Wind farms are costly projects and prior to the construction, comprehensive wind resource assessment processes are carried out in order to predict the future energy yield with a reliable accuracy. These estimations are made to constitute a basis for the financial assessment of the project. However, predicting the future always accommodates some uncertainties and sometimes these assessments might overestimate the production. Many different factors might account for a discrepancy between the pre-construction wind resource assessment and the operational production data. This thesis investigates an underperforming wind farm in order to ascertain the reasons of a discrepancy case. To investigate the case, the relevant data and information along with the actual production data of three years are shared with the author. Prior to the construction, a wind resource assessment was carried out by an independent wind consultancy company and the work overestimated the annual energy production (AEP) by 19.1% based on the average production value of available three years. An extensive literature review is performed to identify the possible contributing causes of the discrepancy. The data provided is investigated and a new wind resource assessment is carried out. The underestimation of the wind farm losses are studied extensively as a potential reason of the underperformance. For the AEP estimations, WAsP in WindPro interface and WindSim are employed. The use of WindSim led to about 2-2.5% less AEP estimations compared to the results of WAsP. In order to evaluate the influence of long term correlations on the AEP estimations, the climatology datasets are created using the two different reanalysis datasets (MERRA and CFSR-E) as long term references. WindSim results based on the climatology data obtained using the MERRA and CFSR-E datasets as long term references overestimated the results by 10.9% and 8.2% respectively.

This thesis is concerned with various aspects of the detection and characterisation of transiting extra-solar planets. The noise properties of photometric data from SuperWASP, a wide-field survey instrument designed to detect exoplanets, are investigated. There has been a large shortfall in the number of planets such transit surveys have detected, compared to previous predictions of the planet catch. It has been suggested that correlated, or red, noise in the photometry is responsible for this; here it is confirmed that red noise is present in the SuperWASP photometry, and its effects on planet discovery are quantified. Examples are given of follow-up photometry of candidate transiting planets, confirming that modestly-sized telescopes can rule out some candidates photometrically. A Markov-chain Monte Carlo code is developed to fit transit lightcurves and determine the depth of such lightcurves in different passbands. Tests of this code with transit data of WASP-3 b are reported. The results of a search for additional transiting planets in known transiting planetary systems are presented. SuperWASP photometry of 24 such systems is searched for additional transits. No further planets are discovered, but a strong periodic signal is detected in the photometry of WASP-10. This is ascribed to stellar rotational variation, the period of which is determined to be 11.91 ± 0.05 days. Monte Carlo modelling is performed to quantify the ability of SuperWASP to detect additional transiting planets; it is determined that there is a good (> 50 per cent) chance of detecting additional, Saturn-sized planets in P ~ 10 day orbits. Finally, the first-ever attempt to detect the secondary eclipse of a transiting extra-solar planet at radio wavelengths is made. Although no eclipse is conclusively detected, upper limits to the flux density from HD 189733 b are established, and compared to theoretical predictions of the flux due to electron-cyclotron maser emission.

La plupart des études sur l’influence de la température sur la production des spermatozoïdes portent en grande partie sur les vertébrés. Néanmoins, les invertébrés constituent la majorité de la biodiversité terrestre animale, sont également plus sensibles à ces variations de température. Les travaux réalisés au cours de cette thèse ont porté sur la compréhension des capacités de reproduction, et sur l’influence d’une augmentation de température sur les fonctions mâles chez Nasonia vitripennis, un hyménoptère parasitoïde. Ce travail de thèse m’a permis de confirmer que chez cette espèce, la spermatogenèse était synchronisée et de décrire pour la première fois, un système de stockage intermédiaire des spermatozoïdes entre les testicules et les vésicules séminales. De plus, j’ai pu mettre en évidence que la spermatogénèse était sensible à une augmentation de température pendant le développement, altérant le sexe ratio de la descendance par des modifications d’allocations des sexes par les femelles. Ces résultats apportent de nouvelles connaissances sur la fertilité mâle chez cette espèce et démontrent la sensibilité de la spermatogenèse à la température. / Many studies on the impact of the temperature on spermatogenesis have largely focused on vertebrates. Nevertheless, invertebrates constitute the vast majority of terrestrial biodiversity, and are especially vulnerable to variations of temperatures. The studies realized during my thesis are focused on understanding male reproductive capacities and effects of heat stress on male fertility in a parasitic wasp Nasonia vitripennis. This work allowed to confirm that spermatogenesis was synchronized, and to describe for the first time a system of spermatozoa regulation between testis and seminal vesicles. Moreover, I was able to demonstrate that spermatogenesis was sensible to temperature variation during male development, and the offspring sex ratio was altered by modifications of sex allocation. These findings open the way to the description of male fertility in this species, and show the sensitivity of spermatogenesis to temperature variation.

