Thesis (M.Dev.) --University of Limpopo, 2007. / This study sets out to explore the challenges faced by grade 9 educators in the implementation of Outcomes-Based Education (OBE) in Maleboho East Circuit in Limpopo Province in view of the role played by this new education approach in the government’s agenda for social transformation. The study is mainly exploratory in design and has been undertaken within a qualitative framework. Thus, the study does not purport to come with explanations of cause and effect relations. It only explores the challenges that impact on successful implementation of the OBE approach. The research results show that the OBE approach is not effectively implemented in schools, due to inadequate teacher training, limited or little support to educators in their classroom practice, overcrowded classes and poor working conditions of educators. There is a need for a multi-dimensional approach that aims to address not only deficiencies in training, but also to impact on the attitudinal changes of educators. / N/A

acase@tulane.edu / Advanced omics technologies have been generating abundant multi-ethnic multi-omics data, including DNA sequences, methylations, gene expressions, and copious clinical traits. Such big data pose unprecedented challenges due to the high complexity of heterogeneous networks between biomarkers. Heteroscedasticity (aka, dispersion heterogeneity of trait residuals) is a common phenomenon in multi-omics data mining. It can be caused by interactions such as gene×gene, gene×enviroment, linkage disequilibrium (LD) between marker loci, and pleiotropic traits as well. Especially, it occurs in the data mining of the multi-omics data of admixed individuals subjects due to broad admixture LD and gene×ancestry interactions. Meanwhile, it can be induced by background confounders, e.g., population structure, cryptic relatedness, polygenetic effects, and correlations between residuals of multiple traits. However, existent univariate and multivariate methods neglect all the high-order effects of both test biomarkers and background confounders. This dissertation contributes systematic harmonious signal augmentation methods with applications for distilling high-order information from multiethnic DNA sequences to microarrays. In Chapter I, we proposed a novel harmonious signal augmentation schemes in single-based association tests. The harmonious single-based association test (HSAT) is more powerful then existent single-based methods in both simulations and real data application. In Chapter II we put forth harmonious gene-based association tests (HGAT) to incorporate high-order effects. Within a gene, the importance of a test variant is measured by the signal of marker-wise high-order effects. Leveraging high-order effects of genetic variants has proven to improve power for identifying susceptive genes. By extensive simulations under published designs, the proposed method properly controlled type I error rates and appeared strikingly more powerful than existent prominent gene-based sequence association methods. We apply HGAT methods in homogeneous population and admixed population. There are two parts in Chapter III, the first part introduced integrating informative mean and variance effects to identify differentially expressed (DE) genes. The second part illustrated the application of harmonious integration of mean and high order effects to identify differentially expressed (DE) genes. In summary, this dissertation demonstrated tremendous potential of explicitly distilling informative higher-order effects in big multiethnic multi-level data mining and offered paradigm applications for integrating high-order information resources while effectively calibrating major heteroscedastic confounders. / 1 / Weiwei Ouyang

