En esta memoria se presenta la identificación y posterior estudio de las características cinéticas, estructurales y funcionales de dos nuevas alcohol deshidrogenasas de Saccharomyces cerevisiae con actividad dependiente de NADP(H). Ambos enzimas, que comparten un 64% de identidad, pertenecen a la superfamilia de alcohol deshidrogenasas de cadena media que unen zinc. Este trabajo se ha estructurado en capítulos en base a la publicación de los datos presentados. En el Capítulo I se presenta la identificación y caracterización de Adh6p con dos publicaciones referentes a la identificación del ORF YMR318C como el gen ADH6 y la siguiente determinación de las propiedades fisicoquímicas y cinéticas de Adh6p. Se trata de una proteína homodimérica compuesta por subunidades de 40 kD, activa con alcoholes primarios o aldehídos en presencia de NADP(H). En el Capítulo II se presenta la identificación y caracterización de Adh7p con una publicación en la que se identifica al ORF YCR105W como el gen ADH7. Las propiedades fisicoquímicas y cinéticas de Adh7p resultaron muy similares a las ya encontradas para Adh6p, ambas proteínas presentaban una amplia especificidad de sustratos, desde alcoholes/aldehídos alifáticos lineales y ramificados hasta alcoholes/aldehídos aromáticos. Tanto Adh6p como Adh7p son más eficientes para la reducción de aldehídos que para la oxidación de sus correspondientes alcoholes (aproximadamente 50-100 veces), por lo que preferentemente funcionaran como reductasas dependientes de NADPH. También se clasifica a estas dos alcohol deshidrogenasas como miembros de la familia de las cinamil alcohol deshidrogenasas, y dadas sus características de secuencia y de especificidad de sustrato, se las clasifica más concretamente dentro de la subfamilia de las CAD-emparentadas. En el Capítulo III se presenta la estructura tridimensional de Adh6p como publicación. La resolución de dicha estructura reveló el patrón característico de las ADHs de cadena media: la subunidad de Adh6p está estructurada en dos dominios, uno estructural y otro de unión al cofactor, separados por una profunda hendidura que aloja el centro de unión a sustrato. También se han identificado los dos iones de zinc, uno con función estructural coordinado por cuatro cisteínas (cisteínas 100, 103, 106 y 113) y otro con función catalítica, coordinado por la His68 y las Cisteínas 46 y 143, siendo el cuarto ligando una molécula de agua que será desplazada por el sustrato en la catálisis. La resolución de la estructura ha permitido identificar los residuos implicados en la unión al coenzima y al substrato. Los datos estructurales obtenidos ponen de manifiesto una heterogeneidad en la unión al coenzima. Al parecer, sólo una de las dos subunidades de Adh6p presenta una alta afinidad por el cofactor, datos que han sido ratificados por estudios de cuantificación de la estequiometría de la unión Adh6p-NADPH. Los datos obtenidos nos han permitido realizar una hipótesis sobre su mecanismo catalítico, que al parecer presenta 'half-of-the-sites reactivity'. En el Capítulo IV se presentan estudios no publicados sobre la función de Adh6p y Adh7p en la levadura. Se ha estudiado la implicación de estos enzimas en la asimilación de productos procedentes de la degradación de la lignina. Los estudios realizados demuestran que Adh6p es la responsable de la desintoxicación de estos productos. Adh7p también tendría un papel en la asimilación de estos aldehídos, pero sería tan solo un papel de apoyo. Los estudios realizados en condiciones de estrés oxidativo demuestran que Adh6p participa en la respuesta al estrés oxidativo. También se ha demostrado que Adh6p es la responsable de la reducción del 3-metilbutanal en la levadura. Finalmente, en estudios comparativos de la cepa silvestre con la cepa adh1? han demostrado la implicación de Adh6p en el mantenimiento intracelular del balance redox NADP+/NADPH. / In this Thesis we present the identification of two new NADP(H)-dependent alcohol dehydrogenases from Saccharomyces cerevisiae and the study of their kinetic, structural and functional properties. Both enzymes share a 64% identity and belong to the zinc-containing medium chain alcohol dehydrogenase superfamily. These studies have been structured in four different chapters. In Chapter I we present the identification and characterization of Adh6p. This chapter contains two publications that refer to the identification of YMR318C ORF as ADH6, and the determination of the physicochemical and kinetic properties of the corresponding gene product, Adh6p. The enzyme is a homodimeric protein composed of 40 kD subunits, active towards primary alcohols or aldehydes using NADP(H) as coenzyme. In Chapter II, the identification and characterization of Adh7p is presented with one publication where the YCR105W ORF is identified as ADH7. Physicochemical and kinetic properties of Adh7p resulted quite similar to those from Adh6p. Both enzymes had a broad substrate specificity, ranging from linear and branches aliphatic alcohols/aldehydes to aromatic alcohols/aldehydes. Adh6p and Adh7p present catalytic efficiency for the reduction of aldehydes 50-100 times higher than the corresponding oxidation of alcohols, therefore, these enzymes would preferently function as NADPH-dependent reductases. These enzymes have been classified as alcohol dehydrogenases belonging to the cinnamyl alcohol dehydrogenase family. Given their sequence characteristics and their substrate specificity, their have been identify as members of the CAD-related subfamily. In Chapter III the resolution of the three-dimensional structure of Adh6p is introduced as a publication. The solved structured revealed the MDR characteristic patterns: Adh6p is structured in two domains, a structural domain and a binding cofactor domain, separated by a deep cleft that would contain the substrate binding site. We have identified two zincs per subunit, one with structural function coordinated by four cysteins (Cys100, Cys103, Cys106 and Cys113) and the other with catalytic function coordinated by His68 and Cysteins 46 and 143, being the fourth ligand a water molecule that would be displaced by the substrate during the catalytic cycle. The structure resolution has allowed us to identified the residues involved in coenzyme and substrate binding. The structural data obtained manifest and heterogeneity in coenzyme binding, where only one of the binding sites would present a high affinity for the coenzyme. This hypothesis is supported with stoichiometric quantification of Adh6p-NADPH binding experiments and has lead us to propose that Adh6p would present 'half-of-the-sites reactivity'. In Chapter IV we present not published studies about the function of Adh6p and Adh7p in the yeast. We have studied the implication of both enzymes in the assimilation of byproducts derived from ligninolysis. The result obtained show that Adh6p is responsible for the detoxification of this toxic products. Adh7p would help in this detoxification. The studies performed in oxidative stress conditions suggest that Adh6p is involved in oxidative stress response in yeast. We have also demonstrate that Adh6p is the enzyme responsible for the 3-methylbutanal reduction in yeast Finally, we have performed comparative studies between wild type and adh1? strains, that have demonstrate that Adh6p is involved in the NADP+/NADPH redox balance maintenance in yeast.

