Pour étudier la capacité cellulaire à s’adapter aux changements de signalisation dépendante des RTKs, nous utilisons un modèle de souris où l’expression du RTK Met sauvage peut être accrue dans un tissu spécifique. La plupart des tissus se protègent contre cette expression anormale des RTK. Mais certains types cellulaires sont sensibles aux altérations des RTKs, c’est le cas du mésenchyme du membre pendant l’embryogenèse. En effet, l’expression de certains gènes du mésenchyme est modifiée et celui-ci n’est plus accessible aux myoblastes qui le colonisent, conduisant à des déficits des muscles du membre. Chez l’adulte une augmentation de l’expression de Met dans le foie (Alb-R26Met) perturbe l’homéostasie tissulaire, conduisant à la tumorigenèse. Pour identifier des gènes qui coopèrent avec les RTKs pendant l’initiation de la tumorigenèse, nous avons combiné les souris Alb-R26Met avec le système de mutagenèse Sleeping Beauty (SB) transposon. 285 gènes putatifs liés au cancer ont été identifiés. Certains sont des proto-oncogènes ou suppresseurs de tumeurs déjà connus, validant le système. D’autres gènes n’avaient, jusqu’à présent, jamais été associés à ce processus. 9 candidats ont été fonctionnellement validés. Pour identifier des signaux assurant le maintien de la tumeur, nous avons analysé le phosphokinome, testé l’efficacité de composés et identifié de nouvelles combinaisons de drogues qui agissent en synergie pour tuer les cellules cancéreuses dérivées de Alb-R26Met. En conclusion, ces travaux montrent qu’une approche génétique non-biaisée combinée à une approche génomique permet d’identifier de nouveaux mécanismes pertinents pour la biologie du cancer. / We explore the cell competence to deal with slight changes in RTK inputs during embryogenesis and tissue homeostasis using a mouse model in which wild-type RTK Met levels can be moderately enhanced in a tissue specific manner. Most tissues buffer enhanced RTK levels thus avoiding perturbation of developmental programs and tissue homeostasis. Nevertheless, certain cell types are vulnerable to RTK levels. During embryogenesis, the limb mesenchyme is sensitive to alterations of the spatial distribution of RTKs, as illustrated by gene expression changes and by loss of accessibility to incoming myoblasts, which lead to limb muscle defects. At adulthood, liver enhanced Met levels (Alb-R26Met) perturbs tissue homeostasis, leading to tumorigenesis. To uncover new genes that cooperate with RTKs during tumour initiation, we combined Alb-R26Met mice with the Sleeping Beauty (SB) transposon mutagenesis system. 285 putative cancer-related genes have been identified. Some correspond to known proto-oncogenes or tumour suppressors, thus validating the overall strategy we employed for cancer gene discovery. Others have not been previously linked to cancer. 9 new tumour suppressors have been functionally validated, demonstrating the validity of our screen strategy. To identify signals involved in tumour maintenance, we employed a phosphokinome-guided drug screen and identified new synergistic drugs deleterious for cancer cells modelled by the Alb-R26Met genetic setting. The overall strategy and outcomes strengthen the value of combining unbiased genetic and genomic approaches to identify new mechanisms relevant for cancer biology and new therapeutic interventions.

I malé změny v Gramatický a lexikální aspekt jsou dva příklady kategorií, které se na této mentální reprezentaci podílí. Pomocí těchto kategorií vytváříme mentální koncepty, pomocí opujeme naše prožívání místa a času. Tato studie zkoumá interakci lexikálního a gramatického vidu a jak se tato interakce odráží na charakteru očních pohybů u mluvčích nizozemštiny. Bylo užito 04). Byly měřeny oční pohyby 20 rodilých mluvčí nizozemštiny, během toho, co sledovali bílou obrazovku bez jakýchkoliv explicitních obrazových stimulů a poslouchali věty vytvořené s ohledem na různé kombinace lexikálního a gramatického vidu. Užité paradigma simuluje případy z běžného života, kdy lidé pasivně poslouchají mluvenou řeč bez doprovodné vizuální složky. Tato studie nabízí důkazy, že gramatický a lexikální aspekt ovlivňují celou řadu očních pohybů. Tato práce je hodnotným rozšířením naší znalosti o psycholingvistické realitě vidu v nizozemštině, tomto ohledu věnována dostatečná pozornost. Výsledky tohoto výzkumu vnáší nové světlo do probíhající diskuse o tom, zda i tak abstraktní ává měřitelné stopy v našem senzomotorickém systému, a zda je schopný ho ovlivňovat. Navíc tato studie otevírá dveře dalšímu výzkumu zaměřenému na spojení mezi jazykem a mozkovými drahami, které se podílí na zpracování vjemových stimulů. klíčová slova:...