acase@tulane.edu / 1 / Weiwei Ouyang

Prevalence of childhood overweight and obesity has tripled in the United States in the last 30 years, resulting in 31.8% of youth (ages 2-19 years of age) classified as overweight or obese.1,2 To date many high-intensity and medium-intensity programs have been developed and tested in efforts to ameliorate the high prevalence of childhood obesity, however there is a gap in the testing and implementation of low-intensity family-based treatments.3–7The Traffic Light Program is the only childhood obesity program that has published long-term outcomes and was developed by Epstein et. al., however it only includes children from ages 6-12. We developed an 8-week family based childhood obesity program (Healthy Hawkeye Program) to test the feasibility and efficacy of an adapted version (light intensity) of the Traffic Light Program in families of overweight and obese children. To our knowledge, this is the first study to test the efficacy of a low-intensity (21 hours) comprehensive family-based intervention specifically tailored for overweight and obese children from 6 to 17 years of age. Measures include body composition (weight, fat mass, lean body mass, body fat %, BMI, waist circumference), sedentary, light and moderate levels of physical activity (wrist-worn Generative Accelerometer), dietary quality (caloric intake, fruit/vegetable daily servings), measures of nutritional and physical activity self-efficacy, Lifestyle Behavior Checklist (LBC), Family Nutrition and Physical activity (FNPA) survey, Satisfaction with Life Scale, and the Healthy Hawkeye Program Evaluation Survey. We hypothesize that participants will improve in selected (1) health measures (weight, caloric intake, daily fruit intake, daily vegetable intake, sedentary, light, and moderate physical activity levels), (2) improve in selected theoretical constructs (self-efficacy, behaviors, environments), and (3) will find the Healthy Hawkeye Program acceptable and helpful. A total of five families were recruited and only 3 families (3 mothers, 2 male children, and 1 female child) completed the program (attended 6 of 8 weekly meetings). The very low sample size of only 3 families limited the statistical analysis. The results showed parents reduced their absolute weight by 5.6 lbs and children slightly increased by 0.1 lbs. Both parents and children decreased their daily sedentary time as well as increased their daily moderate activity. Various measures of self-efficacy, behaviors, nutrition improved among parents and children. Parents and children found the program to be acceptable and helpful.

High symmetry and low coordinated single-ion lanthanides have been a successful recipe to design high performance single molecule magnets (SMMs). However, enhancement of the magnetic properties of polymetallic SMMs is an important challenge. Therefore, this thesis describes the use of redox non-innocent tetrazine-based ligands and d- and f- elements in order to fine-tune the electronic structure of the resulting compounds to promote strong exchange interactions between the spin carriers. As reported in the literature, radical-bridged ligands represent a potential strategy to improve the magnetic properties of polymetallic SMMs. Thus, chapter one introduces principal concepts that govern the physical properties of metal complexes containing radical-bridged ligands. Chapter two describes the magnetic properties of a unique air-stable tetratopic radical- bridged bpymtz•− (3,6-bis(2-pyrimidyl)-1,2,4,5-tetrazine) templating four Ni(II) metal ions. The dc magnetic studies along with DFT calculations reveal strong ferromagnetic exchange coupling between the Ni− bpymtz•− of J = 98 cm-1 with a spin ground state of S = 9/2. Chapter three describes the application of another tetrazine-based ligand, bpytz (3,6- bis(3,5-dimethylpyrazolyl)-1,2,4,5-tetrazine) to probe magnetic exchange interactions in a {CoII4} supramolecular square. The modelling of dc susceptibility data shows significant Co(II) - bpytz•− magnetic coupling of J = - 118 cm-1 for a spin ground state ST = 4. While the non-reduced analog displays weak Co(II)-Co(II) exchange of J = - 0.64 cm-1 (S = 0 ground state). Additionally, the radical-radical magnetic exchange contribution was probed with an analogous {ZnII4} square, where a J = -15.9 cm-1 was found. Chapter four extends the application of reduced tetrazine ligands to lanthanide systems. Here we demonstrate that the systematic reduction of the ligand with cobaltacene (CoCp2) led to the formation of a strongly coupled bpytz•−−bpytz•− bridging ligand. Magnetic measurements combined with ab initio calculations confirm unprecedented intramolecular pi-dimerization preventing strong magnetic Dy(III)−bpytz•− communication. Chapter five describes the synthesis and characterization of {LnIII4} (Ln = Dy, Gd and Lu) where the Ln(III) ions are bridged by peripheral bpytz•−. The oxophilicity and high coordination numbers preferred by lanthanides ions lead to the formation of a cubane core made up of metal ions bridged by hydroxy ligands (M3-OH−). Experimental and computational studies were applied to verify the nature and strength of the magnetic interactions between the spin carriers.

Evidence-based policy and practice (EBPP) in population health in Australia has been promoted largely without sound research. In response, this thesis presents a series of studies undertaken to assess and inform enhancement of capacity for EBPP in Australia. It comprises linked studies designed to examine different yet complementary aspects of capacity for EBPP. Research was conducted at various levels of Australian health care system, from local to national, in order to better understand EBPP and to make a series of recommendations about effective and synergistic response.

