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Univ., Diss.--Bremen, 2005.

Thesis (S.M.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences and the Woods Hole Oceanographic Institution), 2001. / Includes bibliographical references (leaves 44-48).

Thesis (Ph.D.)--University of Wyoming, 2008. / Title from PDF title page (viewed on Mar. 8, 2010). Includes bibliographical references.

No description available.

As many variable pricing projects are still in the implementation stage, long-run driver responses to the variable tolls are largely unknown. This research examined the long-run changes in driver behavior in an existing variable pricing project in Lee County, Florida. Using empirical evidence, it was found that over time the price elasticities of demand on the Lee County toll bridges have decreased from -0.42 to - 0.11 (Midpoint Memorial Bridge) and from -0.31 to -0.06 (Cape Coral Bridge) during the early morning discount period. The elasticities have decreased, but to a lesser extent, during the late morning and early afternoon discount periods. A discount period volume spreading ratio was also developed to analyze these changes. The results from this analysis confirmed the elasticity results. In addition to the empirical analysis of travel patterns discussed above, a telephone survey of drivers was conducted. The survey results indicated that certain driver characteristics such as higher frequency of trips, commute trip purpose, full-time employment status, more people in the household, higher education, and age between 25-34 years, were all indicators that the participant may increase his or her variable pricing usage over time. Other characteristics, including being retired and having a household income less than $16,000, were indicators that the driver may not increase variable pricing participation. Binary logit and semiparametric models were also developed to examine socio-economic and commute characteristics that may influence a driver increasing his or her participation in a variable pricing program. The results from these two variable toll bridges in Lee County indicated a decrease in variable toll price elasticity over time. However, these results may not be typical for variable pricing projects. Factors such as alternative routes, different traveler demographics, traffic congestion levels, and size of the toll discount may influence the results obtained from other variable pricing projects. However, the methodology developed in this research can be applied to other projects in order to determine those toll price elasticities of demand.

CD45 is a protein tyrosine phosphatase that is expressed on all nucleated hematopoietic cells. The major substrates of CD45 in thymocytes and T cells are the Src family kinases Lck and Fyn. The role of CD45 in thymocyte development and T cell activation via its regulation of Src family kinases in T cell receptor signaling has been studied extensively. However, the role of CD45 in processes that affect thymocyte development prior to the expression of the T cell receptor has not been explored. The overall hypothesis of this study was that CD45 is a regulator of spreading, migration, proliferation, and differentiation of early thymocytes during development in the thymus and the absence of CD45 would alter the outcome of thymocyte development. The first aim was to determine how CD45 regulates CD44-mediated signaling leading to cell spreading. The interaction between CD44 and Lck was first examined. CD44 associated with Lck in a zinc-dependent and a zinc-independent manner. Mutation analysis localized the zinc-dependent interaction to the membrane proximal region of CD44, but did not involve individual cysteine residues on CD44. CD44 and Lck co-localized in microclusters upon CD44-mediated cell spreading. CD45 co-localized with Lck and CD44 in microclusters and with F-actin in ring structures. The recruitment of CD45 to microclusters may be a mechanism of how CD45 negatively regulates CD44-mediated spreading. The second specific aim was to determine the role of CD45 in migration, proliferation, and progression and differentiation of early thymocytes. CD45 negatively regulated CXCL12-mediated migration, and positively regulated the proliferation and progression of CD117- DN1 thymocytes. Absence of CD45 led to an altered composition of thymic subsets. The CD45-/- thymus contained decreased numbers of ETPs and an aberrant CD117- DN1 population that lacked CD24, TCRbeta, and CCR7 expression. There were also increased thymic NK and gamma/delta T cells, but decreased NKT cells. In addition, a novel intermediate between DN1 and DN2 that required Notch for progression was identified. Overall, this study identified new roles for CD45 in early thymocytes and provided a better picture of how the development of T cells, a central component of the immune system, is regulated.

One of the most important indicators that characterize moral and social position of a state is criminality. Violence or compulsion, especially against children, have already become one of the most painful problems in our society. Respect to a person’s life and the surrounding world, health, or views, like many other human values, have lost their real value, not only in terms of a separate individual and family, but also in the behaviour and consciousness of all society. However, it can be clearly defined that punishing a child by physical punishments leads him to the other status in society, i.e. lower than of adults. This paper deals with the spreading of violence against children in Kėdainiai. The theoretical part presents the definitions of violence and compulsion. The second part concentrates on the forms of agression and the display of them. The third part outlines the factors which influence violence and compulsion. The fourth part discusses the existing situation in Kėdainiai, and finally, the fifth part presents the ways of violence prevention and provides suggestions how to improve the existing situation. In order to try to stop violence against children, it is necessary to explain actively the phenomena of violence to the society and the children themselves, change the traditional opinion of the society, by stressing the fact that violence and compulsion in a family and society are not only the matters of the family. The view of the society towards children is... [to full text]

Spreading depression (SD) is an interesting and important phenomenon due to its role in mammalian pathologies such as migraine, seizures, and stroke. Until recently investigations of the mechanisms involved in SD have mostly utilized mammalian cortical tissue, however in my thesis I demonstrated that SD-like events occur in the CNS of an invertebrate model, Locusta migratoria. Locusts enter comas in response to stress during which neural and muscular systems shut down until the stress is removed, and this is believed to be an adaptive strategy to survive extreme environmental conditions. Using the ventilatory central pattern generator (vCPG) as a model circuit I was able to show that stress-induced arrest of vCPG function is associated with SD-like events in the locust metathoracic ganglion (MTG) that closely resemble cortical SD (CSD) in many respects, including mechanism of induction, extracellular potassium ion ([K+]o) changes, and propagation in areas equivalent to mammalian grey matter. SD-like events in the locust were characterized as abrupt [K+]o increases associated with electrical activity silence in the locust CNS that propagate to other areas within the MTG. In this thesis I described the generation of comas by several cellular stressors (hyperthermia, metabolic stressors, Na+/K+-ATPase inhibition, and KCl) and the associated SD-like events in the locust, provide a description of the similarities to CSD, and show how they can be manipulated both by stress preconditioning and pharmacologically. I showed that hyperthermic vCPG arrest can be preconditioned by prior heat shock (HS) treatment and induced-thermotolerance was associated with an increased rate of [K+]o clearance associated with vCPG recovery that was not linked to changes in ATP levels or total Na+/K+-ATPase activity. I also provided evidence for the involvement of the stress-sensor AMP-activated protein kinase (AMPK) in stress-induced comas in the locust. AMPK activation was linked to a switch in motor pattern behavior following recovery from anoxia-induced vCPG arrest and exacerbated repetitive SD-like events induced by ouabain (Na+/K+-ATPase inhibitor). I suggested that locust SD-like events are adaptive by conserving energy and preventing cellular damage, and I provided a model for the mechanism of SD onset and recovery in the locust nervous system. / Thesis (Ph.D, Biology) -- Queen's University, 2010-08-05 16:08:19.905

Thesis (Ph. D.)--University of Hawaii at Manoa, 2005. / Includes bibliographical references (leaves 150-166). / Also available by subscription via World Wide Web / xv, 166 leaves, bound col. ill., col. maps (1 fold.) 29 cm