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Science on hold — how federal cuts are shaking up university research
No full text20:03The University of Minnesota’s labs power life-saving science, but now they are being asked to do more with less.McDonnell, Owen; Widge, Alik; Pineda, Delilah. (2025). Science on hold — how federal cuts are shaking up university research. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/272900
Thiamine Sulfur Assimilation by Rhodopseudomonas palustris
No full textFaculty Advisor: Kathryn FixenThiamine is an essential vitamin for plant, mammal, and microbial metabolism, and can be found in many environments, including soil and wastewater. While thiamine biosynthesis has been widely studied, other biological uses of thiamine are unknown. As a complex molecule with three carbons, a nitrogen and a sulfur in its thiazoline ring structure, thiamine could provide carbon, nitrogen, or sulfur in nutrient-poor environments. In particular, in terrestrial soil which is very low in inorganic sulfur sources, I hypothesize that thiamine could be used by soil bacteria as a sulfur source. To test this hypothesis, the purple non-sulfur bacterium Rhodopseudomonas palustris, which lives in freshwater sediments, was grown with thiamine as a sole sulfur source. I found that R. palustris can use thiamine as a sulfur source. R. palustris has nitrogenase enzymes that help break C-S bonds and contribute to the breakdown of volatile organic sulfur compounds and sulfonates. To determine whether these genes might be involved in the thiamine sulfur assimilation pathway, mutants with nitrogenase genes deleted were created. We also carried out random barcoded transposon sequencing and heat mapping to assess which genes are required for assimilation of thiamine as sulfur source.This research was supported by the Undergraduate Research Opportunities Program (UROP).Purandare, Ishanvi. (2025). Thiamine Sulfur Assimilation by Rhodopseudomonas palustris. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/271257
Flowering phenology in a common garden among invasive Canada thistle, Cirsium arvense, and native Cirsium species of the Upper Midwest 2025
No full textNative thistle (Cirsium) species occupy a critical, but often misunderstood position in landscapes across North America. Of significance, native thistle flowers produce a high sugar nectar and pollen source for native pollinators, including a variety of butterflies, bees and other insects. Additionally, native thistle flowers and vegetation provide a food source for insect defoliators and seed feeders and the seeds provide a food source for numerous species of birds. The University of Minnesota herbarium lists six thistles in the Cirsium genus as native to Minnesota. These include three biennials; tall thistle (Cirsium altissimum), field thistle (Cirsium discolor), and swamp thistle (Cirsium muticum), and three perennials: Flodman’s thistle, (Cirsium flodmanii), wavyleaf thistle (Cirsium undulatum) and Hill’s thistle (Cirsium pumilum var. hillii). Although not endemic to Minnesota, Pitcher’s thistle (Cirsium pitcheri), is native to the dune ecosystem of the Great Lakes and is a threatened species. Canada thistle (Cirsium arvense) the ubiquitous invasive perennial, present in the Upper Midwest, is native to Europe and the Mediterranean and has been introduced world-wide. It is considered as one of the worst weeds of agricultural and natural systems. The objective of this study was to compare the flowering phenology of native thistles from the upper Midwest in relation to Canada thistle in a common garden where all thistles grew under the same environmental conditions. The phenology of flowering times could be of interest in native pollinator research or host range studies of biological weed control agents. The length of time between first bud appearance and first flower (defined as the time when ray florets were expanding from the receptacle) was approximately one month for the perennial Flodman’s and Canada thistle. In contrast, the length of the bud stage for the biennial tall, swamp and field thistles ranged from one-and-a-half to two months. Biennial thistle plants formed buds in late-May to early-June, but did not flower until late-July to early-August. The lengthy bud stage of biennial thistles overlapped with bud production and flowering of Canada thistle.Funding for this project was provided by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative‐Citizen Commission on Minnesota Resources (LCCMR).Katovich, Elizabeth J.; Becker, Roger L.. (2025). Flowering phenology in a common garden among invasive Canada thistle, Cirsium arvense, and native Cirsium species of the Upper Midwest 2025. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/270463
Characterization of Lung Surfactant Behavior on Curved Interfaces using Microtensiometer Combined with Confocal Fluorescence Microscopy
No full textLung surfactants are a mixture containing proteins and phospholipids that play a critical role in reducing the surface tension of the liquid-air interface within the alveoli, which eases respiratory function. While clinical surfactants like Survanta and Curosurf are often employed to treat neonatal respiratory distress syndrome (NRDS), the underlying mechanism behind acute respiratory distress syndrome (ARDS) and the impact of alveolar curvature on surfactant function remains underexplored. The Langmuir trough is commonly employed to investigate lung surfactant morphology—often in conjunction with confocal microscopy—and to measure surface pressure–area isotherms. However, the influence of alveolar curvature on surfactant behavior remains underexplored. Recent study (Sachan and Zasadzinksim PNAS, 2018) suggests that curvature introduces a circle-to-strip