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In the current era of deregulated electricity markets, the power distribution systems have attained a very important and crucial role in the industry. A distribution company (referred to as a disco) plays an active and effective role in electricity markets, and can positively impact the market efficiency and make it more reliable, secure and beneficial to customers. Therefore, operation and planning issues of discos in such electricity market environment requires extensive analysis and research in order to improve their operational strategies both in the short-term and long-term. A generic operations framework for a disco operating in a competitive electricity market environment is presented in the thesis. The operations framework is a two-stage hierarchical model in which the first stage deals with disco’s activities in the day-ahead stage, the Day Ahead Operations Model (DAOM). The second stage deals with disco’s activities in real-time and is termed Real-Time Operations Model (RTOM). The DAOM determines the disco’s operational decisions on grid purchase, scheduling of distributed generation (DG) units owned by it, and contracting for interruptible load. These decisions are imposed as boundary constraints in the RTOM and the disco seeks to minimize its short-term costs keeping in mind its day-ahead decisions. A case-study is presented considering the well-known 33-bus distribution system and three different scenarios are constructed to analyze the disco’s actions and decision-making in this context. The thesis presents a new paradigm for distribution system operation taking into account the presence of DG sources and their goodness factors. The proposed concept of goodness factor of DG units is based on the computation of the incremental contribution of a DG unit to distribution system losses. The incremental contributions of a DG unit to active and reactive power losses in the distribution system are termed as the active / reactive Incremental Loss Indices (ILI). The goodness factors are integrated directly into the distribution system operations model. This model seeks to minimize the disco’s energy costs in the short-term taking into account the contribution (goodness factor) of each DG unit. The analysis was carried out considering an 18-bus distribution network, considering two different ownership structures of DG units, and a 69-bus distribution system considering specific characteristics of wind-DG units. The concept of goodness factors is further extended to determine a new set of goodness factors pertaining to a DG’s impact on feeder unloading by virtue of its power injection. A novel long-term planning model has been developed for the disco that considers investments in DG capacity, distribution system feeder addition / expansion and substation transformers capacity addition. The model includes the new set of goodness factors pertaining to both loss reduction and feeder unloading and arrives at an optimal set of new expansion plan, with specified locations, and year of commissioning. The work clearly demonstrates the effectiveness and contribution of DG units in distribution systems both in the short-term and long-term framework.

In the current era of deregulated electricity markets, the power distribution systems have attained a very important and crucial role in the industry. A distribution company (referred to as a disco) plays an active and effective role in electricity markets, and can positively impact the market efficiency and make it more reliable, secure and beneficial to customers. Therefore, operation and planning issues of discos in such electricity market environment requires extensive analysis and research in order to improve their operational strategies both in the short-term and long-term. A generic operations framework for a disco operating in a competitive electricity market environment is presented in the thesis. The operations framework is a two-stage hierarchical model in which the first stage deals with disco’s activities in the day-ahead stage, the Day Ahead Operations Model (DAOM). The second stage deals with disco’s activities in real-time and is termed Real-Time Operations Model (RTOM). The DAOM determines the disco’s operational decisions on grid purchase, scheduling of distributed generation (DG) units owned by it, and contracting for interruptible load. These decisions are imposed as boundary constraints in the RTOM and the disco seeks to minimize its short-term costs keeping in mind its day-ahead decisions. A case-study is presented considering the well-known 33-bus distribution system and three different scenarios are constructed to analyze the disco’s actions and decision-making in this context. The thesis presents a new paradigm for distribution system operation taking into account the presence of DG sources and their goodness factors. The proposed concept of goodness factor of DG units is based on the computation of the incremental contribution of a DG unit to distribution system losses. The incremental contributions of a DG unit to active and reactive power losses in the distribution system are termed as the active / reactive Incremental Loss Indices (ILI). The goodness factors are integrated directly into the distribution system operations model. This model seeks to minimize the disco’s energy costs in the short-term taking into account the contribution (goodness factor) of each DG unit. The analysis was carried out considering an 18-bus distribution network, considering two different ownership structures of DG units, and a 69-bus distribution system considering specific characteristics of wind-DG units. The concept of goodness factors is further extended to determine a new set of goodness factors pertaining to a DG’s impact on feeder unloading by virtue of its power injection. A novel long-term planning model has been developed for the disco that considers investments in DG capacity, distribution system feeder addition / expansion and substation transformers capacity addition. The model includes the new set of goodness factors pertaining to both loss reduction and feeder unloading and arrives at an optimal set of new expansion plan, with specified locations, and year of commissioning. The work clearly demonstrates the effectiveness and contribution of DG units in distribution systems both in the short-term and long-term framework.

