Silicon carbide (SiC) is a wide bandgap semiconductor (energy gap of 3.26 eV and 3.03 eV for 4Hand 6H-SiC, respectively). With outstanding physical and electronic properties, SiC is a promising material for high-power, high-frequency and high-temperature applications. The electronic properties of a semiconductor are to a large extent determined by point defects in the crystal. As known from other semiconductors, defect control is crucially important for the successful device applications. Point defects can be impurities, such as the shallow nitrogen (N) donor or boron acceptor (the residual n- and p-type dopants in SiC), or intrinsic defects, such as vacancies, antisites, interstitials or combinations thereof. One of the key issues in the SiC technology is to develop semi insulating (SI) SiC substrates required for SiC MEtal Semiconductor Field Effect Transistors (MESFETs) and also for III-nitride based High Electron Mobility Transistors (HEMTs), to reduce the parasitic capacitance and to improve the device performance. For achieving the SI behavior the Fermi level should be pinned near the middle of the bandgap. This can be realized using defects with deep acceptor level(s) to compensate the residual shallow N donors which cause the natural ntype doping of as-grown SiC. Vanadium (V) doped SI SiC has been developed since the 1990s. However, SiC MESFETs using V-doped SI SiC substrates are shown to have severe problems with electron trapping to eep levels in the SI substrates which causes reduction of the drain current and instability of the device performance. Since the beginning of this decade, V-free high-purity SI (HPSI) SiC substrates using intrinsic defects to compensate the N donors have been developed. The work in this thesis has been devoted to characterize defects in HPSI SiC using electron paramagnetic resonance (EPR). EPR detects transitions between energy levels split up by the interaction of unpaired electron spins (localized at the defect and neighboring atoms) with an applied magnetic field. Thanks to the sensitivity of the electron spins to their surroundings; especially to nearby nuclear spins that further splits the energy levels by the so-called hyperfine (hf) interaction, one can extract information on the structure and electronic configuration of a defect. The work has been focused on (i) the identification of prominent defects, (ii) the determination of their energy levels and roles in the carrier compensation processes, (iii) the defect interaction and the stability of the SI properties at high temperatures, in order to identify the optimal defect(s) to be used for controlling the SI properties. EPR and ab initio supercell calculations have been the main tools for defect identification and all three common polytypes 3C-, 4H- and 6H-SiC of different conducting types (n-, p-type and SI) have been investigated. For determination of the energy levels in the bandgap, the combined results of EPR and photoexcitation EPR (photo-EPR), Deep Level Transient Spectroscopy (DLTS), the temperature dependence of the resistivity, and ab initio calculations have been evaluated. Annealing studies up to 1600 °C for samples with different defect compositions have been carried out for obtaining knowledge on the defect interaction and thermal stability of the SI properties as well as the change in resistivity, activation energy and defect concentration. Below is a short summary of the papers included in the thesis. In paper 1, the identification of the neutrally charged divacancy (VCVSi 0) in 4H-SiC, by PR and ab initio calculations, is presented. The divacancy is a common defect in SiC and it is thought to play a role in carrier compensation in HPSI SiC. Annealing studies show that it is formed during migration of carbon vacancies (VC) and silicon vacancies (VSi) and in the studied samples it is thermally stable up to at least 1500 °C. Paper 2 presents EPR identification of prominent defects in different types of HPSI 4H-SiC substrates grown by high-temperature chemical vapor deposition (HTCVD) and physical vapor transport (PVT), the determination of some of their deep acceptor levels and their roles in carrier compensation processes. VSi, VC, carbon antisite-vacany pair (CSiVC), and VCVSi were found to be the most common defects in different types of HPSI 4H-SiC. The samples could be grouped into three activation energy ranges Ea~0.8–0.9 eV, ~1.1–1.3 eV, and ~1.5 eV, and the possible defect levels related to these energies were discussed for each group. The samples with Ea~1.5 eV contain high concentrations of VC and VCVSi and low concentrations of VSi and as these samples had the most thermally stable SI properties, due to the increased thermal stability of VC when VSi is absent, we concluded that this defect composition is preferable. A similar study is presented in paper 4 of different types of HPSI 6H-SiC substrates grown by HTCVD. The samples could be grouped into two activation energy ranges Ea~0.6-0.7 eV and ~1.0-1.2 eV. VC, CSiVC and VCVSi were found to be the prominent defects and the relationship between their energy levels and the activation energies was discussed. The  materials were still SI after annealing up to 1600°C although the activation energies were lowered. The (+|0) level of VC was also specifically studied by photo-EPR and determined to be located at ~1.47 eV above the valence band, similar to 4H-SiC. The content of Paper 3 concerns an EPR study of two defects, labeled L5 and L6, in electron irradiated n-type 3C-SiC. The L5 defect could be related to the neutrally charged divacancy as it shows some features similar to the divacancy in 4H-SiC. The L5 defect anneals out at low temperatures (~200°C) and could possibly be carbon interstitial related. Paper 5 presents an attempt to study the energy levels of VC by photo-EPR without the usual interference from other defect levels. By using pure free-standing n-type 4H-SiC epilayers with very low defect concentrations and low-energy electron (200 keV) irradiation we could combine photo-EPR and DLTS to study energy levels related to VC.VC+ and VC- could be detected simultaneously and from the study we concluded that the (+|0) is located at ~EC–1.77 eV and suggested that the (0|−) and (1−|2−) levels are located at ~EC–0.8 eV and ~ EC–1.0 eV, respectively. The investigation in paper 6 concerns the identification of the EI4 EPR center in 4H- and 6HSiC. Based on detailed studies of the hf interactions, the annealing behavior and ab initio supercell calculations we believe the corresponding defect is a complex between a carbon vacancy-carbon antisite and a carbon vacancy at the third neighbor site of the antisite in the neutral charge state, (VC-CSiVC)0. It could be directly involved in carrier compensation in some samples before it anneals out (at ~850 °C in irradiated samples or higher temperatures in as-grown sample) and also seems to be an intermediate state in the formation of the divacancy. In Paper 7, an EPR study of a radiation-induced defect, labeled LE5, in 4H- and 6H-SiC is presented. The observation of the LE5 spectra in samples irradiated at low temperatures (77-100 K) indicates that it is a primary defect. From the low symmetry (C1), the Si hf structures, and the low anneal-out temperature (~600-750 °C) we suggested that the defect may be a complex involving a silicon antisite (SiC) perturbed by a nearby defect. / In the list of included papers is the title of paper VII "A primary complex defect in electron-irradiated 3C-, 4H- and 6H-SiC" but in manuscript the title is "Silicon antisite related defects in electron-irradiated p-type 4H- and 6H-SiC".

