Made available in DSpace on 2015-03-26T13:37:48Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1056837 bytes, checksum: 147af3aea5c0fd4d6961921a210a152c (MD5) Previous issue date: 2012-02-10 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Cowpea mild mottle virus (CpMMV), the causal agent of stem necrosis disease, has drawn attention of soybean producers in recent years due to productivity losses in the main producing regions of Brazil. The disease was first recorded in the Midwest region of Brazil in the 2000/01 soybean season and rapidly spread throughout the country in the following years. CpMMV is usually hard to diagnose due to its wide range of symptoms while the occurrence of asymptomatic soybean cultivars complicates genotypic selection in breeding programs. Serological methods for viral detection require the use of an antiserum of good quality to achieve specificity and sensitivity. The entire coat protein sequence of a Brazilian CpMMV isolate was cloned into a bacterial expression vector and transformed into Escherichia coli BL21::DE3 for in vitro expression. The coat protein, fused to a 6 His-tag, was purified under denaturing conditions by affinity chromatography using a Ni-NTA resin. After renaturation, the integrity and identity of purified recombinant protein was confirmed by SDS-Page and MALDI-ToF/Tof mass spectrometer analyses. New Zealand rabbits were immunized with increasing amounts of the recombinant protein. The specificity and sensitivity of the antisera was shown by Western blot and indirect ELISA assays. The polyclonal antisera raised against recombinant coat protein proved to be a reliable tool for CpMMV detection. / O Cowpea mild mottle virus (CpMMV), agente causal da necrose da haste, tem chamado a atenção dos produtores de soja nos últimos anos devido às perdas de produtividade geradas nas principais regiões produtoras do Brasil. A doença foi relatada pela primeira vez na região Centro-Oeste do Brasil, na safra de 2000/01, e rapidamente se espalhou por todo o país nos anos seguintes. Além disso, tem sido relatada a ocorrência de cultivares de soja assintomáticas, o que dificulta a seleção de genótipos para programas de melhoramento. Os métodos sorológicos para a detecção viral requerem o uso de um antissoro de boa qualidade para alcançar especificidade e sensibilidade. A sequência completa da capa proteica de um isolado brasileiro de CpMMV (Bahia) foi clonado em um vetor de expressão bacteriano e transformado em Escherichia coli BL21: DE3 para expressão in vitro. A proteína capsidial ligada a uma cauda de histidina foi purificada sob condições desnaturantes através de cromatografia de afinidade, utilizando uma resina Ni-NTA. Depois da renaturação, a integridade e a identidade da proteína recombinante purificada foi confirmada por SDS-PAGE e análise de espectrometria de massa (MALDI-ToF/ToF). Dois coelhos da raça Nova Zelândia foram imunizados com quantidades crescentes da proteína recombinante. A especificidade e sensibilidade do antissoro foram avaliadas por Western blot e ELISA indireto. O antissoro policlonal a partir da proteína recombinante da capa proteica provou ser uma ferramenta confiável e eficiente para a detecção CpMMV.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-03-24T12:07:34Z No. of bitstreams: 2 Dissertação - Tássia Tuane Moreira dos Santos - 2017.pdf: 1707301 bytes, checksum: 711b52250570075b4b92d21dd0f3edc0 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-03-24T12:08:10Z (GMT) No. of bitstreams: 2 Dissertação - Tássia Tuane Moreira dos Santos - 2017.pdf: 1707301 bytes, checksum: 711b52250570075b4b92d21dd0f3edc0 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-03-24T12:08:10Z (GMT). No. of bitstreams: 2 Dissertação - Tássia Tuane Moreira dos Santos - 2017.pdf: 1707301 bytes, checksum: 711b52250570075b4b92d21dd0f3edc0 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-02-21 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The main damage of whitefly Bemisia tabaci biotype B on beans is virus transmission such as Bean golden mosaic virus (BGMV) and Cowpea mild mottle virus (CpMMV). Different insecticides mechanisms of action, use of selective molecules and alternative methods of control are important techniques for management of this insect. Therefore, this study was conducted to test the efficiency of chemical insecticides on mortality of whiteflies adults and CpMMV transmission on BGMV-resistant transgenic common bean; and to verify the combination of chemical insecticides in sublethal doses with the entomopathogeni fungus Isaria javanica on control of B. tabaci nymhps in commom bean. In first part of the study two experiments were conducted with seed treatments, one with foliar application and another with the combination with seed treatment and foliar application. Experiments were conducted in screenhouse. In first experiment with seeds treatment thiametoxam FS at 300, 500, 700 mL and imidacloprid+thiodicarb FS at 500, 600 e 800 mL were tested. In second experiment were used higher doses of thiametoxam FS (500, 700 e 900 mL) and imidacloprid+thiodicarb FS (600, 800 