In order to identify new players in fruit development, a forward genetic screen was performed on EMS mutagenized plants. A mutant named elongated gynophore (egy) was identified in the M2 population based on altered fruit morphology. Genetic analysis established that the egy phenotype is due to a monogenic and recessive mutation. The egy plants show additional developmental defects including shorter root, narrower cotyledons and malformed leaf lamina. Molecular mapping and whole genome sequencing analyses showed a G/C deletion at the position 4414980 on the AT5G13680 gene locus which is predicted to encode the ELONGATA2 (ELO2) protein. ELO2 is a constituent member of the elongator complex which helps in transcriptional elongation in association with the phosphorylated form of RNA polymerase II. This complex has been implicated in controlling development, abiotic stress and biotic stress. Genetic complementation test confirmed that egy is indeed allelic to elo2-3. Surprisingly, the EGY overexpression line 35S::EGY showed loss-of-function phenotype, suggesting transgene silencing. In angiosperms, fruit is derived from the fertilized ovary. The initiation of the female reproductive organ commences with a lump of cells which eventually develops into the gynoecium with a stigma, a style, two fused ovaries and a gynophore, arranged from the apical to basal axis in that order. Genetic networks faithfully shapes up the carpel primordium into predetermined gynoecium shape. Following fertilization, siliques elongate concomitantly with developing embryos. Here we show that the egy mutant has apical basal patterning defect with longer gynophore at the base. This gynophore phenotype resembles the phenotype found in the mutants with altered auxin and cytokinin levels/signaling. We show that egy is hypersensitive to cytokinin treatment; egy fruits treated with cytokinin display phenotype similar to the plants expressing IPT7 under fruit-specific promoter. These results suggest that broadened shoulders at the apical region of egy gynoecium possibly results from higher cytokinin level/response. Genetic interaction studies have shown that EGY act independent of AGAMOUS and PEAPOD to suppress the medio-lateral growth of the apical gynoecium region. Genetic and expression studies suggest that PINOID and TMO5/T5L1 work downstream to EGY, while ETTIN acts in parallel to EGY. We also observed larger seeds in the egy mutant and show that this is controlled maternally. Thus, the gametic lethality in egy can possibly be accounted for by the defective ovules. We show that egy primary roots are shorter compared to Col-0, though egy seeds have longer embryonic root to begin with, suggesting a defect in cell division. The root cells are arranged radially in a stereotypic pattern in root meristem from the outer epidermis to the inner stele specific the vascular bundles. The four QC cells are also surrounded by stem cells of various identities. This stereotypic pattern of cell arrangement is perturbed in the egy root. The stele, composed of pericycle and vascular bundles is reduced in the egy mutant, suggesting a positive role of EGY in vascular cell division. Confocal microscopic studies and real-time PCR data suggest that TMO5/T5L1 work downstream to EGY. Thus, the Arabidopsis „ELONGATOR‟ complex regulates the transcription of target genes that are necessary for plant growth and development. A proposed genetic network for the role of EGY in fruit and root development. Based on the genetic interaction studies and expression analysis, we have placed EGY in the existing molecular network that control fruit and root vascular development in Arabidopsis

This thesis presents a part of the research work at Virginia Tech on developing a prototype automatic luggage scanner for explosive detection, and it deals with the automatic detection of elongated objects (detonators) in x-ray images using matched filtering, the Hough transform, and information fusion techniques. A sophisticated algorithm has been developed for detonator detection in x-ray images, and computer software utilizing this algorithm was programmed to implement the detection on both UNIX and PC platforms. A variety of template matching techniques were evaluated, and the filtering parameters (template size, template model, thresholding value, etc.) were optimized. A variation of matched filtering was found to be reasonably effective, while a Gabor-filtering method was found not to be suitable for this problem. The developed software for both single orientations and multiple orientations was tested on x-ray images generated on AS&E and Fiscan inspection systems, and was found to work well for a variety of images. The effects of object overlapping, luggage position on the conveyor, and detonator orientation variation were also investigated using the single-orientation algorithm. It was found that the effectiveness of the software depended on the extent of overlapping as well as on the objects the detonator overlapped. The software was found to work well regardless of the position of the luggage bag on the conveyor, and it was able to tolerate a moderate amount of orientation change. / Master of Science

Eagle syndrome is a rare clinical condition that is characterized by either an elongated styloid process or a calcified stylohyoid ligament. This report describes the case of a 35-year-old woman who presented with Eagle syndrome following the treatment of recurrent laryngeal carcinoma with ionizing radiation.

