Apple mosaic virus (ApMV), Apple stem grooving virus (ASGV), Apple stem pitting virus (ASPV) and Apple chlorotic leaf spot virus (ACLSV) are economically the most important viruses in pome fruit trees, which are distributed worldwide and can caused significantly yield reduction. The major control strategies (namely pathogen detection, exclusion by crop certification or quarantine, control in infected orchards by eradication from infected cultivars and rootstocks, etc.) rely heavily on accurate and sensitive detection methods and on perfect knowledge of pathogens. In the doctoral thesis the diagnostic method quantitative RT-PCR (qRT-PCR) was optimized for detection and quantification of four studied viruses. The results suggested that qRT-PCR method was the most reliable technique in comparison with conventional diagnostic methods DAS/I-ELISA and RT-PCR. In our study the concentration of ASGV, ASPV and ACLSV, measured by qRT-PCR, were stable during vegetation and in different plant tissue. Only the concentration of ApMV changed during vegetation in leaves and inner bark. This result indicates that changes of virus concentration observed by DAS/I-ELISA and RT-PCR in plant tissues are caused by other way (inhibitors, plant senescence, lower sensitivity, ect.) than by changes of virus concentrations in plant. Under the monitoring (at all 351 trees were tested) it was showed, that studied viruses were more spread in orchards and gardens then in wild apple trees. Selected virus isolates from wild apple trees and apples from orchards and gardens were sequenced and molecular variability was studied also with already published isolates. However individual isolates of studied viruses were similar. The variability associated with geographic origin or with type of planting has not been confirmed.

Surveillance of domestic poultry flocks for antibodies against avian influenza and Newcastle disease to detect and differentiate between these diseases is very important. The ability to determine if the detected influenza virus antibodies belong to one of the reportable H5 or H7 subtypes is imperative. These two major viruses are continually responsible for economic loss in poultry industries all over the world. Current serological methods of detection are an effective means of detecting antibody responses to these viruses, however continually investigating improved methods of surveillance is important. Development of a serological assay using Luminex technology which involves the use of recombinantly generated influenza A nucleoprotein, hemagglutinin H5, hemagglutinin H7, and Newcastle disease nucleocapsid proteins bound to Magplex beads allowed for the simultaneous detection of antibodies against these proteins that matches the efficiency of past methods while maintaining high levels of specificity and overall accuracy. Assay development took the form of two connected projects beginning with construction of an assay that operated in duplex, detecting antibodies against influenza nucleoprotein (AIV-NP) and Newcastle disease nucleocapsid protein (APMV-1-NC). Once optimized, the second half of development involved expansion of the assay to include detection of H5 (AIV-H5) and H7 (AIV-H7) subtypes, as well as the addition of internal assay quality controls to monitor assay performance over time. Assay thresholds and overall performance of both of these functional assays were evaluated using large quantities of field and experimental sera from chickens and turkeys to maximize specificity and overall accuracy.