e 1.000 mL). In foliar application were evaluated the insecticides thiamethoxam+cyantraniliprole WG and flupyradifurone SL at 500 e 750 mL ha-1, thiamethoxam + lambda-cyhalothrin SC and thiamethoxam WG both at 300 mL ha-1. In combination of seed treatment and foliar application the treatments were plants treated only with seed treatment or with ST following 1, 2, 3 or 4 foliar applications with different insecticides at five-days intervals. On second stage, at laboratory the compatibility of spiromesifen and buprofezin with I. javanica was observed. Different insecticides concentrations (12.5; 25; 50 and 100 ppm) were added to conidia suspension. Germination of conidia, mycelial growth and conidial production were evaluated. On screenhouse were determined: 1) the sublethal (CL25) doses of insecticides spiromesifen and buprofezin to 2nd ínstar whitefly nymphs; 2) the bio-efficacy of different isolates of I. javanica to 2nd ínstar whitefly nymphs and 3) the effect of the combination between spiromesifen and buprofezin with I. javanica on control of 2nd ínstar whitefly nymphs. Nymphal mortality and sporulation on cadavers (2 and 3) were evaluated. As result was observed that thiametoxam + ciantraniliprole WG and flupiradifurone SL applied in foliar application resulted in higher mortality of whitefly adults. ST added 3 or 4 foliar application proportioned the highest mortality and reduction on CpMMV transmission. Insecticides are efficient on B. tabaci control; however, it does not avoid the virus transmission. The combinations of ST added 3 or 4 foliar application reduce the CpMMV on 50%. All I. javanica isolates caused nymphal mortalities. Spiromesifen and buprofezin were compatible with I. javanica. Additive and synergistic effects were observed. A management program of whitefly is important to reduction of CpMMV incidence on BGMV-resistant transgenic common bean. Besides, the combination of selective chemical insecticides and I. javanica on B. tabaci might increase the success of control. / O principal dano da mosca-branca Bemisia tabaci biótipo B na cultura do feijoeiro é a transmissão de vírus, como o Bean golden mosaic virus (BGMV) e o Cowpea mild mottle virus (CpMMV). A rotação de mecanismos de ação dos inseticidas, o uso de moléculas seletivas e de métodos de controle alternativos são técnicas importantes para o manejo deste inseto. Os objetivos do estudo foram testar a eficiência de inseticidas químicos na mortalidade de adultos de mosca-branca e na transmissão de CpMMV no feijoeiro geneticamente modificado resistente ao mosaico dourado (RMD) e a associação de inseticidas químicos em doses subletais com o fungo Isaria javanica no controle de ninfas de B. tabaci em feijoeiro-comum. Na primeira etapa do estudo em casa telada, dois experimentos foram realizados com tratamento de sementes, um com aplicação foliar e outro com a combinação de tratamento de sementes e aplicação foliar. No primeiro experimento com tratamento de sementes (TS) os inseticidas thiametoxam FS nas doses 300, 500, 700 mL e imidacloprid+thiodicarb FS nas doses 500, 600 e 800 mL foram testados. Já no segundo TS foram utilizados doses maiores de thiametoxam FS (500, 700 e 900 mL) e de imidacloprid+thiodicarb FS (600, 800 e 1000 mL). Em pulverização foram avaliados os inseticidas thiamethoxam+cyantraniliprole WG (500 e 750 mL ha-1), flupyradifurone SL (500 e 750 mL ha-1), thiamethoxam+lambda-cyhalothrin SC (300 mL ha-1) e thiamethoxam WG (300 mL ha-1). Na combinação de tratamento de sementes e aplicação foliar, as plantas foram tratadas apenas com TS ou com TS seguido de 1, 2, 3 ou 4 pulverizações com diferentes inseticidas a cada 5 dias. Na segunda etapa para verificar a compatibilidade dos inseticidas spiromesifen e buprofezin com o I. javanica, concentrações destes inseticidas (12,5; 25; 50 e 100 ppm) foram adicionadas à suspensão de conídios. Foram avaliados a germinação de conídios, crescimento micelial e produção de conídios. Em casa telada foram determinados: 1) a dose subletal (CL25) dos inseticidas spiromesifen e buprofezin a ninfas de mosca-branca; 2) a bio-eficácia de isolados de I. javanica à ninfas de mosca-branca; e 3) o efeito da combinação de spiromesifen e buprofezin e I. javanica no controle de ninfas de mosca-branca. A mortalidade das ninfas e a esporulação nos cadáveres (2 e 3) foram avaliadas. No primeiro estudo o tiametoxam+ciantraniliprole WG e flupiradifurona SL em pulverização foliar resultaram em maiores mortalidades de mosca-branca. Os inseticidas são eficientes no controle de mosca-branca. Apenas a combinação de TS mais 3 ou 4 pulverizações foliares reduzem a incidência de CpMMV. No segundo estudo, todos os isolados causaram morte de ninfas. Os inseticidas foram compatíveis com I. javanica. Efeitos aditivo e sinérgico foram observados entre I. javanica e spiromesifen e buprofezin no controle de ninfas de mosca-branca. Um programa de manejo de B. tabaci é importante para a redução de CpMMV no feijoeiro RMD. Além disso, a combinação de inseticidas sintéticos seletivos e o fungo I. javanica pode aumentar o sucesso do controle de ninfas de mosca-branca.

