For much of America's history, a certain fascination has existed in American culture with the lifestyle of the woodsman who made the hardwood wilderness his home. over time this fascination has given birth to a collection of romantic traits firmly identified with such a frontiersman. The requirements for survival in a deep wilderness forced the pre-American Revolution era woodsman turned long hunter, to be "Indian," to demonstrate a high level of marksmanship, and ultimately to draw most of his needs from the bounty of the forest. Such requirements tended to promote the popular conceptions surrounding the eastern frontiersman. Looking beyond those legendary traits, though, such a lifestyle was often an uphill path made only steeper by a rather monotonous diet, days spent in endless and mundane labor, and the threat of perpetual warfare born of political forces beyond his control.

As there were few studies of older husbands’ experiences associated with providing care at home for spouses with dementia, the researcher designed a two-stage study to examine their experiences, In stage one, a qualitative paradigm guided one-to-one interviews with sixteen care giver husbands to examine their care giving experiences. Analysis of the interview data guided the identification of four models of care giving related to the past, present and future and an overall model over time. In stage two, a comprehensive questionnaire was developed and questionnaire items were identified from multiple sources. In stage two the researcher utilized a quantitative approach to identify to investigate husbands’ experiences. A representative sample of 71 care giver husbands participated by completing the questionnaire and standardized measures of burden and depression along with other measures of husbands’ characteristics and experiences and levels of wives’ illness and associated behaviour. Predictive models of care giver burden were care giving seen as a ‘job’, effects of care giving on the husband-wife relationship, and use of avoidant-evasive coping strategies by husbands. The best predictive models of care giver depression were use of avoidant-evasive coping strategies and changes in husbands’ emotional health status related to care giving. / Doctor Of Philsophy (PhD)

Long-range dependence in discrete and continuous time Markov chains over a countable state space is defined via embedded renewal processes brought about by visits to a fixed state. In the discrete time chain, solidarity properties are obtained and long-range dependence of functionals are examined. On the other hand, the study of LRD of continuous time chains is defined via the number of visits in a given time interval. Long-range dependence of Markov chains over a non-countable state space is also carried out through positive Harris chains. Embedded renewal processes in these chains exist via visits to sets of states called proper atoms. Examples of these chains are presented, with particular attention given to long-range dependent Markov chains in single-server queues, namely, the waiting times of GI/G/1 queues and queue lengths at departure epochs in M/G/1 queues. The presence of long-range dependence in these processes is dependent on the moment index of the lifetime distribution of the service times. The Hurst indexes are obtained under certain conditions on the distribution function of the service times and the structure of the correlations. These processes of waiting times and queue sizes are also examined in a range of M/P/2 queues via simulation (here, P denotes a Pareto distribution).

<p>The background to the thesis is the high rate for sickness absence in Sweden since the end of the 1990s. In an international perspective, the Swedish sickness absence appears exceptionally high. This can appear paradoxical bearing in mind the high standard of living and the high average length of life in Sweden, and there is much to indicate that complex causal correlations are involved.</p><p>The overall aim of the thesis is to study and analyse the return to work or transition to disability pension, for persons on long-term sick leave from their own perspective. The focus of the thesis is the individual in a social context.</p><p>The theoretical frame of reference is within medical sociology and is about sickness concepts and models and on medicalisation. The concept of work capacity is also taken up based on the concepts of disability and impairment.</p><p>The empirical material consists of four studies. Two of these are qualitative interview studies with women. One of them (I) is about Greek women who have been granted Swedish disability pension. The aim of this study is to find explanations why such a large number of Greek women have become disability pensioners in Sweden. The analysis indicated some important factors: the doctors, the family and the social insurance system. The women had unclear psychosomatic complaints, which had been medicalised. The other qualitative study (IV) concerned women who after sick leave and rehabilitation succeeded in returning to work. It was seen to be strong and stubborn women who had to struggle to get back to working life. They had also been well taken care of in rehabilitation.</p><p>The other two studies (II and III) are quantitative, prospective cohort studies with persons on sick leave with unspecified back and neck complaints. One main aim of one study (III) was to investigate the importance of motivation for rehabilitation and return to work. Two specially designed forms were used. It was seen, among other things that the forecasts of the person on sick leave on return to work coincided quite well with a follow-up two years later. One important result was that those who had undergone rehabilitation measures had returned to work to a much lesser extent than those who had not.</p><p>Overall, the results showed the importance of listening to the individual and taking their own assessments of obstacles and possibilities in the rehabilitation process into consideration. The results in study III indicated that rehabilitation had not been sufficiently effective and in many cases did not lead to a return to work.</p>