A avicultura brasileira é atualmente uma atividade de grande sucesso. A utilização de sistemas de planejamento associados a novas tecnologias, reflete-se no extraordinário crescimento da atividade. A produção brasileira de frango ultrapassou a marca anual de 10 milhões de toneladas, em 2007. O Brasil está entre os três maiores produtores de frango no ranking mundial, junto com Estados Unidos e China. Haja vista a importância que a avicultura representa para o país, pela geração de benefícios sociais e econômicos, o risco que a Doença de Newcastle (DNC) constitui para a avicultura brasileira é enorme. Um surto desta doença em um centro de produção avícola representaria um risco à economia e incidiria de forma negativa nos níveis de consumo de proteína de qualidade e economicamente acessível à população. A fim de estabelecermos um monitoramento do vírus da Doença de Newcastle (NDV) em aves selvagens, livres ou de cativeiro, e aves domésticas não vacinadas, residentes em regiões de elevada confluência migratória aviária no Brasil e em pingüins ao redor da Estação Antártica Comandante Ferraz (EACF), coletamos amostras de swabs orais e cloacais para a posterior análise por PCR em Tempo Real (qPCR), além de sangue para testes sorológicos, tendo como objetivos maiores, contribuir para o fortalecimento dos serviços de defesa sanitária animal, aumentar a capacidade de investigação, e finalmente, atualizar e harmonizar normas e procedimentos para a prevenção e controle da DNC, referenciando-se nas recomendações da Organização Mundial de Sanidade Animal (Office International des Epizooties - OIE). Das 1072 aves amostradas em diferentes regiões do Brasil, 8 (0,75%) apresentaram resultado positivo para o NDV por qPCR, sendo 5 (62,5% das positivas) delas provenientes da região Norte, 2 (25% das positivas) do Nordeste e 1 (12,5% das positivas) da região Sul do Brasil. Na Antártica, dos 100 pingüins estudados, 2 apresentaram resultado positivo para o NDV por qPCR e em cerca de 33,3% dos soros testados foi detectada a presença de anticorpo pelo teste de Inibição da Hemaglutinação (HI). Todas as amostras positivas foram re-analisadas por qPCR específico para cepas mesogênicas e/ou velogênicas, resultando negatividade, corroborando os dados que certificam o Brasil como sendo livre da Doença de Newcastle. / Brazilian chicken meat exports ended 2007 with shipments of 3,3 million tons, which represented a 21% increase in comparison with 2006. These results were the best in the history of the poultry sector in Brazil. The production reached 10.2 million tons, a result that kept the country as the worlds largest chicken meat exporter and the third largest producer, only behind USA and China. Thus the risk of an introduction of the Newcastle disease virus (NDV) into domestic poultry is enormous and will play severe consequences for the economy and poltry industries. In order to provide the surveillance of the NDV in wild, free or captive, and non vaccinated domestic birds from some regions of migratory birds confluence in Brazil and in penguins around the brasilian Antarctic Station Comandante Ferraz, we collected oral and cloacal swabs, for the viral detection by Real Time PCR (qPCR), and blood for the serological test (hemaglutination inhibition test HI). A total of 1072 birds were sampled in diferent regions of Brazil, where 8 (0.75%) shown positive results to NDV, in which 5 (62.5% of positive) were from North region, 2 (25% of positive) were from Northeast and 1 (12,5% of positive) was from South. In the Antarctic 100 penguins were studied, in which 2 were detected the NDV (2% of total). HI test showed that 33.3% of penguins were seropositives for NDV, indicating their previous contact with the pathogen. All the positive samples by qPCR were repeated with primers projected to detect only virulent strains and no sample was positive, indicating the absence of velogenic strains in Brazil. The epidemiological profile was richer with the isolament of positive samples in embrioned chiken eggs specific patogen free and latter nucleotidic genomic sequencing of isolate.