Le dé cit cognitif est une cause majeure de handicap de la personne âgée. Du fait de l’augmentation de la durée de vie, le nombre de personnes âgées qui pourraient béné cier d’une prise en charge spécialisée dans le but de ralentir leur perte fonctionnelle va croitre. En dépit de traitement validé qui stoppe le processus neurodégénératif, des interventions spéci ques peuvent en ralentir les manifestations. De nombreuses études expérimentales, neuroscienti ques et comportementales ont démontré la relation étroite entre cognition en motricité.Ce travail doctoral propose d’explorer si certaines caractéristiques de la marche sont des biomarqueurs non-invasifs d’un trouble cognitif et des chutes, et de mieux comprendre les relations entre la cognition et le contrôle de la marche. Le cadre théorique était l’hypothèse de la « Perte de Complexité ». Des analyses multivariées ont été appliquées aux critères de jugement dynamiques de marche en relation avec le statut cognitif-et-chute (Le Chapitre 1).Le Chapitre 2 est une revue systématique de la littérature. Nous avons recensé 20 études longitudinales de prédiction de trouble de la marche et de dé cit cognitif. La vitesse de marche était associée à la cognition, son ralentissement était un prédicteur de la perte cognitive. Cette revue a aussi mis en évidence la nécessité d’améliorer la mesure des phénomènes concernésL’objectif du Chapitre 3 était de déterminer ce qu’apportait l’évaluation cognitive (MMSE, mémoire et fonctions exécutives) et des paramètres dynamiques précis de la marche, au bilan habituel du risque de chute. La précision de la classi cation entre chuteurs et non- chuteurs a augmenté avec l’ajout de la cognition et des paramètres de marche de AUC=0.86 à AUC=0.93. La spéci cité du modèle de classi cation a, quant à elle, augmenté de 60% à 72% avec l’ajout des mesures cognitives, et de 72% à 80% avec l’ajout des paramètres dynamiques de la marche. Dans leur ensemble, ces résultats montrent l’intérêt d’une approche multidimensionnelle incluant l’évaluation des fonctions cognitives et de la marche, dans la prédiction du risque de chute chez la personne âgée.Le Chapitre 4 détermine les paramètres de marche les plus associés au déclin cognitif. La vitesse de marche, la régularité, la prévisibilité et la stabilité ont montré que les simples et doubles-tâches étaient les plus discriminantes (score VIP moyen de 1.12). La marche des patients avec troubles cognitifs est plus lente, moins régulière et moins stable que celle de personnes âgées saines. Cependant, les résultats montrent également que la discrimination des patients âgés avec et sans dé cit cognitif, fondée sur l’exploitation des paramètres de marche uniquement, est faible, avec 57% (simple tâche) et 64% (double-tâche) des patients classés de manière erronée.Le Chapitre 5 présente une étude pilote prospective dans laquelle les paramètres de marche les plus discriminants du Chapitre 4 ont été étudiés. Les résultats ont montré qu’un déclin cognitif signi catif observé après 14.4 mois en moyenne était corrélé avec une marche plus régulière (ρ=0.579*) et plus prévisible (ρ=0.486*) mesurée pendent les mesures de ligne de base, mais pas avec la vitesse de marche de la ligne de base (ρ=0.073). Une augmentationde la régularité et de la prévisibilité de la marche est le re et d’une perte de la complexité de la marche, témoin d’une détérioration future des fonctions cognitives chez les patients âgés.Les résultats de ce travail doctoral sont résumés et discutés dans le Chapitre 6. / The rising life expectancy will result in an increased number of ‘older old adults’ who will need specialized geriatric care to slow functional decline. Cognitive impairment is a major cause of disability in geriatric patients. Even though there is no cure yet to reverse neurodegeneration, tailored interventions can slow disease progression and reduce symptoms. Because of the abundant evidence from experimental, neuroscienti c, and behavioral studies that underscored the close link between motor- and cognitive function, the present thesis proposed to use gait characteristics as non-invasive indicators of cognitive impairment and falls in geriatric patients. The main objective therefore was to increase our understanding of the relationship between gait and cognition in this vulnerable population, in which gait outcomes were calculated from 3D-acceleration signals of the lower trunk that were collected with an iPod Touch 4G. The ‘Loss of Complexity’ hypothesis provided a theoretical framework. Multivariate analyses were applied to dynamic gait outcomes in relation to cognitive- and fall-status (Chapter 1).Chapter 2 presents a systematic literature review including 20 longitudinal studies that examined associations between baseline gait function and future cognitive decline. A slow gait speed was associated with future decline in global cognition and in speci c cognitive functions, and with an increased risk for Mild Cognitive Impairment (MCI) and dementia (maximal odds and hazard ratios of 10.4 and 11.1, respectively) in 4.5 years on average. The review projected that future research could increase the speci city of the gait-cognition link by indexing gait and cognition in more detail.From this perspective, Chapter 3 examined whether an extensive cognitive evaluation (global cognition, memory, and executive functioning) and ne-grained, dynamic gait outcomes could add to a usual fall-risk screening. The overall classi cation accuracy of fallers and non-fallers increased from Area Under the Curve (AUC) =0.86 to AUC=0.93. The speci city of the fall-classi cation model increased from 60% to 72% when cognitive outcomes were added, and from 72% up to 80% when gait dynamics were added to the model. The results underscored the need for a multifactorial approach in fall risk assessment in geriatric patients, including a detailed evaluation of cognitive- and gait function.Chapter 4 explored what gait outcomes are most susceptible to change with cognitive decline, and examined multiple gait outcomes in relation to cognitive impairment. Outcomes related to gait speed, regularity, predictability, and stability revealed with the highest discriminative power, indicated by the Variable Importance in Projection (VIP)-values for single- and dual-tasking (average VIP-score of 1.12, with a VIP-score>1 indicating a high discriminative power). Geriatric patients walked slower, less regular, and less stable than healthy old controls. However, the discrimination of geriatric patients with- and without cognitive impairment based on gait outcomes alone was poor, with 57% (single-task) and 64% (dual-task) of the patients being misclassi ed.In Chapter 5, the gait outcomes with the highest discriminative power in chapter 4 were studied in a prospective pilot study. Signi cant cognitive decline (in global cognition, memory, and executive functioning) over 14.4 months on average correlated with a moreregular (ρ=0.579*) and more predictable (ρ=0.486*) gait at baseline, but not with baseline gait speed (ρ=0.073). The increased gait regularity and predictability re ected a loss of gait complexity and this loss of gait complexity may thus predict future cognitive decline in geriatric patients.The results are summarized and discussed in Chapter 6 of this thesis.

