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Master’s closing work, 64 pages, and 12 pictures, and 12 tables, 41 sources of literature, 4 enclosures and Lithuanian language. KEY WORDS: commercial bank, strategic planning, strategy, environmental factors, service, vision, mission, philosophy, organizational culture, goal. Object of research ��� commercial bank activity. Goal of research –to analyze and to estimate the content of strategic planning of commercial bank activity from theoretical point and to make approach for above – mentioned activity development. Tasks: 1. To explore the peculiarities of commercial bank activity, characterized by specific activity point. 2. To exclude systematized conceptions of strategic planning and determinations of strategy formatting. 3. To dispute the theoretical aspects and the value of commercial bank strategic planning in modern financial mediation market. 4. To analyze the environmental factors and stages of planning of commercial bank. 5. To explore business philosophy of “Hansbankas” and to estimate how organization is propagating organizational provisions among employees. Research methods – Lithuanian and foreign authors’ special literature’s logical, comparable analysis and synthesis, Commercial bank “Hansabankas” employees’ questionnaires. The data of questionnaires have been systematized by Microsoft Excel, data grouping, logical, comparable analysis and synthesis and graphical simulation. With reference of theoretical and data of questionnaires research, there are made... [to full text]

Depuis les années 90, les études réalisées au Canada ont permis d’identifier de nouvelles zones endémiques de l’agent de la maladie de Lyme, Borrelia burgdorferi, ou de sa tique vectrice, Ixodes scapularis. Ces régions représentent des zones privilégiées pour étudier le cycle de transmission dans son contexte environnemental. L’objectif principal de ce projet est d’étudier les relations spirochètes – tiques - hôtes et les facteurs environnementaux impliqués dans le cycle de transmission à partir des données du vecteur et de l’agent pathogène recueilli dans le Sud-Ouest du Québec de 2007 à 2008. Tout d’abord sera décrite la saisonnalité des tiques et des associations entre le vecteur et les hôtes rongeurs capturés. En effet, l’identification de la saisonnalité spécifique à chaque stade de la tique I. scapularis permet d’établir quels seront les mois propices pour effectuer les futures collectes de tiques. La saisonnalité synchrone des tiques immatures en quête peut également être un indicateur de la nature ou des souches de B. burgdorferi retrouvées. L’association des tiques immatures à différentes espèces ou à différentes classes d’hôtes (c.-à-d. âge, sexe, statut reproductif) a également été explorée. Nos résultats montrent que les souris du genre Peromyscus, principalement les mâles adultes, contribuent significativement à la survie et au développement du complexe I. scapularis - B. burgdorferi. Les tamias et les écureuils contribuent aussi à la survie et au développement des populations de la tique I. scapularis. Ensuite les associations entre le vecteur et les hôtes cervidés ont été examinées en tenant compte des facteurs environnementaux associés à leur niveau d’infestation. Ceci a permis d’évaluer l’utilisation des cerfs à titre de sentinelles pour le vecteur et les agents pathogènes. D’après nos résultats, bien qu’ils soient des sentinelles efficaces pour détecter Anaplasma phagocytophilum, les cerfs semblent des sentinelles inefficaces pour détecter les zones d’établissement du complexe I. scapularis-B. burgdorferi. Enfin, une analyse de l’impact de la diversité des hôtes et de l’habitat sur l’abondance de la tique I. scapularis et la prévalence de B. burgdorferi a été effectuée et ce, en tenant compte d’autres facteurs environnementaux. Ces analyses ont permis de déterminer les facteurs critiques pour l’établissement du complexe I. scapularis – B. burgdorferi et d’explorer la contribution relative de diverses espèces d’hôtes. D’après nos études, la diversité de la communauté d’hôte et la diversité de l’habitat influencent le complexe I. scapularis - B. burgdorferi. De plus, le climat (la température et les précipitations) joue un rôle significatif dans l’établissement, la survie et le développement des populations d’I. scapularis. Ce projet de recherche a permis d’explorer et d’identifier divers facteurs environnementaux biotiques et abiotiques influençant l’établissement du