Made available in DSpace on 2015-12-06T23:44:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2011 / Introdução: Nas doenças degenerativas do disco intervertebral, a diminuição da concentração de glicosaminoglicanos (GAGs) mostra-se um marcador precoce. O efeito da atividade física é controverso, podendo causar danos ou proteger o disco. Objetivo: estudar o efeito do overtraining, gerado pela atividade física, nos discos intervertebrais de ratos treinados, por meio do comportamento dos GAGs. Método: Foram utilizados 34 ratos Wistar, dez animais não realizaram o treinamento (GC), oito foram treinados na esteira, mas não realizaram o overtraining (GCAd), oito realizaram o protocolo de overtraining e foram sacrificados em 48 horas (OT 11 semanas) e oito, após duas semanas (OT 13 semanas). Foram retirados os discos L5-L6 e L6-S1 e realizada análise bioquímica dos GAGs. Resultados: Os animais que realizaram todo protocolo de treinamento (OT 11 semanas e OT 13 semanas) atingiram o estado de overtraining, pois não houve melhora do seu desempenho, mesmo após cessar o treinamento. Na análise dos GAGs, notou-se diferença importante entre o grupo OT 11 semanas com os grupos OT 13 semanas e GC. Do mesmo modo, foi observada uma diferença entre os grupos GC-Ad e GC. Nas amostras dos animais submetidos ao treinamento, incluído o grupo GC-Ad, houve predominância de dermatam sulfato. Conclusão: O treinamento físico dos animais foi capaz de produzir efeito nos discos intervertebrais, com aumento da concentração de GAGs, e predominância da expressão de dermatam sulfato. A condição de overtraining não gerou resposta diferente do grupo GC-Ad, o qual não foi submetido ao protocolo completo, com concentração de GAGs reversível após duas semanas de repouso. / Introduction: decreased concentration of glycosaminoglycans (GAGs) shows an early marker of the degenerative intervertebral disc decease. The effect of physical activity is still controversial, may cause damage or protect the disc. Objective: study the effect of overtraining, induced by physical training in the intervertebral discs of trained rats, by mean of the biochemical behavior of GAGs. Methods: 34 Wistar rats were used, ten animals did not undergo physical training (GC), eight were trained on the treadmill, but did not realize the overtraining stage of the training protocol (GC-Ad), eight have completed the protocol of overtraining and were sacrificed within 48 hours (OT 11 weeks) and after two weeks (OT 13 weeks). Discs were removed from the L5-L6 and L6-S1 and performed a biochemical analysis of GAGs. Results: The animals that underwent all the training protocol reached a overtraining status, because no improvement in their performance, even after cessation of training, were observed. In the analysis of GAGs, we noticed an increased concentration of GAGs in the groups OT-11weeks and GC-Ad. An important difference between the group OT-11 weeks with the groups OT 13 weeks and GC were observed. Similarly, there was a difference between the GC and GC-Ad. In samples taken from animals undergoing training, included the GC-Ad group, there was a predominance of dermatan sulfate. Conclusion: the physical training of the animals were able to generate a biochemical response in the intervertebral discs. Been shown an increased concentration of GAGs, with predominant expression of dermatan sulfate. The overtraining status did not generate a different response, compared with the trained group, which was not subjected to the full overtraining protocol. Being observed that the response was reversible after two weeks of rest. / BV UNIFESP: Teses e dissertações