Mexican Americans face a significant health disparity related to the development of Mild Cognitive Impairment (MCI) when compared to other ethnic groups. Recent work has documented the utility of utilizing blood-based biomarkers in the detection of amnestic MCI among this population. Efforts to enhance the utility of biomarkers in detecting disease through the inclusion of select neuropsychological measures, an approach termed Molecular Neuropsychology, has shown promise. The present study sought to utilize the molecular neuropsychology approach and examine biobanked serum samples as well as neuropsychological assessments from the Health and Aging Brain among Latino Elders (HABLE) study. Random Forest analyses were conducted to determine the proteomic profile of MCI. Then separate linear regression analyses were conducted to determine the variance accounted for by the biomarkers within the select neuropsychological measures. Trail Making Test Part B was identified as having the least amount of variance and was combined with top five biomarkers within the MCI proteomic profile to create a biomarker-cognitive profile for detecting disease presence. This same method was applied to the amnestic and non-amnestic forms of MCI. The overall biomarker-cognitive profile was shown to be 90% accurate in the detection of MCI, with no significant increase when demographic variables were included into the model. Among amnestic MCI cases, the detection accuracy of the biomarker-cognitive profile was 92% and increased to 94% upon inclusion of demographic variables.

Engineering : Chemical / M. Tech. (Chemical Engineering)

Made available in DSpace on 2016-04-29T13:17:49Z (GMT). No. of bitstreams: 1 Najara Karine Salomao Pereira Almeida.pdf: 2355640 bytes, checksum: 39d43e135617768e1e42e6084f16eca9 (MD5) Previous issue date: 2013-05-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Chronic Mild Stress (SMS) is an anhedonia experimental animal model, induced by the chronic exposition of rats to a mild stressors protocol, and measured by the intake of sucrose, intracranial stimulation and/or site preference conditioning. Aside from anhedonia, this model is also recognized by the production of losses in the body weight, independently of specific feeding regimes and other characteristics analogous to the conditions that compose the depression diagnosis. The objective of the present study was to investigate if the exposition of the subjects to a water VT concurrent scheme water with sucrose 8% VT, of same value, before and after the stressors protocol, would produce disturbances: (1) in the body weight of the subjects; (2) in the diary consumption of food and water; (3) in the consumption and preference of liquids; (4) in the time during which the subjects remained close to the stimulus water and to the stimulus water with sucrose in the operant conditioning box, and (5) in the time in which the subjects have emitted responses in the site of the water fountain and of the water with sucrose 8% fountain. The design was composed by three experimental conditions: (1) exposition of the subjects VTP3, VTP4, VTP7, VTP8, P5, P6, P13 and P15 to the stressors protocol; (2) submission of the subjects VTP3, VTP4, VTP7 and VTP8 to the concurrent 20s VT sessions and (3) application of consumption and liquids´ preference tests in all of the experimental subjects, including the subject C10. The main disturbances noticed were: (a) decrease in the weight losses during the exposition to the protocol and decrease in weight variations during the role experiment; (b) diary water consumption similar to the ones of the subjects submitted to the FR and VI sessions; (c) increase in the diary food consumption, mainly during the exposition to the protocol; (d) constant consumption and preference by sucrose; (e) preference by sucrose in the 20s VT sessions after the exposition to the protocol, and (f) increase in the subjects´ general activity along the submission to the 20s VT sessions. The subjects exposed only to the protocol and to the liquid consumption tests didn´t present decrease in the sensibility to the reinforcer stimulus water with sucrose, what is commonly observed in other studies / Chronic Mild Stress (CMS) é um modelo animal experimental de anedonia, induzida através da exposição crônica de ratos a um protocolo de estressores pouco severos, e medida a partir de ingestão de sacarose, estimulação intracraniana e/ou condicionamento de preferência de lugar. Além de anedonia, este modelo também é reconhecido por produzir perda de peso corporal, independente de regime alimentar específico, e outras características análogas ao que compõe o diagnóstico de depressão. O objetivo do presente estudo foi investigar se a exposição de sujeitos a um esquema concorrente VT água VT água com sacarose a 8%, de mesmo valor, antes e após o protocolo de estressores, produzia alterações: (1) no peso corporal dos sujeitos; (2) no consumo diário de ração e água; (3) no consumo e preferência de líquidos; (4) no tempo em que os sujeitos permaneceram do lado do estímulo água ou do estímulo água com sacarose na caixa de condicionamento operante, e (5) no tempo em que os sujeitos emitiram respostas na região do bebedouro água ou do bebedouro água com sacarose a 8%. O delineamento foi composto por três condições experimentais: (1) exposição dos sujeitos VTP3, VTP4, VTP7, VTP8, P5, P6, P13 e P15 ao protocolo de estressores; (2) submissão dos sujeitos VTP3, VTP4, VTP7 e VTP8 as sessões concorrentes VT 20s e (3) aplicação dos testes de consumo e preferência de líquidos a todos os sujeitos da pesquisa, incluindo o sujeito C10. As principais alterações observadas foram: (a) menor diminuição de peso durante a exposição ao protocolo e menor variação de peso durante todo o experimento (b) consumo diário de água semelhante aos dos sujeitos submetidos às sessões de FR e VI; (c) aumento no consumo diário de ração, principalmente durante a exposição ao protocolo; (d) consumo de líquidos e preferência por sacarose constantes; (e) preferência por sacarose nas sessões VT 20s após a exposição dos sujeitos ao protocolo, e (f) aumento da atividade geral dos sujeitos ao longo da submissão às sessões VT 20s. Os sujeitos expostos somente ao protocolo e aos testes de consumo de líquido não apresentaram diminuição de sensibilidade ao estímulo reforçador água com sacarose comumente observado nos outros estudos