Biological research is necessary; not only to further our understanding of the processes of life, but also to combat disease, hunger and environmental damage. Bioinformatics is the science of handling biological information. It entails integrating, structuring and analysing the ever-increasing amounts of available biological data. In practise it means using computers to analyse huge amounts of very complicated data taken from a field that is only partially understood, to see the hidden trends and connections, and to draw useful conclusions. My thesis work has mainly concerned the study of protein families, which are groups of evolutionarily related proteins. I have analysed known protein families and created predictive models for them, and developed algorithms for defining new protein families. My principal techniques have been sequence alignments and hidden Markov models (HMM). To aid my work, I have written a lot of software, including MSAView, a visualiser for multiple sequence alignments (MSA). In this thesis, the protein family of inorganic pyrophosphatases (H+-PPases) is studied, as well as the two protein superfamilies BRICHOS and MDR (medium-chain dehydrogenases/reductases). The H+-PPases are tightly membrane bound, proton pumping, dimeric enzymes with ~700-residue subunits and found in bacteria, plants and eukaryotic parasites, and which use pyrophosphate as an alternative to ATP. The BRICHOS superfamily is only present in higher eukaryotes, but encompasses at least 8 protein families with a wide range of functions and disease associations, such as respiratory distress syndrome, dementia and cancer. The sequences are typically ~200 residues with even shorter functional forms. Finally, MDR, is a large and complex protein superfamily; it currently has over 16000 members, it is present in all kingdoms of life, the pairwise sequence identity is typically around 25 %, the chain lengths vary as does the oligomericity, and the members are partaking in a multitude of biological processes. The member families include the classical liver alcohol dehydrogenase (ADH), quinone reductase, leukotriene B4 dehydrogenase, and many more forms. There are at least 25 human MDR genes excluding close homologues. There are HMMs available for detecting MDR superfamily membership, but none for the individual families. For the H+-PPase family, we characterised member sequences found using an HMM of a conserved 57-residue region thought to form part of the active site. This region was found to contain two highly conserved nonapeptides, mainly consisting of the four “very early” residues Gly, Ala, Val and Asp, compatible with an ancient origin of the family. The two patterns have charged amino acid residues at positions 1, 5 and 9, are apparent binding sites for the substrate and parts of the active site, and were shown to be so specific for these enzymes that they can be used for automated annotation of new sequences. For the BRICHOS superfamily, we were able to find three previously unknown member families; group A, which may be ancestral to the ITM2 families (integral membrane protein 2); group B, which is a close relative to the gastrokine families, and group C, which appears to be a truly novel, disjoint BRICHOS family. The C-terminal region of group C has nearly identical sequences in all species ranging from fish to man and is seemingly unique to this family, indicating critical functional or structural properties. For the MDR superfamily, we characterised and built stable HMMs for 17 member families using an empiric approach. From our experiences we were able to develop an algorithm for automated HMM refinement that uses relationships in data to produce stable and reliable classifiers, and we used it to produce HMMs for 86 distinct MDR families. We have made the program freely available and it can be readily applied to other protein families. We also developed a web site (http://mdr–enzymes.org) that makes our findings directly useful also for non-bioinformaticians. In our analyses of the 86 families, we found that MDR forms with 2 Zn2+ ions in general are dehydrogenases, while MDR forms with no Zn2+ in general are reductases. Furthermore, in Bacteria, MDRs without Zn2+ are more frequent than those with Zn2+, while the opposite is true for eukaryotic MDRs, indicating that Zn2+ has been recruited into the MDR superfamily after the initial life kingdom separations. Multiple sequence alignments (MSA) play a central part in most work on protein families, and are integral to many bioinformatic methods. With the ongoing explosive increase of available sequence data, the scales of bioinformatic projects are growing, and efficient and human-friendly data visualisation becomes increasingly challenging, but is still essential for making new interpretations and discovering unexpected properties of the data. Ideally, visualisation should be comprehensive and detailed, and never distract with irrelevant information. It needs to offer natural and responsive ways of exploring the data, as well as provide consistent views in order to facilitate comparisons between datasets. I therefore developed MSAView, which is a fast, modular, configurable and extensible package for analysing and visualising MSAs and sequence features. It has a graphical user interface and a powerful command line client, and can be imported as a package into any Python program. It has a plugin architecture and a user extendable preset library. It can integrate and display data from online sources and launch external viewers for showing additional details. It also includes two new conservation measures; alignment divergences, which indicate atypical residues or deletions, and sequence conformances, which highlight sequences that differ from their siblings at crucial positions. In conclusion, this thesis details my work in analysing two protein superfamilies and one protein family using bioinformatic methods; developing an algorithm for automated generation of stable and reliable HMMs, as well as a new conservation measure, and a software platform for working with aligned sequences.