Ca2+ is a nutrient for plant development, and its deficiency causes poor cellular development in tomato fruits, resulting in a physiological disorder known as blossom-end rot (BER). Studies on this physiological disorder are not recent and mainly focused on Ca2+ deficiency in tissues and on the interaction between plant and the environment. However, new research has been based on hormonal interaction and oxidative mechanisms in fruits. Hormones such as gibberellins, abscisic acid, and brassinosteroids have been implicated in both activation and inhibition of BER symptoms. The application of abscisic acid and epibrasinolide decreased fruit susceitibility to BER. Abscisic acid reduces leaf transpiration, inhibiting xylem sap and calcium flow into the leaves and increasing into the fruit. Epibrassinolide increased fruit antioxidant responses, decreasing hydrogen peroxide and increasing ascorbic acid content, as well as increasing ascorbate peroxidase, catalase, and superoxide dismutase activities. In addition, the selection of varieties more tolerant to BER and the identification of factors that make new varieties resistant are important tools in the selection of new varieties. In this study, many varieties were evaluated in order to understand the relationship between fruit shape and growing environment on BER incidence in the fruit. According to the results, elongated fruit varieties showed higher susceptibility to BER. / O Ca2+ é um nutriente para o desenvolvimento de plantas, e sua deficiência causa mal desenvolvimento celular em frutos de tomate, resultando em desordem fisiológica conhecida como podridão apical ou blossom-end rot (BER). Estudos sobre esta desordem fisiológica não são recentes e são focados principalmente na deficiência de Ca2+ nos tecidos e na interação entre planta e meio ambiente. No entanto, novas pesquisas têm se baseado na interação hormonal e nos mecanismos oxidativos como reguladores desta disordem fisiológica nos frutos. Hormônios como giberelinas, ácido abscísico e brassinosteróides têm sido implicados tanto na ativação quanto na inibição dos sintomas de BER. A aplicação de ácido abscísico e epibrassinolideo diminuiu a incidência de BER, reduzindo a concentração de Ca2+ nas folhas e aumentando-as nos frutos. A aplicação de ácido abscísico provocou diminuição na transpiração, o que explica a mudança no fluxo de seiva e cálcio no xilema que conduz da folha para fruto. O epibrassinolideo, por outro lado, aumentou a resposta antioxidante, diminuindo as concentrações de peróxido de hidrogênio e aumentando as de ácido ascórbico, ascorbato peroxidase, catalase e superóxido dismutase nos frutos. A seleção de genótipos mais tolerantes ao aparecimento de BER e a identificação de fatores que os tornam resistentes, são ferramentas importantes no processo de seleção de novas variedades. Neste trabalho, foram estudados muitos genótipos para compreender a relação entre a forma do fruto e o ambiente de crescimento sobre a incidência de BER. De acordo com os resultados obtidos, genótipos alongados são mais susceptíveis a podridão apical.

L'objectif de cette thèse, la production et la caractérisation de nanovéhicules de morphologies différentes propres au traitement et au diagnostic par radio-isotopes, a conduit à une meilleure compréhension de la façon dont ces véhicules se forment. Les résultats ont permis de concevoir des méthodes de préparation novatrices qui permettent d'obtenir des échantillons de qualité supérieure à ce qui est actuellement l'état de l'art. Un nouveau procédé pour la préparation d'échantillons pour les essais de flexion de microscopie à force atomique a été développé. Cela a permis de mesurer le module d'élasticité de nanofils préparés avec des mélanges copolymère séquencé/homopolymère de composition variable. Enfin, les nanoparticules de morphologies sphérique et allongée ont été comparées dans des études in vivo réalisées avec des souris saines. Les résultats montrent que leur temps de circulation et leur biodistribution peuvent être modulés par leur taille et leur morphologie. / This thesis provides an overview of the formation, characterization and testing of micelles of different morphology for biological applications. One major aspect of this thesis is the understanding of the processes which lead to the formation of block copolymer micelles through the emulsion evaporation method. The results obtained made it possible to develop an innovative micelle formation technique which provides samples which are of superior quality to what the current state of the art. A new method has been developed for the preparation of samples for three point bending tests experiments performed by atomic force microscopy. This has made it possible to determine the elastic modulus of elongated micelles formed with various blends of homopolymers and copolymers. Finally, the behavior of spherical and elongated micelles was compared in vivo in healthy mice. The results have shown that the micelle size and morphology influences their biodistribution and circulation time.

