Thesis (Ed.D.) -- Teachers College, Columbia University, 1989. / Typescript; issued also on microfilm. Sponsor: Elaine L. La Monica. Dissertation Committee: Peter C. Cairo. Bibliography: leaves 72-79.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1962. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1963. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 62-64).

Thesis (Ed. D.)--Harvard Graduate School of Education, 1994. / Vita. Includes bibliographical references (leaves 297-331).

Thesis (Ph. D.)--University of Texas at Austin, 1993. / Vita. Includes bibliographical references (leaves 145-155).

Thesis (Ph.D.)--Aberdeen University, 2009. / Title from web page (viewed on Apr. 1, 2010). Includes bibliographical references.

Thesis (Ph. D.)--Management, Georgia Institute of Technology, 2007. / Khorana Ajay, Committee Chair ; Clarke Jonathan, Committee Member ; Li haizheng, Committee Member ; Jayaraman Narayan, Committee Member ; Eun Cheol, Committee Member.

Wetlands occurring on natural river floodplains typically have more dynamic hydrology, because of influences from the river, than man-made wetlands or those associated with reclaimed minelands. For wetland-associated species, fluctuating water levels can affect patch availability, connectivity and potentially habitat quality, and therefore drive metapopulation dynamics. Differences in hydrology between wetland complexes could change food webs and consequently the trophic diversity of the communities occupying these areas. My first objective was to assess the spatial and temporal variation in occupancy and turnover rates of a semi-aquatic small mammal at 2 hydrologically distinct wetland complexes over 3 years in southern Illinois. My second objective was to determine spatio-temporal variation in the trophic structure of small mammals at 2 wetland complexes (floodplain and mineland) in southern Illinois. To address my first objective, I live-trapped marsh rice rats (Oryzomys palustris) during 2011-2013 at 9 wetland patches on the Mississippi River floodplain and 14 patches at a reclaimed mineland. I used multi-season occupancy modeling to estimate initial occupancy, detection, colonization and extinction rates. Catch per unit effort differed markedly between the 2 sites (27 captures/1,000 trap-nights at the floodplain site vs. 8 at the mining site). Estimates of detection probability increased with an increase in effort (number of traps per night per wetland patch). Occupancy probability was similar between sites and positively related to patch size. Patch colonization probability at both sites was related negatively to total rainfall 3 weeks prior to trapping. In addition, the variation in colonization probability among years, was different between sites, with colonization in 2013 being much lower at the mining site than at the floodplain. An increase in total rainfall 3 months prior to trapping led to a substantial increase in extinction probability on the floodplain, but not at the mining site. Differences in metapopulation dynamics and relative abundance between the 2 sites can be attributed to differences in hydrology and habitat quality. Although rice rats were present at the mining site in much lower numbers than at the floodplain site, these less-natural wetland complexes might serve as valuable refuges for species occurring in increasingly fragmented landscapes. For my second objective, I collected hair samples from 6 species of small mammals (n = 416) occurring at these wetland complexes. I analyzed C and N stable isotopes for 3 mammal taxa (Oryzomys palustris, Peromyscus spp,, Microtus ochragaster) to compare diet between species, sites, and, times. Food sources (vegetation and invertebrates) were collected at each site to form the isotopic baseline. Using stable isotope mixing models, I found no seasonal difference in diet composition, but signatures varied between sites. Oryzomys palustris at both wetland complexes incorporated primarily (70-80%) invertebrates in their diet, and used more C4 vegetation (30%) than C3 (0%). Isotope signatures of Peromyscus diets at the floodplain site were similar to that of Oryzomys, with ~80% invertebrates and >C4 vegetation than C3 vegetation (~20% and 0%, respectively). At the mining site, Peromyscus were at a much lower trophic level and consumed 70% vegetation with C3 plants making up a greater part of their diet than C4 vegetation (50% and 20%, respectively). Microtus was at a lower trophic position than the other 2 species at both sites. These isotope results point to reduced niche overlap between Oryzomys and Peromyscus at the mining site, perhaps due to lower habitat quality and limited suitable resources. Although small mammals had narrower diet breadths at the mining site, none of the species was at a higher trophic position at the mining site than at the floodplain site. At the floodplain site, the more dynamic hydrology might have given rise to higher biodiversity and consequently provided more resources to allow small mammals to use similar food items.

