Theses and Dissertations from UMD
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New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a give thesis/dissertation in DRUM
More information is available at Theses and Dissertations at University of Maryland Libraries.
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Item Are “Thinkers” More Ethical Than “Doers”? How Regulatory Mode Influences Unethical Behavior(2018) CHERNIKOVA, MARINA; Kruglanski, Arie; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Unethical actions can have a significant impact on both individuals and societies; thus, it is critical to identify factors that can predict such actions. The current research investigated two potential predictors of unethical behavior: locomotion and assessment regulatory mode (Kruglanski et al., 2000). Locomotion refers to the desire for continuous progress or movement in goal pursuit, while assessment refers to the desire to critically evaluate and compare among goals and means. Locomotion was expected to increase individuals’ tendency to behave unethically, whereas assessment was expected to decrease this tendency. Guilt proneness was expected to mediate these effects, such that assessors should be more prone to experiencing guilt, and should behave more ethically; locomotors, on the other hand, should be less prone to experiencing guilt, and should therefore behave less ethically. Furthermore, the effect of locomotion on unethical behavior was expected to be stronger when the unethical action saved more (vs. less) time. The effect of assessment on unethical behavior was expected to depend upon the presence of social standards for such behavior: assessors should act less ethically if there is a strong (vs. weak) social norm for unethical actions. Six studies that utilized a variety of designs and different measures of unethical behavior were carried out in order to test these hypotheses. The results were generally inconsistent with the hypotheses. Some potential explanations and theoretical implications of the findings are discussed.Item On the Social Consequences of the Desire for Motion(2016) Chernikova, Marina; Kruglanski, Arie; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Three studies investigated the effects of locomotion regulatory mode on individuals’ evaluations of social partners who disrupt the smooth forward motion of a social interaction. Locomotion was expected to increase individuals’ preference for smooth motion in social interactions. In turn, that preference was expected to lead to less positive evaluations of listeners who disrupted the “flow” of a social interaction. The results generally did not confirm the predictions. Theoretical and practical implications of the studies, as well as future directions for the research, are discussed.Item Kinetics in Individuals with Unilateral Transtibial Amputations Using Running-Specific Prostheses(2012) Baum, Brian Svercauski; Shim, Jae Kun; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Improvements in rehabilitation and prosthetic design are needed to help promote activities such as running that increase physical activity levels of individuals with lower extremity amputation (ILEA). However, effectively developing these improvements requires a detailed understanding of prosthetic and ILEA running biomechanics. Running-specific prostheses (RSPs) have been developed to improve running performance for ILEA runners, but altered running kinetics may still be necessary to accommodate for the loss of musculoskeletal function caused by lower extremity amputation. The few studies investigating ILEA running with RSPs focus on maximal performance, but our understanding of how ILEA using RSPs modulate kinetics to run at submaximal velocities remains limited. The purpose of this study was to characterize changes in kinetics and mechanical energy across a range of running velocities in ILEA wearing RSPs. This dissertation investigated six specific aims through six corresponding experiments that improve our knowledge of mechanical and anthropometric properties of RSPs and the kinetic profiles of ILEA running at submaximal velocities. Four common RSP designs were tested for mechanical and anthropometric properties. ILEA with unilateral transtibial amputations who wear RSPs and an able-bodied control group participated in the running experiments. Mechanical and anthropometric results indicated that RSP marker placement had little effect on joint kinetic estimations proximal to the prostheses, and trifilar pendulums can measure moments of inertia with <1% error. The running experiments provided the first 3D kinetic descriptions of ILEA running. The prosthetic limb typically generated lower peak kinetic parameters and 50% lower total mechanical work than the intact and control limbs, indicating a greater reliance on the intact limb. To counter the prosthetic limb deficiencies, ILEA increased stride frequencies compared to control subjects. Additionally, the prosthetic limb demonstrated prolonged periods of anterior ground reaction force to increase propulsive impulse and prolonged hip stance phase extension moments that generated increased hip concentric work. The data indicated that ILEA wearing RSPs run differently than able-bodied runners and use several adaptive mechanisms to run at the same velocity and to increase running velocity. These mechanisms are discussed and future directions of research are suggested.Item The mechanosensory lateral line system: morphological, physiological, and behavioral study in pre- and post-metamorphic lampreys(2007-06-05) Gelman, Semen; Cohen, Avis H.; Biology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Lampreys are extant jawless vertebrates. The oldest lamprey-like fossil, which dates from approximately 360 million years ago, exhibits many external morphological similarities with modern lampreys. It is thought that lampreys have undergone very conservative evolutionary changes and therefore retain many ancestral characters. Studying lamprey sensory physiology may shed light on the phylogenetic development of various sensory systems in vertebrates. Electrophysiological and microscopic methods were used to investigate the morphology and physiology of the peripheral lateral line system of lampreys with special emphasis on the metamorphic changes. It was established that larval lampreys possess a functional mechanosensory lateral line system. Morphology of larval neuromasts was found to be similar to that of adults. Metamorphic transformations in the lateral line included functional and morphological changes. A general re-patterning of the system of neuromasts on the head and trunk was observed. It appears that three processes are involved in the re-patterning: an increase in neuromasts number, their re-distribution within the pit lines, and shifts of the pit lines relative to external features. Response of the trunk lateral line nerve (TLLN) fibers to vibrational stimulation was qualitatively similar in adults and larvae. Both showed two populations of neurons responding to opposite directions of water flow, with the response magnitude monotonically increasing with stimulus amplitude. At low frequencies, the phase lag of the response with respect to the stimulus maximum was approximately 220, and the gain depended approximately linearly on frequency, confirming the notion that superficial neuromasts are velocity detectors. The changes in phase lag with increasing stimulus frequency were steeper in larva suggesting slower conductance. The response of adults to different frequencies indicated a narrower range of frequency discrimination. The observed changes were hypothesized to be of preparatory nature, as the metamorphosis is in general, making this sensory system more suitable for the active life style of adult lampreys. In light of this hypothesis, the behavioral involvement of the lateral line in locomotion was investigated. It was found that the locomotion of lamprey in still water was not affected by blocking the lateral line. This may indicate that the intraspinal system of mechanoreceptors, so called 'edge' cells, is dominating locomotor feedback during such experimental conditions and is sufficient for normal locomotion. However, the question remains unanswered whether the movement-related feedback from the 'edge' cells is sufficient in complex flow conditions. It may very well be that the information provided by the lateral line in such demanding conditions is necessary for swimming. Thus the behavioral function of the lamprey lateral line remains unknown.