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 Comparison of Structural Interaction Patterns in African American and Caucasian Clinical Couples: The Moderating Effect of Financial Resources(2012) Hart, John Rennie; Epstein, Dr. Norman B; Family Studies; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This study focused on degrees to which African American and Caucasian couples who have sought couple therapy at a community clinic differ on measures of relationship boundaries and power/hierarchy. Potential effects that financial resources may have on the relationship between couples' ethnic group membership and their structural patterns were examined. The sample was 77 couples who previously were assessed and treated at a university-based clinic. These two ethnic groups were examined in order to explore potential cultural differences in relationship interaction patterns. Results showed there were no significant ethnic group differences for the three structural dimensions other than a trend for Caucasian couples to exhibit more autonomy between partners than African American couples. There were moderating effects of financial resources in relation to the boundary between the partners and for power dynamics. No significant gender differences were found other than males being more likely to perceive their partner as controlling.Item Energetics of Drug Interactions(2008-11-26) Todorova, Niya Ancheva; Kelman, Zvi; Schwarz, Frederick P.; Molecular and Cell Biology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The goal of our research is to determine in terms of thermodynamic change of state functions the effects of experimental factors, such as water, mutagenesis, or the presence of a second substrate on the energetics of drug-inhibitor binding interactions. The binding of non-steroidal anti-inflammatory drugs within the rigid cavities of cyclodextrins was investigated by titration calorimetry and spectrofluorimetry. Loss of bulk water structure upon drug binding in the smaller hydrophobic β-cyclodextrin cavity results in an increase in the binding entropy, while restriction of the configurations of the drug in the cavity decreases the binding entropy. This restriction in the hydrophobic β-cyclodextrin cavity enhances the binding enthalpies so that the β-cyclodextrin binding reactions are enthalpy-driven. In the larger γ-cyclodextrin cavity, water is retained so that, not only are the interactions between the drug and the cavity reduced, there is an increase in the drug configurations resulting in increases in the binding entropies and the binding reactions become entropically-driven. These binding reactions also manifest enthalpy-entropy compensation where changes in the binding enthalpies are compensated by changes in the binding entropies. In drug binding to the more flexible p38α MAP kinase mutants, a single-point C→S mutation distal from the binding site, changes the interaction between the N- and C-terminal structural domains of the kinase as evident in differential scanning calorimetry. Calorimetric results show that drug-inhibitor binding affinities to kinase increase with size of the drugs since the binding reactions are all enthalpically-driven. Drug-inhibitors binding to trimeric human purine nucleoside phosphorylase were investigated by calorimetry in the presence of its second substrate, inorganic phosphate (Pi). Increasing concentrations of Pi modulates the driving-nature of the binding reaction, so that the acyclovir binding almost exclusively to the purine substrate binding site becomes more entropically-driven, while the binding reactions of ganciclovir and 9-benzylguanine interacting also with the adjacent Pi substrate site become more enthalpically-driven. A novel calorimetric enzyme activity assay at the low dissociation concentrations of the phosphorylase show an increase in the enzyme activity at low Pi concentrations, but also a decrease in the 9-benzylguanine binding affinity since this drug also interacts with an adjacent subunit.Item Assessing an Age-Graded Theory of Informal Social Control: Are There Conditional Effects of Life Events in the Desistance Process?(2005-06-15) Doherty, Elaine Eggleston; Laub, John H; Criminology and Criminal Justice; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)In 1993, Sampson and Laub presented their age-graded theory of informal social control in Crime in the Making: Pathways and Turning Points Through Life. In essence, Sampson and Laub state that, among offenders, strong social bonds stemming from a variety of life events predict desistance from criminal offending in adulthood. In the past decade, there has been a growing amount of research supporting this general finding. However, little research has examined the potential conditional effects of life events on desistance. Using Sheldon and Eleanor Gluecks' Unraveling Juvenile Delinquency data, their follow-up data to age 32, and the long-term follow-up data collected by John Laub and Robert Sampson, this research focuses on the potential conditional effects of marital attachment, stable employment, honorable military service, and long-term juvenile incarceration on criminal offending over the life course. Specifically, the present study tests Sampson and Laub's notion that strong social bonds predict desistance by asking two fundamental questions that bear on both theory and policy surrounding desistance from crime. First, does a high level of social integration as evidenced by the accumulation of social bonds stemming from life events within the same individual influence a person's level of offending and/or rate of desistance? Second, does the individual risk factor of low self-control or the related protective factor of adolescent competence interact with life events such that they differentially influence adult offending patterns? Using the longitudinal methodologies of semiparametric mixed Poisson modeling and hierarchical linear modeling, the analyses find additional support for Sampson and Laub's theory. First, a person's level of social integration significantly affects his future offending patterns even after controlling for criminal propensity and prior adult crime. Second, no significant interaction effects emerge between life events and individual characteristics on future offending patterns. The conclusion then is that a high level of social bonding within the same individual influences offending, regardless of a person's level of self-control or adolescent competence. The implications of this research for life-course theories of crime, future research, and policies regarding desistance are discussed.