Cette thèse est basée sur le constat du manque d’activité physique (AP) chez les adolescents : environ 80% de cette tranche d’âge n’atteint pas les 60min quotidiennes recommandées. Cette situation aux conséquences sanitaires importantes, impacte davantage les jeunes les plus vulnérables comme les adolescents obèses et ceux issus de familles de position sociale et économique défavorisée. Deux études visant à promouvoir l’AP auprès de ces publics ont été menées : des mesures objectives de l’AP avant, pendant et après des interventions ont été réalisées dans deux contextes de prise en charge différents. L’objectif de la première étude était de tester la faisabilité et l’impact d’un programme d’AP à destination d’adolescents issus de milieux défavorisés en impliquant également un de leur parent. 18 parents et 22 adolescents ont participé au programme 1 parent – 1 ado. Il comportait deux fois deux heures d’AP par semaine pendant onze semaines pour chacun des groupes participants. Les niveaux d’AP ainsi que plusieurs paramètres anthropométriques, physiologiques et psychologiques ont été recueillis. Tous les participants ont suivi les onze semaines d’intervention. Les analyses ont montré que le seuil de 60 min d’AP quotidienne était atteint, uniquement pendant la durée du programme pour les adolescents. Celui de 30 min pour les parents l’était à tous les temps de mesures. Des analyses complémentaires ont révélé 1) des effets de la prise en charge sur l’AP modulés par l'âge chez les adolescents et par l'assiduité chez les parents, 2) une diminution de l’amotivation pour les adolescents les plus assidus et 3) une augmentation du bien-être pour les adolescents. Les résultats de cette étude pilote ont mis en évidence la faisabilité et l'efficacité d'un tel programme qui pourrait maintenant être déployé sous la forme d'un essai randomisé incluant un groupe contrôle.L’objectif de la deuxième étude était de tester les effets d’une prise en charge pluridisciplinaire de 10 mois sur l’indice de masse corporelle (IMC) et les niveaux d’AP d’adolescents obèses (21 garçons et 41 filles âgés de 14 ans avec un IMC de 33 kg/m²) dans un centre de Soins de Suite et de Réadaptation (SSR). Le rôle modulateur du climat parental et de la motivation de l’adolescent sur l’efficacité de la prise en charge a été évalué. Les résultats indiquent un effet positif de la prise en charge avec une diminution de l’IMC et une augmentation de l’AP au cours de la cure et quatre mois après. De type curvilinéaire, la perte de poids est forte en début de cure puis se stabilise à la fin. Le climat parental semble jouer un rôle facilitateur lors de cette amélioration, notamment par le père, lorsqu’il est perçu comme étant plus chaleureux, plus impliqué et soutenant davantage l’autonomie. Ces programmes de promotion de l’AP génèrent des résultats prometteurs sur les niveaux d’AP des adolescents. Cependant, l’étude des déterminants du maintien des changements obtenus pendant les interventions doit être poursuivie. / This thesis is based on the observation of the lack of physical activity (PA) in adolescents: approximately 80% of this age group does not reach the recommended daily 60 minutes. This situation and its important health consequences, has a greater impact on the most vulnerable young people, such as obese adolescents and those from socioeconomically disadvantaged families. Two studies aiming at promoting PA to these audiences were conducted: objective measures of PA before, during and after interventions were performed in two different PA program settings.The goal of the first study was to test the feasibility and the impact of a PA program for adolescents from disadvantaged backgrounds. For each adolescent, one of their parents was also involved. Thus, 18 parents and 22 adolescents participated in the “1 parent - 1 adolescent” program. Two hours of PA twice a week during eleven weeks were proposed for each of the participating groups. PA levels and several anthropometric, physiological and psychological parameters were collected. All participants followed the eleven weeks of intervention. The analyzes showed that the daily 60-min AP threshold was reached only during the program for adolescents. The daily 30 min for parents was reached at all measurements times of. Additional analyzes revealed 1) that program efficacy on PA level was modulated by age for adolescents and by attendance rate for parents, 2) a decreased of amotivation for the most assiduous adolescents, and 3) an increase in well-being for adolescents. The results of this pilot study highlighted the feasibility and effectiveness of such a program, which could now be deployed in the form of a randomized trial including a control group.The goal of the second study was to test the effects of 10-month multidisciplinary residential weight reduction program on body mass index (BMI) and PA levels of obese adolescents (21 boys and 41 girls aged 14 years with a BMI of 33 kg / m²). The modulating role of parental climate and motivation of the adolescent on the effectiveness of the care was evaluated. The results indicated a positive effect of the program with a decrease in BMI and an increase in PA during the course of treatment and four months after. With a curvilinear shape, the weight loss was strong at the beginning of the cure and then stabilized at the end. The parental climate seemed to play a facilitating role in this improvement, especially by the father, when he was perceived as being warmer, more involved and more supportive of autonomy. These PA promotion programs generate promising results on adolescent PA levels. However, the study of the determinants of the maintenance of changes during interventions must be continued.