Fyzikálně přijatelné osvětlení v reálném čase je často dosaženo použitím aproximací. Současné metody často aproximují globální osvětlení v prostoru obrazu s využitím schopností moderních grafických karet. Dva techniky z této kategorie, screen-space ambient occlusion a screen-space directional occlusion jsou popsány detailněji v této práci. Screen-space directional occlusion je zobecněná verze screen-space ambient occlusion s podporou jednoho difúzního odrazu a závislostí na směrové informaci světla. Hlavním cílem projektu bylo experimentování s těmito metodami. Pro uniformní distribuci náhodných vzorek pro obě metody byla použita Halton sekvence. Pro potlačení šumu je použita bilaterální filtrace, která bere do úvahy geometrické vlastnosti scény. Metody jsou dál zrychleny použitím nižších rozlišení pro výpočet. Rekonstrukce výsledků do původní velikosti pro vytvoření konečného obrazu je realizována pomoci joint bilateral upsamplingu. Kromě metod globálního osvětlení byly v práci použity aj metody pro mapování stínů a HDR osvětlení.

Developmental biology adresses how cells are organised into functional structures and eventually into a whole organism. It is crucial to understand the molecular basis for processes in development, by studying the expression and function of relevant genes and their relationship to each other. A gene function can be studied be creating loss-of-function situations, in which the change in developmental processes is examined in the absense of a functional gene product, or in gain-of-function studies, where a gene product is either intrinsically overproduced or ectopically upregulated. One approach for a loss-of-function situation is the creation of specific mutants in single genes, and the zebrafish (Danio rerio) has proven to be an excellent model organism for this purpose. In this thesis, I report on two forward genetic screens performed to find new mutants affecting brain development, in particular mutants defective in development and function of the midbrain-hindbrain boundary (MHB), an organiser region that patterns the adjacent brain regions of the midbrain and the hindbrain. In the first screen, I could identify 10 specific mutants based on morphology and the analysis of the expression patterns of lim1 and fgf8, genes functioning as early neuronal markers and as a patterning gene, respectively. Three of these mutants lacked an MHB, and by complementation studies, I identified these mutants as being defective in the spg locus. The second screen produced 35 new mutants by screening morphologically and with antibodies against acetylated Tubulin, which marks all axonal scaffolds, and anti-Opsin, which is a marker for photoreceptors in the pineal gland. According to their phenotype, I distributed the mutant lines into 4 phenotypic subgroups, of which the brain morphology group with 18 mutant lines was studied most intensively. In the last part of my thesis, I characterise one of these brain morphology mutants, broken heart. This mutant is defective in axonal outgrowth and locomotion, and shows a striking reduction of serotonergic neurons in the epiphysis and in the raphe nuclei in the hindbrain, structures involved in serotonin and melatonin production. Studies in other model organisms suggested a role of factors from the floor plate and the MHB in induction of the serotonergic neurons in the hindbrain, and using broken heart, I show that Fgf molecules such as Fgf4 and Fgf8 can restore partially the loss of serotonergic neurons in the mutant. I conclude that forward genetic screens are an invaluable tool to generate a pool of mutations in specific genes, which can be used to dissect complex processes in development such as brain development.

It is well documented that Augmented Reality (AR) enhances and supports learning. Earlier research compares AR applications with existing methods. Published research typically focuses on one AR in general. Nevertheless, there are different ways of using AR. This paper gives further insight into how to use AR as a learning tool as part of a museum experience. It focuses on AR through smartphones, where the world is measured through the phone’s sensors and the virtual content is displayed on the device’s screen. This thesis presents the results of a comparative study between two types of AR: In-world space and On-screen space. In-world space AR renders the virtual content registered onto the physical exhibition. On-screen space AR renders the virtual content on the screen of the phone and uses the physical space of the exhibition as an index retrieval point. The discussion emerging from this study aims to aid the development and design of AR applications at museum settings, by giving curators better understanding of design options in AR spaces. Qualitative results suggest that In-world space benefits learning. / Det är väldokumenterat att Augmented Reality (AR) förbättrar inlärning. Tidigare forskning jämför AR mot andra existerande metoder. Publicerad forskning fokuserar generellt på AR i allmänhet trots att det finns flera olika typer av AR. Den här rapporten ger vidare insikt i hur AR bör användas med ändamålet att vara ett inlärningsverktyg som en del av en museum-upplevelse. Den fokuserar på AR genom smartphones, där omvärlden beräknas med mobilens sensorer och virtuellt material renderas i relation till omvärlden på mobilens skärm. Den här studien presenterar resultat från en jämförelsestudie mellan två typer av AR: In-world space och On-screen space. In-world space AR renderar det virtuella materialet ovanpå och i relation till den fysiska utställningen. On-screen space AR renderar det virtuella materialet på mobilens skärm utan relation till omvärlden, men använder istället den fysiska omvärlden för att placera ut virtuella indexpunkter. Diskussionen från den här studien ger förhoppningsvis riktlinjer för utveckling och design av AR-applikationer på ett museum, genom att ge kuratorer och museum en bättre förståelse gällande designmöjligheter i en AR-miljö. Kvalitativa result tyder på att In-world space förbättrar inlärning mer än On-screen space.