Comment les différents aspects d'une scène visuelle sont-ils encodés en mémoire visuelle à court-terme (MVCT) ? S'il est communément admis que la MVCT ne peut stocker simultanément qu'un nombre extrêmement limité d'informations, la question du format des représentations est actuellement loin d'être résolue. Cette thèse avait pour objectif d'étudier les influences de l'organisation perceptive des différents éléments d'une scène visuelle sur la capacité de stockage de la MVCT. Pour ce faire, dix expériences, utilisant le paradigme de détection de changement (c'est-à-dire en présentant deux séries de stimuli séparées par un court laps de temps et en demandant aux participants de détecter un éventuel changement entre ces deux séries) ont été réalisées. La principale manipulation expérimentale était la comparaison entre différentes organisations perceptives des stimuli dans le champ visuel. Les résultats de nos recherches ont contribué de façon significative à une meilleure compréhension de la façon dont les différents aspects d'une scène visuelle sont traités et encodés en MVCT et suggèrent l'existence de différents types de représentations organisées hiérarchiquement. Tout d'abord, les relations spatiales entre tous les éléments d'une scène visuelle seraient encodées sous la forme d'une configuration spatiale. Cette représentation configurale permettrait, dans un deuxième temps, l'analyse et l'encodage de l'identité individuelle des différents éléments. A ce niveau, nous avons montré que le nombre d'éléments pouvant être simultanément encodés et maintenus en MVCT pourrait dépendre considérablement de la manière dont ils sont présentés dans le champ visuel des participants. Ainsi, lorsque différents traits (couleur, forme, texture, orientation, etc.) occupent la même localisation spatiale, formant ainsi une même partie d'un objet, ils seraient traités et encodés aussi efficacement qu'un simple trait. Dans ce cas, la capacité de stockage de la MVCT doit être comprise en terme d'objets intégrés. Par contre, lorsque les traits d'un objet sont spatialement séparés les uns des autres, constituant différentes parties d'objets, le nombre d'éléments pouvant être simultanément encodés en MVCT est fonction du nombre de traits présents dans le champ visuel, et non du nombre d'objets. L'organisation perceptive des informations visuelles a donc une influence directe sur le nombre d'éléments pouvant être simultanément encodés en MVCT en modifiant la nature des représentations./ How are the different aspects of a visual scene encoded in visual short-term memory (VSTM)? Although it is acknowledged that only a small number of information can be simultaneously stored in VSTM, the format of representation is far to be understood. The goal of the present thesis was to study the perceptual influences of the items in a visual scene on the VSTM storage capacity. Ten experiments, using the change detection paradigm (i.e., two stimuli arrays were presented and separated by a short period of time, and the task was to detect a possible change between the two arrays) were conducted. The major experimental manipulation was to contrast different perceptual organisations of the stimuli in an array. The results of those experiments have significantly contributed to a better understanding about how the different aspects of a visual scene are processed and encoded in VSTM and suggest the existence of different types of representation, hierarchically organised. Firstly, the spatial relations between items in a visual scene would be encoded though spatial configuration. Then, this configural representation would allow the processing and the encoding of the identities of each individual item. Here, the number of items that can be simultaneously encoded in VSTM might greatly depend on the way they are presented in the visual field. Indeed, we provided evidence that visual features (colour, shape, texture, orientation), that share the same spatial location, are encoded in VSTM as accurately as single features. In that case, the VSTM storage capacity must be understood in terms of integrated objects rather than in terms of single features. In contrast, when visual features are spatially distributed over different spatial locations, the limitation in the storage capacity is function of the number of features. The perceptual organisation of the visual information has thus a direct influence on the number of items that can be simultaneously encoded in VSTM by modulating the nature of representations.