Chez les mammifères, le contrôle de la reproduction est médié par un réseau hypothalamique qui intègre divers stimuli pour réguler la sécrétion de la Gonadotropin Releasing Hormone (GnRH). Ces neurones à GnRH naissent dans la placode olfactive et migrent vers le cerveau le long des axones vomeronasaux et terminaux au cours du développement embryonnaire. Bien que ce processus a bien été étudié chez les rongeurs, sa caractérisation complète chez l'homme reste inachevée. Il est largement admis que des perturbations dans le développement ou dans la sécrétion de GnRH sont associées chez l’homme à un hypogonadisme hypogonadotrope congénital (CHH), qui est un trouble caractérisé par un retard ou une absence de la puberté conduisant à l'infertilité.Les systèmes GnRH et olfactif ont des liens complexes au cours du développement, le syndrome de Kallmann (KS) représente un trouble qui associe l'hypogonadisme dû à une déficience en GnRH et l'anosmie. Le CHH et le KS sont des troubles oligogéniques, les mutations génétiques sous-jacentes n’expliquent que 50% des cas cliniques.Dans cette étude, nous avons entrepris une caractérisation complète du processus migratoire des neurones à GnRH au cours du premier trimestre de gestation sur une grande série d'embryons et de fœtus humains, ce qui nous a permis d’élaborer le premier atlas chronologique et quantitatif de la distribution de GnRH. En effet, l'utilisation d’une nouvelle approche de transparisation des tissus embryologiques humains par de solvants organiques, a permis d’établir pour la première fois, une véritable représentation des neurones dans leur contexte natal in vivo.De plus, les résultats de cette étude ont non seulement révélé que le nombre de neurones GnRH chez l'homme était significativement plus élevé que prévu, mais aussi que ces derniers migrent vers plusieurs régions du cerveau extra-hypothalamique, en plus de l'hypothalamus. Leur présence dans ces régions soulève l'hypothèse qu’ils pourraient exercer des rôles non reproductifs, créant de nouvelles pistes pour la recherche sur les fonctions du système GnRH dans les processus cognitifs, comportementaux et physiologiques.Le second objectif de ce travail a visé à caractériser un nouveau gène candidat impliqué dans le développement du système GnRH: L'hormone Anti-Müllerienne (AMH), connue pour son rôle dans la différenciation de la gonade bipotentielle chez les mâles. Néanmoins, une récente étude menée par notre équipe a mis en évidence son rôle extragonadique sur les neurones à GnRH en période post-natale.Le séquençage complet d'une large cohorte de patients européens a révélé plusieurs nouvelles mutations faux-sens dans le gène de l’AMH chez les patients atteints de CHH et KS, non retrouvés dans la cohorte des témoins. L’évaluation de la pertinence fonctionnelle de ces mutations a ensuite été effectuée par diverses analyses biochimiques in vitro de la bioactivité des mutations, ainsi que par la caractérisation d'une lignée de souris transgénique. Ce qui a entraîné une diminution de la sécrétion de l'AMH et une diminution de la bioactivité de la protéine sécrétée dans les études in vitro; Conduisant à une éventuelle réduction de la capacité migratoire. Cela suggère fortement que ces mutations pourraient avoir un effet pathogène.En outre,nous montrons que le récepteur AMHR2 est exprimé le long des fibres olfactives et par les neurones à GnRH pendant le processus migratoire GnRH. L'analyse pathohistologique des souris Amhr2 -/- a révélé une altération de la migration embryonnaire des neurones à GnRH vers le cerveau antérieur basal, entraînant une réduction significative du nombre total de neurones GnRH dans les cerveaux adultes de ces animaux, conduisant à une fertilité réduite. L’ensemble de ces travaux indiquent que l'insuffisance