The purpose of this study is to investigate the factors that influence the persistence of adult students in online undergraduate courses at the community college level. Quantitative analysis of survey results from 476 students enrolled in on-line courses at two community colleges indicate that desire to complete the degree, previous experience in on-line courses and assignment completion are the strongest predictors of course completion. The findings from this research also provide the basis for making recommendations for future research and improving policy and practice. Finally, the results of this study suggest the basis for developing new models for understanding persistence in on-line courses.

Minority status stress, which is the stress Black college students experience at predominantly White institutions (PWIs) as a result of their racial minority status, has been found to negatively impact their persistence in college. Two manuscripts were developed for this dissertation. The first is a critical literature review which establishes the relationship of minority status stress, persistence, and leadership values within psychological and higher educational scholarship of Black students at PWIs. The paper seeks to clarify the connection between the aforementioned variables as it relates to the Black student experience at PWIs. As minority status stress causes a threat to Black student persistence, leadership conceptualized using the values or the Cs of the Social Change Model of Leadership Development (SCM) were introduced as coping methods Black students have used to increase their persistence and minimize the negative effects of minority status stress. The second article is a quantitative study examining the relationship of minority status stress and persistence employing the Cs of the SCM as mediators in a sample of 340 Black college students. Results indicated that none of the Cs of the SCM fully mediated the relationship between minority status stress and persistence when employed as composite scores. However, when the six individual factors of minority status stress (environmental stressors, race-related stressors, racial-identity stressors, intrapersonal and interpersonal stressors, achievement-related stressors, and minority status stressors) and the 5 factors of persistence (academic and intellectual development, faculty concerns for student development and teaching, interactions with faculty, institutional and goal commitments, and peer group interactions) were employed in a series of multiple mediation analyses with the Cs of the SCM as mediators, there were several instances of full mediation by the Consciousness of Self, Citizenship, and Change values. The findings emphasized the importance of these three values in conceptualizing Black student leadership at PWIs and in understanding the role of leadership in Black student persistence in lieu of minority status stress. Suggestions for future research, implications, and recommendations for student affairs practitioners, other student services providers, faculty, and staff are discussed.

This thesis consists of four essays on the topic of asset management. The first essay, Performance and Characteristics of Swedish Mutual Funds studies the relation between fund performance and fund attributes in the Swedish market. The results show, among other things, that good performance is to be found among small equity funds, low-fee funds, funds whose trading activity is high, and in some cases, funds with good past performance. The second essay, Does Active Trading Create Value? An Evaluation of Fund Managers' Decisions decomposes fund performance and examines how it is influenced by fund managers' strategic and tactical decisions. The results support the value of active portfolio management in Sweden. The essay also finds a positive relation between performance and fund managers' voluntary trading decisions. In contrast, there is some evidence of inferior trading decisions when fund managers are forced to trade. The third essay, Investment Strategies, Fund Performance, and Portfolio Characteristics analyzes the relation between fund performance and fund managers' investment strategies. The results show that neither momentum characteristics nor the valuation of stocks in the fund portfolio can explain differences in fund performance. The findings also show a positive relation between performance and the degree of diversification of the fund portfolio. The last essay, Costly Information, Diversification, and International Mutual Fund Performance examines how fund managers' costly search for information affects the performance of mutual funds that invest in Asia and Europe. The essay shows that fund managers who select from a smaller set of Asian stocks perform better than those who select from a larger set. Moreover, the performance of large international mutual fund companies is similar to that of their small competitors. This suggests that there are no economies of scale in the costly search for information. / Diss. Stockholm : Handelshögskolan, 2001

