Showing 561 - 570 of 2095 Items

“Something most girls don’t do” An Ethnographic Study of Women in Extreme Sports

Date: 2022-01-01

Creator: Jacqueline Boben

Access: Open access

Extreme sports, like skateboarding, whitewater kayaking, and skiing, have historically been male-dominated. As women’s participation in these sports grows, my research asks: how do women navigate sports spaces and cultures that have for so long been defined by men? To answer this question, I draw on ethnographic research on communities of skateboarders, whitewater kayakers and skiers conducted during the summer of 2021 in Bozeman, Montana. I found that the specific landscapes where these extreme sports take place are often conceptualized by participants as more masculine spaces. Within these spaces and communities, women participants often leverage gender performances associated with masculinity to gain entry into these male-dominated communities. Performing in more masculine ways mitigates feelings of hypervisibility, while also helping to build connections to established members of the community. More than simply fitting in, women find that these gendered performances also help them to build competence in the sport. At the same time, women are transforming skateboarding, whitewater kayaking, and skiing through their participation by creating opportunities for more dynamic and fluid gender performances.


Modeling UV Light Through N95 Filters

Date: 2023-01-01

Creator: Lorenzo Hess

Access: Open access

Reuse of N95 FFRs helps mitigate the effects of shortages. UV-C exposure is an ideal method for the decontamination necessary for FFR reuse. Recent research quantifies the transmittance of UV-C through the 3M1870+ and 3M9210+ FFRs [1]. Other research measures the reduction in viral load in relation to UV-C exposure time [11]. We design and program a ray tracing simulator in MATLAB to characterize the distribution of scattered photons in N95 FFRs. We implement an object-oriented FFR with configurable physical characteristics. We use the simulator to record the number of photons available for decontamination in each sub-layer of the filtering layers of the 3M1870+ and 3M9210+ for a given number of photons incident to the layers. We make assumptions about the photon absorption and viral deactivation in each sub-layer to derive a relation between the number of incident photons and the number of viruses remaining. The transmittance computed by our simulator matches the experimentally measured transmittance. The diameter of the simulated scattered beam also matches the experimentally measured scattered beam diameters. Our data, combined with our assumptions about absorption and deactivation, however, fail to account for the dropoff in viral load observed at about 25 seconds of exposure time in the 3M1870+.


Stretch Feedback in the Lobster Heart: Experimental and Computational Analysis

Date: 2016-05-01

Creator: Katelyn J Suchyta

Access: Open access



N,N’-Dimethyimidazolium-2-Carboxylate as a Ligand Precursor for the Accession of a Constrained Olefin Dimerization Catalyst

Date: 2020-01-01

Creator: Michael Harris

Access: Open access

A significant market share of modern plastics is held by long-chain hydrocarbon polymers, such as polyethylene and polypropylene, properties of which can be dramatically changed by addition of linear α-olefins. Production of linear α-olefins involves the creation of many unwanted byproducts, representing significant quantities of both economic and ecological waste. While catalysts have been designed to selectively produce industrially useful olefins, these catalysts often encounter challenges such as synthesis of other unwanted byproducts, slow reaction times, and difficulty of synthesis. Based on one such prior catalyst, we report here synthetic work towards a cobalt catalyst with a constrained N-heterocyclic carbene supporting ligand predicted to allow for more favorable product distributions. Synthesis of two precursors to a sterically unhindered N-heterocyclic carbene, as well as development of a synthetic protocol for the coordination of N,N’- dimethylimidazolium-2-carboxylate to Cp*Co(ethene)2 was completed. Activation of the precatalyst and preliminary catalytic experiments were performed, though abbreviated research periods made complete analysis impossible. Finally, we report evidence of the formation of a novel cobalt-NHC dimer as a temperature controlled byproduct of the desired catalyst synthesis.


Alongside Despair: Signs of Life on the River des Peres

Date: 2020-01-01

Creator: Marina Henke

Access: Open access

This River des Peres is a partially enclosed river which runs through St. Louis, Missouri. Used since prior to the city’s founding, the des Peres has gone through two considerable engineering projects: one in 1901 in light of the World’s Fair, and one in 1923, which encapsulated more than half of the river and placed nearly five miles of it underground. Presently, the des Peres constitutes the backbone of the sanitary and sewer system of St. Louis city and county. Ultimately, the river offers a broad meditation on what it means to live around and in a “natural” waterway that is simultaneously not natural at all. Themes of St. Louis are equally reflected in the river: of environmental racism, of Midwestern decline, and of urban decay and renewal. Additionally, those who interact with the river prove a broad cast of characters. Through using a selection of interviews with locals, alongside an engagement with the work of contemporary poet Donald Finkel, this piece of creative nonfiction explores the multiplicity, and ultimately the value, of distorted natural spaces.