Many biological processes rely on specific protein-protein interactions, for example immune responses, cell signaling, transcription, and blood coagulation. Blood coagulation is initiated when a vessel wall is damaged, exposing tissue factor (TF) to the circulating factor VII/factor VIIa (FVII/FVIIa) which results in the formation of the TF:FVIIa complex and thereby the initiation of blood coagulation. One of the substrates for the TF:FVIIa complex is factor X (FX), which is activated to factor Xa (FXa), subsequently leading to a series of reactions resulting in clot formation. Tissue factor pathway inhibitor (TFPI) is the major physiological inhibitor of the sTF:FVIIa complex, involved in regulation of coagulation by forming the TF:FVIIa:FXa:TFPI complex. Occasionally, the blood coagulation mechanism malfunctions, resulting in conditions such as the inability to stop bleeding or thrombosis. The fact that TF is the main initiator of the coagulation makes this an interesting protein to study, in the hunt for means to interfere with players involved in the blood clotting process. Throughout the studies included in this thesis the site-directed labeling technique is utilized to attach spectroscopic probes to cysteines, introduced at specific positions by mutagenesis, in the protein of interest. These fluorescent or spin-probes are sensitive for changes in their immediate environment and can thus, for example be used to monitor protein-protein complex formation and conformational changes. No complete structure has been obtained as yet for the large complex involving sTF, FVIIa, FXa, and TFPI. Therefore, we introduced a fluorescent probe at specific positions in soluble tissue factor (sTF) and the changes in fluorescence emission were detected upon sTF:FVIIa:FXa:TFPI complex formation. From these measurements it was concluded that not only parts of the C-terminal domain of sTF (TF2), but also residues in the N-terminal domain (TF1) are involved in binding to FXa in the quaternary complex. In order to investigate conformational changes occurring in the extended interface between sTF and FVIIa upon binding of different inhibitors spectroscopic probes were introduced in sTF, in the vicinity of the interaction region. From the obtained data it was concluded that the exosite-binding inhibitor E-76 induces equivalent structural changes at the interface of sTF and the protease domain (PD) of FVIIa, as do the active-site inhibitors FFR and TFPI, i.e. makes the region around the active-site more compact. Binding of these inhibitors shows similar effects despite their differences in size, binding site, and inhibitory mechanism. In addition, the Ca2+ dependence of the formation of the sTF:FVIIa complex was studied. Association between sTF and FVIIa during Ca2+ titration begins by Ca2+ binding to the first EGF-like domain of FVIIa. However, Ca2+ saturation of the γ-carboxyglutamic acid-rich (Gla) domain of FVIIa is required for complete sTF:FVIIa complex formation, and we were also able to detect that a Gla domain with vacant Ca2+ sites hinders the docking to sTF. Finally, we investigated the structural changes of free inhibited FVIIa upon sTF and Ca2+ binding by FRET and quenching measurements. From this it was concluded that inhibited FVIIa does not seem to undergo large global structural changes upon binding to sTF, when taking the dynamics of free FVIIa into account. However, Ca2+ binding induces minor local conformational changes in the active-site region of the PD of inhibited FVIIa and subsequent binding of sTF causesfurther structural rearrangements in this area.

