<p>This report consider a system describing three competing species with populations <em>x</em>, <em>y</em> and <em>z</em>. Sufficient conditions for every positive equilibrium to be asymptotically stable have been found. First it is shown that conditions on the pairwise competitive interaction between the populations are needed. Actually, these conditions are equivalent to asymptotic stability for any two-dimensional competing system of the three species. It is also shown that these alone are not enough, and that a condition on the competitive interaction between all three populations is also needed. If all conditions are fulfilled, each population will survive on a long-term basis and there will be a stable coexistence.</p>

This report consider a system describing three competing species with populations x, y and z. Sufficient conditions for every positive equilibrium to be asymptotically stable have been found. First it is shown that conditions on the pairwise competitive interaction between the populations are needed. Actually, these conditions are equivalent to asymptotic stability for any two-dimensional competing system of the three species. It is also shown that these alone are not enough, and that a condition on the competitive interaction between all three populations is also needed. If all conditions are fulfilled, each population will survive on a long-term basis and there will be a stable coexistence.

The natural occurrences of high (&gt;10 μg/L) dissolved arsenic (As) in groundwater of Bengal Basin has put millions of people under the threat of chronic As exposure through drinking water. Present study has examined the processes that regulate As mobilization and its distribution in shallow aquifers and the potentiality of finding safe aquifers within shallow depth (&lt;50 m) for drinking water supply. The results indicate that in terms of aquifer sediment colors and water quality two types of aquifer namely brown sand aquifer (BSA) and grey sand aquifer (GSA) can be distinguished within the depth, accessible by low-cost drilling. The redox condition in the BSA is delineated to be Mn oxyhydroxides reducing, not sufficiently lowered for As mobilization resulting in high Mn and low Fe and As in groundwater. While in GSA, currently the reductive dissolution of Fe oxyhydroxides is the prevailing redox process causing As mobilization into groundwater of this aquifer type. It is revealed that the vertical distribution of As and other aqueous redox parameters is related to the redox zonation within aquifer. The decoupling of As and Fe release into groundwater is evident in the shallowest part of aquifer because of Fe enrichment by weathering of silicate minerals especially of biotite, the precipitation of secondary mineral phases like siderite and vivianite and incomplete reduction of Fe oxyhydroxides. It is characterized that the seasonal variations of As and other aqueous solutes are limited within the upper portion of aquifer only (&lt;30 m bgl) and can be related to seasonal cycling of redox status, aggregation and dispersion of As scavenging colloids, local groundwater abstraction and monsoonal recharge. The results of surface complexation modeling indicate that PO43- is the major competitor of As(III) and As(V) adsorption onto Fe oxyhydroxides. This study concludes that the reductive dissolution of Fe oxyhydroxides followed by competitive sorption reactions with the aquifer sediment is the process conducive for As enrichment in groundwater of Bengal Basin. Present study advocates that despite low concentration of As in groundwater, a rigorous assessment of attendant health risk for Mn is necessary prior to considering mass scale exploitation of the BSA for sustainable drinking water supply. This study also validates that TW platform colors can be used as a rapid screening tool for As and Mn in drinking water wells to prioritize As mitigation management. / <p>QC 20130919</p> / EURINDIA 2009-1665

Clinical trials play an important role in advancing therapeutic and preventive care with many current modalities resulting from prior research. While prior research has described barriers to participation in therapeutic clinical trials, much less in known about barriers related to participation in trials aimed at prevention, prostate cancer prevention in particular. Physicians have been shown to play a critical role in access to trials; however, less is known about the individual and structural factors that influence their participation in prostate cancer prevention trials. This research provides rich ethnographic detail within the context of an ongoing trial. Research participants included physician/investigators who were either directly (serving as a co-investigator) or peripherally (referring patients for participation) involved in prostate cancer prevention intervention clinical trial (PCPICT), as well as those who were considered for participation but declined. Methods included open ended semi-structured interviews, participant-observation and a survey. Participants were recruited via direct inquiry, email and/or letter regarding participation. The results of this study show that individual and structural factors intersect, influencing both the willingness and ability of physician/investigators to participate or refer patients for participation in a prostate cancer prevention intervention clinical trial. Individual factors such as explanatory views on prevention, notions of risk and uncertainty, shared decision-making and duality of roles appear to have a greater influence on the willingness of physicians to participate while structural factors such as staffing, other resources and time are more influential in regards to the ability to participate. This research served as a critical first step towards providing an in-depth understanding of the individual and structural factors that influence a physician's participation in this type of trial. It builds from prior work where a better understanding of barriers and identification of successful strategies to overcome them was a noted void. The researcher identifies areas where additional research would be beneficial and provides applied recommendations for those considering the design of future cancer prevention intervention projects.