The purpose of this study was to investigate the work of three administrators and their staffs as they attempted to solve the ill-structured problem of integrating students with fetal alcohol spectrum disorders (FASD) into their schools. A further purpose of the study was to investigate the role played by schools in influencing community responses that would enhance the post-school lives of students with FASD.<p>The study was conducted throughout one academic year and involved three schools in northern Canada. The use of Problem Based Methodology (PBM) permitted research to be conducted within the schools to generate solutions to the problem. By working with their staff, administrators were afforded opportunities to examine their theories in action and engage in double-loop learning as they searched for new theories of action and alternate constraint constructs.<p>The data for the study were derived from interviews with participating practitioners, parents, health professionals, and District Educational Authority (DEA) members. This permitted the gathering of spontaneous comments and general opinions to be turned into systemic records and detailed statements. The use of PBM determined that data selection involved a search for behaviours in classes of interest. Potential classes of interest were identified prior to the beginning of the study. By the use of a constraint structure, parameters were established for acceptable solutions that generated a theory of action for the ill-structured problem. The four criteria of explanatory accuracy, effectiveness, coherence and improvability were used in theory adjudication (Robinson 1993). Critical dialogue was used between the researcher and participants to collectively make decisions and solve problems through the exchange of the best possible information.<p>The study suggested implications for organizational theory that could better enable administrators and staff to address this ill-structured problem. The isolation and lack of resources oblige staff to create conditions conducive to inquiry and learning (Schon 1983). In the case of initial solutions the theories in action were similar, suggesting that assumptions surrounding the role of contextual factors caused by the heterogeneous nature of the schools are misleading. Prior to the study by Godel et al. (2000) lack of diagnosis diffused the urgency of the problem. Following the publication of the data from that study the lack of screening and diagnosis was a major challenge to stakeholders. Generation of data on the children with FASD in northern communities is essential to generate an organizational and professional focus.

Testing centers are a useful tool to help instructors deliver computer-based tests, but computers resources are expensive and therefore limited. This paper describes a method by which testing center(s) may use iNetTest, a web-based computer aided testing system, to house and administer exams. The algorithm discussed in this paper makes it possible for instructors to schedule tests for a given time frame while ensuring that enough computer resources will be available to all of the students. The algorithm prevents the testing center from getting overwhelmed with students while attempting to maximize the usage of the valuable computer resources.

The purpose of this study was to investigate the work of three administrators and their staffs as they attempted to solve the ill-structured problem of integrating students with fetal alcohol spectrum disorders (FASD) into their schools. A further purpose of the study was to investigate the role played by schools in influencing community responses that would enhance the post-school lives of students with FASD.<p>The study was conducted throughout one academic year and involved three schools in northern Canada. The use of Problem Based Methodology (PBM) permitted research to be conducted within the schools to generate solutions to the problem. By working with their staff, administrators were afforded opportunities to examine their theories in action and engage in double-loop learning as they searched for new theories of action and alternate constraint constructs.<p>The data for the study were derived from interviews with participating practitioners, parents, health professionals, and District Educational Authority (DEA) members. This permitted the gathering of spontaneous comments and general opinions to be turned into systemic records and detailed statements. The use of PBM determined that data selection involved a search for behaviours in classes of interest. Potential classes of interest were identified prior to the beginning of the study. By the use of a constraint structure, parameters were established for acceptable solutions that generated a theory of action for the ill-structured problem. The four criteria of explanatory accuracy, effectiveness, coherence and improvability were used in theory adjudication (Robinson 1993). Critical dialogue was used between the researcher and participants to collectively make decisions and solve problems through the exchange of the best possible information.<p>The study suggested implications for organizational theory that could better enable administrators and staff to address this ill-structured problem. The isolation and lack of resources oblige staff to create conditions conducive to inquiry and learning (Schon 1983). In the case of initial solutions the theories in action were similar, suggesting that assumptions surrounding the role of contextual factors caused by the heterogeneous nature of the schools are misleading. Prior to the study by Godel et al. (2000) lack of diagnosis diffused the urgency of the problem. Following the publication of the data from that study the lack of screening and diagnosis was a major challenge to stakeholders. Generation of data on the children with FASD in northern communities is essential to generate an organizational and professional focus.