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A normalised cDNA library was constructed from the synganglia of unfed adult <i>R. sanguineus.  </i>Of interest from a drug discovery perspective were ESTs encoding a chitinase enzyme and four transmembrane receptors including two glutamate-gated chloride receptors, a leucokinin-like receptor and a nicotinic acetylcholine receptor (nAChR) α subunit. The nAChR α subunit was chosen for further study.  This is the first identified full-length arachnid nAChR subunit.  Phylogenetically it is most similar to insect α1 nAChR group and has been called Rsα1.  This subunit is expressed in larval, nymphal and adult stages and within partially fed adult females.  <i>Rsα1 </i>was most abundant in the synganglion and also present in Malpighian tubules and oviduct yet was undetected in the salivary glands and gut tissues.  Using two-electrode voltage clamp in <i>Xenopus laevis </i>oocytes, Rsα1 did not functionally express as a homomer or when co-expressed with the vertebrate chicken β2 subunit using either RNA or DNA.  Chimeric constructs consisting of the tick N-terminal and the transmembrane portion of the <i>D. melanogaster </i>α2 nAChR (Dα2) (Rsα1-Dα2) and vice-versa were prepared.  Responses to acetylcholine were obtained from the Dα2-Rsα1 chimera showing that the Rsα1 nAChR can form a functional pore region.  However, no responses were obtained from the Rsα1-Dα2 chimera.  This preliminary data suggests that the Rsα1 nAChR cannot form a functional ligand binding region when expressed in Xenopus oocytes. The present study has proven that the tick synganglion is a rich source of transmembrane receptor targets for exploitation in future drug discovery.

O valor extrínseco é uma das variáveis que mais carregam informações sobre o valor de uma opção; características como a probabilidade de exercício e a trajetória até o vencimento dizem muito sobre como o mercado está influenciando pelo menos a ação-objeto. Como o valor extrínseco é uma variável bastante sensível, é importante que sua mensuração seja a mais detalhada o possível. Este trabalho buscou captar a geração instantânea de valor intrínseco avaliando as cotações \"tick by tick\" das ações e opções de compra da VALE5, PETR4, OGXP3, BVMF3 e ITUB4 durante os anos de 2011 e 2012. Foi possível demonstrar que mesmo uma mínima diferença de valor extrínseco captado possibilitou uma maior capacidade de explicação em diferentes modelos testados, comparando com a captação de final de dia (EOD). / The intrinsic value is one of the variables that most carry information on the value of a stock option. Characteristics such as exercise probability and path to maturity summarize how the market is working at least for the stock. As extrinsic value is very sensitive, it is important that its measurements happen in the most possible detailed way. This study focus on capture the instantaneous extrinsic value generation, analyzing \"tick by tick\" quotes of VALE5, PETR4, OGXP3, BVMF3 e ITUB4 stocks and related call options in the years of 2011 and 2012. It was possible to demonstrate that even a minimal difference of extrinsic value captured resulted in a better explanation capacity based on different tested models, in comparison with the extrinsic value captured by end of day data.

Thesis (Ph. D.)--Washington State University, May 2007. / Includes bibliographical references.

Ticks belong to the ectoparasites which are dangerous for the human beings because of the transmission of bacterial, viral, and protozoan pathogens. The development of a vaccine against tick is very important. Cystatins play important role in tick digestion and they have an immunomodulation effects. For this reason cystatins are possible candidates for this vaccines. This thesis focuses on experimental mice vaccination with recombinant cystatin from Ixodes ricinus.