To measure losses in a transformer with today’s methods is either slow or insecure. There s a new method developed by Alstom that hasn't been actualize in to a test-system and that has been the assignment in this project. The idea is built on a switched system and a CLR- circuit in the resonant frequency. The test-system has a calculated power-loss that make the efficiency to be as high as 99,8% and in reality over 95%. But in the end it was discovered that the circuit was only able to deliver 70A when the thought was 200 A. More over was with the frequency of 200 kHz the signal was so distorted that all results over 100 kHz should be questioned. The goal was a efficiency of 99%. That was one of the basis in our calculation and dimensioning. When we order the components we foundbetter than we needed och the efficiency was improved. In the reality the efficiency is 95% and we think it's because the measurements-instruments accuracy and the distortion. In some measurements the efficiency went over 100% and that greatly improve that idea. Every part of the circuit was simulated piece bye piece and then together. That to increase the understanding of the system and to see that themodel works. The simulated efficiency was very low compared to calculated and in reality. The fact was gathered from literature, technical reports from Alstom and meetings with Per Ranstad et. al. / Om man vill mäta förluster på en transformator skerdetta antingen väldigt osäkert eller väldigt långsamt. Det finns en ny metod som Alstomtagit fram, som inte realiserats i ett bestående testsystem förrän nu, vilket har varit detta projekt. Det hela bygger på ett switchat system och en CLR krets i resonansfrekvens. Det resulterade testsystemet hade en beräknad verkningsgrad på 99,8 % och i verkligheten över 95%. Dock i slutskedet upptäcktes att kretsen endast orkade mata ut 70 A jämfört med det tänkta 200 A. Dessutom vid frekvensen 200 kHz blev signalen väldigt förvrängd av störningar och de resultat för frekvenser från 100 kHz och uppåt kan därför ifrågasättas. Vi satte ett mål på en verkningsgrad på 99% som vi grundade våra räkningar och dimensioneringar på. När materialet skulle beställas hittades bättre komponenter än vad vi satt upp och verkningsgraden förbättrades. Varför verklighetens verkningsgrad hamnar på 95% tror vi har med noggrannheten på mätinstrumenten att göra och störningssignalen. Vissa mätningar uppgick till över 100% verkningsgrad som gör att misstankarna för mätinstrumenten stiger. Alla kretsdelar simulerades bit för bit och ihop för att öka förståelsen för systemet samt se att lösningen funkar. Den simulerade verkningsgraden blev väldigt lågt jämfört med beräknat och verkligheten. Fakta vi använt kommer från flera litteraturer, tekniska rapporter från Alstom och möten med Per Ranstad m.fl.

We consider the problem of testing the equality of two sample means, when the number of tests performed is large. Applying this problem to the context of gene expression data, our goal is to detect a set of genes differentially expressed under two treatments or two biological conditions. A null hypothesis of no difference in the gene expression under the two conditions is constructed. Since such a hypothesis is tested for each gene, it follows that thousands of tests are performed simultaneously, and multiple testing issues then arise. The aim of our research is to make a connection between Bayesian analysis and frequentist theory in the context of multiple comparisons by deriving some properties shared by both p-values and posterior probabilities. The ultimate goal of this work is to use the posterior probability of the one-sided alternative hypothesis (or equivalently, posterior probability of the half-space) in the same spirit as a p-value. We show for instance that such a Bayesian probability can be used as an input in some standard multiple testing procedures controlling for the False Discovery rate.