complexe I. scapularis - B. burgdorferi dans le Sud-Ouest du Québec. Ceux-ci pourraient être utilisés à titre d’indicateurs environnementaux du risque de la maladie de Lyme au Québec et possiblement ailleurs au Canada. / Since the 90s in Canada, studies have identified new endemic areas for the agent of Lyme disease, Borrelia burgdorferi and the tick vector, Ixodes scapularis. These newly endemic areas for complex I. scapularis - B. burgdorferi are prime areas to study the transmission cycle in its environmental context. The main objective of this project is to study the spirochete-tick-host relationships and environmental factors involved in the transmission cycle from the data of the vector and the pathogen collected in southwestern Quebec, 2007 to 2008. First, a description of the seasonality of ticks and associations between the vector and captured rodent hosts was performed. The identification of specific seasonality at each stage of the tick I. scapularis establishes months conducive to make the future collections of ticks. Synchronous seasonality of questing immature ticks may also be an indicator of the nature or strain of B. burgdorferi found. In addition, the association of immature ticks in different species or different classes of hosts (i.e. age, sex, reproductive status) was explored. The Peromyscus mice and adult males in particular contributed significantly to the survival and development of complex I. scapularis-B. burgdorferi. Chipmunks and squirrels also contributed to the survival and development of I. scapularis populations. Second, the associations between vector and examined deer was described taking into account the environmental factors associated with the level of infestation and the use of deer as sentinels for the vector and the pathogen was evaluated. According to our results, the deer are effective sentinels to detect Anaplasma phagocytophilum, but seem ineffective or imprecise to detect endemic areas for complex I. scapularis-B. burgdorferi. Finally, an analysis of the impact of the host diversity and habitat on the abundance of I. scapularis and prevalence of B. burgdorferi considering other environmental factors was performed. These analyzes were used to determine the critical factors in the establishment of complex I. scapularis-B. burgorferi and explore the relative contribution of various host species. According to our studies, the diversity of the host community and habitat influences the complex I. scapularis-B. burgdorferi. On the other hand, the climate (temperature and precipitation) plays a significant role in the establishment, survival and development of the I. scapularis populations. This study allowed us to explore and identify various biotic and abiotic environmental factors influencing the establishment of complex I. scapularis-B. burgdorferi in southwestern Quebec. These environmental factors could be used as environmental indicators of the risk of Lyme disease in Quebec and possibly elsewhere in Canada.

No description available.

Introdução O transtorno de déficit de atenção/hiperatividade (TDAH) afeta entre 3 e 10% das crianças em idade escolar, ocasionando prejuízos no funcionamento individual, acadêmico e social na infância e adolescência. Apesar disso, sua etiologia ainda não é totalmente conhecida. A alta herdabilidade do TDAH leva a crer que fatores genéticos exerçam papel fundamental na predisposição para o transtorno. Entretanto, a ocorrência da patologia vai depender ainda da interação de genes com fatores de risco ambientais. Restam muitas questões a serem esclarecidas, uma delas é se há relação entre os fatores de risco ambientais e a expressão fenotípica, resultando nos diferentes subtipos do TDAH. Objetivo O objetivo do presente estudo é investigar a associação entre complicações perinatais (complicações ocorridas nos períodos pré, peri e pós-natal imediato - CPPs) e TDAH do subtipo desatento (TDAH-D). Método Participaram desse estudo, crianças e adolescentes entre 6 e 17 anos, provenientes de doze escolas estaduais e de um ambulatório especializado em TDAH de Porto Alegre. Após a realização de extensa avaliação diagnóstica, foram incluídas 124 crianças e adolescentes com o diagnóstico de TDAH-D e 124 controles sem o transtorno, pareados por idade e sexo. Informações sobre complicações ocorridas durante os períodos pré, peri e pós-natal imediato, assim como sobre potencias confundidores, foram coletadas diretamente com as mães biológicas dos sujeitos. Resultados