Dietary supplements sold for anabolic benefits or performance enhancement often contain substances, which are nonapproved and might lack quality controls. With regard to athletes, the inclusion of substances or methods in the prohibited list of the World Anti-Doping Agency is based on medical or scientific evidence. 5α-hydroxy-laxogenin is a synthetic spirostane-type steroid, which is contained in dietary supplements and advertised as anabolic agent. To date, evidence is missing on anabolic or androgenic activity of 5α-hydroxy-laxogenin. We investigated its androgenic potential in two in vitro bioassays. While no activity was observed in the yeast androgen screen, 5α-hydroxy-laxogenin was able to trans-activate the androgen receptor in human prostate cells in a dose-dependent manner. Interestingly, a biphasic response was observed with antagonistic properties at lower concentrations and agonistic effects at higher concentrations tested. The demonstrated androgenic properties of the higher concentrations demonstrate that further investigations should focus on the safety as well as on potential anabolic effects of 5α-hydroxy-laxogenin. This is of interest with regard to abuse for doping purposes.

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Underwater explosions pose a significant threat to waterborne infrastructure though destructive pressure waves that can travel significant distances through the water. However, the use of bubble screens can attenuate the peak pressure and energy flux created by explosions to safe levels. This study investigates the prediction of pressure wave characteristics based on accumulated data, the damage potential of underwater explosions based on applied loads and effective material strength, and the bubble screen parameters required to prevent damage. The results were compiled to form a procedure for the design and implementation of a bubble screen the protection of waterborne infrastructure.

This dissertation is a concise examination of the complete obverse manuscript (document 1) of the pre-Hispanic pictogram screen-fold painted by the Mixtec Indians of Oaxaca. The study begins with the historiography of Native American Mexican screen-fold books as related by the first historian of the New World, Peter Martyr d’Anghera, in his De orbe novo and proceeds through major authors from the early twentieth century to present day. The nature of “native” history is explored as is the nature of pictogram narrative history. The superficial narrative structure of Codex Zouche-Nuttall, document 1 is then defined and interpretative reading techniques employed in this dissertation are applied to it. The codex document 1 contents (pages 1-41) are then listed in detail by section, structure, personnel, events, and native dates corresponded with the European calendar, this latter in so far as is possible. This definition explicates each of three bifurcated sections of the document, each section consisting of a story plus genealogy or genealogies. Additionally, essays on codex contents are provided to further elaborate these divisions of study within Codex Zouche-Nuttall document 1. These essays explore certain mysterious parts of the stories, as in the case of the Ladies Three Flint and the Four Lords from Apoala. Inferences are made from codex text regarding Postclassic Period Mixtec social organization via both political structure and religion. The end result is a concise elaboration and explanation of the entire document. / text

This thesis presents an investigation of fluorescence resonance energy transfer (FRET) as a reporting signal for protein-protein interactions. Quantitative optical assays to measure protein binding, conjugation and deconjugation are developed and results validated by conventional biochemical techniques. The optical techniques developed provide fast, cheap, quantitative and accurate alternatives to conventional methods. Fluorescent protein fluorophores ECFP and Venus-EYFP were chosen as they are a non-interfering FRET pair and provide an inexpensive and convenient cloning-based labelling method. The small ubiquitin-like modifier SUMO and the SUMOylation pathway leading to its conjugation to target proteins is investigated as a model system. These assays are hence particularly relevant to research on post-translational modification and ubiquitin systems. In protein-protein binding assays we utilise both steady-state and time-resolved FRET detection to measure the equilibrium binding constant of the well-characterised pair SUMO1 and Ubc9. An assay in multi-well plate format is also presented, which uniquely enables repeat measurements under varying conditions and under the addition of further substances. The multi-protein binding interactions of the SUMOylation pathway including RanBP2 are analysed in binding inhibition assays. Our results clarify the role of RanBP2: a covalent SUMO1-Ubc9 link is required for the formation of a trimeric complex, although mutual binding sites are present on all three proteins. Furthermore, the binding of SUMO1 and Ubc9 is disrupted by RanBP2, which may be an essential step in transferring SUMO1 to its target protein. A FRET-based kinetic study of this conjugation process to RanGAP1 is presented. An assay to monitor the deconjugation of SUMO1 by specific proteases is established using a doubly-tagged SUMO construct. This enables a quantitative analysis of protease and substrate specificity based on real-time kinetic data, a characterisation of crude cell extracts and a high-throughput screen for protease inhibitors using FRET. A screen of the National Cancer Institute (NIC) diversity set for SenP1 inhibition reveals nine suitable compounds, which are potential anti-cancer drugs. The results of two further projects, the study of protein-protein binding by measuring small refractive index changes and the autofluorescence of normal and neoplastic cervical tissue models are also presented. In the latter, principal component analysis was used to systematically identify emission regions of significant variation between samples, enabling discrimination between healthy and pre-cancerous tissue models.