Drosophila melanogaster has been widely used as a model organism to study the immune responses against bacteria, fungi, parasites and viruses. Here, I present a D. melanogaster virus as a model to study persistent virus infections. I have discovered and characterized the Nora virus, a small picorna-like RNA virus able to persistently infect D. melanogaster. The Nora virus genome encodes four open reading frames; a feature not present in other picorna-like viruses. The Nora virus is not closely related to any other virus family, but rather is the first virus in a new family of picorna-like viruses. The major replicative proteins of this virus are encoded in the second open reading frame and the capsid proteins are encoded in the fourth open reading frame. The sequence of the capsid proteins are not obviously related to any other previously described protein. By looking at expressed sequence tags (EST) projects, we identified an EST sequence from the parasitic wasp Nasonia which appears to encode proteins that have sequence similarity to the Nora virus capsid proteins. I have shown that the Nora virus persists in the fly intestine however I did not observe serious pathological effects in the infected flies. The virus is shed through feces and the transmission occurs horizontally via the ingestion of virus-contaminated food. Moreover, I observed variability in the viral titers among single flies of the same infected stock. Some flies are able to clear the Nora virus but not others and this phenomenon seems to be titer-dependent. Surprisingly, none of the known Drosophila antiviral responses play a role against the Nora virus. In conclusion, my work shows that studying the Nora virus interaction with the Drosophila immune system can lead to new findings on viral persistence mechanisms of RNA viruses and of Drosophila viral innate immunity.

The asymptomatic nature of chlamydial infection renders the differential diagnosis of acute and chronic infection difficult. An untreated Chlamydia trachomatis infection can become chronic, result in disease sequelae such as salpingitis and pelvic inflammatory disease (PID), and ultimately culminate in tubal occlusion and infertility. Diagnostic tests for C. trachomatis such as nucleic acid amplification testing (PCR), antigen detection and serological methods have variable performance capabilities with respect to sensitivity, specificity and stage of infection. The use of PCR as a diagnostic tool is somewhat limited, as specimen collection is routinely sampled from the lower genital tract; hence, infections in the fallopian tube where inflammatory damage is most significant, escape detection. Furthermore, PCR can only detect selected Chlamydia DNA sequences from readily accessible sites of the genital tract, and therefore cannot differentiate between acute and chronic infection. Other serological assays aim to discriminate the various stages of C. trachomatis infection through identification of key antigens. The efficacy of these assays however is impeded due to cross-reactivity between chlamydial species and the subsequent antibody response against the target antigen is not restricted to patients with a specific stage of infection. To identify antibody responses capable of differentiating various states of chlamydial infection, samples were collected from both men and women given the variability of immune responses between the two genders. Samples were assigned to a patient group according to infection status and then probed against protein extracts of HEp-2 cells infected with C. trachomatis serovar L2 and HEp-2 cells pre-treated with IFN-γ and infected with C. trachomatis serovar L2. (persistence cell culture) Serological analysis revealed the presence of five antigens (denoted bands A, B, C, D and M) which were shown to be differential between patient groups. Identification of bands B and C by N-terminal sequencing provided two possible candidates for each antigen, ie. CT727 and CT396 (band B) and CT157 and CT423 (band C). In contrast, band M which was unique to males was a PmpB (probable outer membrane protein B) fragment. The four target antigens (CT157, CT423, CT727 and CT396) were expressed as recombinant proteins using autoinduction media and were subsequently probed by both male and female sera to evaluate their diagnostic potential. Results showed that two chlamydial antigenic targets (CT157 and CT727) have the potential to discriminate between acute and chronic C. trachomatis infection. However, since only a small number of samples (n = 3) were used for this aspect of the study, the findings should simply be viewed as preliminary. In females, sensitivity and specificity values were derived using various combinations of the four target antigens into a panel format for the purpose of detecting chronic C. trachomatis infections. The preferred format was B + C with a sensitivity and specificity of 80% and 84% respectively. Using the IFN-γ-mediated persistence model, only two of the five antigenic targets were shown to be differentially expressed. PmpB in males and CT157 (the most likely band C candidate) in females were shown to be up-regulated to varying degrees in samples across the patient groups. We also demonstrated that no other chlamydial antigens are up-regulated during a persistent C. trachomatis infection. In conclusion, although combinations of bands A, B, C, D and M differentiate between male and female patient groups under normal chlamydial growth conditions, during IFN-γ-induced persistence, only bands C (CT157) and M (CT413 - PmpB) are up-regulated thus suggesting a potential role in chronic C. trachomatis infection.

