Engineering. Advisors: Turan Birol, Paul Dauenhauer. 1 computer file (PDF); xxv, 145 pages.Polarization—the net dipole moment per unit volume—is the fundamental response of insulating materials to an external electric field. Ferroelectrics are a unique class of insulators capable of sustaining spontaneous polarization even in the absence of an applied field. Since their discovery nearly a century ago, our understanding of ferroelectrics has rapidly advanced, driving significant technological innovations. However, recent findings suggest that ferroelectricity still harbors unexplored phenomena with the potential to revolutionize future applications. In this dissertation, I present the core body of research conducted during my graduate studies, beginning with first-principles simulations of polarization switching in ferroelectrics using density functional theory, combined with group theory and the Landau-Ginzburg-Devonshire theory. I then explore an emerging application of ferroelectric-supported catalysis. Specifically, I present a method to examine how polarization switching modulates adsorption and reaction processes in dynamic catalysis. Next, I investigate the competitive coupling between octahedral rotations and polarization in perovskites, which can give rise to antiferroelectric behavior. Finally, I introduce the concept of "hybrid-triggered" ferroelectricity, arising from unconventional phonon couplings. This discovery gives rise to the concept of higher-order dynamical charges, which may provide a key mechanism underlying the mitigation of one of the most significant barriers to the technological deployment of ferroelectrics: the depolarization field in the thin-film limit.Jung, Seongjoo. (2025). A first-principles study of ferroelectricity via symmetry-mode couplings. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/277368
Spatial variation in GHG emissions for U.S. soybean biodiesel supply chains
Get PDFUniversity of Minnesota M.S. thesis. June 2025. Major: Bioproducts/Biosystems Science Engineering and Management. Advisors: Natalie Hunt, Nathaniel Springer. 1 computer file (PDF); ix, 84 pages.Biofuels are widely promoted as an alternative to fossil fuels for decarbonizing transportation. However, concerns have been raised about the environmental integrity of these fuels. Most U.S. biofuel life cycle assessments (LCA) rely on large or national-scale assumptions that can overlook supply-chain variations. This study enhances the spatial resolution of U.S. soybean biodiesel LCA by integrating emissions data from county-level soybean production, supply-chain-specific transportation, and regional energy mixes. A least-cost optimization approach was applied to create subnational supply chains using complete U.S. soybean oil supply and demand. Then, emissions were aggregated to quantify cradle-to-processing gate global warming potential (GWP). Emissions ranged from 34-135 (avg. 58) gCO2eq MJ-1; excluding land use change (LUC), the range was reduced to 28-41 (avg. 33) gCO2eq MJ-1. Results showed that LUC largely drove variations in emissions. These results underscore the importance of spatial resolution and the contributions of LUC emissions in accurately assessing biodiesel emissions.Lau, Annabella. (2025). Spatial variation in GHG emissions for U.S. soybean biodiesel supply chains. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/276712
A phenomenological study of nurses who have diverted controlled substances with Temporal Representations of their experiences
Get PDFUniversity of Minnesota Ph.D. dissertation.May 2025. Major: Nursing. Advisor: Kathleen Krichbaum. 1 computer file (PDF); viii, 158 pages.AbstractBackground: There is limited information about the lived experiences of nurses who have diverted controlled substances. Drug diversion by nurses puts patients at risk of harm and is costly for the health care system. The literature is focused on processes to secure controlled substances, detecting and prosecuting diverters, substance disorder treatment for health care providers, and the efficacy of nurse monitoring programs.
Objective: The purpose of this study was to describe the experiences of nurses who have diverted controlled substances to develop knowledge of the factors and life events associated with diversion and the temporal relationships between them.
Method: This study used the complementary methods of descriptive-phenomenological interviews (Beck, 2016; Giorgio, 1992; van Manen, 2014), modified life history calendars (Axinn & Pearce, 2006; Nelson, 2010), and Visual Graphic Analysis (Brown, et al., 2007) to guide the planning and development of this study. In depth interviews and completion of life history calendars were completed with seven nurses who had diverted drugs. Themes reflecting the participants’ experiences emerged from the data and Temporal Representations were developed and analyzed for temporal relationships.