Die Wespengiftallergie stellt eine typische allergische Sofortreaktion dar. Für diese IgE-vermittelten, pathologischen Immunreaktionen ist die spezifische Immuntherapie (IT) die einzige zur Zeit zur Verfügung stehende kausale Therapie. Die Wirkmechanismen sind trotz intensiver Bemühungen weiterhin nicht vollständig aufgeklärt. Als wichtigste These wird zur Zeit eine Verlagerung des pathologischen, TH2-dominierten Zytokinmilieus in Richtung "normales" TH1-Milieu diskutiert. Es wurde auch eine reduzierte Mediatorfreisetzung von Effektorzellen, eine verminderte Leukozytenproliferation, eine verminderte Endorganantwort und charakteristische Ig-Titer-Veränderungen mit initialem Anstieg und längerfristigem Abfall des sIgE und Anstieg des sIgG4 beschrieben. In der vorliegenden Arbeit wurde der Einfluß der IT auf periphere B-Zellen hinsichtlich ihrer Ig-Produktion und ihres Phänotyps untersucht. 15 Patienten mit systemischen Reaktionen nach Wespenstich, Nachweis von spezifischem IgE und positivem Hauttest, bei denen eine Schnell-Immuntherapie eingeleitet wurde, wurden vor Beginn der Therapie (Tag 1), am Tag ihrer Entlassung (Tag 6), also einen Tag, nachdem die Erhaltungsdosis von 100 µg erreicht wurde, und vor der 2. ambulanten Allergeninjektion am 26. Tag untersucht. Die Expression von CD5, CD23, CD32, CD40, CD54, CD86, CD95, HLA-I-ABC und HLA-II-DR wurde auf peripheren mononukleären Blutzellen durchflußzytometrisch bestimmt. Anti-CD19 FITC wurde als spezifischer B-Zellmarker benutzt. Die Serum-Titer des Gesamt-IgE, Wespengift-spezifischen IgE und Wespengift-spezifischen IgG4 wurden mittels ELISA bestimmt. Zur statistischen Auswertung wurde der Wilcoxontest für nicht-parametrische, verbundene Daten benutzt. Die Expression von CD54, CD5, CD32 und HLA-II-DR wurde durch die IT signifikant und die von CD23 tendentiell modifiziert. So war die Expression dieser Moleküle auf der Oberfläche peripherer B-Zellen am Tag 6 im Vergleich zum Ausgangswert vom Tag 1 reduziert. Am 26. Tag wurden wieder Werte auf der Höhe der Ausgangswerte vom Tag 1 gemessen. Dagegen veränderte sich die Expression von CD40, CD86, CD95 und HLA-I-ABC während der untersuchten Zeitpunkte nicht. Die Ig-Titer veränderten sich in der für die IT charakteristischen Weise. So stieg nach 3 Wochen der Gesamt-IgE-, sIgE- und sIgG4-Titer hochsignifikant an. Die Expression der untersuchten Oberflächenmoleküle ist als Indikator für Veränderungen der Aktivationslage und des funktionellen Status der Zellen während der IT zu interpretieren. So spricht die Reduktion der Expression von CD32, CD54 und HLA-II für eine verminderte Aktivierungslage der peripheren B-Zellen. Ferner deutet die Reduktion von CD5 und CD32 auf eine Anergie der B-Zellen hin. Durch die reduzierte Expression von CD23 und CD54 könnte die T-B-Zell-Interaktion verschlechtert werden, die für die Effektorfunktionen beider Zellen bedeutsam ist.Einen wesentlichen Beitrag zur Wirksamkeit der IT könnte auch die verminderte Expression des HLA-II leisten, da HLA-II für die Ag-Präsentation essentiell ist. In dieser Arbeit wurde gezeigt, daß die spezifische Immuntherapie einen Einfluß nicht nur auf die Ig-Produktion der B-Zellen hat, sondern auch auf deren Phänotyp. Dies könnte Hinweise auf bisher nicht bekannte Mechanismen bieten, die an der Wirksamkeit der IT beteiligt sind. / Wasp-venom allergy is a typical IgE-mediated allergic reaction. Specific immunotherapy (IT) is the only currently available causal therapy for IgE-mediated allergies. The mechanisms responsible for the efficacy of IT are still not fully understood. So far, the main focus of research has been on changes of T-helper cell (TH) cytokine production with a shift from TH2 to TH1 cytokines. Reduced mediator secretion from effector cells of allergic reactions, decreased leukocyte proliferation, lowered responsiveness of end organs and changes in immunoglobulin levels have been reported as well. The purpose of this study was to investigate the influence of IT on phenotype and Ig-production of B-lymphocytes. 