Thesis (Ed. D.)--Illinois State University, 1995. / Title from title page screen, viewed May 9, 2006. Dissertation Committee: Larry Kennedy (chair), John V. Godbold, John Goeldi, William Tolone. Includes bibliographical references (leaves 81-87) and abstract. Also available in print.

Thesis (Ph. D.)--State University of New York at Binghamton, Psychology Department, 2005. / Includes bibliographical references.

Thesis (Ph.D.)--Duquesne University, 2006. / Title from document title page. Abstract included in electronic submission form. Includes bibliographical references (p.93-103) and index.

abstract: The objective of this research was to predict the persistence of potential future contaminants in indirect potable reuse systems. In order to accurately estimate the fates of future contaminants in indirect potable reuse systems, results describing persistence from EPI Suite were modified to include sorption and oxidation. The target future contaminants studied were the approximately 2000 pharmaceuticals currently undergoing testing by United States Food and Drug Administration (US FDA). Specific organic substances such as analgesics, antibiotics, and pesticides were used to verify the predicted half-lives by comparing with reported values in the literature. During sub-surface transport, an important component of indirect potable reuse systems, the effects of sorption and oxidation are important mechanisms. These mechanisms are not considered by the quantitative structure activity relationship (QSAR) model predictions for half-lives from EPI Suite. Modifying the predictions from EPI Suite to include the effects of sorption and oxidation greatly improved the accuracy of predictions in the sub-surface environment. During validation, the error was reduced by over 50% when the predictions were modified to include sorption and oxidation. Molecular weight (MW) is an important criteria for estimating the persistence of chemicals in the sub-surface environment. EPI Suite predicts that high MW compounds are persistent since the QSAR model assumes steric hindrances will prevent transformations. Therefore, results from EPI Suite can be very misleading for high MW compounds. Persistence was affected by the total number of halogen atoms in chemicals more than the sum of N-heterocyclic aromatics in chemicals. Most contaminants (over 90%) were non-persistent in the sub-surface environment suggesting that the target future drugs do not pose a significant risk to potable reuse systems. Another important finding is that the percentage of compounds produced from the biotechnology industry is increasing rapidly and should dominate the future production of pharmaceuticals. In turn, pharmaceuticals should become less persistent in the future. An evaluation of indirect potable reuse systems that use reverse osmosis (RO) for potential rejection of the target contaminants was performed by statistical analysis. Most target compounds (over 95%) can be removed by RO based on size rejection and other removal mechanisms. / Dissertation/Thesis / Ph.D. Civil and Environmental Engineering 2011

abstract: The purpose of this study was to help increase success for first-generation Latina students at Arizona State University by providing a group mentoring support experience during the spring semester of their sophomore year. Thirteen first-generation Latinas in their sophomore year were recruited from the Obama Scholars Program at Arizona State University. These students participated in one or two 90-minute group mentoring intervention sessions during the spring semester of their sophomore year and responded to reflection questions at the end of each session. Additional data were collected through e-journaling and field notes to document the mentoring process and the short-term effects of the group mentoring intervention. Study participants named three themes as critical to their college success: college capital, confidence, and connections. Participants also reported that the intervention of group mentoring sessions helped them increase their knowledge of available resources, feel more confident about their remaining years in college, make connections with other first-generation Latinas, and convinced them to recommit themselves to working hard for immediate academic success to achieve their goal of becoming the first in their families to become a college graduate. / Dissertation/Thesis / Ed.D. Educational Leadership and Policy Studies 2011