de signalisation AMH contribuerait à la pathogenèse des troubles de CHH chez l’homme, et met en évidence un nouveau rôle de l'AMH dans développement et la fonction des neurones GnRH. / The control of mammalian reproduction is mediated by a hypothalamic network that integrates various stimuli to regulate the periodic secretion of gonadotropin-releasing hormone (GnRH). GnRH neurons, originate in the olfactory placode and enter the brain along vomeronasal and terminal axons during embryonic development. This process has been well studied in rodents, however, a full characterisation in humans was lacking. Alterations either in the development of this system or in the secretion of GnRH are associated with congenital hypogonadotropic hypogonadism (CHH) in humans, a condition characterized by failure of sexual competence. Due to the inextricable links in the development of the olfactory and GnRH systems, there also exists the developmental condition, Kallmann syndrome (KS), associating hypogonadism due to GnRH deficiency and anosmia. Both CHH and KS are oligogenic disorders, with the underlying genetic mutations only explained in 50% of the clinical cases.At the heart of this study, we have undertaken a full characterisation of the GnRH migratory process during the first trimester of gestation in a large series of human embryos and foetuses and provide the first chronological and quantitative atlas of GnRH distribution. This has been aided by the novel application of organic solvent based tissue clearing techniques to human embryological tissue. This allows, for the first time, a true representation and appreciation of cells in their native, in vivo context. The results of this study have revealed not only that the number of GnRH neurons in humans is significantly higher than previously thought, but that GnRH cells migrate into several extrahypothalamic brain regions in addition to the hypothalamus. Their presence in these areas raises the possibility that GnRH has non-reproductive roles, creating new avenues for research on GnRH functions in cognitive, behavioural and physiological processes.The second aim of this work has been to characterise a novel candidate gene responsible for the development of the GnRH system. Anti-Müllerian hormone (AMH), best known for its role in facilitating the differentiation of the bipotential gonad in males, has recently been shown by our lab to exert significant effects on GnRH neurons postnatally. Here we have undertaken whole exome sequencing of a large cohort of European CHH and KS patients, identifying several novel missense mutations in the Amh gene that are not present in the control cohort. Various in vitro and biochemical analyses of mutations bioactivity as well as analysis of a transgenic mouse line have been used to assess the functional relevance of these mutations.Mutations in Amh resulted in impaired secretion of AMH and reduced bioactivity of the secreted protein in in vitro studies; eventually leading to reduced migratory capacity. This strongly suggests that these mutations could have a pathogenic effect. We also show that its receptor AMHR2 is expressed along the olfactory fibres and by GnRH neurons during the GnRH migratory process. Pathohistological analysis of Amhr2-/- mice revealed defective embryonic migration of GnRH cells to the basal forebrain, leading to a significant reduction in the total number of GnRH neurons in the adult brains of these animals resulting in reduced fertility. We therefore propose that AMH signalling insufficiency contributes to the pathogenesis of human CHH conditions and highlights a novel role for AMH in the correct development and function of GnRH neurons.

No description available.

