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Årligen slutar 30 procent av eleverna gymnasieskolan utan betygsbehörighet. På individuella program (IV) är siffran 85 procent. För att kartlägga skolsituationen för en elevgrupp på IV-programmet intervjuades 24 elever. Utöver detta gjordes en kognitiv bedömning samt en självskattning av upplevd psykisk hälsa. Huvuddelen av eleverna presterade på en ojämn kognitiv nivå, inom normalvariationen. Arton elever bearbetade information långsamt. Eleverna skattade att de mådde psykiskt sämre än normgruppen. De rapporterade tidiga skolsvårigheter som i vissa fall uppmärksammats,men lämnats utan adekvat åtgärd. Elever med långvariga skolproblem,försvårande additiva faktorer kombinerat med ett begåvningsvärde i normalvariationens nedre spann samt långsamhet vid informationsbearbetning upplever negativa individuella konsekvenser. De negativa effekterna kan mildras med tidiga interventioner på en för eleverna adekvat nivå och beaktat elevernas relativa kognitiva styrkor.

Background: A younger age at onset of use of a specific substance is a well-documented risk-factor for a substance use disorder (SUD) related to that specific substance. However, the cross-substance relationship between a younger age at onset of alcohol use (AU) and nicotine use (NU) and the risk of cannabis use disorders (CUD) in adolescence and early adulthood remains unclear. Aims: To identify the sequence of and latency between initial AU/NU and initial cannabis use (CU). To investigate whether younger age at AU- and NU-onset is associated with any and earlier CU-onset and a higher risk of transition from first CU to CUD, taking into account externalizing disorders (ED) and parental substance use disorders as putative influential factors. Methods: Prospective-longitudinal community study with N = 3021 subjects (baseline age 14–24) and up to four assessment waves over up to ten years with additional direct parental and family history information. Substance use and CUD were assessed with the DSM-IV/M-CIDI. Results: Most subjects with CU reported AU (99%) and NU (94%). Among users of both substances, 93% reported AU prior to CU (87% for NU). After adjustment for ED and parental substance use disorders younger age at AU-onset was associated with any CU. Younger age at NU-onset was associated with earlier CU initiation. Younger age at AU- and NU-onset was not associated with a higher risk of CUD. Conclusions: The cross-substance relevance of younger age at first AU and NU for the risk of CUD is limited to early CU involvement.

Macrocyclic ligand-complexed transition metal-oxo intermediates are the active oxidizing species in a variety of important biological and catalytic oxidation reactions. Many transition metal catalysts have been designed to mimic the predominant oxidation catalysts in nature, namely the cytochrome P450 enzymes. Iron porphyrin complexes have been the center of research as catalysts. In this study 5,10,15,20- tetramesitylporphyrin (H2TMP) and its corresponding iron complexes FeIII(X)TMP (X= Cl, ClO4, ClO3, NO3, NO2, and BrO3) have been successfully synthesized and fully characterized by UV-vis and NMR spectroscopies. For the catalytic selective oxidation of organic sulfides, the potential of iron(III) porphyrin complexes with iodobenzene diacetate [PhI(OAc)2] have been investigated. Iodobenzene diacetate was found to be an efficient oxygen source in the iron(III) porphyrin-catalyzed oxidation of sulfides to sulfoxides. Iron(III) porphyrin catalysts show an excellent conversion and selectivity for the sulfoxidation reactions. Reaction conditions and environments that effect the catalytic sulfoxidation including solvent, catalytic amount, axial ligand, water, and thioanisole substrates, have been investigated to identify the optimal conditions and the substrate scope. Under optimized conditions, excellent substrate conversions (up to 100%) as well as product selectivies (sulfoxide:sulfone > 95:5) have been achieved. To probe the nature of the oxidizing species in above catalytic sulfoxidations, iron(IV)-oxo porphyrin radical cations model of Compound I were chemically produced from the corresponding iron(III) tetramesitylporphyrin precursors with excess amounts of PhI(OAc)2 (20-50 equivalents) in CH3CN solvent. All O=FeIV(X)TMP·+ (X= Cl, ClO4, ClO3, and NO3) show weaker Soret band and broader Q band that are characteristic of Compound I analogues. A new photochemical method that led to generation of the iron(IV)-oxo porphyrin radical cations was also successfully developed. Iron(IV)-oxo porphyrin radical cations were generated by irradiation of iron(III) porphyrin chlorate or bromate complexes that result in heterolytic cleavage of the O-X bond in the axial ligand.