15 venom allergic patients with a history of systemic reactions after a wasp sting and venom-specific skin test reactivity as well as serum IgE were investigated before VIT (day 1), one day after reaching maintenance dose of 100 µg (day 6) during inpatient rush VIT, and again on day 26 during continued outpatient maintenance therapy. Changes in the serum levels of total IgE, allergen-specific IgE (sIgE) and sIgG4 were measured by ELISA. Expression of CD5, CD23, CD32, CD40, CD54, CD86, CD95, HLA-I-ABC and HLA-II-DR on double labeled B cells was studied by flow cytometry of peripheral blood mononuclear cells. On day 6, cell surface expression of CD54, CD5, CD32 and HLA-II-DR was decreased significantly in intensity and numbers of positive cells, compared to day 1, while on day 26, expression of these molecules approached again baseline levels. Furthermore, a trend to decreased CD23 was noted on day 6. No changes were observed for CD40, CD86, CD95 and HLA-I-ABC. Levels of total IgE, sIgE and sIgG4 showed a significant increase after 26 days of VIT. These data show that initiation of rush VIT has profound effects on B-cell phenotype and Ig-production. Reduced expression of surface molecules can be interpreted as a reduction of activation status of B-cells as well as reduced ability to present antigen and to costimulate other leukocytes. B cells may thus be additional direct or indirect targets of high dose antigen therapy and contribute to the efficacy of IT.

Made available in DSpace on 2014-06-11T19:30:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-08-18Bitstream added on 2014-06-13T19:19:38Z : No. of bitstreams: 1 cabrera_mps_dr_sjrp.pdf: 1625766 bytes, checksum: 6073fec2bef34125e9db4700102a3680 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Neste trabalho estudamos a conformação em ambientes anisotrópicos e a atividade lítica em vesículas aniônicas e zwitteriônicas de um conjunto de peptídeos biologicamente ativos, extraídos de veneno de vespas solitárias, que se caracterizam por usar seus venenos para paralisar as presas com as quais alimentam suas larvas. Esses peptídeos que são desgranuladores de mastócitos, apresentam atividade antimicrobiana e a maioria deles não é hemolítica. Possuem entre 10 e 15 resíduos, são catiônicos, com alta proporção de resíduos carregados e polares, e são lineares e helicoidais em meios miméticos de membranas. Buscamos correlacionar a atividade lítica em vesículas de diferentes composições, analisada em experimentos de fluorimetria, às mudanças conformacionais, induzidas por diferentes ambientes miméticos, monitoradas por dicroísmo circular, complementando com a análise das características físico-químicas como comprimento da cadeia, amidação do terminal-C, carga líquida, influências no macrodipolo da hélice, hidrofobicidade, momento hidrofóbico e ângulo polar. Observamos que estes peptídeos apresentam intensa atividade em membranas modelo, interagem preferencialmente com bicamadas aniônicas, e sua atividade lítica acontece de modo cooperativo tanto em vesículas aniônicas como nas zwitteriônicas. Com exceção de Anoplin, todos os peptídeos com ação antimicrobiana apresentam curvas de dose-resposta que mostram uma dependência sigmoidal com a concentração do peptídeo. Isso sugere que esses peptídeos se acumulam na superfície da vesícula até atingir uma concentração crítica, além da qual o vazamento aumenta cooperativamente. De uma forma geral os peptídeos mais eficientes como antimicrobianos, são também aqueles caracterizados pela maior eficiência em permeabilizar vesículas aniônicas do tipo PCPG 7030 e por baixas razões limite P/L. / Solitary wasps use their venoms to paralise prays to feed their larvae. A set of biologically active peptides, obtained from these venoms, have been investigated in relation to the conformational changes they undergo in anisotropic environments and their lytic activity on zwitterionic and anionic vesicles. These peptides are mast cell degranulators, present antimicrobial activities and most of them are not hemolytic. They are cationic, their chain length are 10 to 15 residues long, with high hydrophilic / hydrophobic ratio; they are linear and