Cette thèse étudie certains évènements particuliers des carnets d’ordre - les ”trades traversants”. Dans le premier chapitre, on définit les trades traversants comme étant ceux qui consomment la liquidité présente dans le carnet d’ordres sur plusieurs limites, sans laisser le temps à la meilleure limite de se remplir par l’arrivée de nouveaux ordres limites. On étudie leurs propriétés empiriques en fournissant des statistiques de liquidité, de volume, de distribution de leurs temps d’arrivées, de clustering et de relaxation du spread. Leur impact de marché est supérieur à celui des trades classiques, et ce même à volume comparable : les trades traversants présentent donc un contenu informationnel plus grand. On propose deux applications au problème du lead-lag entre actifs/marchés, d’abord pour répondre à la question de savoir quel actif bouge en premier, et ensuite pour mesurer la force du signal des trades traversants dans le cadre d’une stratégie d’investissement basée sur le lead-lag entre actifs. Le chapitre suivant approfondit l’étude empirique du clustering de l’arrivée des trades traversants. On y modélise leur arrivée par des processus stochastiques auto-excités (les processus de Hawkes). Une étude statistique de la calibration obtenue avec des modèles à noyaux exponentiels pour la décroissance temporelle de l’impact est menée et assure une modélisation satisfaisante avec deux processus indépendants, un pour le bid et un pour l’ask. La classe de modèles proposée à la calibration est bien adaptée puisqu’il n’existe pas d’effet inhibiteur après l’arrivée d’un trade traversant. On utilise ces résultats pour calculer un indicateur d’intensité basé sur l’arrivée des trades traversants, et améliorer ainsi une stratégie d’investissement de type ”momentum”. Enfin, une calibration non-paramétrique du noyau de décroissance temporel d’impact fournit une décroissance empirique encore plus forte qu’une loi exponentielle, et davantage proche d’une loi-puissance. Le dernier chapitre rappelle une méthode générale de détection statistique de sauts dans des séries temporelles de prix/rendements qui soit robuste au bruit de microstructure. On généralise les résultats empiriques connus à de nouveaux indices financiers. On adapte cette méthode de détection statistique de sauts à des trajectoires intraday afin d’obtenir la distribution de la proportion de sauts détectés au cours de la journée. Les valeurs extrémales et les plus grandes variations de cette proportion se déroulent à des heures précises de la journée (14 :30, 15 :00 et 16 :30, heure de Paris), déjà rencontrées dans l’étude des trades traversants. Grâce à eux, on propose une explication des caractéristiques principales du profil intraday de la proportion de sauts détectés par le test, qui s’appuie sur une modification de la part relative de chacune des composantes de sauts dans la trajectoire des actifs considérés (la composante des mouvements continus et celle liée aux mouvements de sauts purs). / This thesis aims at studying particular events occurring in the limit order books - the ’tradesthrough’. In the first chapter, we define trades-through as those who consume the liquidity available on several limits of the limit order book, without waiting for the best limit to be filled with new incoming limit orders. We study their empirical properties and present statistics about their liquidity, their volume, their arrival time distribution, their clustering and the spread relaxation that follows their arrival. Their market-impact is higher than the one of the other trades, even with a comparable trading volume : trades-through have a higher informational content. We present two applications linked to the lead-lag between assets/markets : to find which asset moves first, and also to measure the trades-through intensity signal in a simple trading strategy based on lead-lag. The next chapter goes into more detail about the trades-through arrival time clustering. We model their arrival time with self-excited stochastic processes (Hawkes processes). A statistical study of the calibration obtained with models based on exponential-decay kernels for the temporal impact ensures a satisfactory modelling with two independent processes, one for the bid and one for the ask. The model class under scrutiny for the calibration is well-adapted as no inhibitory effects are measured after trades-through arrival. We use those results to compute an intensity indicator based on trades-through arrival, and thus we enhance a simple trading strategy that relies on them. Finally, a non-parametric calibration of the empirical decay kernel for the temporal impact of trades-through indicates a decrease faster than exponential, and closer to a power-law. The last chapter recalls a general statistical method robust to market microstructure noise to find jumps in prices/returns time series. We generalize the empirical results already known in the literature to new financial indices and we adapt this statistical jump detection method to intraday trajectories in order to obtain the intraday proportion of detected jumps. Extreme values and biggest intraday variations of this jump proportion occurs at very specific hours of the day (14:30, 15:00 and 16:30, Paris time reference), already linked with trades-through. Using trades-through, we explain the main characteristics of the intraday proportion of detected jumps with the test using a modification in the relative importance of each jump component in the assets trajectories (the continuous moves component and the pure-jumps component).

O valor extrínseco é uma das variáveis que mais carregam informações sobre o valor de uma opção; características como a probabilidade de exercício e a trajetória até o vencimento dizem muito sobre como o mercado está influenciando pelo menos a ação-objeto. Como o valor extrínseco é uma variável bastante sensível, é importante que sua mensuração seja a mais detalhada o possível. Este trabalho buscou captar a geração instantânea de valor intrínseco avaliando as cotações \"tick by tick\" das ações e opções de compra da VALE5, PETR4, OGXP3, BVMF3 e ITUB4 durante os anos de 2011 e 2012. Foi possível demonstrar que mesmo uma mínima diferença de valor extrínseco captado possibilitou uma maior capacidade de explicação em diferentes modelos testados, comparando com a captação de final de dia (EOD). / The intrinsic value is one of the variables that most carry information on the value of a stock option. Characteristics such as exercise probability and path to maturity summarize how the market is working at least for the stock. As extrinsic value is very sensitive, it is important that its measurements happen in the most possible detailed way. This study focus on capture the instantaneous extrinsic value generation, analyzing \"tick by tick\" quotes of VALE5, PETR4, OGXP3, BVMF3 e ITUB4 stocks and related call options in the years of 2011 and 2012. It was possible to demonstrate that even a minimal difference of extrinsic value captured resulted in a better explanation capacity based on different tested models, in comparison with the extrinsic value captured by end of day data.

No description available.

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No description available.