Alumni Dissertations

 

Alumni Dissertations

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  • HOUSEHOLD DENSITY AND ACADEMIC STANDING AMONG COMMUNITY COLLEGE STUDENTS: THE EFFECTS OF TIME ORIENTATION AND SPATIAL SELF-REGULATION

    Author:
    Grace Campagna
    Year of Dissertation:
    2012
    Program:
    Psychology
    Advisor:
    Gary Winkel
    Abstract:

    The purpose of the study was to develop a multifactorial model tracing paths from housing affordances to academic outcomes in higher education. The study sought to connect two areas of psychological research: on one side, the adverse effects of environmental stressors and inadequate self-regulation upon life course prospects and, on the other, the affective, behavioral, and cognitive elements of purposive self-regulation used by college students toward long-term goal attainment. The study design was cross-sectional and used self-reported survey data as well as official academic records for 490 student participants. Three new measures were developed. The first, Housing Inadequacy, gave a subjective assessment of domestic environments by comparing availability of household features with their rated importance to individual students. The second, Perceived Housing Stress, was adapted from the Perceived Stress Scale (Cohen & Williamson, 1988), an existing validated measure of global appraised stress, to identify stressors specific to the home setting. The third, Spatial Self-Regulation, introduced a new construct with two components: the ability to recognize whether a setting is conducive to one's goals and the ability to engage or change that setting in order to move toward those goals. In the current study, the affective, behavioral, and cognitive aspects of Spatial Self-Regulation were measured in both home and campus settings. Two existing measures were used. Temporal factors from the Zimbardo Time Perspectives Inventory (Zimbardo & Boyd, 1999) were hypothesized to attenuate or amplify adverse effects of Housing Inadequacy and Perceived Housing Stress in predicting academic motivations and strategies. These motivations and strategies were measured using components of the Motivated Strategies for Learning Questionnaire (Pintrich, Smith, Garcia, and McKeachie, 1993), an instrument widely used in higher education assessment. Structural equation modeling was used to refine, integrate, and confirm linkages among the above variables. A statistically significant model linked sub-factors for Housing Inadequacy, Perceived Housing Stress, Spatial Self-Regulation, and Time Orientation with Motivated Strategies for Learning. Since the model reliably predicted GPA, the study presented a new approach to explaining college student academic standing as an outcome of the interaction of person-level variables with environmental factors.

  • The Role of the Dorsal Hippocampus in the Contextual Control of Appetitive Responding

    Author:
    Vincent Campese
    Year of Dissertation:
    2011
    Program:
    Psychology
    Advisor:
    Andrew Delamater
    Abstract:

    Four experiments were run using rat subjects in order to assess the impact of manipulations to the dorsal hippocampus (DH) on the contextual and temporal control of extinguished appetitive learning (e.g., magazine approach). Subjects were trained to associate discrete stimuli with food in specific locations or at specific times. The subjects then had these associations extinguished by means of omitting the food reinforcers following stimulus presentations. In order to assess contextual and temporal modulation of learning the stimuli were tested within as well as outside of the contexts or times where/when they were extinguished. Control subjects showed reduced responding when stimuli were presented within their extinction contexts (physical and temporal) whereas responding recovered outside of these extinction contexts (i.e., renewal and spontaneous recovery). In order to assess DH function in these different instances of response recovery, neurotoxic lesions of the DH prior to tests or temporary muscimol-induced inactivation of the structure were used. The results of these studies indicate that while DH manipulations fail to affect conditional control of appetitive extinction learning by physical contexts, they do impair control when temporal contexts are used as a conditional cue.

  • "Small Village/Large Hell": Cocaine & Incarceration in Lima, Peru

    Author:
    Stephanie Campos
    Year of Dissertation:
    2013
    Program:
    Anthropology
    Advisor:
    Leith Mullings
    Abstract:

    The Establecimiento Penitenciario de Mujueres de Chorrillos (commonly referred to by its previous name, Santa Monica) in Lima, Peru was built in 1952 as a reformatory to hold 300 women but by June 2012 it held over 3,500, many of them serving sentences for drug trafficking. This is the largest female prison in this Andean nation. An intersectional analysis of prisoners' narratives collected during fieldwork conducted from 2008 to 2009 demonstrates two inter-related processes. First, inequality was produced and reproduced inside this prison through the interconnections of race, gender, class and citizenship. Prisoners' daily lives and access to resources were constrained by the same inequalities that led to their incarceration. Multiple divisions among women mirrored national and globalized structural inequalities and citizenship in particular emerged as a dividing force. Santa Monica's stratification system was continuously reproduced as prisoners competed for life dependent resources. Secondly, I show the ways in which women's labor was the linchpin between the transnational cocaine commodity chain and the prison. Santa Monica transformed into a place to "dispose of" low-level workers of the transnational cocaine commodity chain. Because the majority of these workers were women, their labor became the bond between illegal cocaine and the prison. Those who worked as drug couriers and minor retailers were laboring at the riskiest and most visible jobs to police surveillance. They were arrested when they were no longer needed or once they become a threat to the day-to-day operation of trafficking drugs while the (mostly male) middle managers above them remained in the background. Women's labor therefore created a symbiotic relationship between the prison and this chain where each side helped the other grow and expand. Once incarcerated, these women faced a hierarchy that shaped options for survival as they served their sentences.

  • The role of apoptosis and mitosis in LDL transport across endothelial cell monolayers

    Author:
    Limary Cancel
    Year of Dissertation:
    2010
    Program:
    Engineering
    Advisor:
    John Tarbell
    Abstract:

    We have previously shown that leaky junctions associated with dying or dividing cells are the dominant pathway for LDL transport under convective conditions in vitro, accounting for more than 90% of the transport. To explore the role of apoptosis in the leaky junction pathway, TNFα and cycloheximide (TNFα/CHX) were used to induce an elevated rate of apoptosis in cultured bovine aortic endothelial cell (BAEC) monolayers and the convective fluxes of LDL and water were measured. Control monolayers had an average apoptosis rate of 0.30%. Treatment with TNFα/CHX induced a 18.3-fold increase in apoptosis and a 4.4-fold increase in LDL permeability (Pe). Increases in apoptosis and permeability were attenuated by treatment with the caspase inhibitor Z-VAD-FMK. Water flux (Jv) increased by 2.7-fold after treatment with TNFα/CHX, and this increase was not attenuated by treatment with Z-VAD-FMK. Immunostaining of the tight junction protein ZO-1 showed that TNFα/CHX treatment disrupts the tight junction in addition to inducing apoptosis. This disruption is present even when Z-VAD-FMK is used to inhibit apoptosis, and likely accounts for the increase in water flux. We found a strong correlation between the rate of apoptosis and the permeability of BAEC monolayers to LDL. To explore the role of mitosis in the leaky junction pathway, the microtubule stabilizing agent paclitaxel was used to alter the rate of mitosis and the fluxes of LDL and water were measured. Control monolayers had an average mitosis rate of 0.029%. Treatment with paclitaxel (2.5μM) for 1.5, 3, 4.5 or 6 hours yielded increasing rates of mitosis ranging from 0.099% to 1.03%. Pe increased up to 5-fold, while Jv increased up to 3-fold over this range of mitosis rates. We found a strong correlation between the mitosis rate and both the convective LDL permeability and the water flux. These results demonstrate the potential of manipulating endothelial monolayer permeability by altering the rates of apoptosis and mitosis pharmacollogicaly. This has implications for the treatment of atherosclerosis.

  • The Ethical Pact: Storytelling in Contemporary Autobiography

    Author:
    Veruska Cantelli
    Year of Dissertation:
    2012
    Program:
    Comparative Literature
    Advisor:
    Ammiel Alcalay
    Abstract:

    Abstract The Ethical Pact: Storytelling in Contemporary Autobiography by Veruska Cantelli Advisor: Ammiel Alcalay In the last thirty years a body of work has developed about autobiography as a literary genre and its ontological value. Philippe Lejeune's essay "The Autobiographical Pact" is now a classic in autobiographical studies. The essay was published in 1975 and translated into English in 1989 when it was anthologiesed by Paul John Eakin with its revision "The Autobiographical Pact (bis)" in which Lejeune revisits his original formalist definition of autobiography. James Olney's edited volume Autobiography, Essays Theoretical and Critical published in 1980 is generally recognized as the beginning of autobiography studies in the United States. The book, which does not include Lejeune's essay, represents an important ground for the study of autobiography and for its place as a genre distinct from the novel, a genre that, as Olney states, "like the life it mirrors refuses to stay still long enough for the genre critic to fit it out with the necessary rules, laws, contracts, and pacts [my emphasis]; it refuses, simply, to be a literary genre like any other." (Autobiography, Essays Theoretical and Critical, 25) In his introduction to the collected essays, Olney relates his experience in reading, and later translating, the 1956 important essay "Conditions et limites de l'autobiographie" by French critic Georges Gusdorf, "In translating `Conditions et limites de l'autobiographie' into English for the present volume, I have been repeatedly astonished at the overwhelming similarities between that essay and my book." (Autobiography, Essays Theoretical and Critical, 10). With this statement Olney endorses Gusdorf's problematic views on autobiography as an act of "conscious awareness", not possible "in a cultural landscape where consciousness of self does not, properly speaking, exist. But this unconsciousness of personality, characteristic of primitive societies such as ethnologists describes to us, lasts also in more advanced civilizations that subscribe to mythic structures, they too being governed by the principle of repetition." ("Conditions and Limits of Autobiography", 31) Gusdorf's view leaves out the rest of the nonwestern world and creates an image of the autobiographical self as male, isolated, individualistic. In my dissertation I seek to further discuss Eakin's work on the relationality of the self. I will show how in a small group of 20th century autobiographies such as Dust Tracks on a Road, Family Sayings, Borderlands/LaFrontera, Storyteller and Keeping House stories come to express or represent the relation between the identity of the self and the community. I will examine the ways in which these relations are manifested in the body of the text. Stories of mythological figures as Yellow Woman in Leslie Marmon Silko's Storyteller and stories of family members as in Natalia Ginzburg's Family Sayings passed down from one generation to the next, provide the foundation of the history of a community and/or a family. As Mary Mason observed, female authors use stories to affirm their identity, but the stories used by the authors aforementioned, come straight from the traditions, myths and rituals shared with the community to which they belong and form an essential point of junction with its members. These autobiographies besides representing the story of the life of the author, delineate and affirm the history of a family and a community; they take on the characteristics and functions of storytelling, those of counseling, teaching, comforting and critiquing.

  • The American Teacher Memoir: From Confessions to the Inspirational True Story

    Author:
    Jessica Cantiello
    Year of Dissertation:
    2012
    Program:
    English
    Advisor:
    Nancy Miller
    Abstract:

    Over 225 American teachers have published autobiographies that recount their lives in public school classrooms, but the teacher memoir, as a literary genre, has yet to receive sustained scholarly consideration. Since at least the beginning of the common school movement in the 1830s, a movement that is chronicled by the first teacher memoirist William Alcott in his aptly named Confessions of a School Master (1839), Americans have put enormous faith in the power of schooling to create an educated citizenry that can sustain a functional democracy. Teacher memoirs combine with portrayals by historians, administrators, policymakers, and scientists to assess the success or failure of education, which is often entangled with the perceived success or failure of America itself. I read teacher memoirs in the context of educational policy and literary history to demonstrate how the cultural climate in a given era shaped the way in which teachers narrated their experiences, and, in turn, how the memoirs influenced educational debates. This study raises complex questions about the political efficacy of literary texts, contributes to discussions within autobiography theory of the ethical considerations of life writing, and enriches historical narratives of teaching and learning.

  • Perceptions of Community Corrections: Understanding how Women's Needs are met in an Evidence-Based/Gender-Responsive Halfway House

    Author:
    Andrea Cantora
    Year of Dissertation:
    2011
    Program:
    Criminal Justice
    Advisor:
    Jeff Mellow
    Abstract:

    This dissertation presents a qualitative study on how women perceive and experience services at an evidence-based, gender-responsive halfway house. The primary focus was to understand how the halfway house helps women address their needs as they prepare to reenter the community. The secondary focus was to understand how the halfway house implements evidence-based principles and gender-responsive strategies. This study analyzed in-depth qualitative interviews with 33 women. Data from these interviews were triangulated with observations of treatment groups and daily interactions, review of program documents, review of participant case files, and informal conversations with staff. Findings suggest that many positive and negative features of the halfway house - including social context, relationships with staff, and program policies - contribute to women's ability to address their needs and prepare for reentry. Findings also draw attention to the influence of external factors including outside resources, social networks, housing availability, the stigma of a criminal record, systemic policies, geographic boundaries, and program length of stay. The interconnections between ecological systems also influence the transitional process and were highlighted in this study. Recommendations for improving community correctional services for women were discussed.