helical in membrane mimetic environments. We searched correlation between the lytic activity in vesicles of different compositions, monitored in fluorimetric experiments, and conformational changes, induced by varied mimetic media, monitored by circular dichroism. The results have been also correlated with peptides' physical-chemical parameters such as chain length, amidated or carboxylated C-terminal, net charge, influences on the helix macrodipole, hydrophobicity, hydrophobic moment and polar angle. We observed that these peptides present intense activity on model membranes, they interact preferentially with anionic bilayers, and their lytic activity is a cooperative process either in anionic or in zwitterionic vesicles. Exception made to Anoplin, all the other peptides that have antimicrobial activity present in their dose-response curves a sigmoidal dependence with the peptide concentration. This fact suggests that these peptides accumulate on the vesicles surface until they reach a threshold concentration, beyond which leakage increases cooperatively. As a general rule, the most efficient antimicrobial peptides are also those characterized by efficient permeabilization of anionic vesicles, namely PCPG 7030 and by small threshold P/L ratios.

La localisation des sources infrasonores est un exercice difficile, de par les grandes distances de propagation en jeu et en raison de la complexité du milieu atmosphérique. La compréhension de la propagation des ondes, le rôle et l'influence de l'atmosphère et de ses variations spatiales et temporelles, la connaissance des sources et des différents paramètres de détection, mais aussi la configuration et la répartition des stations du réseau de surveillance sont autant d'informations essentielles pour appréhender cet exercice. Dans l'optique de de l'obtention de localisations précises des évènements infrasonores, deux méthodes de construction de tables de propagations dépendant des stations, de la date et de l'heure sont introduites. Ces tables se basent sur des simulations par tracé de rayons par WASP-3D Sph (Windy Atmospheric Sonic Propagation), outil intégrant l'estimation de l'amplitude à l'aide de rais paraxiaux et la prise en compte des champs de vents horizontaux, en espace et en temps, le longs des trajectoires des rais. Les deux méthodes sont ensuite discutées et leurs performances comparées. Les tables sont centrées sur le récepteur, elles décrivent les variations spatiales des principaux observables infrasonores. Celles-ci offrent alors un instantané de la propagation atmosphérique dépendant de la distance entre la source et le récepteur, pour tout type de phases simulées. Pour chaque trajectoire de rai, les paramètres de propagation tels que la célérité, la déviation d'azimut, l'atténuation et l'altitude de retour sont prédits et permettent la construction des tables. Ces dernières aident à identifier les phases détectées et sont intégrées dans une démarche précise de localisation de source. La procédure de localisation est ensuite testées sur plusieurs cas d'études, tels que l'explosion d'une conduite de gaz à Ghislenghien, Belgique, le 30 juillet 2004, l'explosion d'une usine militaire à Novaky, Slovaquie, le 2 mars 2007 ou encore l'explosion du dépôt de carburant de Buncefield, Angleterre, le 11 décembre 2005. Les spécificités de chacun des évènements, les paramètres de propagations et les configurations utilisées pour les trois cas sont également introduites. L'accent est mis sur la précision de la localisation et son optimisation. Une étude de validation des tables de propagation est enfin abordée en considérant des stations du Système de Surveillance Internationale (SSI) situées le long d'un méridien - I18DK (Groenland, Danemark), I51UK (Bermudes, Angleterre), I25FR (Guyane, France), I08BO (La Paz, Bolivie), I01AR (Paso Flores, Argentine), I02AR (Ushuaia, Argentine), I54US (Antarctique, États-Unis). Ces tables permettent d'évaluer les variabilités spatiales, saisonnières et quotidiennes obtenues pour différents modèles atmosphériques empiriques HWM-93/MSISE-90 et réalistes ECMWF.