Soit p un nombre premier, soit K/k une extension galoisienne finie de corps de nombres de degré premier à p et soit S un ensemble fini de premiers de k. Le groupe de Galois G(K,S) de la pro-p extension maximale de K non ramifiée en dehors de S est l'objet central de ce mémoire.On se place dans un premier temps dans le cas modéré : on suppose que S ne contient pas les places divisant p. Les travaux combinés de Labute, Minac et Schmidt sur les pro-p groupes mild ont permis d'exhiber les premiers exemples de groupes G(K,S) de dimension cohomologique 2. En implémentant un corollaire de leur critère dans le logiciel PARI/GP, on observe un phénomène de propagation : si k=Q et si le groupe G(Q,S) est mild, un fort pourcentage des groupes G(K,S) l'est également, pour K quadratique imaginaire. En associant au groupe G(K,S) deux graphes orientés dont les arcs sont définis par la ramification dans des extensions p-élémentaires, on démontre un critère théorique pour que ce phénomène de propagation ait lieu.On considère ensuite le cas sauvage : toutes les places au-dessus de p sont contenues dans S. Le groupe de Galois Δ:=Gal(K/k) agit sur G(K,S) ; on note G le plus grand quotient de G(K,S) sur lequel Δ agit trivialement et H le sous-groupe fermé de G(K,S) correspondant. Maire a étudié la liberté du Zp[[G]]-module H^{ab}. Nous poussons plus loin ses résultats en considérant les φ-composantes de H^{ab} sous l'action de Δ. Sous de bonnes hypothèses et sous la conjecture de Leopoldt, on démontre une condition nécessaire et suffisante pour que les φ-composantes soient libres ou non. La théorie du corps de classes permet de ramener cette condition à l'étude du régulateur normalisé, et donc à la p-rationalité du corps K. Les expérimentations faites sur PARI/GP dans des familles d'extensions cubiques cycliques, diédrales et cycliques de degré 4 du corps des rationnels corroborent une conjecture de Gras selon laquelle tout corps de nombres est p-rationnel pour p suffisant grand. / Let p be a prime number, let K/k be a Galois extension of number fields and let S be a finite set of primes of K. We suppose that the degree of K/k is finite and coprime to p. We denote by G(K,S) the Galois group of the pro-p maximal extension of K unramified outside S. We focus on this thesis on two differents aspects of this pro-p group.We are first interested in the tame case : we suppose that S does not contain any place above p. The works of Labute, Minac and Schmidt about mild pro-p groups brought the first examples of groups G(K,S) of cohomological dimension two. Using a corollary of their criterium, we compute some examples with PARI/GP and we observe a propagation phenomenum : if we take K=Q and if we suppose that G(Q,S) is mild, a large part of the pro-p groups G(K,S) with K imaginary quadratic are mild too. We then associate two oriented graphs to G(K,S) and we show a theoretical criterium proving mildness of some imaginary quadratic fields.We then consider the wild case where all the places dividing p belong to S. The Galois group Δ:=Gal(K/k) acts on G(K,S). The action of Δ is trivial on some quotients of G(K,S) ; we denote by G the maximal one and by H the corresponding closed subgroup of G(K,S). Maire has studied the Zp[[G]]-freeness of the module H^{ab}. We extend his results considering the φ-component of H^{ab} under the action of Δ. In a favourable context and under Leopoldt's conjecture, we show a necessary and sufficient condition for the freeness of the φ-components. This condition is connected to p-rational fields by class field theory. We present experiments with PARI/GP in some families of cubic cyclic, dihedral and quartic cyclic extensions of Q which support the following conjecture from Gras : every number field is p-rational for sufficiently large p.

Introdução: Com o envelhecimento da população mundial projeta-se o crescimento das taxas de doenças potencialmente relacionadas à idade como as demências, especialmente a doença de Alzheimer (DA). Os sujeitos com Comprometimento Cognitivo Leve (CCL) são considerados uma população de risco para desenvolver demência, no entanto, as taxas de incidência de CCL e conversão para demência apresentam considerável variabilidade em parte atribuída a características da amostra e aos diferentes critérios utilizados. Objetivos: Determinar a incidência de demência e Comprometimento Cognitivo Leve em uma coorte de idosos saudáveis de base comunitária; determinar as variáveis demográficas, clínicas e sociais associadas ao desenvolvimento de prejuízo cognitivo, e avaliar o risco de progressão dos indivíduos com Comprometimento Cognitivo Leve para demência comparada com sujeitos cognitivamente normais. Métodos: Os dados foram derivados de uma coorte de idosos residentes na comunidade (N = 345), inicialmente saudáveis e independentes (Estudo PALA - Porto Alegre Longitudinal Aging - study). O seguimento inicial com duração máxima de oito anos teve o objetivo de avaliar a incidência de DA e CCL. Para avaliar a progressão de CCL para DA partimos de 10 anos de seguimento, incluindo os oito anos da primeira análise e consideramos um máximo de 70 meses (média de 45 meses) para avaliar a ocorrência dos novos desfechos. Os participantes que preencheram os critérios de inclusão do estudo e consentiram em participar foram avaliados com uma detalhada entrevista clínica composta de variáveis demográficas, clínicas e sociais. Os sintomas psiquiátricos foram avaliados pela escala SRQ - Self Report Questionnaire, escala MADRS - Montgomery-Asberg Depression Rating Scale e aplicados os critérios para depressão maior do Manual de Diagnóstico e Estatístico de Transtornos Mentais (4ª Edição; DSM-IV). O Mini Exame do Estado Mental (MEEM) e a Escala Clínica de Demência (CDR – Clinical Dementia Rating) foram aplicados para avaliação cognitiva. Adicionalmente a independência para as atividades da vida diária foram acessadas pela escala ADL - Activities of Daily Living. Para diagnóstico dos casos incidentes de doença de Alzheimer foi utilizado os critérios diagnósticos do DSM-IV e do NINCDS/ADRDA, associado à descrição dos critérios de Kawas para DA consistente. Para diagnóstico de Comprometimento Cognitivo Leve, o critério da Clínica Mayo foi aplicado para a primeira análise, e o critério para CCL do tipo Alzheimer (ou DA prodrômica) foi utilizado para a segunda análise tendo em vista a incorporação de dados disponíveis e a evolução dos critérios. As trajetórias possíveis do CCL foram classificadas em três categorias: conversão, estabilização e reconversão. Os sujeitos considerados para a primeira análise - casos incidentes de CCL e DA foram os participantes que apresentavam pelo menos uma visita de seguimento no período de oito anos a partir da linha de base (N = 245) e as análises estatísticas