  • THEORETICAL MODELING OF ELECTROMECHANICAL COUPLING BEHAVIOR OF FERROELECTRICS AND THEIR COMPOSITES

    Author:
    Yang Cao
    Year of Dissertation:
    2009
    Program:
    Engineering
    Advisor:
    Jackie Li
    Abstract:

    The aim of this dissertation is to develop suitable theoretical models to study the physical properties of ferroelectrics in terms of temperature and size, and the nonlinear electromechanical coupling behavior of ferroelectrics and their composites under the different loading conditions. Three different models are introduced following applicable scale ranges. First, Texture and Anisotropy theory is used to model nonlinear behaviors of piezoelectric poly-crystals (Taylor-Bishop-Hill like model) without considering interaction between grains or domains. It is suitable in macro-scale range and can be used on both polycrystals and single crystals. Second, a micromechanics approach based on irreversible thermodynamic principle and morphology of spontaneous polarization and domain switch has been extended to study the temperature effects on BaTiO3 single crystals and further for electromechanical coupling behavior of ferroelectric composites by considering the microstructure of the system. The micromechanics approach reaches its limitation when the material size reduces to nano-scale. Finally, Ginzburg-Landau theory has been chosen to determine BaTiO3 nanowire behaviors under external loading. This powerful phenomenological method was originally developed for macro scale. Here we extend the model to be applicable at nano-scale range and study the polarization field and transition temperature in terms of the size of ferroelectric nanowires. The advantages and disadvantages of each model are discussed. All three models are also compared and verified by existing experiments.

  • Design of Large Pore Ordered Mesoporous Silicas, Related Silica/Polymer Composites and Carbon Replicas

    Author:
    Liang Cao
    Year of Dissertation:
    2010
    Program:
    Chemistry
    Advisor:
    Michal Kruk
    Abstract:

    This dissertation includes four chapters, namely, the introduction to development and current research interests in mesoporous materials, the "soft-templating" synthesis of large pore 2-D hexagonal ordered mesoporous silicas, the synthesis of mesoporous polymer/silica composites via surface-initiated controlled polymerization, and the "hard-templating" method to fabricate ordered mesoporous carbons. In Chapter 2, the synthesis of SBA-15 silica with 2-D hexagonal structure of large and ultra-large cylindrical mesopores is outlined. Our work on hexane and 1,3,5-triisopropylbenzene, as suitable micelle expanders, allowed us to tailor SBA-15 pore diameter up to ~15 nm and ~30 nm, respectively. Silica precursors tetraethylorthosilicate (TEOS) and tetramethylorthosilicate were both found suitable, but TEOS was preferred. We also developed a facile and rapid method to synthesize SBA-15 and other mesoporous silicas (FDU-12) in a few hours instead of at least 2 days as originally reported. We also found that the use of static conditions can induce formation of large-pore SBA-15 with platelet morphology. In Chapter 3, the synthesis of well-defined mesoporous polymer/silica composites via surface-initiated atom transfer radical polymerization (ATRP) was described. 2-(4-chlorosulfonylphenyl)ethyltrichlorosilane was successfully proven as a cost-effective and powerful initiator to initiate polymerizations of various monomers from SBA-15 silicas. We further demonstrated the ATRP with activators regenerated by electron transfer (ARGET) as a more convenient and more environmentally friendly pathway to synthesize polymer/silica composites under mild conditions with hundred ppm levels of copper catalyst and tolerance of limited initial amount of air. In both methods, tunable surface properties, such as adjustable polymer loadings and polymer film thicknesses, can be achieved. In Chapter 4, high quality ordered mesoporous carbons were synthesized using mesophase pitch or grafted polyacrylonitrile (PAN) as carbon precursors. The infiltration of mesophase pitch into the silica host was effective for synthesis of semi-graphitic carbons with different framework geometries, such as 2-D hexagonal array of nano-rods or cubic carbon structures, even at low carbonization temperature (850 oC). After stabilization and carbonization of silica/PAN composites, and removal of silica templates, mesoporous carbon materials had ordered structures with hollow nanoscale features, nanopipes or nanospheres from replication of SBA-15 or FDU-12 silicas, respectively.