Cotesia congregata est une guêpe parasitoïde qui se développe à l’intérieur de la larve du Lépidoptère, Manduca sexta. Ce parasitoïde a développé une stratégie de virulence qui utilise un symbionte viral de la famille des Polydnavirus nommé Cotesia congregata bracovirus. Mon travail de thèse a permis de caractériser le dialogue moléculaire au cours de l’interaction par des approches de transcriptomique à haut débit et de physiologie. Ces travaux ont permis d’établir la première carte fonctionnelle du génome viral et de visualiser l’ensemble des gènes de M. sexta régulés au cours du parasitisme. La régulation des gènes de l’immunité a révélé que le parasitisme n’empêche pas l’induction de peptides antimicrobiens, mais entraine la sous-expression de gènes impliqués dans la réponse cellulaire. De plus j’ai pu mettre en évidence une réduction du nombre de cellules adhérentes au cours de l’interaction et décrire l’induction d’un phénotype de type apoptose d’une catégorie de cellules immunitaires. Ces résultats permettent d’identifier des gènes acteurs de l’interaction et apportent de nouvelles connaissances relatives aux interactions hôtes-parasitoïdes. / Cotesia congregata is a parasitoid wasp that develops inside the lepidopteran larvae, Manduca sexta. This parasitoid wasp has evolved virulence strategies using an obligate viral symbiont from the Polydnavirus family named Cotesia congregata bracovirus. My thesis work has allowed us to characterize the molecular dialogue during the interaction by physiological and high-throughput transcriptomic approaches. This work allowed to obtain the first functional map of the viral genome and to identify all M. sexta genes regulated during parasitism. Regulation of immune genes revealed that parasitism does not prevent induction of antimicrobial peptides, but leads to the down-regulation of genes involved in the cellular response. Moreover, I was able to demonstrate a reduction in the number of adherent cells during the interaction and to describe this induction as an apoptosis-like phenotype targeting a specific population of immune cells. These findings open the way to the identification of candidate genes involved in this particular interaction and provide new insights into host-parasitoid interactions in general.

Altruism is defined as a trait in an individual that increases some other individual’s fitness at the expense of her own. Therefore, existence of such traits in a population is an evolutionary paradox, as natural selection should eliminate such a trait. Extreme altruism in the form of eusociality where individuals relinquish their own reproduction to help raise other’s offspring has been an enigma in evolutionary biology since Darwin. Primitively eusocial organisms provide one with a unique system to study the evolution and maintenance of altruism as in these kind of species most of the individuals are capable of developing their reproductive organs, although at a certain point in time, only one or a few individuals actually reproduce. Ropalidia marginata is a primitively eusocial wasp belonging to the insect order Hymenoptera, Family Vespidae. R. marginata colonies are monogynous, although serial polygyny is observed in a colony’s lifetime. Colony initiation happens either by single founding or multiple founding. Newly founded colonies may accept individuals from other colonies, but mature colonies seldom do. Production of males is irregular, and once eclosed, they generally leave their natal nest within a week. The haplodiploidy of Hymenopteran species, i.e. the males being haploid and the females diploid, make them uniquely genetically predisposed for eusociality to evolve as was shown by William Donald Hamilton in his kin selection theory. Primitvely eusocial Hymenopteran species, being susceptible to experimental manipulation, allows one to test the predictions of this theory. In this thesis I have addressed three aspects of the biology of R. marginata using microsatellite markers, which are the following: 1) Distribution of nestmate genetic relatedness in early founding (pre‐emergence) and mature ( post‐emergence colonies) and their comparison (Chapter 3) 2) Role of relatedness and fertility in predicting the queen’s successor (Chapter 4) 3) Genetic structure of populations (Chapter 5) CHAPTER 1. INTRODUCTION: This chapter gives a brief outline of the field of molecular ecology putting its techniques to the context of insect sociobiology. CHAPTER 2. METHODS: This chapter gives a general outline of the molecular genetic methods involved. In addition, the issue of the mutation process in R. marginata microsatellites has also been addressed. There are two main models of mutation for microsatellite evolution i.e. infinite alleles model (IAM) and the step‐wise mutation model (SMM). To understand the actual process of mutation in R. marginata, sets of alleles with continuous sizes were sequenced and aligned. This was repeated for several of the loci. Seven out of the nine loci genotyped revealed clear step‐like mutation