The Escherichia coli small RNA (sRNA) MicA was identified recently in a genomewide search for sRNAs. It is encoded between the genes gshA and luxS in E. coli and its close relatives. The function of sRNAs in bacteria is generally believed to be in maintenance of homeostasis via stress-induced modulation of gene expression. Our studies on MicA have been aimed at attributing function(s) to this molecule. We carried out high throughput assays aimed at identifying genes that are differentially regulated upon knocking out or overexpressing MicA. Among the protein candidates identified was the outer membrane protein, OmpA. Subsequent analysis allowed us to show this regulation to be antisense in nature with MicA binding within the translation initiation region of ompA mRNA. Furthermore, blocking the ribosome from loading caused a translational decoupling that instigates degradation of the mRNA. The regulation was apparent in early stationary phase and seen to be dependent on the RNA chaperone Hfq. We went on to characterize the regulation of MicA, looking at its own transcription. Testing various stress conditions, we were able to identify putative promoter elements that we confirmed using transcriptional fusions. The results showed MicA to be dependent on the extracytoplasmic function ECF sigma E (σE) and could not detect MicA in mutants deleted for this factor. Lastly, we identified an additional target for MicA being the adjacently encoded luxS mRNA. The LuxS protein is essential for the synthesis of the quorum sensing AI-2 molecule. Transcription of the luxS mRNA is commences within the gshA gene, on the other side of MicA coding region. We were able to show that MicA interacts with luxS mRNA and is recognized by RNase III which processes this complex leading to a shorter luxS mRNA isoform. The significance of this processing event is as yet undetermined. Our data elucidated a new promoter driving transcription of luxS, and we demonstrated this promoter to be stationary phase responsive. In summary, the work presented here characterizes the sRNA MicA as a dual regulatory sRNA molecule, moonlighting between its cis-encoded target and its trans-encoded target. .

In this thesis we study the standard probabilistic model for hashing with linear probing. The main purpose is to determine the asymptotic distribution for the maximum displacement. Depending on the ratio between the number of items and the number of cells, there are several cases to consider. Paper I solves the problem for the special case of almost full hash tables. That is, hash tables where every cell but one is occupied. Paper II completes the analysis by solving the problem for all remaining cases. That is, for every case where the number of items divided by the number of cells lies in the interval [0,1]. The last two papers treat quite different topics. Paper III studies the area covered by the supremum process of Brownian motion. One of the main theorems in Paper I is expressed in terms of the Laplace transform of this area. Paper IV provides a new sufficient condition for a collection of independent random variables to be negatively associated when conditioned on their total sum. The condition applies to a collection of independent Borel-distributed random variables, which made it possible to prove a Poisson approximation that where essential for the completion of Paper II.

The energy dependent response of silicon diodes in photon beams is a known problem. A new approach to solve this problem is by correcting the response, a response model was suggested by Yin et al. (2002, 2004), and later refined by Eklund and Ahnesjö (2009). In this work a prototype software was developed to calculate correction factors for arbitrary measurement points in MLC shaped fields using fluence pencil beam kernels to calculate the spectra used by the model of Eklund and Ahnesjö (2009). This work investigate this approach for large field sizes. It was found that the relative dose measurements of the corrected unshielded diode agreed with ionization chamber measurements within 1% at the central axis. Measurements made off axis (square and irregular fields) agreed within 2%, better results were achieved within the fields when the off axis beam softening were taken into consideration. This work has also shown that this new approach is an alternitive to shielded diodes and that corrected diodes will in some cases provide more reliable results.

The efficient market hypothesis (EMH) has long been perceived as the cornerstone of modern finance theory. However, the EMH has also recently been dismissed as "the most remarkable error in the history of economic theory" (Wall Street Journal, Oct. 23. 1987). Most of the early research was concerned with detecting the efficiencies or inefficiencies by autocorrelation tests, run tests, and filtering tests. In general, the inefficiencies detected are relatively small. Recently, however, there has been an explosion of research activity to detect inefficiencies in the general area which we call "nonlinear science". This dissertation aims at the applications of these kinds of new methodologies to the Swedish stock market and the Korean stock market. This dissertation consists of 8 chapters. Chapter 1 reviews the challenges to stock market efficiency, and chapter 2 criticizes traditional financial models and assumptions for the EMH tests. Chapter 3 discusses the sample data. In chapter 4, the estimated results under the product process model are presented. Chapter 5 is focused on the low power spectrum law. The power exponent is calculated for the samples. In chapter 6, the types of patterns (memory) are uncovered by Rescaled range (R/S) analysis. Chapter 7 deals with the market inefficiency arising from nonlinear dynamical systems theory. The BDS test for detecting nonlinear dependence is applied to the sample markets. Finally, chapter 8 summarizes the conclusions. / Diss. Stockholm : Handelshögsk.

The dynamic behaviour in the audible frequency range of magneto-sensitive (MS) rubber is the focus of this thesis consisting of five papers A-E. Paper A presents results drawn from experiments on samples subjected to different constant shear strains over varying frequencies and magnetic fields. Main features observed are the existence of an amplitude dependence of the shear modulus referred to as the Fletcher-Gent effect for even small displacements, and the appearance of large MS effects. These results are subsequently used in Paper B and C to model two magneto-sensitive rubber isolators, serving to demonstrate how, effectively, by means of MS rubber, these can be readily improved. The first model calculates the transfer stiffness of a torsionally excited isolator, and the second one, the energy flow into the foundation for a bushing inserted between a vibrating mass and an infinite plate. In both examples, notable improvements in isolation are obtainable. Paper D presents a non-linear constitutive model of MS rubber in the audible frequency range. Characteristics inherent to magneto-sensitive rubber within this dynamic regime are defined: magnetic sensitivity, amplitude dependence, elasticity and viscoelasticity. A very good agreement with experimental values is obtained. In Paper E, the magneto-sensitive rubber bushing stiffness for varying degrees of magnetization is predicted by incorporating the non-linear magneto-sensitive audio frequency rubber model developed in Paper D, into an effective engineering formula for the torsional stiffness of a rubber bushing. The results predict, and clearly display, the possibility of controlling over a large range through the application of a magnetic field, the magneto-sensitive rubber bushing stiffness. / QC 20100816

