Research in hyperactivity has been primarily concerned with demon-strating casual relationships with cerebral dysfunction of the effects of drugs on improving learning performance. Studies which have attempted to focus on other factors influencing learning performance have demonstrated IQ and perceptual motor differences between hyperactive and normal children. More recently Koegel and Covert have shown that, among a group of autistic children, over-selectivity of components from stimulus complex may adversely influence learning performance on a simultaneous discrimination task. There have been no demonstrations of this phenomena with hyperactive children. The present study employed a simultaneous discrimination task composed of two stimulus complexes. Each complex in turn consisted of three geometric forms. Children were randomly selected, rated for activity level and then trained to respond reliably to specific complex. Once the discrimination to one of the complexes was established, the child was exposed to random pairs of components (one from the SD complex and one from the SΔ complex). Responses to either SD or SΔ were recorded. A significant relationship was found between over-selectivity for one or more SD components as a function of increasing activity level. Response errors were found to be related to selectivity but not to activity level. It would appear that performance deficits in learning a discrimination task may be, in part, related to over-selective focusing which results in failure to learn and hence, to integrate the entire stimulus complex.

The evolution of plant genomes is notable for manifesting a cycle of whole genome doubling, fractionation (gradual loss of redundant genes) and speciation. The thesis is based on a branching process model of the doubling and fractionation process, integrated with a standard model of sequence divergence. The immediate application of this work is to account for the distribution of sequence similarity for duplicate gene pairs, both within plant genomes and between two related plant genomes in terms of a cycle of polyploidization, fractionation and speciation. We derive a mixture distribution for duplicate gene pair similarities generated by speciation and/or repeated episodes of polyploidization. We account not only for the timing of these events in terms of local modes or peaks of the component distributions, but also their volume, or amplitude, and variance. We outline how to infer the parameters of the model. We illustrate with analyses of the distribution of homolog similarities in a number of plant families: Brassicaceae, Solanaceae and Malvaceae. To our knowledge, this is the first method to account for the volume of the component normals of a distribution of similarities, preliminary to an evolutionarily meaningful inference procedure. In addition, we solve the problem of identifying the ploidy level of a series of two or three polyploidizations by invoking the observed and predicted gene triple profiles for each model, i.e., by calculating the probability of the four types of triple with origins in one or the other event, or both.

<p>Syftet med uppsatsen är att analysera Gunnar Sjöbloms modell om programrealisering utifrån ett fall, Östersjömiljardprojektet, samt att följa upp modellen med aspekten om Multi-level governance. Detta görs med hjälp av tre frågeställningar. För att uppfylla syftet har jag med hjälp av en textanalys bearbetat material hämtat från Rikslex, Riksdagens arkiv, i form av propositioner, motioner, betänkande, och protokoll. Den teoretiska utgångspunkten har tagits ifrån Gunnar Sjöbloms modell som bygger på partistrategi i ett flerpartisystem. Partiernas främsta mål är att uppnå programrealisering. För att åstadkomma detta krävs inflytande på tre arenor: väljararenan, den interna arenan och den parlamentariska arenan.Östersjömiljardprojektet var ett förslag i sysselsättningspropositionen 1995 som byggde på att en miljard kronor skulle ingå i en fond avsatt för att främja svensk export inom områdena livsmedel, energi, ömsesidigt kunskapsutbyte, stärkt infrastruktur samt samarbete för att miljöskydd runt Östersjön. De områden som ingår i projektet är nordvästra Ryssland, Estland, Lettland, Litauen samt Polen. Resultatet visar att Sjöbloms modell är hållbar för det valda fallet. För att avgöra om det är ett fall av multi-level governance krävs ytterligare forskning på vilka påtryckningar utanför den politiska arenan som var betydande för beslutet.</p>