pattern and was binned accordingly. Two loci were dropped as the actual nature of step‐sizes in these two loci was unclear. Therefore, the final dataset consisted of genotype for 7 loci. This chapter also discusses the initial steps in data formatting and analysis. CHAPTER 3. GENETIC RELATEDNESS IN DIFFERENT STAGES OF COLONY DEVELOPMENT: In this chapter I have estimated nestmate genetic relatedness using seven polymorphic microsatellite loci in two different stages of colony development of the primitively eusocial wasp Ropalidiamarginata and compared them. In both kinds of nests the average colony relatedness was observed to be less than 0.75, i.e., what is expected for full sib females in Hymenoptera. Moreover, it was observed that the nestmates at the initial colony founding stage are on average less related to each other than in mature colonies. From this, one may postulate that the indirect component of inclusive fitness plays a relatively minor role than its direct component as individuals chose to leave a higher relatedness background in favour of a lower relatedness background. As newly founded colonies are relatively smaller in size than mature colonies, the probability of an individual wasp becoming the queen in this kind of colony is higher than in mature colonies. CHAPTER 4. TESTING THE ROLE OF RELATEDNESS AND FERTILITY IN PREDICTING THE QUEEN’S SUCCESSORS: R. marginata colonies are headed by docile queens. When this queen dies or is removed, one of the workers becomes extremely aggressive. She is known as the potential queen because within a few days she becomes the new queen of the colony and her aggression comes down. Predicting the successor in the presence of the queen has eluded most of the approaches attempted so far. The probability of an individual becoming the queen has been found to be uncorrelated with her body size, aggression, ovarian status or mating status. The only trend that has been observed till date, is a positive correlation with age, but the pattern is not perfect. However, the workers themselves seem to be perfectly aware of who their immediate successor going to be. In this chapter, I have tested several models of queen succession constructed in an inclusive fitness framework. These models have been tested both using relatedness alone as well as using fertility along with relatedness. Predictions of none of the models actually matched the observed sequence of successors. The wasps do not seem to be choosing their successor to maximize their inclusive fitness. CHAPTER 5. GENETIC STRUCTURE OF NATURAL POPULATIONS: I have also looked at the genetic structure of R. marginata populations in a large part of its natural distribution. I have used both F and R statistics to estimate the level of structuring and compared them. Both Fat as well Rst were found to be significantly larger than 0. Also Fis and Ris both were small and not significant suggesting lack of inbreeding. Rst was observed to be higher than Fst. Permutation test revealed a higher contribution of mutation in this structuring than migration, suggesting Rst to be a better measure of genetic structuring in this case. Similar pattern was observed with Anlysis of MOlecular VAriance. Pairwise Fst/(1‐Fst) values were found to be uncorrelated with distance, whereas barely significant trend was observed with Rst/(1‐Rst). The scatter across the trend line in both the cases suggested lack of migration drift equilibrium, with drift being more relative to migration. Higher level of structuring was observed at the level of the colony. However, colonies were rather outbred as was suggested by high and negative values of Fia and Ria values. This is not at all surprising as nestmates are related to each other. The pattern of isolation by distance at the colony level was similar to that observed in case of the populations. However, there was even higher degree of scattering of the individual points in this case. CHAPTER 6. CONCLUSIONS: Hamilton’s inclusive fitness theory has received a wide attention from and acceptance by sociobiologists, and relatedness have been measured in a wide variety of social insects. In this thesis relatedness in the context of colony founding was measured and compared with mature colonies. Also, several models constructed in an inclusive theory framework were experimentally tested. In both, support for indirect fitness was found wanting. The population genetic structure of R. marginata revealed that the sub populations are small in size and migration among them low. It also suggested significant contribution of colony level structuring on the population genetic structuring. Using more modern molecular genetic and statistical techniques, these and similar other questions can be addressed with higher precision and rigour, and such studies are expected to greatly advance our understanding of the basic premise of this thesis, i.e., how can eusociality evolve and be maintained? We hope that the current work will encourage others to ask such questions in other species.