A avicultura brasileira é atualmente uma atividade de grande sucesso. A utilização de sistemas de planejamento associados a novas tecnologias, reflete-se no extraordinário crescimento da atividade. A produção brasileira de frango ultrapassou a marca anual de 10 milhões de toneladas, em 2007. O Brasil está entre os três maiores produtores de frango no ranking mundial, junto com Estados Unidos e China. Haja vista a importância que a avicultura representa para o país, pela geração de benefícios sociais e econômicos, o risco que a Doença de Newcastle (DNC) constitui para a avicultura brasileira é enorme. Um surto desta doença em um centro de produção avícola representaria um risco à economia e incidiria de forma negativa nos níveis de consumo de proteína de qualidade e economicamente acessível à população. A fim de estabelecermos um monitoramento do vírus da Doença de Newcastle (NDV) em aves selvagens, livres ou de cativeiro, e aves domésticas não vacinadas, residentes em regiões de elevada confluência migratória aviária no Brasil e em pingüins ao redor da Estação Antártica Comandante Ferraz (EACF), coletamos amostras de swabs orais e cloacais para a posterior análise por PCR em Tempo Real (qPCR), além de sangue para testes sorológicos, tendo como objetivos maiores, contribuir para o fortalecimento dos serviços de defesa sanitária animal, aumentar a capacidade de investigação, e finalmente, atualizar e harmonizar normas e procedimentos para a prevenção e controle da DNC, referenciando-se nas recomendações da Organização Mundial de Sanidade Animal (Office International des Epizooties - OIE). Das 1072 aves amostradas em diferentes regiões do Brasil, 8 (0,75%) apresentaram resultado positivo para o NDV por qPCR, sendo 5 (62,5% das positivas) delas provenientes da região Norte, 2 (25% das positivas) do Nordeste e 1 (12,5% das positivas) da região Sul do Brasil. Na Antártica, dos 100 pingüins estudados, 2 apresentaram resultado positivo para o NDV por qPCR e em cerca de 33,3% dos soros testados foi detectada a presença de anticorpo pelo teste de Inibição da Hemaglutinação (HI). Todas as amostras positivas foram re-analisadas por qPCR específico para cepas mesogênicas e/ou velogênicas, resultando negatividade, corroborando os dados que certificam o Brasil como sendo livre da Doença de Newcastle. / Brazilian chicken meat exports ended 2007 with shipments of 3,3 million tons, which represented a 21% increase in comparison with 2006. These results were the best in the history of the poultry sector in Brazil. The production reached 10.2 million tons, a result that kept the country as the worlds largest chicken meat exporter and the third largest producer, only behind USA and China. Thus the risk of an introduction of the Newcastle disease virus (NDV) into domestic poultry is enormous and will play severe consequences for the economy and poltry industries. In order to provide the surveillance of the NDV in wild, free or captive, and non vaccinated domestic birds from some regions of migratory birds confluence in Brazil and in penguins around the brasilian Antarctic Station Comandante Ferraz, we collected oral and cloacal swabs, for the viral detection by Real Time PCR (qPCR), and blood for the serological test (hemaglutination inhibition test HI). A total of 1072 birds were sampled in diferent regions of Brazil, where 8 (0.75%) shown positive results to NDV, in which 5 (62.5% of positive) were from North region, 2 (25% of positive) were from Northeast and 1 (12,5% of positive) was from South. In the Antarctic 100 penguins were studied, in which 2 were detected the NDV (2% of total). HI test showed that 33.3% of penguins were seropositives for NDV, indicating their previous contact with the pathogen. All the positive samples by qPCR were repeated with primers projected to detect only virulent strains and no sample was positive, indicating the absence of velogenic strains in Brazil. The epidemiological profile was richer with the isolament of positive samples in embrioned chiken eggs specific patogen free and latter nucleotidic genomic sequencing of isolate.