Half-sibling reconstruction is the task of determining maternal and paternal sibling relationships from observed genotypes of same-generation individuals in a population. Knowledge of how populations are structured allows biologists to understand mating habits of different species, how threatened a population is, and how best to protect threatened or endangered species. This thesis examines the problem of half-sibling reconstruction and explains an accurate and fast heurstic for reconstructing half-siblings. The heuristic reconstructs half-sibling relationships with high accuracy on large biological populations where existing algorithms fail due to running time constraints. In addition to identifying and discussing some of the major problems with half-sibling reconstruction, we also prove that even the task of determining whether a half-sibling reconstruction obeys genetic inheritance laws is NP-complete. Some solutions for overcoming the inherent difficulty of half-sibling reconstruction are also proposed.

For energy conservation of sensorless two-phase half-wave brushless DC fan, this thesis develops a driver based on analogy circuits with current feedback control and speed feedback control. The main parts of the system include a sensorless start-up circuit, a sensorless commutation detection circuit, a speed feedback control circuit and a current feedback control circuit. Finally, we design experiments to compare it with outside PWM open-loop control and speed feedback control on experiment, the result shows that the driver with both current feedback control and speed feedback control displays better efficiency and lower vibration.

The Lead-Acid battery has become the power source of several electron product. The major drawback is that it requires long charging time. This thesis is to design a programmable rapid charger and energy recovery scheme with DSP. Furthermore zero-voltage-switching(ZVS) capability of the adopted asymmetrical half-bridge topology enhances the power density of the charger. The energy recovery cell stores the negative pulse energy into DC bus capacitor temporarily to avoid unnecessary energy consumption in conventional schemes. This thesis is experimentally verified on 12V/7.5Ah nonspillable sealed-lead assembled batteries. According to experimental results, the charger can achieve the goal of rapid charge within 1 hour. Because of using the rapid charge algorithm, it can give different charging section depends on temperature and voltage of battery, and it can adjust the over-temperature and the over-voltage of battery to guarantee the battery be charged safely. In this thesis, a prototype module is implemented with mature protection condition. Some experiments are shown to verify the feasibility of the proposed scheme.

This thesis presents the design and implementation of a single-stage with high power factor asymmetrical half-bridge converter. The main structure combines a boost converter with an asymmetrical half-bridge. An Asymmetrical half-bridge converter has many advantages such as soft-switching properties and fewer components. Therefore it is suitable for DC/DC cell. The boost converter is used in a PFC cell that operating in discontinuous condition mode have innate ability of power factor correction without additional controller. In this thesis, the complete analysis of operation principle and design of controller for the equivalent circuits of a single-stage AC/DC converter in every operating stage have been described in detail. Finally, we construct the single-stage circuit and experimental result show that it can reach the expected goal for power-factor correction.

The photoabsorption cross sections of NO have been measured in the wavelength range 150~200nm, and the cross sections deviation from Beer-Lambert law due to the insufficient resolution of light source is discussed qualitatively. From the steady state approximation of quenching reactions, the pressure dependence of foreign gas on the ratio of absorption intensity to the fluorescence intensity is derived. Furthermore, the non-Stern-Volmer behaviors of the C2£S(n=0) state of NO were discussed by assuming the non-predissociated (J<9/2) and the predissociated (J>9/2) rotational levels following different quenching mechanisms.

<p>In this thesis, a multirate realization of an interpolation operation is explored. As one of the requirements for proper functionality of the digital pulse-width modulator, a 16-bit digital input signal is to be upsampled 32 times. To obtain the required oversampling ratio, five separate interpolator stages were designed and implemented. Each interpolator stage performed uppsampling by a factor of two followed by an image-rejection lowpass FIR filter. Since, each individual interpolator stage upsamples the input signal by a factor of two, interpolation filters were realized as a half-band FIR filters. This kind of linear-phase FIR filters have a nice property of having every other filter coefficient equal to zero except for the middle one which equals 0.5. By utilizing the half-band FIR filters for the actual realization of the interpolation filters, the overall computational complexity was substantially reduced. In addition, several multirate techniques have been utilized for deriving more efficient interpolator structures. Hence, the impulse response of individual interpolator filters was rewritten into its corresponding polyphase form. This further simplifies the interpolator realization. To eliminate multiplication by 0.5 in one of two polyphase subfilters, the filter gain was deliberately increased by a factor of two. Thus, one polyphase path only contained delay elements. In addition, for the realization of filter multipliers, a multiple constant multiplication, (MCM), algorithm was utilized. The idea behind the MCM algorithm, was to perform multiplication operations as a number of addition operations and appropriate input signal shifts. As a result, less hardware was needed for the actual interpolation chain implementation. For the correct functionality of the interpolator chain, scaling coefficients were introduced into the each interpolation stage. This is done in order to reduce the possibility of overflow. For the scaling process, a safe scaling method was used. The actual quantization noise generated by the interpolator chain was also estimated and appropriate system adjustments were performed.</p>

Thesis--Odense. / Summary in Danish. Includes indexes. Includes bibliographical references (p. 153-159).