A análise de regressão logística condicional mostrou que, para as crianças e adolescentes cujas mães apresentaram maior número de complicações perinatais, o risco de TDAH-D foi significativamente mais elevado (p = 0.005; OR= 1.25; IC95%: 1.1 – 1.5). Conclusões Em um estudo de caso-controle, foi possível expandir para o TDAH predominantemente desatento os achados prévios que sugeriam a associação entre fatores perinatais e TDAH sem um subtipo específico. / Introduction Attention-deficit/hyperactivity disorder (ADHD) affects between 3% and 10% of school aged children, leading to impaired individual, academic and social functioning in childhood and adolescence. Despite of that, the etiology of ADHD remains unclear. The high heritability points to a large genetic contribution to the etiology of ADHD. However, the development of the disorder will also depend of an interaction between genetic and environmental risk factors. Many questions remain to be answered, such as the association between the ADHD phenotypic heterogeneity and the environmental risk factors, leading to different subtypes of the disorder. Objective The objective of the present study is to investigate the association between pre-, peri-, and early postnatal complications (PDPC) and ADHD predominantly inattentive type (ADHD-I). Method: Children and adolescents between 6 and 17 years old from 12 public schools, and from an ADHD outpatient program both in Porto Alegre were assessed. After an extensive diagnostic evaluation, 124 ADHD-I cases and 124 non-ADHD controls, matched by sex and age, were included in the study. Informations about prenatal, delivery and early postnatal complications, as well as potential confounders were obtained by direct interview with biological mothers. Results: Conditional logistic regression analysis showed that children and adolescents whose mothers presented more PDPC had a significant higher risk for ADHD-I (p = 0.005; OR= 1.25; CI95%: 1.1 – 1.5). Conclusions: In a case-control study, we expanded to ADHD-I previous findings suggesting the association between perinatal factors and broadly defined ADHD.

The International Classification of Functioning, Disability and Health (ICF) is a tool that could help improve the coordination between health and social services. This classification will help with communication as a common language in interprofessional rehabilitation team. The research objective of our thesis is to investigate the practical applicability of ICF in health and social services in the field of regulations governing entitlement to "special aids", i.e. Act No. 329/2011 and Decree No. 388/2011, as amended.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Hematogones are B-lineage lymphoid precursors cells normally found in bone marrow. The B-cell Acute Lymphocytic Leukemia (B-ALL) is a lymphocytic precursors neoplasia with consequent accumulation of immature cells called lymphoblasts in bone marrow. The increase of hematogones after treatment for B-ALL or marrow transplantation may cause doubt to the prognosis due to morphological and immunophenotypic similarities between these normal and malignant precursors cells. The aim of this study was to differentiate subpopulations of hematogones and B lymphoblasts by immunophenotyping using flow cytometry, attempting to identify the hematological laboratory profile at diagnosis and the environmental factors that characterize patients with B-ALL. Group 1 consisted of healthy controls free of hematologic malignancy and group 2 consisted of pediatric patients recently diagnosed with B-ALL before the start of chemotherapy, both in bone marrow samples. Antibodies directed against CD45, CD10, CD19, CD34 and mIgM (membrane) were used, which enabled us to distinguish the degree of cell maturation. Despite of the morphological and immunophenotypic similarities, hematogones and B lymphoblasts were differentiated by flow cytometry through distribution and continuous expression of antibodies on the association of CD45 x CD10 and mIgM x CD34 in B population. This technique allowed a better characterization of hematogones in healthy patients, with a progressive maturational pattern within the same cell population, with immature, intermediate and mature cells. The B lymphoblasts exhibited an incomplete maturation spectrum represented by a single population with immaturity characteristics. Among leukemia patients evaluated, 100% were white, with a predominance of children under 10 years (73%) and