Memoria para optar al Título Profesional de Médico Veterinario / Se realizó un estudio series de casos con el propósito de reconocer y comprender los cambios ocurridos en la médula espinal tras ser afectada por una hernia discal tipo I a nivel toracolumbar y ser sometida a hemilaminectomía. Para esto se realizó una mielografía prequirúrgica y 48 horas después de la cirugía, una postquirúrgica en cada paciente de un grupo de 10 caninos de talla no gigante. Para cada mielografía se obtuvieron cuatro vistas radiográficas que incluyeron una proyección latero – lateral, ventro – dorsal, oblicua izquierda y oblicua derecha, y se registró la presencia de los patrones mielográficos extradural (ED), intradural – extramedular (ID – EM) e intramedular (IM). En las mielografías prequirúrgicas se observó la presencia del patrón ED e IM, y la ausencia del patrón ID – EM en todos los pacientes. En las mielografías postquirúrgicas se observó la permanencia del patrón ED en ocho pacientes, mientras que el patrón IM estuvo ausente o leve en todos los pacientes, lo que representa una buena respuesta hemodinámica medular frente al tratamiento quirúrgico. Se observó también el patrón ID – EM en cinco pacientes, cuyo origen podría estar determinado por un divertículo subaracnoídeo o un artefacto mielográfico

Este trabalho tem como objetivo abordar a modelagem da formação e migração de um núcleo sólido planetário . Para isso, foi utilizado um modelo de acreção de planetesimais, baseado no trabalho de Inaba et al. (2000), no qual a taxa de acreção média depende da inclinação e excentricidade dos planetesimais, obtidas através da situação de equilbrio entre a interação com o protoplaneta e o arrasto do gás (Fortier et al., 2013). Para complementar esse cenário, foi includa a migração de tipo I, que ocorre devido à interação do planeta com o disco de gás. O modelo analtico que descreve essa migração teve como base o trabalho de Tanaka et al. (2002). O perfil de densidade de gás e sólidos foi obtido com base em três modelos diferentes para o disco. O primeiro é o modelo clássico da Nebulosa Solar, no qual o perfil de densidade decai com r 3/2 ; o segundo é um modelo hbrido, que utiliza medidas observacionais da densidade superficial do gás (Andrews e Williams, 2005) e uma estimativa analtica para a densidade volumêtrica do gás; por fim, o terceiro modelo é um disco de acreção que utiliza a parametrização de Shakura e Sunyaev (1973) com constante. Com o uso desses três perfis diferentes para o disco, foi possvel explorar a variação dos parâmetros livres do modelo e a possibilidade de formação de núcleos sólidos, da ordem de 10M Terra , num tempo menor que o tempo de vida do disco, estimado como menor que 10 × 10^6 anos. Em geral, a migração de tipo I é muito rápida, de modo que o protoplaneta cai na estrela antes mesmo de adquirir massa suficiente para iniciar a acreção de gás. No entanto, a análise revelou, para o disco hbrido, a possibilidade de se obter massas próximas de 10MTerra , num tempo da ordem de 2 × 10^6 anos, em distâncias de até 3.5 UA. Conclui-se, então, que modelos de acreção mais completos, assim como a obtenção deperfis de densidade de gás e sólidos dos discos protoplanetários mais coerentes, podem explicar a formação de núcleos sólidos num tempo hábil para a formação de planetas gigantes, sem a necessidade de fatores numéricos que reduzam a taxa de migração de tipo I. / The aim of this paper is to model the planetary formation and migration of a solid core. Therefore, it was used a model of planetesimal accretion, based on the paper of Inaba et al. (2000), in which the average accretion tax depends on the inclination and eccentricity of that planetesimals. These parameters were obtained through the balance situation between the interaction with the protoplanet and gas draft (Fortier et al., 2013). In order to complete this scenario, the migration type I, which occurs due to an interaction of the planet with the gas disc, was included. The analytical model that describes this migration has its basis on (Tanaka et al., 2002). The density of solids and gas profile was based on three different models for the disc. The first one is a classical of Nebulosa Solar, in which the density profile varies r^3/2 , the second is a hybrid model that uses observational measures of the gas superficial density (Andrews et al., 2010) and an analytical formula for the gas volumetric density; at last, the third model is an accretion disc which uses the parameterization of (Shakura e Sunyaev, 1973) with constant. Using these three different disc profiles, it was possible to explore the variation of the model free parameters and the possibility of the solid cores formation with 10M Earth within time smaller than 10 × 10^6 years, which is the estimated limit lifetime of the disc. In general, migration type I is very fast, so that the protoplanet falls on the star before acquiring enough mass to begin the gas accretion. However, the analysis has revealed, for the hybrid disc, the possibility to obtain masses up to 10MEarth within time 2 × 10^6 , for distance up to 3.5 AU. In conclusion, more complete models of accretion as well as the more coherent density gas and solid profiles of the protoplanet obtained may explain the formation of solid coreswithin a useful time for the giant planets formation, not using numerical factors that reduce the migration type I tax.

