Thesis: M.S., Massachusetts Institute of Technology, Sloan School of Management, 1993 / Includes bibliographical references (leaves 87-88). / by Edoardo Demarchi. / M.S. / M.S. Massachusetts Institute of Technology, Sloan School of Management

Thesis: M.S., Massachusetts Institute of Technology, Sloan School of Management, 1992 / Includes bibliographical references (leaves 93-97). / by Hans Patrick Griesser. / M.S. / M.S. Massachusetts Institute of Technology, Sloan School of Management

Research has shown that individuals are able to realize positive changes in their lives following traumatic experiences. Tedeschi and Calhoun (1996) have labeled these benefits as post-traumatic growth (PTG), a multidimensional construct that includes growth within five distinct areas. Researchers have documented PTG in youth, which tends to co-occur with posttraumatic stress symptoms (Laufer & Solomon, 2006; Ickovics, et al., 2006). Further, initial research with youth indicates these populations may experience dimensions of growth beyond the scope of domains prevalent in the adult literature. The current study examined PTG within a sample of African American middle school students attending a parochial school in New Orleans six months following Hurricane Katrina using qualitative methods, a departure from the inventorybased methodology typical of most PTG studies. The first hypothesis was that participants would provide responses that extend beyond the five established domains. Due to cultural aspects of African American populations, the second hypothesis was that Relating to Others and Spiritual Change would be particularly prominent within the study's sample. The final hypothesis was that participants with clinically significant symptoms of posttraumatic stress disorder (PTSD) would show more evidence of PTG than those without clinically significant symptoms. T-tests and z-tests were used to compare participants' endorsement of domains, and analyses of variance were used to compare the PTSD and No-PTSD groups. Results show that participants provided examples of PTG both within and beyond the five-domain paradigm, and tended to endorse more concrete than complex domains like that of Relating to Others and Spiritual Change. Participants with clinically significant symptoms of PTSD provided more examples of PTG than those without significant PTSD symptoms, and the relationship between PTSD and PTG was strongest when considering the five-domain model of PTG / acase@tulane.edu

The neurons of the dentate gyrus play a critical role in the hippocampal tri-synaptic pathway. Granule cells located in this cellular layer are responsible for integrating large amounts of information emitted from the entorhinal cortex before propagating signals via the mossy fiber pathway to the CA3 subfield of the hippocampus. This circuitry has been shown to be critical to the formation of episodic and declarative memories. This type of memory is impaired in schizophrenics. Animal models based on the popular glutamate hypothesis have used NMDA antagonist such as PCP and ketamine to mimic the symptoms of schizophrenia to good effect. One such animal model utilizes sub-chronic administration of PCP to non-human primates. Numerous studies have shown that this treatment paradigm reliable produces deficits in prefrontal cortex functioning that mimics the dysfunctions associated with the schizophrenic phenotype. The present study used late adolescent vervet monkeys treated in the sub-chronic paradigm and sought to determine if structural changes occurred in the dentate gyrus. We report that no structural alterations to dentate granular cell morphology were linked to sub-chronic PCP administration. This result may be due to the fact that the late adolescent subjects used had yet to develop fully mature glutatmatergic circuitry and were thus not susceptible to the changes in brain chemistry commonly associated with NMDA antagonist administration / acase@tulane.edu