foram baseadas no diagnóstico estabelecido na última visita de seguimento. Para os falecidos durante o período, dados retrospectivos foram obtidos através de uma entrevista telefônica com um informante confiável. Os dados clínicos e demográficos de linha de base foram utilizados para cálculo dos fatores preditivos dos desfechos do estudo. Para a segunda análise – risco de conversão de CCL para DA – trajetórias do CCL, a amostra foi composta dos 21 indivíduos que desenvolveram CCL e 220 indivíduos cognitivamente normais (N = 241). Resultados: Os resultados da primeira análise mostraram taxa de incidência de CCL de 13,2 por 1.000 pessoas-ano e incidência de DA de 14,8 por 1.000 pessoas-ano. O desenvolvimento de prejuízo cognitivo foi associado com educação (razão de chance [RC] = 0,86) e o escore do MEEM de base (RC = 0,81). Os resultados da segunda análise mostraram que dos 21 sujeitos com CCL, 38% desenvolveram demência, 24% permaneceram estáveis e 38% melhoraram. A taxa de conversão anual para DA foi de 8,5%, CCL foi associado significativamente a maior risco de conversão para DA (HR = 49,83; p = 0,004), mesmo ajustado para idade, escolaridade, sexo e escore no MEEM. Conclusão: A incidência de DA nessa amostra foi maior do que a descrita em estudo prévio realizado no Brasil, mas está dentro da variabilidade observada internacionalmente. Escores mais baixos no Mini Exame do Estado Mental na linha de base, mesmo que dentro da normalidade, e níveis mais baixos de educação foram preditores da ocorrência de prejuízo cognitivo. Quanto à trajetória do CCL, independentemente da heterogeneidade observada, os participantes com CCL do tipo Alzheimer apresentaram risco significativamente maior de desenvolver demência na DA, demonstrando o impacto do uso destes critérios que enfatizam o comprometimento da memória episódica de longo prazo e buscam identificar sujeitos com maior probabilidade de ser portadores de patologia Alzheimer. / Background: The increase of the rates of age-related diseases as dementia, especially Alzheimer's disease (AD), is projected with the aging of the world population. Subjects with Mild Cognitive Impairment (MCI) are considered a population at risk for developing dementia. However, MCI incidence rates and rates of conversion to dementia have shown considerable variability that could be partially attributed to characteristics of the sample and to different criteria. Objective: To determine the incidence of dementia and mild cognitive impairment in a cohort of community-based healthy elderly individuals; to determine the demographic, clinical and social variables associated with the development of cognitive impairment; and to assess the risk of progression of individuals with mild cognitive impairment to dementia compared with cognitively normal subjects. Methods: Data were derived from a cohort of elderly community residents (N = 345), who were initially healthy and independent (PALA – Porto Alegre Longitudinal Aging – study). The follow-up of a maximum of eight years was used to evaluate the incidence of AD and MCI. To evaluate the progression of MCI to dementia due to AD we set off the 10-year follow-up, including the previous 8-year of the first analysis, and consider the maximum of 70 months (mean 45 months) for these new outcomes. Participants who met the inclusion criteria of the study and consented to participate were evaluated with a detailed clinical interview consisted of demographic, clinical and social variables. Psychiatric symptoms were assessed with the SRQ scale (Self Report Questionnaire), the MADRS (Montgomery-Asberg Depression Rating Scale), and the Diagnostic and Statistical Manual of Mental Disorders (4th edition, DSM-IV) criteria for Major Depression. Cognitive assessment was checked with the Mini Mental State Examination (MMSE) and the Clinical Dementia Rating Scale (CDR). Independence for the activities of daily living was assessed with the ADL scale (Activities of Daily Living). Incident cases of probable Alzheimer's disease were assigned through the DSM-IV and the NINCDS-ADRDA diagnostic criteria, with the additional designation from Kawas and colleagues of consistent AD. Detection of Mild Cognitive Impairment for the first analysis was carried out with the MCI Mayo Clinic criteria. The MCI of the Alzheimer type criteria (or Prodromal AD) were used for the second analysis, incorporating available data of the sample and the ongoing evolution of the criteria. The possible MCI trajectories were classified into three categories: conversion, stabilization, and reconversion. The subjects for the first analysis – MCI and AD incidence – were the participants who had at least one follow-up visit in the 8-year period from the baseline (N = 245), and the statistical analyzes were based on the diagnosis established in last follow-up interview. For the deceased during the period, retrospective data were obtained through a telephone interview with a knowledgeable collateral source focusing on dementia. The baseline clinical and demographic data were analyzed as predictors of the study outcomes. For the second analysis – risk of MCI progression to AD, and MCI trajectories – the sample was composed of 21 individuals who developed MCI and 220 cognitively normal subjects (N = 241). Results: The results of the first analysis showed the MCI incidence rate of 13.2 per 1,000 person-years and the AD incidence of 14.8 per 1,000 person-years. The development of cognitive impairment was associated with education (odds ratio [OR] = 0.86) and baseline MMSE scores (OR = 0.81). The results of second analysis showed that of the 21 MCI subjects, 38% developed dementia, 24% remained stable, and 38% improved. The annual AD conversion rate was 8.5%, and MCI was significantly associated with increased risk of progression to AD (HR = 49.83; p = 0.004), even adjusted for age, education, gender and MMSE scores. Conclusion: The AD incidence in this sample was higher than that described in a previous study carried out in Brazil, but was within the international estimates. Lower baseline scores on the Mini Mental State Examination, although within the normal range, and lower levels of education were predictors of cognitive impairment. Regardless the observed heterogeneity of the MCI trajectories, participants with MCI of the Alzheimer type showed significantly higher risk of developing dementia due to AD, demonstrating the impact of the emphasis on the episodic long-term memory impairment of the criteria, which finally searches to identify those individuals more likely to have Alzheimer's pathology.