Findings: Results revealed the following themes. The themes were: the impact of childhood exposure to family dysfunction; the seeds of substance abuse and dysfunction were planted; lost and alone in a caring profession; opiates flipped a switch; slippery slope to diversion; in the grip of diversion use; the signs were there and the alarms were sounding; the roles of diversion enablers; depression, anxiety, and other psychiatric and behavioral issues impact diversion; with subthemes of: manipulating the system in a full-time job; and nurse heal thyself – I’m trying. The visual graphic analysis of the temporal representations revealed two findings. The most significant finding was that opiate use disorder occurred for all the nurse participants after they began diverting, apart from one participant who developed opiate use disorder during treatment for pain and began diverting when opiate treatment was terminated by the provider. The second finding that was identified was that the initiation of drug diversion is most likely to occur in the first year of nursing practice.
Conclusion: The results of this study provide nurses, nurse managers, nurse educators, nurse regulators, treatment providers, employers, law enforcement insights regarding nurse identified factors that impact initiation of drug diversion. Information from this study will assist with the development of future studies to improve treatment and monitoring, changes to nursing practice to reduce factors contributing to initiation of drug diversion, and strategies to reduce the opportunity for diversion in healthcare settings and the risk to patients.Miller, Kimberly. (2025). A phenomenological study of nurses who have diverted controlled substances with Temporal Representations of their experiences. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/276796
Enumeration 2024: What We Know and What We Wish We Knew About the Governmental Public Health Workforce in a COVID-19 Recovery Landscape
Get PDFObjectives: To expand on previous enumerations by assessing the size and composition of the governmental public health workforce in the wake of the COVID-19 pandemic, identifying workforce trends, occupational distributions, and potential gaps in staffing.
Methods: From 2023 to 2024, using 2022 data in the United States, we conducted 3 distinct analyses: (1) estimating the total workforce size, (2) profiling occupation-specific distributions, and (3) evaluating the role and prevalence of public health nurses using novel data sources. For total counts, we used multiple imputation by chained equations to develop robust agency-level estimates and address missingness from multiple data sets.
Results: State and local public health agencies grew to approximately 239 000 staff in 2022, up from an estimated 206 500 in 2019. The largest occupation groups included office and administrative support workers (37 576) and public health or community health nurses (29 387). We found that 73 478 (1.8%) of registered nurses nationwide served in governmental public health roles.
Conclusions: The size of the workforce during the COVID-19 response has returned to 2008 levels although temporary staff largely constitute the increase.
Public Health Implications: An undersized workforce leaves the United States vulnerable to future disasters and current challenges. (Am J Public Health. 2025;115(5):707–715.This work was supported by the Centers for Disease Control and Prevention (CDC), US Department of Health and Human Services (HHS), National Center for State, Tribal, Local, and Territorial Public Health Infrastructure and Workforce (grant OE22-2203: Strengthening US Public Health Infrastructure, Workforce, and Data Systems).
We obtained Public Health Workforce Interests and Needs data from the Public Health Workforce Interests and Needs Survey, a project supported through a collaboration of the ASTHO and the de Beaumont Foundation. Our use of the data does not imply ASTHO’s or the de Beaumont Foundation’s endorsement of the research, research methods, or conclusions contained in this article.
