Thesis (Ph. D.)--Washington State University, December 2009. / Title from PDF title page (viewed on Dec. 28, 2009). "Department of Mathematics." Includes bibliographical references (p. 101-104).

No description available.

Thesis (Ph. D.)--Washington State University, August 2008. / Includes bibliographical references (p. 86-88).

Thesis (doctoral)--Universiẗat, Hamburg, 2004.

Introduction: The HIV epidemic has had a significant impact on the existing inpatient and outpatient health systems. The cost of inpatient care for HIV positive people has been shown to be greater than for HIV negative people and HIV infection has been associated with a higher inpatient mortality. These dynamics, in the face of an established antiretroviral program, have not been studied at district hospital level previously. Aim: The aim of this study was to describe the clinical patterns and cost implications in medical admissions at Helderberg Hospital, with particular reference to HIV infection and treatment. It includes a comparative analysis of HIV positive and HIV negative admissions. Methodology: This was a descriptive, quantitative study in the form of a cross-sectional survey. All medical admissions over defined 24 hour periods were recorded and data extracted from the medical records retrospectively. Results: 165 records were analysed. HIV prevalence was 19% and overall mortality 7%. 23(72%) of the 32 HIV positive patients had not yet accessed HIV services. The median CD4 count was 87cells/microl. The comparative analysis showed the HIV positive admissions to have a longer length of stay (5.9 days versus 3.6 days, p<0.01), higher laboratory costs (R717.28 versus R327.23, p<0.01) and higher pharmacy costs (R40.69 versus R11.72, p<0.01) than the HIV negative admissions. Outcomes for the HIV positive and negative patients were similar (p=0.64). Conclusion: Inpatient cost of care for HIV positive patients in this district hospital is more expensive than for HIV negative patients. Mortality rates in both groups are comparable. Antiretroviral therapy may be contributing to a decreased inpatient HIV prevalence and mortality rate. HIV positive patients are not accessing treatment in time to avoid morbidity requiring costly hospital admission. Further efforts are needed to expand outpatient HIV services, to explore the reasons why people with HIV are not accessing treatment timeously and to encourage rigorous treatment of HIV infected inpatients to ensure optimal outcomes.

Individuals with developmental disabilities often have limited verbal repertoires and may engage in maladaptive behaviors in lieu of appropriate behaviors to access preferred stimuli. Functional Communication Training (FCT), although an efficacious treatment to reduce occurrences of maladaptive behavior, may result in unmanageable rates of the communicative response. Research has shown that gradually introducing a multiple schedule of reinforcement can ameliorate these high rates. To date, no studies have attempted the gradual introduction of a multiple schedule with behavior sensitive to negative reinforcement. Moreover, although evidence exists in the basic literature for the use of auditory stimuli as discriminative stimuli for the components of a multiple schedule, there is a paucity of applied research on multiple schedules with auditory signals. In the current study, two participants with developmental disabilities and intact vision and hearing received FCT to teach a functionally communicative response (e.g., touching a "break" card). Once the participants acquired the response, they were exposed to a multiple schedule condition, in which either auditory or visual signals were arranged to signal the components, and a mixed schedule (control) condition in which neither component was signaled

No description available.

A novel Gram negative, capsule-forming bacterium was previously isolated in Dr. G. Roland Vela's laboratory. The distribution of this bacterium in soils from various locations was investigated. Soil samples from 188 locations around the world were examined. Isolates of the bacterium were obtained from 50 of these soils, with 48 of the isolates found in soils from the southwestern United States and northern Mexico. This suggests that this region is the natural habitat of the bacterium. The other two isolates were obtained from Madrid, Spain and Taipei, Taiwan. None were found in soils from South America or Australia. A lack of variation in morphology and physiological properties in the isolates suggests that a homogeneous population exists, even from widespread geographical locations.

In pursuit of negatively associated measures, this thesis focuses on certain negative correlation properties in matroids. In particular, the results presented contribute to the search for matroids which satisfy $$P(\{X:e,f\in X\}) \leq P(\{X:e\in X\})P(\{X:f\in X\})$$ for certain measures, $P$, on the ground set. Let $\mathcal M$ be a matroid. Let $(y_g:g\in E)$ be a weighting of the ground set and let $${Z = \sum_{X}\left( \prod_{x\in X} y_x\right) }$$ be the polynomial which generates Z-sets, were Z $\in \{$ B,I,S $\}$. For each of these, the sum is over bases, independent sets and spanning sets, respectively. Let $e$ and $f$ be distinct elements of $E$ and let $Z_e$ indicate partial derivative. Then $\mathcal M$ is Z-Rayleigh if $Z_eZ_f-ZZ_{ef}\geq 0$ for every positive evaluation of the $y_g$s. The known elementary results for the B, I and S-Rayleigh properties and two special cases called negative correlation and balance are proved. Furthermore, several new results are discussed. In particular, if a matroid is binary on at most nine elements or paving or rank three, then it is I-Rayleigh if it is B-Rayleigh. Sparse paving matroids are B-Rayleigh. The I-Rayleigh difference for graphs on at most seven vertices is a sum of monomials times squares of polynomials and this same special form holds for all series parallel graphs.

In pursuit of negatively associated measures, this thesis focuses on certain negative correlation properties in matroids. In particular, the results presented contribute to the search for matroids which satisfy $$P(\{X:e,f\in X\}) \leq P(\{X:e\in X\})P(\{X:f\in X\})$$ for certain measures, $P$, on the ground set. Let $\mathcal M$ be a matroid. Let $(y_g:g\in E)$ be a weighting of the ground set and let $${Z = \sum_{X}\left( \prod_{x\in X} y_x\right) }$$ be the polynomial which generates Z-sets, were Z $\in \{$ B,I,S $\}$. For each of these, the sum is over bases, independent sets and spanning sets, respectively. Let $e$ and $f$ be distinct elements of $E$ and let $Z_e$ indicate partial derivative. Then $\mathcal M$ is Z-Rayleigh if $Z_eZ_f-ZZ_{ef}\geq 0$ for every positive evaluation of the $y_g$s. The known elementary results for the B, I and S-Rayleigh properties and two special cases called negative correlation and balance are proved. Furthermore, several new results are discussed. In particular, if a matroid is binary on at most nine elements or paving or rank three, then it is I-Rayleigh if it is B-Rayleigh. Sparse paving matroids are B-Rayleigh. The I-Rayleigh difference for graphs on at most seven vertices is a sum of monomials times squares of polynomials and this same special form holds for all series parallel graphs.