The binding of molecular hydrogen to a metal center leads to the elongation of the H−H bond and subsequently to its cleavage along the reaction coordinate for the oxidative addition of H2. There has been considerable interest in the study of the activation of dihydrogen and map out the reaction coordinate for the homolysis of H2 on a metal center. A large number of H2 complexes reported to date possess H−H distances ranging from 0.8 to 1.0 Å. A relatively fewer examples of elongated dihydrogen complexes wherein the H−H distances fall in the range of 1.0 to 1.5 Å, are known. Study of the elongated dihydrogen complexes is of great significance because of its relevance in important catalytic processes such as hydrogenation, hydrogenolysis, and hydroformylation. Objectives The objectives of this work are as follows: (a) Synthesis and characterization of elongated dihydrogen complexes with chelating phosphine coligands by varying the electron donor ability. (b) Trap the various intermediate states in the process of oxidative addition of H2 to a metal center. (c) Map the reaction coordinate for the oxidative addition for the oxidative addition of H2 to a metal center. Results We have synthesized and characterized two new elongated dihydrogen complexes cis-[Ir(H)(η2-S2CH)(η2-H2)(PR3)2][BF4] (PR3 = PCy3, PPh3) wherein hydrogen atom undergoes site exchange between the H2 and the hydride sites. The dynamics of the exchange was studied using NMR spectroscopy. In addition, a series of ruthenium dihydrogen complexes of the type trans-[Ru(Cl)(η2-H2)(PP)][BF4] (PP = 1,2- Synopsis bis(diarylphosphino)ethane) has been synthesized and characterized wherein the aryl group is a benzyl moiety with a substituent (p-fluoro, H, m-methyl, p-methyl, p-isopropyl); in this series of complexes, a small increment in the electron donor ability (decrease in Hammett substituent constants) of the chelating phosphine ligand resulted in an elongation of the H−H bond by a small, yet significant amount. We also synthesized a series of 16-electron dicationic dihydrogen complexes bearing elongated dihydrogen ligand. In addition, we prepared a series of dihydrogen complexes of the type [RuCp/Cp*(PP)(η2-H2)][OTf] (PP = 1,2-bis(diarylphosphino)ethane, 1,2-bis(diarylphosphino)methane, 1,2-bis(dialkylphosphino)methane) bearing elongated H2 ligand (dHH = 1.0 to 1.17 Å); in this series of complexes as well, we found that the H−H bond distances increased as the donor ability of the chelating phosphines increased in small increments, along the reaction coordinate for the oxidative addition of H2 to a metal center. This investigation therefore, has established a very nice correlation between the H−H bond lengths and the Hammett substitutent constants (donor properties) resulting in the construction of dihydrogen complexes along the reaction coordinate for the oxidative addition of H2 to a metal center.