Objective: Utilizing a conceptual model of the impact of disasters on children╒s functioning, the current study examined unhealthy diet and sedentary activity levels of children exposed to Hurricane Ike. Exposure stressors (perceived and actual life threat) and recovery stressors (hurricane-related stressors and major life events), were hypothesized to be associated with unhealthy diet and sedentary activity. Exposure stressors, recovery stressors, and child demographic characteristics were also expected to be associated with posttraumatic stress (PTS) symptoms. It also was predicted that physical activity would attenuate the relationship between recovery stressors and children╒s PTS symptoms. Finally, the feasibility of collecting health behavior information from children was examined. Method: Utilizing a cross-sectional design, 204 children (51% girls; M age = 9.23, SD = .79; grades 3 and 4) from Galveston, Texas were evaluated 8 months after Hurricane Ike (Time 1). At Time 1, children completed self-report measures of traumatic experiences, major life events, PTS symptoms, height and weight, and health behaviors. 53 children were reevaluated two weeks later (Time 2) to examine the stability and validity of health-related measures. Children completed a second measure of their height, weight, and health behavior measures, and actual measurements of height and weight were also taken. Results: Consistent with expectations, exposure and recovery stressors were associated with sedentary activity and PTS symptoms. Exposure stressors were indirectly related to sedentary activity and PTS symptoms through recovery stressors. However, contrary to expectations, stressors were not associated with unhealthy diet. African American ethnicity, Hispanic ethnicity, and female gender were related to PTS symptoms through recovery stressors. Physical activity did not attenuate the relationship between recovery stressors and children╒s PTS symptoms. In terms of health behaviors, children╒s self-reported weight was both stable and valid from Time 1 to Time 2. Self-reported height was stable but invalid. Measures of children╒s unhealthy diet and sedentary activity showed moderate stability. The measure of physical activity exhibited low stability and low validity. Conclusions: Sedentary activity may be a particularly important health behavior to examine after disasters. Implications for schools, families, and future research are discussed. Alternative measures of physical activity should be considered.

This thesis analyses three aspects of the link between a woman’s educational trajectory and her childbearing behaviour. Special attention is paid to educational field as a further dimension of education next to educational enrolment and educational level. It is argued that this dimension has to be taken into account to fully understand the complex interplay between women’s educational careers and fertility. The empirical investigations are based on Swedish register data for the period 1990 to 2004 and carried out by means of event history analyses. Regarding the impact of women’s education on fertility, this study confirms that educational enrolment generally impedes childbearing. Further, in addition to differences in first, second and third birth risks among women with different levels of education, the analyses reveal strong variations in the fertility behaviour of women with different types of education. To investigate the impact of fertility on women’s educational careers, this study examines how becoming a mother influences a woman’s risk to pursue further training in a different field of education. The effect of motherhood on the risk of educational change varies strongly depending on the field Swedish women initially were trained in. Especially women with degrees in fields in which it is difficult to get established in the labour market are found to have a high risk of educational change. For these women giving birth to a child appears to lead them to strive for further training in a field that offers more stable and family friendly employment prospects. Finally, the study explores the impact of unobserved factors on education and fertility. By estimating a simultaneous hazard equation for a woman’s childbearing behaviour and her choice of educational field, it is shown that women’s decisions about education and fertility are correlated due to the existence of unobserved determinants that simultaneously influence both life domains.

Using x-ray absorption spectroscopy (XAS), x-ray emission spectroscopy (XES) and x-ray photoelectron spectroscopy (XPS) in combination with density functional theory (DFT) the changes in electronic and geometric structure of hydrocarbons upon adsorption are determined. The chemical bonding is analyzed and the results provide new insights in the mechanisms responsible for dehydrogenation in heterogeneous catalysis. In the case of alkanes, n-octane and methane are studied. XAS and XES show significant changes in the electronic structure upon adsorption. XES shows new adsorption induced occupied states and XAS shows quenching of CH*/Rydberg states in n-octane. In methane the symmetry forbidden gas phase lowest unoccupied molecular orbital becomes allowed due to broken symmetry. New adsorption induced unoccupied features with mainly metal character appear just above the Fermi level in XA spectra of both adsorbed methane and n-octane. These changes are not observed in DFT total energy geometry optimizations. Comparison between experimental and computed spectra for different adsorbate geometries reveals that the molecular structures are significantly changed in both molecules. The C-C bonds in n-octane are shortened upon adsorption and the C-H bonds are elongated in both n-octane and methane. In addition ethylene and acetylene are studied as model systems for unsaturated hydrocarbons. The validity of both the Dewar-Chatt-Duncanson chemisorption model and the alternative spin-uncoupling picture is confirmed, as well as C-C bond elongation and upward bending of the C-H bonds. The bonding of ethylene to Cu(110) and Ni(110) are compared and the results show that the main difference is the amount of back-donation into the molecular π* orbital, which allows the molecule to desorb molecularly from the Cu(110) surface, whereas it is dehydrogenated upon heating on the Ni(110) surface. Acetylene is found to adsorb in two different adsorption sites on the Cu(110) surface at liquid nitrogen temperature. Upon heating the molecules move into one of these sites due to attractive adsorbate-adsorbate interaction and only one adsorbed species is present at room temperature, at which point the molecules start reacting to form benzene. The bonding of the two species is very similar in both sites and the carbon atoms are rehybridized essentially to sp2.