Ubiquitous chemical sensing aims at exploiting consumer electronic devices as temporary chemical sensing platforms. These devices are a highly disseminated infrastructure, not presently being exploited for chemical sensing purposes. The goal of the ubiquitous chemical sensing field is to create the methodologies and adapted devices to profit from this unexploited resource. DVD drives, flat bed scanners and computer screens used in combination with web cameras, and mobile phones have been demonstrated as measuring platforms, during the past 10 years. In particular the combination of computer screens with web cameras, a technique called the computer screen photo-assisted technique (CSPT), is the most versatile approach to support multiple types of optical detection phenomena, and together with mobile phones are the most ubiquitous type of platforms. The versatility of CSPT comes from the ease with which one can configure a spectrally controlled, 2D micro-positioned, linearly polarized, wide angle and internally modulated illumination with a programmable screen, just by controlling the displayed contents. Concurrently, the imaging devices in CSPT enable one to capture arbitrary assay layouts, the evaluation of which can then be numerically customized. The full exploitation of the CSPT platform requires optically adapted sensing interfaces and specialized methods, in order to increase sensitivity and make use of all available information, for a thorough and complete chemical sensing analysis. In this thesis I have explored the foundations of CSPT sensing on integrated devices, developing methods and sensing’s interfaces that provide enhanced optical detection customized to the CSPT platform.

No description available.

Sammanfattning Kånneby är doktorand på Naturhistoriska riksmuseet i Stockholm. Han har skrivit en ny publikation om bukhårsdjur (Gastrotricha). Målgruppen är forskare inom biologi, zoologi och studenter. Publikationen innehåller bland annat beskrivning av en ny art och tre arter som hittas för första gången i Sverige samt en identifieringsnyckel över släktet Ihthydium. Syftet med arbetet har varit att underlätta det visuella tänkandet för målgruppen genom att lyfta in illustrationer, som passar till publikationen. Det för att publikationen skulle fungera optimalt. De illustrationer som behövdes diskuterade jag och Kånneby tillsammans fram. Det behövdes illustrationer till publikationens identifieringsnyckel och till den nya arten. En uppgift tillkom mitt under arbetsgången som skulle stödja publikationen ytterligare, en samlingsbild över bukhårsdjurets anatomi. Kånneby ville också ha en visuell målning av bukhårsdjuret i dess naturliga miljö. Det blev en uppgift som gjordes fastän den inte var nödvändig för publikationens användbarhet. Illustrationerna har utförts med hjälp av mycket underlag och diskussioner. Fakta som stödjer mina teorier är hämtade ur litteratur. Praktiskt arbete har genomförts för hand med valda pennor, akvarell och med dator. I rapporten redogörs de teorier och metoder som har varit lämpliga för att lösa uppgifterna samt arbetsgången för varje uppgift. En utprovning har gjorts och resultat redogörs och visas även i bilagor. Arbetet har utförts på Naturhistoriska riksmuseet i Stockholm under perioden 2009-03-24 - 2009-05-21. Publikation,

No description available.