The electrochemical corrosion behavior of mild steel in apple, grape, mango, orange and the mixture of these juices was investigated in this study. Open circuit potential and weight loss analytical techniques were employed to establish the comparative corrosion rates of this material in the agro media over the interval of five days for a sixty-day immersion period at an ambient temperature. The chemical compositions of both mild steel and the agro media were determined to ascertain corrosion mechanism for the reaction. Polarization behavior of mild steel in the agro media were determined by Tafel extrapolation curves. The analysis showed that cathodic polarization curves were almost identical irrespective of the concentration of the various media while the anodic polarization curves exhibited varying active and passive corrosion behaviour due to passivating oxide films. The analysis of the results further showed that the corrosion rate of the metallic sample decreased with longer immersion periods which could be attributed to a gradual decline in acidity of these media as revealed by the pH results. Hence, the evolution of hydrogen gas and reduction of dissolved oxygen molecules from the reacting system were presumed to be major factors retarding corrosion of the solution involved. Similarly, the presence of suspended particles on the surface of the test steel sample could have also led to the impediment to corrosion rates from the surrounding atmosphere. Microscopic analysis of the corroded mild steel specimens revealed uniform and localized corrosion with Fe2O3 spotted as the main corrosion product. The result obtained from the electrochemical study showed that the corrosion rate of the mild steel sample was highest in the orange medium (1.53mm/yr), followed by grape medium (1.40mm/yr), mixture of these media (0.67mm/yr), mango medium (0.40mm/yr) while the metal corroded least in the apple medium (0.30mm/yr) over the duration of immersion. / Engineering : Chemical / M. Tech. (Chemical Engineering)

Introdução: Com o envelhecimento da população mundial projeta-se o crescimento das taxas de doenças potencialmente relacionadas à idade como as demências, especialmente a doença de Alzheimer (DA). Os sujeitos com Comprometimento Cognitivo Leve (CCL) são considerados uma população de risco para desenvolver demência, no entanto, as taxas de incidência de CCL e conversão para demência apresentam considerável variabilidade em parte atribuída a características da amostra e aos diferentes critérios utilizados. Objetivos: Determinar a incidência de demência e Comprometimento Cognitivo Leve em uma coorte de idosos saudáveis de base comunitária; determinar as variáveis demográficas, clínicas e sociais associadas ao desenvolvimento de prejuízo cognitivo, e avaliar o risco de progressão dos indivíduos com Comprometimento Cognitivo Leve para demência comparada com sujeitos cognitivamente normais. Métodos: Os dados foram derivados de uma coorte de idosos residentes na comunidade (N = 345), inicialmente saudáveis e independentes (Estudo PALA - Porto Alegre Longitudinal Aging - study). O seguimento inicial com duração máxima de oito anos teve o objetivo de avaliar a incidência de DA e CCL. Para avaliar a progressão de CCL para DA partimos de 10 anos de seguimento, incluindo os oito anos da primeira análise e consideramos um máximo de 70 meses (média de 45 meses) para avaliar a ocorrência dos novos desfechos. Os participantes que preencheram os critérios de inclusão do estudo e consentiram em participar foram avaliados com uma detalhada entrevista clínica composta de variáveis demográficas, clínicas e sociais. Os sintomas psiquiátricos foram avaliados pela escala SRQ - Self Report Questionnaire, escala MADRS - Montgomery-Asberg Depression Rating Scale e aplicados os critérios para depressão maior do Manual de Diagnóstico e Estatístico de Transtornos Mentais (4ª Edição; DSM-IV). O Mini Exame do Estado Mental (MEEM) e a Escala Clínica de Demência (CDR – Clinical Dementia Rating) foram aplicados para avaliação cognitiva. Adicionalmente a independência para as atividades da vida diária foram acessadas pela escala ADL - Activities of Daily Living. Para diagnóstico dos casos incidentes de doença de Alzheimer foi utilizado os critérios diagnósticos do DSM-IV e do NINCDS/ADRDA, associado à descrição dos critérios de Kawas para DA consistente. Para diagnóstico de Comprometimento Cognitivo Leve, o critério da Clínica Mayo foi aplicado para a primeira análise, e o critério para CCL do tipo Alzheimer (ou DA prodrômica) foi utilizado para a segunda análise tendo em vista a incorporação de dados disponíveis e a evolução dos critérios. As trajetórias possíveis do CCL foram classificadas em três categorias: conversão, estabilização e reconversão. Os sujeitos considerados para a primeira análise - casos incidentes de CCL e DA foram os participantes que apresentavam pelo menos uma visita de seguimento no período de oito anos a partir da linha de base (N = 245) e as análises estatísticas foram baseadas no diagnóstico estabelecido na última visita de seguimento. Para os falecidos durante o período, dados retrospectivos foram obtidos através de uma entrevista telefônica com um informante confiável. Os dados clínicos e demográficos de linha de base foram utilizados para cálculo dos fatores preditivos dos desfechos do estudo. Para a segunda análise – risco de conversão de CCL para DA – trajetórias do CCL, a amostra foi composta dos 21 indivíduos que desenvolveram CCL e 220 indivíduos cognitivamente normais (N = 241). Resultados: Os resultados da primeira análise mostraram taxa de incidência de CCL de 13,2 por 1.000 pessoas-ano e incidência de DA de 14,8 por 1.000 pessoas-ano. O desenvolvimento de prejuízo cognitivo foi associado com educação (razão de chance [RC] = 