Orientador: João Ruggiero Neto / Banca: João Procópio de Araújo Filho / Banca: Maria Teresa Lamy / Banca: Roberto da Silva / Banca: Valmir Fadel / Resumo: Neste trabalho estudamos a conformação em ambientes anisotrópicos e a atividade lítica em vesículas aniônicas e zwitteriônicas de um conjunto de peptídeos biologicamente ativos, extraídos de veneno de vespas solitárias, que se caracterizam por usar seus venenos para paralisar as presas com as quais alimentam suas larvas. Esses peptídeos que são desgranuladores de mastócitos, apresentam atividade antimicrobiana e a maioria deles não é hemolítica. Possuem entre 10 e 15 resíduos, são catiônicos, com alta proporção de resíduos carregados e polares, e são lineares e helicoidais em meios miméticos de membranas. Buscamos correlacionar a atividade lítica em vesículas de diferentes composições, analisada em experimentos de fluorimetria, às mudanças conformacionais, induzidas por diferentes ambientes miméticos, monitoradas por dicroísmo circular, complementando com a análise das características físico-químicas como comprimento da cadeia, amidação do terminal-C, carga líquida, influências no macrodipolo da hélice, hidrofobicidade, momento hidrofóbico e ângulo polar. Observamos que estes peptídeos apresentam intensa atividade em membranas modelo, interagem preferencialmente com bicamadas aniônicas, e sua atividade lítica acontece de modo cooperativo tanto em vesículas aniônicas como nas zwitteriônicas. Com exceção de Anoplin, todos os peptídeos com ação antimicrobiana apresentam curvas de dose-resposta que mostram uma dependência sigmoidal com a concentração do peptídeo. Isso sugere que esses peptídeos se acumulam na superfície da vesícula até atingir uma concentração crítica, além da qual o vazamento aumenta cooperativamente. De uma forma geral os peptídeos mais eficientes como antimicrobianos, são também aqueles caracterizados pela maior eficiência em permeabilizar vesículas aniônicas do tipo PCPG 7030 e por baixas razões limite P/L. / Abstract: Solitary wasps use their venoms to paralise prays to feed their larvae. A set of biologically active peptides, obtained from these venoms, have been investigated in relation to the conformational changes they undergo in anisotropic environments and their lytic activity on zwitterionic and anionic vesicles. These peptides are mast cell degranulators, present antimicrobial activities and most of them are not hemolytic. They are cationic, their chain length are 10 to 15 residues long, with high hydrophilic / hydrophobic ratio; they are linear and helical in membrane mimetic environments. We searched correlation between the lytic activity in vesicles of different compositions, monitored in fluorimetric experiments, and conformational changes, induced by varied mimetic media, monitored by circular dichroism. The results have been also correlated with peptides' physical-chemical parameters such as chain length, amidated or carboxylated C-terminal, net charge, influences on the helix macrodipole, hydrophobicity, hydrophobic moment and polar angle. We observed that these peptides present intense activity on model membranes, they interact preferentially with anionic bilayers, and their lytic activity is a cooperative process either in anionic or in zwitterionic vesicles. Exception made to Anoplin, all the other peptides that have antimicrobial activity present in their dose-response curves a sigmoidal dependence with the peptide concentration. This fact suggests that these peptides accumulate on the vesicles surface until they reach a threshold concentration, beyond which leakage increases cooperatively. As a general rule, the most efficient antimicrobial peptides are also those characterized by efficient permeabilization of anionic vesicles, namely PCPG 7030 and by small threshold P/L ratios. / Doutor