The authors thank the following data owners and contributors: the de Beaumont Foundation (Public Health Workforce Interests and Needs Survey), National Association of County and City Health Officials (NACCHO Profile), Association of State and Territorial Health Officials (ASTHO Profile), and the State Associations of County and City Health Officials and their members who participated in confirmation of their staffing levels. The authors also thank the Public Health Accreditation Board and the CDC for their partnership and the National Council of State Boards of Nursing for providing their data. The authors thank members of the Consortium for Workforce Research in Public Health for their feedback and guidance, including Heather Krasna, Beth Resnick, and Valerie Yeager.Leider, Jonathon P.; Balio, Casey P.; Hogg-Graham, Rachel; Weiss, Nicole M.; Vogel, Abby; Onal, Sezen O.; Zang, Xiao; Kett, Paula; Edmonds, Joyce; Karnik, Harshada; Dockery, Nathan; Joseph, Bibin; Pak, Morgan; Thomas, Amy Belflower; Bekemeier, Betty. (2025). Enumeration 2024: What We Know and What We Wish We Knew About the Governmental Public Health Workforce in a COVID-19 Recovery Landscape. Retrieved from the University Digital Conservancy, 10.2105/AJPH.2024.307960
GABAB receptor-dependent regulation of cAMP dynamics in hippocampal neurons
Get PDFUniversity of Minnesota M.S. thesis. July 2025. Major: Pharmacology. Advisor: Kevin Wickman. 1 computer file (PDF); ix, 58 pages.Dysregulation of inhibitory G protein-dependent signaling, including signaling controlled by the GABAB receptor (GABABR), is implicated in many neurological disorders. In neurons, GABABR exerts much of its inhibitory influence by activating G protein-gated Inwardly Rectifying K+ (GIRK/Kir3) channels and inhibiting Adenylyl Cyclase (AC). Inhibitory G protein-dependent signaling is mediated by the Gαi/o subfamily of G proteins, which includes 3 Gαi isoforms (Gαi1, Gαi2, Gαi3), Gαo and Gαz, 5 Gβ isoforms (Gβ1-5) and 12 Gγ isoforms (Gγ1-12). However, the specific Gα subunits and Gβγ complexes that mediate GABABR-dependent regulation of these effectors in neurons is poorly understood. Here, we present the development of an imaging platform that enables systematic genetic interrogation of G protein subtypes and regulatory components shaping GABABR-AC signaling dynamics in mouse hippocampal (HPC) neurons. The platform involves viral expression of a cAMP luminescence sensor (GloSensorTM) in cultured neurons. GloSensorTM reliably reports a dose-dependent increase in cAMP in response to forskolin induced AC simulation, as well as a dose-dependent suppression of cAMP levels induced by the GABABR agonist baclofen. To investigate molecular mechanisms underlying the GABABR-dependent suppression of cAMP levels in neurons, we employed a CRISPR/Cas9 strategy. HPC neuron cultures derived from a Cas9-expressing mouse line were infected with adeno-associated virus (AAV) vectors carrying guide RNA (gRNA) sequences targeting specific genes of interest. In neurons treated with vectors containing a GABABR-specific gRNA, baclofen no longer suppressed the forskolin-induced increase in cAMP. When neurons were treated with either pertussis toxin (which inhibits Gαi/o proteins) or a mixture of AAVs carrying gRNAs targeting Gαi1, Gαi2, Gαi3, and Gαo, baclofen-induced cAMP suppression was abolished. Using this validated system, we then found that simultaneous ablation of Gαi1 and Gαo was sufficient to eliminate the baclofen-evoked suppression of cAMP. Simultaneous ablation of Gβ1-4 similarly eliminated the baclofen-induced cAMP decrease, whereas deletion of individual Gβ isoforms was without effect. Interestingly, either Gβ1 or Gβ2 alone was sufficient to support maximal GABABR-dependent cAMP suppression. Similarly, combined ablation of Gγ isoforms expressed at the highest levels in the adult HPC (Gγ2,3,4,7,10,12), but not any single Gγ isoform, abolished most of the baclofen response, while leaving either Gγ2 or Gγ3 as the sole Gγ isoform enabled maximum baclofen-induced suppression of cAMP. Our findings provide key insights into the composition of GABABR-AC signalosome in neurons, thus advancing our understanding of GPCR-effector compartmentalization in the central nervous system.Kim, Jaeyoon. (2025). GABAB receptor-dependent regulation of cAMP dynamics in hippocampal neurons. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/277316
Minutes: Senate Committee on Equity, Access, and Diversity: October 13, 2025
Get PDFIn these minutes: Welcome; Addressing Antisemitism and Addressing Islamophobia Consultation; Office for Equity and Diversity (OED) Update; Working Group Breakout-Current issuesUniversity of Minnesota: Senate Committee on Equity, Access, and Diversity Committee. (2025). Minutes: Senate Committee on Equity, Access, and Diversity: October 13, 2025. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/277098
Episode 08 - Research agendas with LibParlor, Library Table Talk
Get PDF53:28 minutes runtime. For more information, please visit the Library Table Talk website at z.umn.edu/LibraryTableTalkIn which we talk with Nimisha Bhat, Hailley Fargo, Chelsea Heinbach, and Amber Sewell of The Librarian Parlor about their journeys into LIS research and these things called research agendas. They offer reassuring perspective that the road to and through research can be winding, but you never have to travel it alone.Cabullo, Hannah; Sparrow, Stephanie. (2025). Episode 08 - Research agendas with LibParlor, Library Table Talk. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/276534