M.Comm. (Business Management) / An exploration into the level of high staff turnover in the recruitment industry and the possible reasons for the turnover. A quantitative study using a survey with carefully considered reasons for why consultants would leave the recruitment industry. Making use of Binary Logistic Regression modelling and Boosted Regression Tree analysis (BRT), the main reasons for why consultants leave the recruitment industry were identified with applicable outcomes and recommendations for future study.

The purpose of this study was to determine factors that impacted on engineering professionals’ decision to seek alternative employment, as well as to determine the decision making processes applied by engineering professionals when seeking alternative employment. A conceptual model was developed to illustrate the impact of various factors on labour turnover and the decision making processes that could be followed by engineering professionals when seeking alternative employment. The factors impacting on labour turnover were organised into four categories, namely external, internal, expectations and personal trait factors. The theoretical study revealed that employees were more likely to leave their present organisations if they perceived that there was ample opportunity for acceptable alternative employment (Bigliardi, Petroni & Dormio, 2005). Zimmerman (2008) stated that employee turnover was a problem faced by all organisations globally. In their study they mentioned that high labour turnover rates have been associated with decreased customer satisfaction, productivity, future revenue growth and profitability. A sense of instability and frustration can also cause work backlogs and slow productivity. At times employees lose faith in their organisations as more individuals seek alternative employment (Drake International, 2010). When the organisation experiences high turnover, burnout also increases and could possibly lead to stayers also seeking alternative employment. Previous studies contain evidence of an extensive poaching of South African engineering professionals (technologists and engineers) by overseas companies (Du Toit & Roodt, 2009). As a result of this mobility and the lack of significant engineering graduates entering the industry, companies competed for a limited number of engineering professionals. This challenge resulted in a higher labour turnover rate among engineers as the demand for engineering professionals was higher than the supply. The skills shortage of engineering professionals in South Africa was one of the perceived contributing factors impacting engineering professionals’ decision to seek alternative employment. Apart from the shortage of skills there were other factors that impacted on engineering professionals’ decision to seek alternative employment. External factors, such as slow recruitment due to the low economy, have been identified as having an impact on labour turnover rates. Bigliardi et al (2005) stated that external factors, also referred to as push factors, such as changes in economic, social and technological conditions,created challenges for retaining engineering professionals. Through developing multivariate models that combine a number of factors contributing to labour turnover and empirically testing these models, researchers have attempted to predict why individuals decide to seek alternative employment (MINTRAC, 2010). The job search process was evaluated and referred to as the process of looking for alternatives to a current job, and the evaluation of those alternatives (Brown, 2009). Various decision making models, including the rational decision making model, Steers and Mowday’s model, image theory and the unfolding path model were studied to provide an understanding of how engineering professionals decided whether to seek alternative employment. Donnell and Quirin (2006) explained two decision making models. These are the image theory and Lee and Mitchell’s unfolding model. According to Zimmerman (2008), the studies carried out did not clearly reflect the impact of individual characteristic factors. An empirical study, by means of a survey and a questionnaire as a data collecting tool, was conducted to determine the factors that impacted on engineering professionals at GIBB to seek alternative employment and the decision making process they applied in seeking alternative employment. This study reflected that personal traits such as openness to new experiences, high levels of competency, the ability to form relationships at work, a general level of commitment, ability to incorporate other people’s views at work and a general positive attitude towards work itself influenced the decision to seek alternative employment. The external, internal, expectancy and personal trait factors that were perceived to be the most influential in impacting on engineering professionals’ decision to seek alternative employment were presented in a revised concept model. This model could be valuable for developing retention strategies at GIBB. Future research that could be beneficial to GIBB and the engineering industry was also identified.