female sex (64%). These patients had lower hemoglobin levels (91% of cases), platelets (82%) and leukocytes (45.45%), with elevated leukocyte count in 27.3% of subjects. Predominant signs and symptoms were pallor, weakness, petechiae or bruising presence and fever. The same proportion of leukemic patients resided in both rural and urban zones. Patients living in rural area had features that can justify the etiology of ALL, as the professional connection of their parents to contact with toxic products. Morphological revision combined with immunophenotyping has allowed the correct cell identification and distinction between phenotypic subpopulations of hematogones and B lymphoblasts, contributing to an accurate laboratorial prognostic. Due to number of patients with B-ALL of this study, further researches are suggested to correlate the exposure of parents and leukemia patients to potentially oncogenic environmental factors, with the objective of preventing this neoplasia. / As hematogônias são células jovens linfoides de linhagem B normalmente encontradas na medula óssea. A leucemia linfocítica aguda de células B (LLA-B) é uma neoplasia de precursores linfocíticos com consequente acúmulo de células imaturas denominadas linfoblastos na medula. O aumento das hematogônias após o tratamento para LLA-B ou um transplante medular pode causar dúvidas quanto ao prognóstico, devido às semelhanças morfológicas e imunofenotípicas entre essas células jovens normais e malignas. O objetivo deste trabalho foi diferenciar subpopulações de hematogônias e linfoblastos B por imunofenotipagem através da citometria de fluxo, buscando identificar o perfil laboratorial hematológico ao diagnóstico e os fatores ambientais que caracterizam os pacientes de LLA-B. O grupo 1 foi constituído de controles sadios isentos de neoplasia hematológica e o grupo 2 constou de pacientes pediátricos recém-diagnosticados com LLA-B antes do início do tratamento quimioterápico, ambos em amostras de medula óssea. Foi utilizado um painel de anticorpos monoclonais composto por: CD45, CD10, CD19, CD34 e mIgM (membrana), que possibilitaram a distinção do grau de maturação das células. Apesar das semelhanças morfológicas e imunofenotípicas, hematogônias e linfoblastos B foram diferenciados por citometria de fluxo através da distribuição e expressão contínua dos anticorpos diante da associação de CD45 x CD10 e mIgM x CD34 na população B. Esta técnica permitiu uma melhor caracterização das hematogônias nos pacientes sadios, apresentando um padrão maturacional progressivo dentro da mesma população celular, com células imaturas, intermediárias e maduras. Os linfoblastos B exibiram um espectro maturacional incompleto representado por única população com características de imaturidade. Entre os pacientes com leucemia avaliados, 100% eram de raça branca, com predomínio de crianças menores de 10 anos (73%) e do sexo feminino (64%). Estes pacientes apresentaram valores reduzidos de hemoglobina (91% dos casos), plaquetas (82%) e leucócitos (45,45%), com leucometria elevada em 27,3% dos indivíduos. Os sinais e sintomas predominantes foram: palidez, astenia, presença de petéquias ou equimoses e febre. A mesma proporção de pacientes leucêmicos residia nas zonas rural e urbana. Os pacientes que moram na área rural apresentaram características que podem justificar a etiologia da LLA, como a ligação profissional dos pais ao contato com produtos tóxicos. A revisão morfológica combinada com a imunofenotipagem permitiu a correta identificação celular e a distinção entre as subpopulações fenotípicas das hematogônias e dos linfoblastos B, contribuindo para um preciso prognóstico laboratorial. Devido ao número de portadores de LLA-B deste estudo, pesquisas adicionais são sugeridas para correlacionar a exposição de pais e pacientes com leucemia aos fatores ambientais potencialmente oncogênicos, com o objetivo de prevenir essa neoplasia.