Sécuriser un approvisionnement fiable de micro-algues est récemment devenu un enjeu industriel. Pour assurer la croissance de micro-algues dans des photobioréacteurs clos, un transfert de masse optimum de l'oxygène et du dioxyde de carbone doit être assuré. Dans cette thèse, une étude du transfert de masse gaz-liquide dans les conduites horizontales a été menée. Dans les trois premiers chapitres, un modèle unidimensionnel de transfert de masse dans le photobioréacteur a été développé. Tout d'abord, le transfert de masse entre une bulle de gaz allongée et un écoulement liquide turbulent a été 'étudié expérimentalement. En considérant l'interface comme étant plane, les coefficients de transfert de masse mesurés sont proches d'une corrélation de Lamourelle (1972). Le modèle de Taitel pour les écoulements stratifiés a été comparé à des modèles plus complets pour la prédiction de l'interface des bulles allongées. Une approche analytique basée sur un bilan de masse et utilisant les modèles testés a ensuite été développée et adaptée à un photobioréacteur afin de prédire l'efficacité de la conversion du CO2 en biomasse en fonction des paramètres d'exploitation. Les deux derniers chapitres visent à développer une simulation numérique du transfert de masse gaz-liquide. Une mesure de la concentration en CO2 dans le sillage d'une bulle de gaz ascendante a été effectuée à l'aide d'une méthode améliorée de traitement des données de Fluorescence Induite par Plan Laser (FIPL). Enfin, une simulation numérique a été réalisée sous COMSOL / Securing a reliable supply of microalgae has recently become an industrial stake. To ensure successful growing of microalgae in enclosed, tubular photobioreactor systems as in Microphyt, an optimum mass transfer of oxygen and carbon dioxide should be secured. In this thesis an investigation of the gas-liquid mass transfer in horizontal pipes has been conducted. In the first three chapters, a one dimensional mass transfer model in horizontal gas-liquid flows will be developed and applied to horizontal photobioreactors. Firstly, a study of mass transfer between an elongated gas bubble under a turbulent liquid flow immobilized in a duct has shown that under the hypothesis considering the interface as a flat plane estimated, the measured mass transfer coefficients appear to be well fitted by a correlation from Lamourelle (1972). The interface prediction for stratified flows have been compared to more complete unit-cell models for intermittent flow interface and found to be a good first estimate. The photobioreactor’s conversion efficiency of CO2 into biomass as a function of operating parameters is investigated using an analytical approach to complete the mass balance and classical two-phase flow approach from Taitel (1976). The last two chapters aim at developing a numerical simulation of gas-liquid mass transfer. A measurement of CO2 wake structures behind free rising bubbles have realized using an improved data treatment method for Planar laser-induced fluorescence (PLIF) and pH sensitivity of fluorescein sodium. Finally, an implementation of the experimental measurements under COMSOL has been realised

Notre stratégie de stockage d’électrons repose sur la formation et la rupture de liaisons chimiques fonctionnant comme des réservoirs d’électrons. Le processus de formation réversible de liaisons est rendu possible grâce à la pré-organisation de groupements électroactifs – des pyridiniums – autour de plateformes aromatiques rigides et semi-rigides. Le relargage des électrons stockés au sein des réservoirs d’électrons par rupture de liaison suggère de manipuler des liaisons de nature affaiblie, c’est-à-dire allongées et contraintes stériquement, comme celles résultantes d’interactions hors-du-plan des groupements électrophoriques. Les contraintes stériques permettent ainsi la formation et la rupture de ces liaisons dans une gamme d’énergie raisonnable. Les pyridiniums sont des unités électrophoriques de choix dû à la versatilité de leurs propriétés de réduction. Les assemblages obtenus sont des systèmes bistables qui montrent des propriétés électrochimiques hystérétiques remarquables. En général, ce comportement repose sur la proche proximité des groupements électrophoriques qui permettent la formation d’une (ou plusieurs) orbitale(s) supramoléculaire(s) vacante(s) et liante(s) (SupLUMOs). Lors de la réduction, cette orbitale accueille deux électrons créant ainsi la liaison d’intérêt. Une famille de composés modèles a ainsi été conçue et synthétisée impliquant la formation réversible de liaisons homonucléaires (Csp3‒Csp3). Ces liaisons sont de nature localisée dans des systèmes à deux pyridiniums (bi-électroniques) et délocalisée dans des systèmes de plus de deux pyridiniums. / Our strategy to store electrons is based on chemical bond formation/cleavage being used as electron reservoirs. Reversible bond formation results from the preorganization of electrophoric moieties – pyridiniums – around aromatic rigid and semi-rigid scaffold. Using lower energy bonds is required to release stored electrons from the reservoirs. Such bonds can be obtained from sterically hindered out-of-plan bond formation between two electrophorical subunits. The resulting elongated bond can be cleaved in an available level of energy. Pyridiniums are prime candidates to achieve such properties based on their noteworthy redox behavior. The resulting molecular devices are bistable systems that display remarkable hysteretic electrochemical properties, based on close proximity of electrophoric subunits allowing one (or more) unoccupied supramolecular bonding orbital(s) (SupLUMOs). Upon reduction, two electrons are injected in this orbital resulting in the bond of interest. An entire family of compounds has been designed and synthesized to highlight reversible homonuclear bond formation (Csp3‒Csp3). Those bonds are localized in the case of a two-pyridiniums system, and delocalized when more pyridiniums are involved.