It is of interest that researchers study competing risks in which subjects may fail from any one of K causes. Comparing any two competing risks with covariate effects is very important in medical studies. This thesis develops omnibus tests for comparing cause-specific hazard rates and cumulative incidence functions at specified covariate levels. In the thesis, the omnibus tests are derived under the additive risk model, that is an alternative to the proportional hazard model, with by a weighted difference of estimates of cumulative cause-specific hazard rates. Simultaneous confidence bands for the difference of two conditional cumulative incidence functions are also constructed. A simulation procedure is used to sample from the null distribution of the test process in which the graphical and numerical techniques are used to detect the significant difference in the risks. A melanoma data set is used for the purpose of illustration.

This thesis investigates the relationship between foster care placement settings and discharges. Placement settings are where foster children live: foster homes, group homes, etc. There may be one or several placements for any individual child. In the interest of stability, federal funding to states depends in part on low numbers of placement moves. Federal reviews, however, do not consider whether the placement settings resemble permanent family life (foster homes compared to congregate care) or the direction of placement moves. Competing risks regression was used to analyze time to discharge data of foster children in Georgia. Discharges (competing risks) were compared based on the number and the direction of placement moves. Children with movement patterns that favored placements similar to permanent family life were found to have higher probabilities of discharges to safe permanence. This thesis promotes “proximity to permanence” as an important, but often overlooked, consideration in foster care placements.

This thesis presents health care organizations as heterogenic and highly complex in nature with particular normative structures underpinning their formal rational structures. It seeks to explore the evolution of organization structure as applied to a medical corporation in Qatar and to examine the nature of organizational culture and multi professional cohesiveness. In doing so it assesses a range of models on organizational design and change. The three hospitals that compose the corporation are investigated through triangulated interpretative qualitative and quantitative methodologies and the application of the Competing Values Framework. The comprehensive approach of the investigation resulted in a series of conclusions on the evolution of hospital organizational structures, the link between life cycle and structure, forms of organizing health services, characertistics of professional structures, the nature and success of change management strategies, coordination mechanisms, organizational and professional cultures, and health service, organizational and team effectiveness assessment. Findings demonstrated that autonomous and sometimes conflicting professions worked in harmony and cohesiveness as a consequence of shared core values and the human relations focus of health organizations. In examining organizational design it showed that coordination mechanisms were preferred to integration mechanisms with the former playing an important role in conflict resolution and human relations. Finally, findings indicated that when organizational design has shortcomings, the organization substitutes through other mechanisms.

The presented dissertation reports the findings of an exploratory study that mapped the perceptions of stakeholders on the changing nature of the organisational culture, in terms of the corporatisation of higher education, in a single faculty from a large Australian university. The study used a mixed-method, case study approach and it tested the usefulness of an organisational culture measuring instrument based on the Competing Values Framework (Quinn & McGrath, 1985; Quinn & Rohrbaugh, 1981, 1983). The presented work argues that the institution of higher education can be viewed as being rudimentarily comprised of having two symbiotic cultural parts - a collegial and a mercantile part and that these parts form the corporation that is an institution of higher education. The generated hypothesis is that when the values of these two competing cultures are in a particular configuration of influence with each other, a university has its best opportunity to effectively attend to its core functions. The research found that the relationship between the collegial and the mercantile parts in the study site's culture had shifted in favour of a mercantile culture and further research is needed to determine if that means the organisation is operating at an optimal effectiveness.

Exploration of Australian public sector executive leadership roles using the competing values framework, and analysis of skills corresponding to each of the four roles: vision setter, motivator, analyzer and task master. / PhD Doctorate

Thesis (Ph. D.)--State University of New York at Binghamton, Department of Mathematical Sciences, 2009. / Includes bibliographical references.