Alkoholkonsumtion och narkotikaanvändning ökar i världen idag och leder till konsekvenser för den somatiska sjukvården då patienter med missbruksproblematik blir mer vanligt förekommande. Personer med missbruksproblematik upplever sig ofta som tillhörande en stigmatiserad grupp och mötet med vården som något negativt. Syftet med studien var att undersöka upplevelser av mötet med vården hos patienter med missbruksproblematik. Litteraturstudien baseras på 11 vetenskapliga artiklar som analyserades. I resultatet framkom 3 kategorier, negativa upplevelser i mötet med vården, barriärer till att söka vård samt positiva upplevelser i mötet med vården. Stigmatisering och att bli annorlunda behandlad var negativa upplevelser av vården och även barriärer till att söka vård. God vård beskrevs främst som att ha en god relation till vårdaren och då missbruket sågs som en sjukdom istället för ett personligt misslyckande. En ökad kunskap skulle kunna eliminera de fördomar och den stigmatiserade syn som existerar gentemot denna patientgrupp. Det skulle kunna möjliggöras genom att medicinsk utbildning inom området blev obligatorisk för vårdpersonal. Vidare skulle kvantitativ forskning kunna bidra med resultat för ökad generaliserbarhet. / Alcohol consumption and drug abuse are increasing around the world today. This leads to consequences for somatic health care when patients with substance abuse disorders gets more common. People living with an addiction often experience themselves as belonging to a stigmatized group and their interaction with health care as something negative. The purpose of this study was to examine experiences of health care among substance abusers. The literature study was based on 11 scientific articles that were analyzed. In the result 3 categories emerged, negative experiences in the interaction with health care, barriers to health care seeking and positive experiences in the interaction with health care. To be stigmatized and treated differently was negative experiences from health care and even a barrier to health care seeking. High quality care was mostly described as having a good relation with the health care provider and when the substance abuse was seen as a disease, not a personal failure. An increased knowledge could eliminate the prejudices and the stigmatization that exists toward this group of patients. This could be made by making the education about this subject compulsory to health care staff. Furthermore quantitative research could contribute with a result to an increased generalization.

Syftet med studien var att öka kunskapen om och förståelsen för hiv-smittade narkomaner i kriminalvård. Den övergripande frågeställningen löd; Hur beskriver ett mindre urval av hiv-smittade narkomaner i föremål för kriminalvård sina tankar och känslor kring sin sjukdom och sin livssituation? Studien var av kvalitativ design och den vetenskapliga positionen av hermeneutisk karaktär. Det empiriska materialet bestod av intervjuer med fem hiv-smittade narkomaner i kriminalvård. Tre teman var grundläggande i intervjuerna; Tankar, känslor och reaktioner kring hiv-diagnosen, Existentiella frågor, drivkraft och copingstrategier samt Bemötande i och utanför kriminalvården. Studiens teoretiska perspektiv; kristeori, existentialistisk teori, upplevelseteori och hälsoteori, valdes i syfte att nå en ökad förståelse för intervjupersonernas upplevelse av sin livssituation. Studiens resultat och analys visade att hiv-smittan fått olika konsekvenser för de intervjuade. För tre personer blev livet bättre genom sjukdomen; två av dem menade att de annars skulle varit döda. För de övriga två innebar sjukdomen i stället att döden kommit närmare och grusat alla förhoppningar om ett bättre liv. Tolkningen visade att en möjlig förklaring till de olika förhållningssätten kunde bero på skillnader i vilken inre privat betydelse sjukdomen haft för de intervjuade, samt i vilken mån de lyckats komma igenom krisen.

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In this paper, I examine the existence and roles of state dependence and switching costs in the mass transition from MySpace to Facebook during the 2007-2008 time period. Using a dataset that compiles individual browsing behavior and a discrete multinomial logit model, I find precise, yet extremely small amounts of state dependence for users of only MySpace, of only Facebook, and users of both MySpace and Facebook. Positive state dependence directly implies the existence of switching costs for each firm. While there is an abundance of literature regarding switching costs in the brick and mortar setting with tangible products and services, my work extends similar analysis to the relatively new online, social networking industry by studying consumer usage trends of the two networking powerhouses: MySpace and Facebook.

The extensive suffering related to a complex life situation with bipolar disorder and the reported difference between care needs and the needs that are actually met implicates that there are still questions about management of life with bipolar disorder that need to be answered. The present study therefore aims to describe the meaning of the conditions that enable a good life with bipolar disorder. Ten persons, six women and four men, (aged 30 – 61), diagnosed with bipolar disorder were interviewed. A reflective lifeworld perspective based on phenomenological philosophy was used. The findings present the essential meaning of the conditions that enable a good life with bipolar disorder as a dependence that empowers, which is further described by its constituents: “turning the course of life”, “protecting oneself from running out of energy”, “being needed”, “being oneself through reliable others”, “personal landmarks for navigating through life”. A voluntary chosen dependence, as described in the present study, is a new approach of care that enables a good life with bipolar disorder, while enhancing own power, freedom and control. The conditions that enable a good life with bipolar disorder are more than separate supporting measures. Therefore a holistic perspective is preferable while providing care for individuals with bipolar disorder.