Introdução O transtorno de déficit de atenção/hiperatividade (TDAH) afeta entre 3 e 10% das crianças em idade escolar, ocasionando prejuízos no funcionamento individual, acadêmico e social na infância e adolescência. Apesar disso, sua etiologia ainda não é totalmente conhecida. A alta herdabilidade do TDAH leva a crer que fatores genéticos exerçam papel fundamental na predisposição para o transtorno. Entretanto, a ocorrência da patologia vai depender ainda da interação de genes com fatores de risco ambientais. Restam muitas questões a serem esclarecidas, uma delas é se há relação entre os fatores de risco ambientais e a expressão fenotípica, resultando nos diferentes subtipos do TDAH. Objetivo O objetivo do presente estudo é investigar a associação entre complicações perinatais (complicações ocorridas nos períodos pré, peri e pós-natal imediato - CPPs) e TDAH do subtipo desatento (TDAH-D). Método Participaram desse estudo, crianças e adolescentes entre 6 e 17 anos, provenientes de doze escolas estaduais e de um ambulatório especializado em TDAH de Porto Alegre. Após a realização de extensa avaliação diagnóstica, foram incluídas 124 crianças e adolescentes com o diagnóstico de TDAH-D e 124 controles sem o transtorno, pareados por idade e sexo. Informações sobre complicações ocorridas durante os períodos pré, peri e pós-natal imediato, assim como sobre potencias confundidores, foram coletadas diretamente com as mães biológicas dos sujeitos. Resultados A análise de regressão logística condicional mostrou que, para as crianças e adolescentes cujas mães apresentaram maior número de complicações perinatais, o risco de TDAH-D foi significativamente mais elevado (p = 0.005; OR= 1.25; IC95%: 1.1 – 1.5). Conclusões Em um estudo de caso-controle, foi possível expandir para o TDAH predominantemente desatento os achados prévios que sugeriam a associação entre fatores perinatais e TDAH sem um subtipo específico. / Introduction Attention-deficit/hyperactivity disorder (ADHD) affects between 3% and 10% of school aged children, leading to impaired individual, academic and social functioning in childhood and adolescence. Despite of that, the etiology of ADHD remains unclear. The high heritability points to a large genetic contribution to the etiology of ADHD. However, the development of the disorder will also depend of an interaction between genetic and environmental risk factors. Many questions remain to be answered, such as the association between the ADHD phenotypic heterogeneity and the environmental risk factors, leading to different subtypes of the disorder. Objective The objective of the present study is to investigate the association between pre-, peri-, and early postnatal complications (PDPC) and ADHD predominantly inattentive type (ADHD-I). Method: Children and adolescents between 6 and 17 years old from 12 public schools, and from an ADHD outpatient program both in Porto Alegre were assessed. After an extensive diagnostic evaluation, 124 ADHD-I cases and 124 non-ADHD controls, matched by sex and age, were included in the study. Informations about prenatal, delivery and early postnatal complications, as well as potential confounders were obtained by direct interview with biological mothers. Results: Conditional logistic regression analysis showed that children and adolescents whose mothers presented more PDPC had a significant higher risk for ADHD-I (p = 0.005; OR= 1.25; CI95%: 1.1 – 1.5). Conclusions: In a case-control study, we expanded to ADHD-I previous findings suggesting the association between perinatal factors and broadly defined ADHD.

Les facteurs environnementaux que sont le Bisphénol A (BPA), un perturbateur endocrinien, et le Benzo[a]pyrène (B[a]P), un agent génotoxique, représentent un véritable enjeu parmi les facteurs de risques du cancer du sein associés à l'exposition environnementale. Nos objectifs sont d'explorer l'impact d'une exposition chronique à de faibles doses (10-10 M) de BPA et/ou de B[a]P sur l'agressivité de la lignée cellulaire pré-cancéreuse mammaire MCF10AT1 (immortelle, transformée, ER-, PR-, HER2-). Les buts principaux sont : (i) d'explorer si la combinaison de deux molécules possédant deux mécanismes d'action distincts conduit à un effet potentialisé par rapport à l'exposition aux molécules seules ; (ii) d'identifier et de prévenir les mécanismes moléculaires et cellulaires associés à cette exposition multiple. Nos résultats démontrent que l'exposition chronique des MCF10AT1 à de faibles doses de BPA et/ou de B[a]P induit un phénotype cellulaire agressif de façon temps-dépendant, avec un effet potentialisé pour la combinaison BPA+B[a]P, comparée aux molécules seules. Le phénotype observé est un phénotype acquis, car toujours présent 30 jours post-exposition. Nous avons également déterminé dans les cellules MCF10AT1 la présence et la fonctionnalité de deux récepteurs : le récepteur Aryl hydrocarbon (AhR) liant le B[a]P et le récepteur couplé à la protéine G (GPER1/GPR30) liant le BPA. D'un point de vue mécanistique, ces deux récepteurs sont impliqués