Mechanisms underlying variable responses to the neuropeptide C-type allatostatin (AST-C) across isoforms and among individuals in the American lobster, Homarus americanus

Date: 2020-01-01

Creator: Audrey J. Muscato

Access: Open access

Central pattern generators (CPGs) produce patterned outputs independent of sensory input. The cardiac neuromuscular system of the American lobster (Homarus americanus) is driven by a CPG called the cardiac ganglion (CG), which is composed of nine neurons, making it a model system of study. Modulation of CPGs allows for functional flexibility. One neuropeptide family that modulates the CG is C-type allatostatin (AST-C I-III). Previous research has shown variation in the responses of the CG across the three isoforms and among individuals. First, we investigated why AST-C I and III elicit responses that are more similar to each other than they are to the responses elicited by AST-C II. We hypothesized that an amino acid difference in the conserved sequence was responsible for the observed variation in responses. We synthesized isoforms of AST-C that replaced the endogenous amino acid and recorded responses to these isoforms. The identity of one particular amino acid in the conserved sequence seems to be responsible for variations in responses in frequency. Next, we focused on variation among individuals in their responses to AST-C I and III. We hypothesized that the mechanism behind this individual variation is differential expression of AST-C receptors and/or their downstream targets. We recorded physiological responses of the cardiac system to AST-C and then sequenced CG RNA from the same lobsters. Differential expression of one of the AST-C receptors and a number of downstream factors is correlated with physiological response. These findings inspire further experimentation investigating molt cycle as the underlying cause.


A Stepping-Stone? An Analysis of How the Minimum Wage Impacts the Wage Growth of Individuals in Monopsonistic Industries

Date: 2022-01-01

Creator: Levi McAtee

Access: Open access

Do minimum wage increases serve as stepping-stones to higher-paying jobs for low-pay workers? This paper analyzes the impact of state minimum wage policy on the one-year wage growth rates of individuals across the wage distribution and whether that impact changes for individuals in highly monopsonistic industries. I review the recent literature on the disemployment effect, the impact of the minimum wage on wage growth rates, the nature of monopsonistic industries, and the relationship between the minimum wage and monopsony power. I offer theoretical reasons why the minimum wage may impact the wage growth rates of individuals in monopsonistic industries differently than it impacts those of individuals in competitive industries. I then re-estimate Lopresti’s and Mumford’s (2016) panel fixed effects model to determine how the effect of a minimum wage increase depends nonlinearly on the size of the increase. Using data from 2005-2008, Lopresti and Mumford found that small minimum wage increases have a significant negative impact on wage growth rates, while large minimum wage increases have a significant positive impact. Using data from 2016-2019, I find similar results. As my primary empirical contribution, I test whether individuals in highly monopsonistic industries experience minimum wage changes differently than individuals in more competitive industries. I find monopsony power in the form of high labor immobility primarily impacts the wage growth rates of high-pay workers and does not influence how low-pay workers experience minimum wage changes. Finally, I recommend policymakers impose larger minimum wage increases to avoid impeding the wage-growth of low-pay workers.


The Structure and Unitary Representations of SU(2,1)

Date: 2015-05-01

Creator: Andrew J Pryhuber

Access: Open access



Antimicrobial Peptides (AMPs) in the Lobster, Homarus Americanus: Isolation and Activity

Date: 2021-01-01

Creator: Ruby Chimereucheya Ahaiwe

Access: Open access

The American lobster Homarus americanus uses its innate immune system for protection against foreign bodies and diseases. Hemocytes in the innate immune system are responsible for the rapid and effective cellular response against pathogens and infections observed in lobsters. These hemocytes, particularly semi-granulocytes and granulocytes, store antimicrobial peptides (AMPs) which specifically target and destroy microbes. Hemocyte samples from the American lobster Homarus americanus hemolymph or circulatory fluid, mixed and fractionated into separated semi-granular and granular cell samples, were analyzed for possible AMP presence. A defensin AMP, Hoa-D1, (SYVRSCSSNGGDCVYRCYGNIINGACSGSRVCCRSGGGYamide; with C representing a cysteine participating in a disulfide bond) was successfully isolated and identified by mass using reversed-phase high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS/MS). Preliminary results also show the defensin AMP to be concentrated in the semi-granulocytes and granulocytes.Hoa-D1 was isolated via HPLC fractionation. Isolated Hoa-D1 and semi-granular and granular hemocyte extracts were tested for bioactivity against the gram-negative bacteria, Escherichia coli, using the Kirby-Bauer disk diffusion assay. The assay did not show any activity, an outcome attributed to concentrations of the AMP that were too low to have any antimicrobial effect on E. coli. Subsequent work on this study should involve increasing the concentration of Hoa-D1 in test samples. Studying function of AMPs in the American lobster can provide more information on the depth of their cellular immune responses in other crustaceans, and possibly contribute to the development of novel antibiotics for treating diseases in humans.


Assigning Legal Punishment: Individual Differences in Justice Sensitivity and Selective Attention

Date: 2015-05-01

Creator: Emily C. Weinberger

Access: Open access

Selective attention and justice sensitivity (JS), a personality trait reflecting individual differences in perceptions of injustice, have been shown to affect how people assign punishments. In the present study peoples’ decision-making processes were investigated to better understand the inconsistencies in legal punishment decisions, particularly when using retributive versus restorative justice. Subjects participated in three phases of the experiment. First, subjects completed a justice sensitivity scale and then rated the appropriateness of punishment options to handle a criminal scenario. Second, participants’ selective attention was indicated by their recall of pertinent features from three ambiguous criminal scenarios. Finally, participants were primed with either restorative justice or neutral control words, and rated the appropriateness of punishment options to handle a new criminal scenario. Results revealed no significant associations between JS and ratings of punishment options, although patterns suggested negative relationships between observer JS and retributive justice ratings, and victim JS and restorative justice ratings. Results did show a significant effect of JS in predicting the facts remembered, such that as observer JS increased, more restorative justice facts were recalled, and as victim JS increased, fewer restorative justice facts were recalled. No significant effect of the restorative justice prime was observed. These results may contribute to better understanding of criminal justice policy in the United States.