  • Aggregation and Gelation of Silica Nanoparticles

    Author:
    Xiujuan Cao
    Year of Dissertation:
    2011
    Program:
    Engineering
    Advisor:
    Jeffrey Morris
    Abstract:

    The gelation mechanism was explored in a comprehensive way both experimentally and numerically. The gelation dynamics of a sol of colloidal silica of approximately 7 nm radius particles is studied using a combination of light scattering and rheometry. By changing the ionic strength (by addition of a salt solution resulting in different ultimate molarities) of the mixture, a stable sol can be destabilized, leading to aggregation and later gelation. The gel time t gel can be varied from hours to weeks, indicating a reaction-limited aggregation process. Static light scattering is used to extract the fractal dimension D f of the aggregates, which is found to be approximately 2. The evolution of cluster size is probed by dynamic light scattering, and follows an exponential growth. Rheometry is used to assess the gelation time and further development of the network strength after gelation. The elastic modulus (G' ) is found to scale as G' ~ &phi3.3, where &phi is the silica particle volume fraction. It was observed that the gel time (after salt solution addition) depends on both the particle volume fraction and salt concentration, showing a divergence at low volume fraction or low salt concentration. For a single solid fraction, data for the cluster hydrodynamic radius, normalized by the single particle radius, from experiments with a wide range of gel times can be collapsed onto a master curve when the time after the salt addition, t , is scaled as t/tgel; a similar collapse of viscosity and the linear viscoelastic data after gelation can be obtained using the same scaling of time. Salt concentration affects the gel time but not the strength of the gel network, thus allowing very accurate prediction of network formation times and mechanical properties. The effects of both hydrodynamic and repulsive forces on the rate of aggregation, and on the microstructure and mechanical properties of particle aggregates, are investigated by Brownian dynamics (BD) and Stokesian Dynamics (SD) simulation, over a range of solid volume fraction of 0.04&le &phi &le 0.12. The simulation methods differ in their treatment of the role of the suspending fluid, as SD includes the configuration-dependent hydrodynamic interactions between particles, whereas BD includes the fluid only though a viscous drag independent of configuration. Typical simulations useO(1000) particles in the simulational unit cell, which is periodically replicated in three dimensions. The interparticle potential is parameterized to include a roughly constant primary minimum near contact with Umin/kB T > 6, along with a variable repulsive barrier at slightly larger separations; hereUmin is the depth of the primary minimum. The structure is characterized through the pair distribution function, g(r), and the static structure factor. The repulsive barrier reduces the rate of aggregation and is also seen to affect the structure, with a large repulsion associated with a more tenuous structure. This is reflected in the potential having a strong effect on the evolution of `bonds' per particle (defined by a pair of particles being inside the repulsive barrier), with larger repulsion leading to smaller numbers of bonds and hence a more loose and open structure. Hydrodynamics was found to reduce the solid fraction required for percolation, with the influence depending upon the form of the potential; the difference in percolation threshold was significant, &phic, SD &doteq 0.06 and &phic,BD &ge 0.08 for an intermediate level of repulsive force, where the largest fractional difference is observed. The hydrodynamic interactions were examined through analysis of the statistics of the evolution of numerous independent three-particle aggregates. These show that hydrodynamics slows the evolution toward a condensed aggregate of lowest potential energy in a way which cannot be simply scaled by altering the local drag. The interparticle bonding potential was investigated in a two dimensional system with or without restrictions in the rotational and stretching motion of particles. Two types of non-restrictive bonding force were studied, FENE (finitely extensible nonlinear elastic) and spring potential. Both of the bonding forces are effective in binding two particles together and forming clusters with chain-like structure under the condition that there is no repulsive barrier between particles. However, in the presence of repulsive force, systems with FENE bonding potential form clusters without branched structure; while with spring potential, particles form chain-like clusters which interconnect with each other and evolve into large clusters filling the whole space. In addition, we introduced a spring type of bonding potential that is created on the surface of the two particles within the critical distance instead of the center. The particle pair is restrained in both translational and rotational motion. The particles with high repulsive force form one dimensional chain-like structure. The restrictive bonding potential is also investigated in three dimensional system. We found that only the systems with small repulsive barriers together with restrictive bonding for volume fraction &phi = 0.1 can form a percolated network at aggregation time t = 33.