<p>There is a body of research on the effect of physical activity oncognition in the old adult population. Less research areconducted on adolescents. The aim for this study is to find out ifadolescents long-term memory is affected by physical activity.144 pupils were asked to rate their physical activity each week.Thereafter their long- term memory was tested through tests onepisodic- and semantic memory. The results showed that thosewho are physically active more than 4 hours had a better scoreon part of the semantic test but no effect was found in theepisodic test. This result indicates that physical activity not onlyaffects working memory, as was shown by previous research butalso has an effect in parts of the semantic long-term memory.</p>

This study explored the influence of motivations on the volunteer experience. The relationship among motivations. volunteer satisfaction, acceptance and support of the organizational goals, and outcomes of success in the volunteer role (pattern of participation and ombudsman effectiveness) were explored using Multiple Linear Regression analyses. Motivational Systems Theory (Ford, 1992) was applied to the investigation of relationships among these variables. It was proposed that alignment between the individual volunteer's motivations and the organization's goals should predict higher levels of satisfaction, organizational commitment, and success. Psychological aspects of the volunteer experience proved valuable to the explanation of certain indicators of success in the Ombudsman role. The rates of case reporting and the time devoted to the Ombudsman role seemed to be influenced by the importance of particular motivations toward volunteerism, the extent to which these motivations are fulfilled by involvement with the Ombudsman program, and the commitment expressed toward the organization. Communal (offering) motivations were rated among the most important for the majority of volunteers. However, satisfaction scores were higher for both agentic and affiliation motivational factors than for the communal motivational factor. Overall, Ombudsmen were least motivated by motivations characterized as agentic or self-oriented. Volunteers with lower importance ratings for agentic motivations had moderately higher reporting rates than did participants attributing less importance to self-oriented motivations. Volunteers expressed high levels of organizational commitment and overall satisfaction in the role. The more committed these participants were to the organization, the more likely they were to experience satisfaction in their roles, and the more likely they were to express high levels of importance for all factors of motivation in this model. A significant effect was found for the influence of organizational commitment on time commitment, case reporting, and the frequency of visits. Motivational Systems Theory was found to be a useful framework for analyzing the effects of personal characteristics and psychological aspects of the volunteer experience on success and satisfaction in the Ombudsman role. / Graduation date: 2000

The computational ability of principal neurons and interneurons in the brain and their ability to work together in concert are thought to underlie higher order cognitive processes such as learning, memory, and attention. Dendrites play a very important role in neuronal information processing because they receive and integrate incoming input and can undergo experience-dependent changes that will alter the future output of the neuron. Here, I have used whole-cell patch clamp recordings and fluorescent Ca2+-imaging to examine the modulation of dendritic excitability in principal neurons of the rat and human hippocampus and neocortex. First, I determined that dendrites of dentate granule cells of the hippocampus are tuned to high frequencies of both afferent input and backpropagating action potentials. Under these conditions they are also capable of generating regenerative dendritic activity that can propagate to the soma, which is prone to modulation. In particular, Neuropeptide Y (NPY) Y1 receptors can decrease frequency-dependent dendritic Ca2+ influx. Dopamine D1 receptors (D1Rs) have an opposite effect; they potentiate frequency-dependent dendritic excitability. These two neuromodulators also have an opposing effect on plasticity, with dopamine acting to induce, and NPY acting to inhibit long-term potentiation (LTP). Parallel observations of D1-induced LTP and an NPY-mediated decrease in dendritic excitability in rodents were complemented by findings in human dentate granule cells. Second, I examined the role of NPY receptors on dendrites of layer 5 pyramidal neurons. In these neurons I found that NPY acts post-synaptically on distal dendrites via the Y1 receptor to inhibit frequency-dependent Ca2+-currents, similar to the findings in dentate granule cells. NPY also decreased regenerative Ca2+ currents caused by the appropriate pairing of pre- and post-synaptic input. Together, these observations demonstrate that the role of NPY in the hippocampus and neocortex is not solely as an anti-epileptic agent. NPY release, likely to occur during high frequency oscillatory activity, can act locally to limit dendritic excitability, which can have a profound effect on plasticity. In the dentate gyrus, NPY can inhibit a D1R induced increased dendritic excitability and resultant changes in synaptic strength. These findings will further the understanding of dendritic information processing in the hippocampus and neocortex.