Natural disasters such as Hurricane Katrina can cause a range of psychological problems in youth, including posttraumatic stress (PTS) symptoms (Norris et al., 2002). Not everyone who experiences a disaster develops PTS symptoms. Individual characteristics such as gender (Tolin & Foa, 2008) and coping style (LaGreca et al., 1996) can influence the development of PTS symptoms post-disaster. Substance use (SU) is one type of coping strategy that increases among adolescents after exposure to disasters (Chemtob et al., 2009; Reijneveld et al., 2003). While adult studies have found that drug use as a form of coping has the potential to increase the risk of developing PTS as well as prolong and exacerbate symptoms (Stewart et al., 1998), few studies have examined this relationship in adolescents. Furthermore, preliminary evidence suggests that SU may uniquely influence the three PTS symptom clusters (Overstreet et al., 2010). The goal of this study will be to explore the effect of SU on PTS symptoms in general, and the individual symptom clusters. Participants included 687 predominately White females, ages 13-18 attending a private, Catholic school. Hurricane exposure was assessed via a 9-item questionnaire addressing loss and disruption caused by the hurricane. PTS was assessed using the17-item subscale of the Los Angeles Symptoms Checklist (LASC; King et al., 1997). SU was measured using two LASC items that assessed problem SU. Hierarchical regression analysis was used to test the moderating role of SU on the relationship between disaster exposure and symptoms of PTS. Results indicate that in general, while SU is independently associated with PTS symptoms, it does not influence the relationship between exposure and overall PTS symptoms. However, for highly exposed youth, it does potentiate the relationship between exposure and avoidance/numbing symptoms of PTS / acase@tulane.edu

A critical mass of adopters, a majority of which are usually opinion leaders, is required for the diffusion of any innovation to become self-sustaining. All public wastewater facilities in Vermont and New Hampshire were surveyed to determine which facilities exchange information, which have adopted UV, and what characteristics are common among adopters, non-adopters, and opinion leaders. Two networks, based on the exchange of general information and information about disinfection technology, were constructed using UCINET; they indicate UV has likely been adopted by a critical mass. Opinion leader facilities' employees interact with consultants and vendors. Opinion leader facilities' managers work closely with their staff and are active in professional organizations. Non-adopter opinion leader facilities are fiscally conservative while innovative opinion leader facilities are shaped by decisions of the community's elected officials. Distance between facilities was mapped using GIS software and did not influence the type of disinfection technology adopted / acase@tulane.edu

This longitudinal study was undertaken to examine the developmental progression of banging during the second half year of life. The second purpose was to determine if and when banging is used 'appropriately,' that is, as a function of object properties. Twenty infants were videotaped while presented with five pairs of objects, one pair at a time, for one minute each at monthly intervals. Object pairs were varied systematically along the hardness/sound potential dimension, to promote more or less banging. Results indicate that in some instances banging may go through a short period of indiscriminate use before it is applied appropriately, as with the cubes. In other instances, banging appears to be used selectively upon its emergence, as was the case with the dowel. Infants evidenced more banging of hard or rigid objects than of soft and flexible ones. An independent group of ten-month-olds exhibited the same discriminate banging, suggesting that the present findings may reflect developmental change rather than the effects of repeated testing / acase@tulane.edu

A bench-scale aerobic microbial degradation study of soil contaminated with Saudi Arabian crude oil was conducted. The effects of nutrient additions and seeding with naturally-occurring microorganisms were evaluated, through comparison of results from a control reactor, a second reactor with nutrients, and a third reactor with nutrients and seed microorganisms. A separate weathering experiment was conducted under identical environmental conditions for evaluation of abiotic weathering losses of the crude oil The total petroleum hydrocarbon (TPH) content of soil contaminated with crude oil was measured as a function of time. During a five-week evaluation period, a TPH reduction of 60 to 70% was observed for the nutrient evaluation. Based on the weathering tests, approximately 17% of the TPH loss was attributed to abiotic losses For the specific environmental conditions, crude oil, seawater, and soil evaluated, the addition of nutrients stimulated the biodegradation of crude oil over the test period. Due to the availability of indigenous bacteria, seeding with naturally-occurring bacteria did not improve the rate of TPH loss / acase@tulane.edu

Ball State University LibrariesLibrary services and resources for knowledge buildingMasters ThesesThere is no abstract available for this thesis.

Ball State University LibrariesLibrary services and resources for knowledge buildingMasters ThesesThere is no abstract available for this thesis.