Syftet med denna fallstudie är att undersöka lärares inställning till och undervisning i naturvetenskap för att därefter koppla detta till lärarnas upplevda erfarenheter av barns intresse för naturvetenskap. Metoden som har används är en empirisk undersökning och semistrukturerade personintervjuer. Resultatet visade att samtliga lärare som deltog i undersökningen hade en positiv inställning till de naturvetenskapliga ämnena. De ansåg att eleverna var mycket intresserade och att de tyckte att det var intressant med naturvetenskaplig undervisning. Slutsatsen är att lärarna ansåg att problemen med den naturvetenskapliga undervisngen är material, det finns inget eller dåligt på skolorna. Sedan visar undersökningen att de barnen i de tidigare åren är intresserade av naturvetenskap men att något händer under högstadiet som gör att detta intresse försvinner hos många elever.

Abstract This study examined the combined effectiveness of Tier I and Tier II instruction in the context of a Response to Intervention framework with sixth, seventh and eighth grade students both in ELA and Math. The Tier I interventions emphasized topics from the Grade Level Expectations that the students were having difficulties grasping during regular classroom instruction. Tier II instruction mainly emphasized preparing students for the standardized iLEAP and LEAP tests. These students were then compared with a group of similar students who did not receive tiered instructions (control group). Students who participated in Tier I or Tier II instructions outperformed the control group in Math on standardized tests and the post tests. There was no significant difference found between the two groups in ELA.

Jag fick i uppdrag av WSP Samhällsbyggnad i Karlstad, att presentera data med hjälp av programmet ArcGIS. Data som skulle uppvisas var: trafikmängden, polisrapporterade olyckor, gång- och cykelvägar, trafiksignaler, trafikplatser, skyltad hastighet, skolor och fritidsaktiviteter längs E18 i Karlskoga. Vidare skulle föreslagna åtgärder i utredningen presenteras med GIS. Arbetet inkluderar fältstudier i Karlskoga för att ta foto och videoklipp på de berörda korsningarna, som sedan skulle länkas till kartan. Uppgifterna skulle sedan framföras i en karta, i en skärmpresentation av avdelningschefen Bo Lindelöf. Arbetet tar upp problem och möjligheter med användning av GIS i presentationsskedet. Karlskoga kommun och Vägverket föreslår åtgärder i Karlskoga tätort, en ombyggnad av E18:s korsningar med Viaduktgatan, Boåsvägen och Hyttåsvägen. Kommunen kommer att investera i ett nytt campusområde söder om Hyttåsvägen vilket kommer att kräva en ombyggnad av Industrivägen och Hyttåsvägen. Från hösten 2003 har Örebro Universitet placerat en viss utbildning i Campus Karlskoga, som kommer att utökas successivt. I närheten av Bofors industriområde och sjön Möckeln kommer det nya campuset att byggas upp. / WSP´s department of physical planning, Karlstad, gave med the task to present data using ArcGIS. The data presented were: Traffic flow, accidents, noise, walk- and bikeways, schools and recreation areas alongsides E18 in Karlskoga. I was also supposed to present the proposed actions. I also had to visit Karlskoga for some on-site investigations of my own, such as taking pictures and video-sequences of concerned traffic intersections. Those images I would intergrate in my maps. All this information is being presented for the head of department. Karlskoga municipality and Vägverket suggest reconstruction of three major intersections on E18, Viaduktgatan, Boåsvägen and Hyttåsvägen. Reconstruction of Hyttåsvägen and Industrivägen is also needed, due to the new Campus built south of Hyttåsvägen. From the fall of 2003, Örebro University has placed an education on Campus Karlskoga that expects to be expanded. This expansion will be between lake Möckeln and Bofors industries.