A new algorithm for detection of longitudinal crack-like indications in radiographic images is developed in this work. Conventional local detection techniques give unsatisfactory results for this task due to the low signal to noise ratio (SNR ~ 1) of crack-like indications in radiographic images. The usage of global features of crack-like indications provides the necessary noise resistance, but this is connected with prohibitive computational complexities of detection and difficulties in a formal description of the indication shape. Conventionally, the excessive computational complexity of the solution is reduced by usage of heuristics. The heuristics to be used, are selected on a trial and error basis, are problem dependent and do not guarantee the optimal solution. Not following this way is a distinctive feature of the algorithm developed here. Instead, a global characteristic of crack-like indication (the estimation function) is used, whose maximum in the space of all possible positions, lengths and shapes can be found exactly, i.e. without any heuristics. The proposed estimation function is defined as a sum of a posteriori information gains about hypothesis of indication presence in each point along the whole hypothetical indication. The gain in the information about hypothesis of indication presence results from the analysis of the underlying image in the local area. Such an estimation function is theoretically justified and exhibits a desirable behaviour on changing signals. The developed algorithm is implemented in the C++ programming language and testet on synthetic as well as on real images. It delivers good results (high correct detection rate by given false alarm rate) which are comparable to the performance of trained human inspectors. / In dieser Arbeit wurde ein neuer Algorithmus zur Detektion rissartiger Anzeigen in der digitalen Radiographie entwickelt. Klassische lokale Detektionsmethoden versagen wegen des geringen Signal-Rausch-Verhältnisses (von ca. 1) der Rissanzeigen in den Radiographien. Die notwendige Resistenz gegen Rauschen wird durch die Benutzung von globalen Merkmalen dieser Anzeigen erzielt. Das ist aber mit einem undurchführbaren Rechenaufwand sowie Problemen bei der formalen Beschreibung der Rissform verbunden. Üblicherweise wird ein übermäßiger Rechenaufwand bei der Lösung vergleichbarer Probleme durch Anwendung von Heuristisken reduziert. Dazu benuzte Heuristiken werden mit der Versuchs-und-Irrtums-Methode ermittelt, sind stark problemangepasst und können die optimale Lösung nicht garantieren. Das Besondere dieser Arbeit ist anderer Lösungsansatz, der jegliche Heuristik bei der Suche nach Rissanzeigen vermeidet. Ein globales wahrscheinlichkeitstheoretisches Merkmal, hier Schätzfunktion genannt, wird konstruiert, dessen Maximum unter allen möglichen Formen, Längen und Positionen der Rissanzeige exakt (d.h. ohne Einsatz jeglicher Heuristik) gefunden werden kann. Diese Schätzfunktion wird als die Summe des a posteriori Informationsgewinns bezüglich des Vorhandenseins eines Risses im jeden Punkt entlang der hypothetischen Rissanzeige definiert. Der Informationsgewinn entsteht durch die Überprüfung der Hypothese der Rissanwesenheit anhand der vorhandenen Bildinformation. Eine so definierte Schätzfunktion ist theoretisch gerechtfertigt und besitzt die gewünschten Eigenschaften bei wechselnder Anzeigenintensität. Der Algorithmus wurde in der Programmiersprache C++ implementiert. Seine Detektionseigenschaften wurden sowohl mit simulierten als auch mit realen Bildern untersucht. Der Algorithmus liefert gute Ergenbise (hohe Detektionsrate bei einer vorgegebenen Fehlalarmrate), die jeweils vergleichbar mit den Ergebnissen trainierter menschlicher Auswerter sind.

This thesis concentrates on the design of crank-type mechanism of engine with elongated expansion. The main attention is paid to examination of the progress of kinematic quantities and inertial forces in mechanism. Further on in the thesis, the analysis of piston-rod stress is carried out and is compared to the piston-rod of standard engine. In the last part of the thesis, there is an evaluation of advantages and disadvantages of the proposed mechanism solution.