Neste trabalho investigaram-se os usos que um grupo de atores sociais ligados à música clássica fizeram do disco, do rádio e da história da música como instrumentos de educação e divulgação musicais. A investigação se concentrou no arco temporal compreendido entre os anos de 1922 a 1945. Como preocupação metodológica procurou-se levar em conta a rica semântica do termo \"história da música\", conceito investigado por meio dos periódicos consultados. Privilegiou-se uma orientação interdisciplinar para o tratamento das questões levantadas. Utilizou-se como fontes primárias um conjunto de periódicos brasileiros especializados em música, além de cartas, documentos oficiais, entrevistas, depoimentos e materiais impressos de apoio a programas de rádio. Como fontes bibliográficas destacaram-se obras de história cultural, musicologia e etnomusicologia. Como resultado da investigação, constatou-se a centralidade dos novos meios tecnológicos (disco e rádio) na pauta das discussões dos especialistas musicais. Verificou-se a importância da questão pedagógica e da divulgação em inúmeras iniciativas desses atores sociais, bem como uma produção significativa de trabalhos de história da música com objetivo de \"vulgarização\". O levantamento permitiu identificar também certo caráter autoritário nas ações dos promotores da música de concertos, comportamento caracterizado pela desconfiança e até certo desprezo pelas práticas musicais dos indivíduos visados por tais iniciativas. Perceberam-se também algumas mudanças no horizonte de escrita da história da música, em favor de uma orientação científica e de maior especialização para o pesquisador musical. / This study investigates the uses, made by a group of social actors related to classical music, of the records, radio and music history as instruments of music education and popularization. The investigation is focused on the time period from 1922 to 1945. As a methodological concern, we have taken into account the rich semantics of the expression \"music history\", a concept investigated by means of the periodicals consulted. An interdisciplinary orientation was favored for the treatments of the issues raised. The author used as primary sources an ensemble of Brazilian periodicals specializing in music, besides letters, official documents, interviews, testimonies and printed materials supporting radio programs. Bibliographical sources included particular works of cultural history, musicology and ethnomusicology. As a result of the investigation, the study evidenced the centrality of the new technological media (record and radio) in music specialists\' discussion agenda. It was demonstrated the importance of the pedagogical issue and of the broadcasting in numberless initiatives of those social actors, as well as a significant production of music history works with the purpose of \"vulgarization\". The research allowed us to identify also some authoritarian features in the actions of promoters of concert music, a behavior characterized by the mistrust and even certain contempt for the musical practices of the individuals targeted by such initiatives. It was possible to notice also some changes in the horizon of the writing of music history, in favor of a scientific approach and a greater specialization for music researchers.

Submitted by Dominick Jesus (dominickdejesus@hotmail.com) on 2016-01-26T18:40:34Z No. of bitstreams: 2 Dissertação_Felipe Rossoni Cardoso.pdf: 11919591 bytes, checksum: 4748e327f8f6c2c782f22c8a29fcc110 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-01-26T18:40:34Z (GMT). No. of bitstreams: 2 Dissertação_Felipe Rossoni Cardoso.pdf: 11919591 bytes, checksum: 4748e327f8f6c2c782f22c8a29fcc110 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2008-04-08 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Historically ornamental fish have been commercially exploited in the Amazon. Nevertheless this exploitation has been carried out without much planning with little attention to the vulnerability of the fish population or to the social economical aspects of the activity for the local fishermen. Among the most known ornamental fish species commercially used is the discus fish (Symphysodon spp.) but very little is known about its biology and ecology. The little information available about this species comes from individuals raised in captivity. This study aimed: a) describe the fishing of discus (Symphysodon aequifasciatus, Cichlidae Pellegrin, 1904), b) determine the abundance