Les réacteurs GEN IV (GFR) nécessitent l'emploi de matériaux d'enrobage ayant une bonne transparence aux neutrons, une conductivité thermique élevée et agissant comme barrière de diffusion pour les produits de fission. Le but de cette étude est de déterminer le rôle de la température et de l'irradiation sur le comportement du xénon implanté dans l'oxycarbure de zirconium (ZrCxOy). A cet effet, des poudres de deux stoechiométries ZrC0,95O0,05 et ZrC0,8O0,2 ont été synthétisées puis frittées par frittage flash, ou sous charge. Pour étudier le rôle de la fluence d'implantation sur la migration thermique du xénon dans le ZrC0.95O0.05, des ions 136Xe2+ ont été implantés à une énergie de 800 keV à trois fluences : 1015, 1016 et 1017 at/cm². Les échantillons ont ensuite été recuits sous vide secondaire dans une gamme de températures de 1500 à 1800°C. Les profils de distribution du xénon ont été mesurés par RBS ou par SIMS. Des analyses par MET, MEB, NBS et PAS-DBS ont été réalisées à chaque étape. Cette étude a montré qu'à 1015 et 1016 at/cm2 le xénon est piégé dans des bulles nanométriques dans les murs de dislocations. A 1017 at/cm2, la coalescence des bulles de plus grandes tailles conduit au relâchement du xénon aux joints de grains. Pour les échantillons de ZrC0,8O0,2, les recuits conduisent à une oxydation de surface corrélée à un important relâchement du xénon. Parallèlement, des expériences d'irradiation ont été effectuées sur la plateforme JANNUS et auprès du Tandem afin de déterminer le rôle respectif des dégâts balistiques et électroniques sur la migration du xénon. Nous avons observé que ces conditions d'irradiation n'entrainaient pas de migration du xénon

In this thesis, higher derivative theories are investigated. Ostrogradskian instability of higher derivative theories is examined both at the classical and quantum levels. It is shown that avoiding the instability in nondegenerate higher derivative theories is impossible. Moreover, the degenerate model of relativistic particle with a curvature term is studied as a viable higher derivative theory. Most of the work we present here is not original. We give a review of the literature and compile various detached works that already exist.

The aim of this work was to find a correlation between the electrical, optical and microstructural properties of thin SiO2 layers containing group IV nanostructures produced by ion beam synthesis. The investigations were focused on two main topics: The electrical properties of Ge- and Si-rich oxide layers were studied in order to check their suitability for non-volatile memory applications. Secondly, photo- and electroluminescence (PL and EL) results of Ge-, Si/C- and Sn-rich SiO2 layers were compared to electrical properties to get a better understanding of the luminescence mechanism.

This paper introduces a high-gain, low-noise band-pass filter system for detection/amplification of small signals. In addition, related theory and methodology are described for a specific design implementation. Simulation and experimental results are presented and discussed. The purpose of the implemented design was to construct a band-pass filter system with 102 dB gain and with an output noise level of less than 0.8V. The design of the high-gain band-pass filter system was achieved mainly with the help of Filter Pro, LTSpice IV, and Multisim 12. The thesis provides important support for the project Marker Locator and constitutes a valuable reference for future active filter system design and small signal detection/amplification. / Marker Locator

In this master thesis a small modular sodium-cooled metal-fuelled pool-type fast reactor design, called SPARC - Safe and Passive with Autonomous Reactivity control, has been designed. The long term reactivity changes in the SPARC are managed by implementation of the the Autonomous Reactivity Control (ARC) system, which is the novelty of the design. The overall design is mainly based on the Integral Fast Reactor project (IFR), which experimentally demonstrated the passive safety characteristics of a metal fuelled, sodium-cooled, pool-type reactor system. Whilst mimicking the passive safety features of the IFR, the vision of the SPARC design is a battery type reactor, which can operate with minimum interference from human actors. In this thesis, two reactor examples have been developed which operate using different fuel compositions. One reactor operates on recycled nuclear waste from today's nuclear power plants, and the other reactor operates on enriched uranium. Both reactors have a thermal power of 150 MW, and are meant to operate for 30 years without refuelling. The design was developed using the ADOPT software, and was simulated in Serpent. Using Serpent, criticality analyses were carried out which show that the ARC system is able to control the long term reactivity changes of the reactors.

Type IV pili (T4P) are bacterial biomolecular machines that mediate interactions with the environment. Bacterial pathogens such as Pseudomonas aeruginosa require T4P for virulence. Significant progress has been made in recent years towards our understanding of how the proteins in the T4P system interact and function. While over 50 different proteins are involved in T4P biogenesis, the two outer membrane components, PilF and PilQ, are the focus of the work presented in this thesis. PilF was found to be required for assembly of PilQ into secretins, the outer membrane channels through which T4P fibers exit the cell. The functions of PilF are consistent with a family of lipoproteins called pilotins, to which the roles of secretin assembly and/or localization are attributed. Structure determination by X-ray crystallography revealed that PilF is composed of six tetratricopeptide (TPR) protein-protein interaction motifs. Functional mapping of PilF indicated that a hydrophobic groove on the first TPR is involved in secretin assembly. Secretin localization correlated directly with that of PilF. The effects of pilF mutations and the structural data led to the hypothesis that PilF and PilQ interact directly. We propose that PilF and PilQ interact at the inner membrane and are co-transported to the outer membrane by the Lol lipoprotein sorting system. PilQ multimerizes into secretins upon outer membrane insertion and aligns with inner membrane T4P proteins to form a complete molecular machine. PilQ mutagenesis mapping showed that: the N-terminal “system specific” domain is important but not essential for secretin function; the central “multimerization” domain is critical for secretin assembly and function; and the C-terminal tail implicated in secretin-pilotin interactions is dispensable for PilQ function. Purified PilQ enabled copurification of PilF from cell lysates, providing the first evidence for their interaction. These data provide a framework for future exploration of T4P assembly in P. aeruginosa.