dans le phénotype cellulaire agressif BPA et/ou B[a]P-dépendant, et notre travail révèle un nouveau cross-talk fonctionnel entre ces deux récepteurs. L'inhibition in vitro d'AhR et de GPR30 (inhibiteurs chimiques ou siRNA) permet de bloquer les effets délétères de l'exposition chronique au BPA et/ou au B[a]P. Enfin, l'analyse rétrospective de tumeurs primitives du sein ER-négatives démontre que la signature moléculaire GPR30/AhR possède une valeur de mauvais pronostic, alors que l'expression de GPR30 ou d'AhR n'en possède pas. L'ensemble de ces résultats souligne donc le rôle particulier que joue la présence concomitante d'AhR et de GPR30 dans des cellules précancéreuses/cancéreuses mammaires. En conclusion, nos résultats permettent d'identifier des cibles potentielles pour le développement de nouvelles stratégies préventives capables de bloquer la carcinogenèse mammaire due à l'exposition chronique au BPA et/ou B[a]P, et d'envisager des nouveaux biomarqueurs de cette exposition environnementale / Environmental factors such as Bisphenol A (BPA), an endocrine disruptor, and Benzo[a]pyrene (B[a]P), a genotoxic agent, represent a real issue among the environmental risk factors for breast cancer. Our objectives are to investigate the impact of chronic and low doses exposure to BPA (10-10 M) and/or B[a]P on the aggressiveness of the mammary pre-cancerous cell line MCF10AT1 (immortal, transformed, ER-, PR-, HER2-). The main aims are: (i) explore whether an exposure to the combination of two molecules with two distinct mechanisms of action has a greater impact than the molecules tested alone; (ii) identify and prevent the associated molecular and cellular mechanisms. Our results demonstrate that chronic exposure of MCF10AT1 to low doses of BPA and/or B[a]P induces an aggressive cell phenotype in a time-dependent manner, with a greater effect for (BPA + B[a]P) combination compared to single molecules. The observed phenotype is an acquired phenotype, as it still persists 30 days post-exposure. We also determined the presence and functionality of two receptors in the MCF10AT1 cells: the Aryl hydrocarbon receptor (AhR) binding B[a]P and the G binding protein receptor (GPER1 / GPR30) binding BPA. Mechanistically, these two receptors are involved in the BPA and/or B[a]P-induced aggressive phenotype, and our study reveals a new functional cross-talk/interplay between these two receptors. In vitro, the inhibition of AhR and GPR30 (chemical inhibitors or siRNA) can block the deleterious effects of chronic exposure to BPA and/or B[a]P. Finally, a retrospective analysis of primary ER-negatif subclass breast tumors demonstrates that the GPR30/AhR gene expression signature has a poor prognosis value, whereas GPR30 or AhR mRNA levels were poorly informative. All these results underline the particular role played by the concomitant presence of AhR and GPR30 in mammary precancerous/cancerous cells. In conclusion, our results allow us to identify potential targets for the development of new preventive strategies capable of blocking mammary carcinogenesis due to chronic exposure to BPA and/or B[a]P, and to consider new biomarkers for environmental exposure

Made available in DSpace on 2014-12-17T14:10:17Z (GMT). No. of bitstreams: 1 CimariaPROS.pdf: 1137578 bytes, checksum: 6105cd049ff9ace294e10673c0d93fea (MD5) Previous issue date: 2008-08-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The shrimp farming industry is the most profitable area of the aquaculture at Rio Grande do Norte (RN) state, which is one of the largest producers in Brazil. However the infections that affect the shrimp cause major economic losses. The infection is a result of the interaction between the shrimp, the environment and pathogen. The change of these factors may lead to a condition of stress and susceptibility to opportunistic infections. One of these infections caused by Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV) is widely distributed in several countries and affects a wide range of hosts. To optimize conditions for production of Litopenaeus vannamei shrimp, the more species cultivated in Brazil, it is necessary to understand the effects of environmental factors in the susceptibility of this species to infections. The aim of this study was to determine the IHHNV prevalence and to investigate the influence of environmental factors as salinity, temperature, stocking density, dissolved oxygen and rainfall in the IHHNV incidence in L. vannamei grown in