University of Northern Iowa

To test the hypothesis that caffeine intake would increase heat strain and markers of acute kidney injury (AKI), intestinal injury, and endotoxemia after physical work in the heat. Using a double-blind, crossover design, 14 (6 male) active, caffeine-habituated adults ingested 5 mg/kg of bodyweight (up to 400 mg) of caffeine or placebo 30 min before a 2-hr heat trial (35 °C dry bulb, 50% relative humidity) involving walking (40% V̇O2peak) and box-lifting. Bodyweight was measured pre- and post-trial. Core temperature (Tcore) and heart rate (HR) were recorded every 10 min. Blood and urine samples were collected pre-, post-, and 1-hr post-trial to assess markers of AKI, intestinal injury, and endotoxemia. Caffeine increased peak Tcore (38.2 ± 0.4 vs 38.0 ± 0.3 °C; p = 0.02), peak HR (147 ± 18 vs 138 ± 17 bpm; p = 0.02) and bodyweight loss (1.7% ± 1.0% vs 1.5% ± 1.1%, p = 0.04) compared to placebo. There were no differences in markers of AKI (urinary IGFBP7•TIMP-2, NGAL) (p > 0.05). Serum cystatin C increased from pre- to post-trial in the caffeine (∆0.24 ± 0.43 mg/L, p = 0.03) but not placebo (∆-0.07 ± 0.17 mg/L, p = 0.81) condition, suggesting a reduction in glomerular filtration. There were no differences in markers of intestinal injury (I-FABP) or endotoxemia (LBP, sCD14) (p > 0.05). Caffeine ingestion before work in the heat exacerbated increases in Tcore but did not affect biomarkers of kidney or intestinal injury. Workers performing labor in hot environmental conditions should consider that caffeine during work in the heat may increase the rate of Tcore rise.

With the rapid growth of computer science in K-12 education has come a significant increase in the need for computer science teachers. This demand has meant that a large number of K-12 educators are being asked to teach computer science with very little formal preparation in the subject. For many, this creates a unique experience in which they are often learning the content for the first time while simultaneously preparing to teach or actively teaching in their own classrooms. Although this can be a challenging situation, the circumstances present a somewhat rare situation in which educators can meaningfully reflect on the intersection between teaching and learning by examining their experiences and lessons learned as they participate in both worlds simultaneously. With this poster, we discuss some of the more common observations about learning programming from an analysis of responses from over 220 participants in a state-wide CS teacher preparation program. These observations may be broadly valuable for educators teaching programming courses.

Math anxiety represents a substantial barrier to many students' math learning. In this paper, we apply interdisciplinary perspectives to data on over 13,200 ninth graders and their math teachers from the High School Longitudinal Study. Results suggest that being perceived as dis/abled relates to heightened math anxiety regardless of adolescents' gender, or race and ethnicity. Our intersectional approach reveals that adolescents' expressions of math anxiety do not always correspond with gender, racial, and ethnic stereotypes, with Black girls, Black boys, and Latine boys expressing relatively low levels of math anxiety. Finally, consistent with the principles of inclusion and universal design, placing students into groups of mixed ability is the only teacher approach to grouping that does not relate to high levels of math anxiety for any subgroup of students. With intersectionality and interdisciplinariness the pillars of Disability Studies in Education, this study contributes to critical research approaches and policy considerations.

Here, we present the results of a combined computational and experimental study of electronic, magnetic, and structural properties of V2CoGa, a Heusler alloy that exhibits high spin polarization values in an ordered crystal structure. Our calculations indicate that this compound crystallizes in an inverted cubic structure. The magnetic alignment is ferrimagnetic, due to the anti-aligned magnetic moments of two vanadium sub-lattices. The calculated magnetization value for the ordered structure is 1.97 μB/f.u. at the equilibrium lattice constant of 5.898 Å. Our calculations indicate that V2CoGa in its ordered crystal structure retains high spin polarization values of around 90% under mechanical pressure. At the same time, this material exhibits a strong tendency toward A2-type atomic disorder, which has a detrimental impact on spin polarization values. In addition, the magnetization magnitude for the disordered cell is 0.38 μB/f.u. Experimentally, arc-melted samples crystallize in the predicted inverted cubic structure with A2-type disorder. To optimize the crystal structure, the samples were annealed at various temperatures. The cubic phase is preserved up to 700 °C, while annealing above this temperature leads to phase separation. X-ray diffraction patterns, analyzed using Rietveld refinement for a cubic crystal structure (space group F-43m), yields a lattice parameter of 5.929 Å, consistent with theoretical predictions. Thermomagnetic measurements reveal a magnetic transition near room temperature (295 K). Above the transition, the DC susceptibility follows Curie–Weiss behavior, with a calculated effective magnetic moment of 3.6 μB per formula unit. Given the detrimental effect of A2 disorder on spin polarization, minimizing this disorder is essential to realize the full potential of V2CoGa as a high-spin-polarization material.

Abstract Men’s Sheds began in Australia during the 1990’s and they now have a presence in eight other countries, including the U.S. The purpose of this study was to investigate intergenerational relationships at one of the only known intergenerational sheds in the U.S. Ten members participated in interviews about their experiences with Men’s Sheds. Interviews were audio recorded and transcribed verbatim. Braun and Clark’s (2020) six-step thematic approach were utilized to analyze the transcripts. Steps include data familiarization, coding, early theme generation, refining themes, paring down themes, and results write up. Results revealed, Theme 1: Intergenerational Transmission and Generativity, represented by older members commenting on a sense of purpose when sharing advice or perspectives with younger members. “There’s a purpose for us being here and that is to help each other…there’s several men that we are able to just share things with.” Another member said, I would rather be here doing whatever needs doing encouraging other people than doing anything else.” Younger members appreciated the guidance with learning how to use tools or saws in the woodshop, commenting, “So I’ve learned pretty well how to use everything over there.” Theme 2: Community Outreach represented the community partnerships members created with youth organizations ranging from “bringing the Cub Scouts out” to helping home schooled children “build birdhouses.” These findings indicate that there is potential to build meaningful intergenerational relationships at Men’s Sheds that are mutually beneficial, providing a purposeful outlet for older adults and teaching younger adults practical skills such as woodworking.