and colonization rate through artificial fishing atractors commonly used by local fishermen, c) estimate size at first reproduction, fecundity, sex ratio to develop a management plan for rational commercial use of the species. I also evaluated the efficiency of underwater auditory methods to estimate presence and abundance of discus and the impact of the cutting of the branches on the riparian plant species (“araçá”, Eugenia sp.) used as fish atractors in the water. This study was carried out in three areas of the Sustainable Development Reserve Piagaçu-Purus (SDR-PP) in the dry season from September to November in 2006 and 2007. This study revealed that the fishing of discus occurs in very low intensity and contributes little to the local economy at the SDR-PP and it uses very artesanal forms of capturing, storage and transport. Fishing atractors showed high efficiency as capturing grounds for discus and other commercially important fish species. S. aequifasciatus was the most abundant species representing more than 50% of all cichlids found in the attractors. Mean fecundity was 1.490 eggs (± 304 SD), and population sex ratio was 1:1. Estimated L 50 (body size at which 50% of the population is mature) was 98,4mm (0,38 SD) and 95,8mm (0,86 SD) for females and males respectively. Underwater auditory estimates of discus abundance by the local fishermen predicted the number of discus in the attractors with more than 75% accuracy. Ninety eight percent of the individuals of Eugenia sp. which branches were cut to serve as fish attractors for discus showed regeneration indicating that the impact on this plant species is neglectable. The biological information allied to the local ecological knowledge and understanding of the social aspects involved in the exploitation of discus generated by this study will be incorporated in the management plan for the species. / Historicamente, peixes ornamentais são explorados na Amazônia. Esta exploração vem acontecendo de forma desordenada, sem nenhum cuidado sobre a vulnerabilidade populacional das espécies e a sustentabilidade sócio- econômica para os sujeitos locais envolvidos na atividade. Da grande variedade de peixes explorados, o acará-disco (Symphysodon spp.) é um dos mais conhecidos. É evidente a carência de informações científicas sobre as espécies desse gênero em vida livre, sendo as disponíveis advindas de criadores e aquariofilistas. Os objetivos deste estudo foram: 1) descrever a pesca do acará-disco Symphysodon aequifasciatus Pellegrin, 1904; 2) avaliar experimentalmente a abundância e a colonização dos acarás-disco em atratores de pesca (galhadas), utilizados por pescadores locais; 3) avaliar alguns parâmetros reprodutivos e populacionais da espécie, na época de sua máxima exploração (vazante/seca). Também avaliamos duas técnicas auxiliares utilizadas na pesca do acará-disco: 1) avaliação da técnica de percepção e quantificação de discos através de mergulho em apnéia, por pescadores locais; 2) avaliação da poda e/ou corte de ramos e arbustos de vegetação ripária, que são utilizados para a construção dos atratores. O estudo foi realizado em três áreas da Reserva de Desenvolvimento Sustentável Piagaçu-Purus (RDS-PP), durante a época de vazante/seca, nos períodos de setembro a novembro de 2006 e 2007. Os resultados revelam que a pesca de acará-disco é incipiente na RDS-PP e envolve técnicas artesanais de captura, armazenamento e transporte. Os atratores de pesca mostraram-se eficientes para a captura de discos, além de mostrar um potencial para a captura de outras espécies de interesse comercial. S. aequifasciatus foi a espécie mais abundante nas galhadas, representando pouco mais de 50% de toda a fauna de Cichlidae. A fecundidade média foi de 1.490 ovócitos (± 304 dp), e a proporção sexual populacional foi de 1:1. O L 50 estimado para a espécie foi de 98,4mm (0,38 dp) para fêmeas e 95,8mm (0,86 dp) para machos. A técnica de percepção e quantificação de discos em mergulhos por pescadores locais mostrou-se eficiente, apresentando uma taxa em torno de 75% de acurácia. 98% dos indivíduos de araçá (Eugenia sp.) cortados e/ou podados para a construção dos atratores de pesca apresentaram regeneração, indicando um baixo impacto nessa vegetação. As informações biológicas, aliadas ao conhecimento ecológico local e o entendimento sobre os aspectos sociais relacionados à pesca de acará-disco gerados no presente estudo poderão ser incorporados a um plano de manejo para a exploração sustentável da espécie.