Based on Self-Determination Theory (e.g., Deci & Ryan, 1985a, 2000; Ryan & Deci, 2002) this research focused on the motivation of ten elite Ethiopian male and female long distance runners. The semi-structured interview guide based on the SDT was transcribed verbatim and subjected to an inductive-deductive analysis approach based on the methodological guidance provided by Maykut & Morehouse (1994). Results revealed the integrated type of motivation to be the most evident among the runners. The data were organized into three broad categories that emerged through the interviews. The three categories are nationalism, economics and fame. Within each category there are themes or subcategories that emerged across various perceptions of the Ethiopian runners. The data revealed that among different types of motivation classified by the Self-Determination Theory (e.g., Deci & Ryan, 1985a, 2000; Ryan & Deci, 2002) there are multiple social factors that influence Ethiopian runners as well.

An analytical and experimental study of boundary gravity currents propagating through a two-layer stratified ambient of finite vertical extent is presented. The theoretical discussion considers slumping, supercritical gravity currents, i.e. those that generate an interfacial disturbance whose speed of propagation matches the front speed, U and follows from the classical analysis of Benjamin [J. Fluid Mech. 31, pp. 209-248, 1968]. In contrast to previous investigations, the amplitude of the interfacial disturbance is parameterized so that it can be determined straightforwardly from ambient layer depths. The theoretical model, which is applicable to the special case where the depth, D, of the gravity current fluid at the initial instant spans the channel depth, H, shows good agreement with experimental measurements and also analogue numerical simulations performed in conjunction with the present investigation. Unfortunately, it is difficult to extend our theoretical results to the more general case where D < H. Reasons for this difficulty will be discussed. From experimental and numerical observations, the interface thickness is observed to negligibly affect the speed of supercritical gravity currents even in the limit where the interface spans the channel depth so that the ambient fluid is linearly stratified over the whole of its depth. Conversely, subcritical gravity currents show a mild upward trend of U on the interface thickness. Finally, the effects of densities, ambient depths, interface thickness and D on the horizontal position, X where deceleration first begins are considered. In contrast to the uniform ambient configuration, the gravity current can propagate without decelerating beyond 12 lock lengths and decelerate as early as 1 lock length. / Thermo Fluids

Sound transmission through a fluctuating deep ocean environment is considered. It is assumed that the environment consists of a range-independent background, on which a small-scale perturbation, due for example to internal waves, is superimposed. The modal description of underwater sound propagation is used extensively. The temporal spread of modal group arrivals in weakly range-dependent deep ocean environments is considered. The phrase "modal group arrival" refers to the contribution to a transient wavefield corresponding to a fixed mode number. It is shown that there are three contributions to modal group time spreads which combine approximately in quadrature. These are the reciprocal bandwidth, a deterministic dispersive contribution, and a scattering-induced contribution. The latter two contributions are shown to be proportional to the waveguide invariant beta, a property of the background sound speed profile. The results presented are based mostly on asymptotic theory. Some extensions of the asymptotic modal theory are developed. These theoretical results are shown to agree well with full-wave numerical wavefield simulations and available exact mode theoretical results. Theoretical predictions of modal group time spreads are compared to estimates derived from data that was collected during the 2004 LOAPEX experiment. The effects of deficiencies in the receiving array on estimates of modal group time spreads are discussed. It is shown that in spite of array deficiencies in the LOAPEX measurements it is possible to estimate modal group time spreads for almost all propagating modes and these estimates agree well with results obtained from numerical simulations and the developed theory. The effect of ocean internal waves on sound speed fluctuations is also considered, motivated by the observation that the amount of energy being scattered along the propagation path is sometimes greater in the experimental data than predicted by numerical simulations and theory. It is shown that the usual assumption that the potential sound speed gradient is proportional to the squared buoyancy frequency is often not a good approximation.