farms, in the RN state. To determine the IHHNV prevalence were used 1089 samples of L. vannamei collected in seven farms. To perform the study about the influence of environmental factors, 525 samples of L. vannamei shrimp were collected in eight farms located in regions of low (0-1 ), medium (21-30 ) and high (38-57 ) salinity, using extensive (&#8804;15 shrimp/m2 ), semi-intensive (18-33 shrimp/m2) or intensive (>36 shrimp/m2) stocking density systems. The IHHNV infection was determined in pleopod and hemolymph using the polymerase chain reaction (PCR). The environmental factors were recorded during the collection of animals, using a refractometer to measure the salinity and a multi-parameter meter to measure the temperature and concentration of dissolved oxygen in the water. The IHHNV prevalence in RN was 43% (468 infected shrimp out of 1089), varying on different farms. On the seven farms studied, IHHNV prevalence ranged from 18.6% to 54.8%. The infection rates in the shrimp cultured in low, medium and high salinity were respectively 43.10% (125/290), 31.2% (15/48) and 24.6% (46/187) and was significantly higher in shrimp grown in low salinity (P<0.001). The infection rates in ponds of extensive, semi-intensive and intensive systems were respectively, 28.7%, 28.28% and 47.84%, and was significantly higher in high stocking densities (P<0.001). This study indicated a high IHHNV prevalence and a significant effect of salinity and stocking density, but not of the temperature, rainfall and dissolved oxygen on the IHHNV infection rate in the L. vannamei shrimp cultured in the northeastern Brazil / A carcinicultura ? a ?rea da aquicultura mais rent?vel do Rio Grande do Norte (RN), que ? um dos maiores produtores do Brasil. Por?m, as infec??es que acometem os camar?es v?m causando importantes perdas econ?micas. A infec??o ? resultado da intera??o entre o camar?o, o meio ambiente e o pat?geno. A altera??o desses fatores, pode levar a uma situa??o de estresse e suscetibilidade ? infec??es oportunistas. Uma dessas infec??es, causada pelo v?rus da Infec??o Hipodermal e Necrose Hematopoi?tica (IHHNV), encontra-se largamente distribu?da em v?rios pa?ses e apresenta uma grande variedade de hospedeiros. Para otimizar as condi??es de produ??o do camar?o de cultivo Litopenaeus vannamei, a esp?cie mais cultivada no Brasil, ? necess?rio compreender os efeitos dos fatores ambientais na suscetibilidade dessa esp?cie ?s infec??es. O presente estudo teve por objetivo determinar a preval?ncia do IHHNV e investigar a influ?ncia de fatores ambientais como a salinidade, temperatura, densidade de estocagem, oxig?nio dissolvido e pluviosidade na incid?ncia do IHHNV em fazendas de cultivo do L. vannamei, no estado do RN. Para determinar a preval?ncia do IHHNV foram utilizados 1089 amostras de L. vannamei coletados de sete fazendas. Para a realiza??o do estudo sobre a influ?ncia de fatores ambientais 525 amostras do camar?o L. vannamei foram coletadas em oito fazendas localizadas em regi?es de ?guas oligohalinas (0-1 ), mesohalinas (21-30 ) e hipersalinas (38-57 ), utilizando sistema de densidade de estocagem extensivo (&#8804;15 camar?es/m2), semi-intensivo (18-27 camar?es/m2) e intensivo (>30 camar?es/m2). A infec??o pelo IHHNV foi determinada em ple?podos e hemolinfa utilizando a rea??o da polimerase em cadeia (PCR). Os fatores ambientais foram registrados durante a coleta dos animais nos viveiros das fazendas, utilizando um refrat?metro para medir a salinidade e um medidor multi-par?metro para medir a temperatura e o oxig?nio dissolvido da ?gua. A preval?ncia do IHHNV no RN foi 43% (468 camar?es infectados de 1089), variando nas diferentes fazendas. Nas sete fazendas estudadas, a preval?ncia do IHHNV variou de 18,6% a 54,8%. As taxas de infec??o nas fazendas de ?guas oligohalinas, mesohalinas e hipersalinas foram respectivamente 43,10% (125/290), 31,2% (15/48) e 24,6% (46/187) e foi significativamente maior em camar?es cultivados em ?guas oligohalinas (P<0,001). As taxas de infec??o nos viveiros de sistema extensivo, semi-intensivo e intensivo foram respectivamente, 28,7%, 28,28% e 47,84% e foi significativamente maior em alta densidade de estocagem (P<0,001). Neste trabalho foi encontrado uma alta preval?ncia do IHHNV e um efeito significativo da salinidade e da densidade de estocagem, mas n?o da temperatura, pluviosidade e concentra??o do oxig?nio dissolvido sobre a taxa de infec??o pelo IHHNV no camar?o L. vannamei cultivado no Nordeste brasileiro