Made available in DSpace on 2016-02-26T14:53:15Z (GMT). No. of bitstreams: 1 ThiagoSantosMontagna.pdf: 613204 bytes, checksum: 2a211678879852b9631ef5ba895c2b41 (MD5) Previous issue date: 2009-03-09 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Aspects of the social biology of the Neotropical wasp Mischocyttarus consimilis Zikán, 1949 (Hymenoptera, Vespidae) - This work had for objective to study aspects social biology of the Neotropical wasp Mischocyttarus consimilis, of the which specifically understand: 1. colonial phenology; 2. architectonic model of nests and pattern of construction of nests; 3. colonial productivity; 4. foundation pattern and colonial success; 5. duration of the immature stage and 6. duration of the colonial stage and flotation s in the offspring density and adults. The observations were led at the own nidification places. The nests of M. consimilis presented an only discovered comb that is arrested to the substratum by an only petiole. Architectural data of the nest showed a correlation significantly positive between the size of the comb and diameter of the petiole, and still between the length and width of the cells. The nidification happened in substrata of plan horizontal, vertical and tilted, without seemingly to exist any preference for either specific orientation. The colonies produced 72.85 cells and 40.71 adults on average. The medium frequency of productive cells was of 33.27% and the maximum number of maximal number of cell utilization was on average 2.07 times. The medium duration of the all immature stage was of 69.73 days, and the stage of egg, larva and pupa had medium duration of 14.86, 36.03 and 18.84 days, respectively. The duration of each immature stage was significantly smaller in the hot-humid station, and the stage of larva and pupa were only smaller during the colonial stage of pre-emergence. The foundation periodicity and abandonment s of colonies in this species followed a pattern asynchrony. Most of the abandonment s happened for natural causes and they were more frequent in the preemergence colonial stage. The through colonial cycle had medium duration of eight months, however, some colonies had duration above one year. The colonies were found rather in human constructions and in sheltered places, without direct incidence of solar light and water of the rain. The foundations of colonies happened so much for haplometrosis as for pleometrosis, being the first the predominant pattern. In the foundations pleometrotics the foundress number varied among two and six / Este trabalho tem por objetivo estudar aspectos da biologia social da vespa Neotropical Mischocyttarus consimilis, dos quais especificamente compreendem: 1. descrever a fenologia das colônias; 2. descrever o modelo arquitetônico e padrão de construção de ninhos; 3. determinar a produtividade colonial; 4. determinar o padrão de fundação e o sucesso colonial; 5. descrever a duração dos estágios imaturos e 6. descrever a duração dos estágios colonial e as flutuações na densidade de prole e adultos. As observações foram conduzidas nos próprios locais de nidificação. Os ninhos de M. consimilis apresentaram basicamente um único favo descoberto que se prende ao substrato por um único pedicelo. Dados arquitetônicos do ninho mostraram existir uma correlação significativamente positiva entre o tamanho do favo e diâmetro do pedicelo, e ainda entre o comprimento e largura das células. As nidificações ocorreram em substratos de plano horizontal, vertical e inclinado, sem existir aparentemente qualquer preferência por uma ou outra orientação específica. As colônias produziram em média 72,85 células e 40,71 adultos. A freqüência média de células produtivas foi de 33,27% e o número máximo de reutilizações foi em média 2,07 vezes. A duração média de todo o estágio imaturo foi de 69,73 dias, sendo que os estágios de ovo, larva e pupa tiveram duração média de 14,86, 36,03 e 18,84 dias, respectivamente. A duração de cada estágio imaturo foi significativamente menor na estação quente-úmida, e somente os estágios de larva e pupa foram menores durante o estágio colonial de pré-emergência. A periodicidade de fundação e abandonos de colônias seguiu um padrão assincrônico. A maior parte dos abandonos ocorreu por causas naturais e foram mais freqüentes no estágio colonial de pré-emergência. O ciclo colonial teve uma duração média próxima de oito meses, entretanto, algumas colônias tiveram duração acima de um ano. As colônias foram encontradas preferencialmente em edificações humanas e em locais abrigados, sem incidência direta de luz solar e água da chuva. As fundações de colônias ocorreram tanto por haplometrose quanto por pleometrose, sendo a primeira o padrão predominante. Nas fundações pleometróticas o número de fundadoras variou entre duas e seis