0,86) e o escore do MEEM de base (RC = 0,81). Os resultados da segunda análise mostraram que dos 21 sujeitos com CCL, 38% desenvolveram demência, 24% permaneceram estáveis e 38% melhoraram. A taxa de conversão anual para DA foi de 8,5%, CCL foi associado significativamente a maior risco de conversão para DA (HR = 49,83; p = 0,004), mesmo ajustado para idade, escolaridade, sexo e escore no MEEM. Conclusão: A incidência de DA nessa amostra foi maior do que a descrita em estudo prévio realizado no Brasil, mas está dentro da variabilidade observada internacionalmente. Escores mais baixos no Mini Exame do Estado Mental na linha de base, mesmo que dentro da normalidade, e níveis mais baixos de educação foram preditores da ocorrência de prejuízo cognitivo. Quanto à trajetória do CCL, independentemente da heterogeneidade observada, os participantes com CCL do tipo Alzheimer apresentaram risco significativamente maior de desenvolver demência na DA, demonstrando o impacto do uso destes critérios que enfatizam o comprometimento da memória episódica de longo prazo e buscam identificar sujeitos com maior probabilidade de ser portadores de patologia Alzheimer. / Background: The increase of the rates of age-related diseases as dementia, especially Alzheimer's disease (AD), is projected with the aging of the world population. Subjects with Mild Cognitive Impairment (MCI) are considered a population at risk for developing dementia. However, MCI incidence rates and rates of conversion to dementia have shown considerable variability that could be partially attributed to characteristics of the sample and to different criteria. Objective: To determine the incidence of dementia and mild cognitive impairment in a cohort of community-based healthy elderly individuals; to determine the demographic, clinical and social variables associated with the development of cognitive impairment; and to assess the risk of progression of individuals with mild cognitive impairment to dementia compared with cognitively normal subjects. Methods: Data were derived from a cohort of elderly community residents (N = 345), who were initially healthy and independent (PALA – Porto Alegre Longitudinal Aging – study). The follow-up of a maximum of eight years was used to evaluate the incidence of AD and MCI. To evaluate the progression of MCI to dementia due to AD we set off the 10-year follow-up, including the previous 8-year of the first analysis, and consider the maximum of 70 months (mean 45 months) for these new outcomes. Participants who met the inclusion criteria of the study and consented to participate were evaluated with a detailed clinical interview consisted of demographic, clinical and social variables. Psychiatric symptoms were assessed with the SRQ scale (Self Report Questionnaire), the MADRS (Montgomery-Asberg Depression Rating Scale), and the Diagnostic and Statistical Manual of Mental Disorders (4th edition, DSM-IV) criteria for Major Depression. Cognitive assessment was checked with the Mini Mental State Examination (MMSE) and the Clinical Dementia Rating Scale (CDR). Independence for the activities of daily living was assessed with the ADL scale (Activities of Daily Living). Incident cases of probable Alzheimer's disease were assigned through the DSM-IV and the NINCDS-ADRDA diagnostic criteria, with the additional designation from Kawas and colleagues of consistent AD. Detection of Mild Cognitive Impairment for the first analysis was carried out with the MCI Mayo Clinic criteria. The MCI of the Alzheimer type criteria (or Prodromal AD) were used for the second analysis, incorporating available data of the sample and the ongoing evolution of the criteria. The possible MCI trajectories were classified into three categories: conversion, stabilization, and reconversion. The subjects for the first analysis – MCI and AD incidence – were the participants who had at least one follow-up visit in the 8-year period from the baseline (N = 245), and the statistical analyzes were based on the diagnosis established in last follow-up interview. For the deceased during the period, retrospective data were obtained through a telephone interview with a knowledgeable collateral source focusing on dementia. The baseline clinical and demographic data were analyzed as predictors of the study outcomes. For the second analysis – risk of MCI progression to AD, and MCI trajectories – the sample was composed of 21 individuals who developed MCI and 220 cognitively normal subjects (N = 241). Results: The results of the first analysis showed the MCI incidence rate of 13.2 per 1,000 person-years and the AD incidence of 14.8 per 1,000 person-years. The development of cognitive impairment was associated with education (odds ratio [OR] = 0.86) and baseline MMSE scores (OR = 0.81). The results of second analysis showed that of the 21 MCI subjects, 38% developed dementia, 24% remained stable, and 38% improved. The annual AD conversion rate was 8.5%, and MCI was significantly associated with increased risk of progression to AD (HR = 49.83; p = 0.004), even adjusted for age, education, gender and MMSE scores. Conclusion: The AD incidence in this sample was higher than that described in a previous study carried out in Brazil, but was within the international estimates. Lower baseline scores on the Mini Mental State Examination, although within the normal range, and lower levels of education were predictors of cognitive impairment. Regardless the observed heterogeneity of the MCI trajectories, participants with MCI of the Alzheimer type showed significantly higher risk of developing dementia due to AD, demonstrating the impact of the emphasis on the episodic long-term memory impairment of the criteria, which finally searches to identify those individuals more likely to have Alzheimer's pathology.