No description available.

The purpose of the thesis was to explore the possibilities of using a Level-Set method to design a time-optimal path planar of a subject to direction-dependent maximum velocities. A promising application for such a planning approach lies in sailboat navigation planning, because of the dynamic ocean waves, current, wind and the characteristics of a sailboat. In the thesis, we developed an IOS application to simulate such scenario as environment properties with wind, static obstacles and the sailboat mapped into direction-dependent velocities in different locations of the environment.  Considering the wind is the main power for the sailboat, a wind speed generation function was created, based on different locations. The Level-Set method is widely used in image processing because of its various advantages, for instance, the ability to deal with topology change and stability. It also can be applied in path planning, in which the process of the Level-Set method can be considered as a continuous wave front propagating with a speed from the start location. A grid-based map was used to represent the environment. While the wave front was crossing the cell on the grid, a time was recorded for every cell, following the negative gradient direction of such crossing time, and then an optimal path could be found. In addition, we used the Narrow Band method to speed up the calculation of processing the level set equation. Finally, this report gives the results of the experiments of static obstacle avoidance, wind effects and smooth path planning.

Purpose: The purpose of this research program was three-fold. First it aimed to determine the effectiveness of smoking cessation interventions in increasing cessation rates in smokers with cerebrovascular disease and whether smoking cessation reduces stroke recurrence. Second it aimed to determine the prognostic influence of smoking and its association with stroke severity, disability, length of stay in hospital and mortality. Third it aimed to identify multi-level correlates of smoking cessation in Canadians who reported stroke symptoms in a large population based survey. Methods: Two systematic reviews and meta-analyses were performed to achieve the first objective. For the second objective, a retrospective cohort study was undertaken using variables from the Registry of the Canadian Stroke Network. Finally, the third objective was achieved by analyzing respondents from the Canadian Community Health Survey. Results: There is a paucity of intervention studies examining the effectiveness of smoking cessation in smokers with cerebrovascular disease. Most intervention studies that were found, failed to employ evidence-based approaches to smoking cessation. No evidence was found in regards to the effect of smoking cessation on stroke recurrence. We found smokers had strokes at a younger age compared to non-smokers. We found that in transient ischemic attacks and intracerbral haemorrhage, smoking was a significant predictor of stroke severity, disability, length of stay in hospital and 1 year mortality. Correlates of smoking cessation among Canadians who have experienced symptoms of a stroke included: higher education and income, implementation of household and vehicle smoking restrictions, access to a general practitioner and the use of smoking cessation pharmacotherapies and counselling support. Co-morbidities such as depression and alcohol consumption reduced the likelihood of successful cessation. Conclusions: This three-phase research program elucidated the gaps in intervention research for this population along with co-morbidities that hinder success in cessation. Smoking negatively impacted outcomes such as disability, hospital length of stay and mortality in patients with transient ischemic attacks and intracerebral haemorrhage strokes. Future interventions should take into account modifiable smoking cessation correlates in order to increase cessation rates in smokers with cerebrovascular disease.

Given the complexity and functionality of todays software, task-specific, system-suggested help could be beneficial for users. Although system-suggested help assists users in completing their tasks quickly, user response to unsolicited advice from their applications has been lukewarm. One such problem is lack of knowledge of system-suggested help about the users expertise with the task they are currently doing. This thesis examines the possibility of improving system-suggested help by adding knowledge about user expertise into the help system and eventually designing an expertise-sensitive help system. An expertise-sensitive help system would detect user expertise dynamically and regularly so that systems could recommend help overtly to novices, subtly to average and poor users, and not at all to experts.<p> This thesis makes several advances in this area through a series of four experiments. In the first experiment, we show that users respond differently to help interruptions depending on their expertise with a task. Having established that user response to helpful interruptions varies with expertise level, in the second experiment we create a four-level classifier of task expertise with an accuracy of 90%. To present helpful interruptions differently to novice, poor, and average users, we need to design three interrupting notifications that vary in their attentional draw. In experiment three, we investigate a number of options and choose three icons. Finally, in experiment four, we integrate the expertise model and three interrupting notifications into an expertise-sensitive system-suggested help program, and investigate the user response. Together, these four experiments show that users value helpful interruptions when their expertise with a task is low, and that an expertise-sensitive help system that presents helpful interruptions with attentional draw that matches user expertise is effective and valuable.