phase transition of liquid condensed (LC) domains . Therefore, we aim to further investigate how surfactant monolayers behave under curvature variations, temperature, and compositional changes. A controlled-pressure microtensiometer, integrated with a confocal fluorescence microscope, was employed to analyze adsorption dynamics and also image the interface on alveolar-sized microbubbles (~ 60 um) simultaneously. We observed unreported liquid-liquid coexistence in the absence of cholesterol and further examined the relationship between the stripe width and the bubble radius. The line tension is extracted from analyzing the Brownian motion of small domains and the relaxation of distorted liquid domains. By refining our understanding of surfactant behavior in curved environments, this study will enhance the knowledge of the stability and effectiveness of therapeutic surfactants, improving treatment outcomes for patients with respiratory disorders.This research was supported by the Undergraduate Research Opportunities Program (UROP).Yoon, Soyoon. (2025). Characterization of Lung Surfactant Behavior on Curved Interfaces using Microtensiometer Combined with Confocal Fluorescence Microscopy. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/272343
U of M Crookston to host four March events for 2025 International Dinner Series
No full textBengtson, Jess. (2025). U of M Crookston to host four March events for 2025 International Dinner Series. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/271184
Zine Exhibition (2025-04-23)
No full textWednesday 4/23, 12:00pm - 1:30pm, Kathryn A. Martin Library, Room 116Snacks! Drinks! Free! Drop in! WS 3100: "Feminist & Queer Thought," by Women, Gender, & sexuality Studies programUniversity of Minnesota Duluth. Department of Studies in Justice, Culture, and Social Change. (2025). Zine Exhibition (2025-04-23). Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/272259
Chancellor Community Letter February 2025
No full textHolz-Clause, Mary. (2025). Chancellor Community Letter February 2025. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/271193
Longitudinal Study of Assessment Participation: Tracking Consistency and Transitions Between General and Alternate Assessments for Students with Disabilities
No full textThe 2015 reauthorization of the Elementary and Secondary Education Act put a 1% cap on participation in the alternate assessment based on alternate academic achievement standards (AA-AAAS) for students with the most significant cognitive disabilities. To meet the 1% alternate assessment participation cap, some students were transitioned from the alternate assessment to the general assessment; a transition in which many special and general educators still need to prepare. The purpose of this study was to examine the state assessment data over time to identify the assessment participation patterns for students with disabilities in both reading and math assessments. The longitudinal dataset included demographic and assessment data for students in grades 3-8 with 5 years of testing records, which were used to examine the assessment participation patterns over time. Results showed that some students have been transitioned between general and alternate assessments over time. Additionally, the performance data showed students who were proficient in AA-AAAS in Year 1 were more likely to be transitioned to the general assessment than those who were not proficient in AA-AAAS in Year 1.Funded by the U.S. Department of Education’s Office of Elementary and Secondary Education (Award #S368A220001)Wu, Yi-Chen. (2025). Longitudinal Study of Assessment Participation: Tracking Consistency and Transitions Between General and Alternate Assessments for Students with Disabilities. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/270699
Undergraduate Research and Artistic Showcase (2025 Spring)
No full textUniversity of Minnesota Duluth. Undergraduate Research Opportunity Program. (2025). Undergraduate Research and Artistic Showcase (2025 Spring). Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/271242
Self-Compassion and Role Transition in Young Mothers
No full textA Plan B Research Project submitted to the faculty of University of Minnesota Duluth by Allison L. Colberg in partial fulfillment of the requirements for the degree of Master of Arts, May 2025. This item has been modified from the original to redact the signature present.Previous research on self-compassion has demonstrated its association with improved well-being and functioning among adolescents and mothers. However, there is little research on the role of self-compassion among young adult or adolescent mothers. Self-compassion and adult role attainment, moderated by social support, may be essential to assisting young parents with their role transition into parenthood. Using a community based participatory research approach, adolescent and young adult parent participants took a self report digital survey to obtain scores of self-compassion, markers of adulthood, maternal role attainment, and social support. Results were analyzed through a multiple regression. The overall model was not found to be statistically significant. However, early adulthood role attainment was the only variable with significant correlation to maternal role attainment. Maternal role attainment was negatively skewed, suggesting lower overall attainment than would typically be expected, while scores of self-compassion were within the moderate range consistent with other studies. Implications and directions for future research are discussed.Funding was provided by UMN Duluth Department of PsychologyColberg, Allison L. (2025). Self-Compassion and Role Transition in Young Mothers. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/272023