11 research outputs found
Ecologia do acará-disco (Symphysodon aequifasciatus, Pelegrin, 1904) (Perciformes: Cichlidae) em igarapés no lago Amanã, Amazonas, Brasil
No full textOrnamental fishing has become an important economic activity for Amazonas state, withgreen discus Symphysodon aequifasciatus (Pelegrin, 1904) being one of the most important species in the ornamental fish trade in the state, and also the main species traded in the middle Solimões region. Despite its economic importance, little is known about its biological and ecological characteristics. Autoecology studies the relationships of a single species within its environment, essentially defining the limits of tolerance and preference of the species in face of several ecological factors, examining the action of the environment on its morphology, biology, physiology and behavior. Biological and ecological parameters of the main exploited species are poorly known, nevertheless, these studies are fundamental for a better understanding of relationships between fishes and their natural environments, creating subsidies for sustainable management plans for these species. The present study aimed to investigate aspects of the S. aequifasciatus autoecology at Amana Sustainable Development Reserve, in Amazonas state, Brazil. The following aspects were studied: the species diet, evaluating the items consumed and its temporal variation, the trophic category occupied by the species, its growth rate and longevity. The species reproductive biology was also studied by checking its population
structure, estimating the average size of first maturation, investigating its breeding season and determining its spawning type. Additionally, the S. aequifasciatus genetic populations structure was analyzed within streams associated with Amana Lake, identifying different populations and characterizing potential geographic barriers to gene flow. In addition, a revision of the management norms described in the ornamental fishes Management Plan for the study area was carried out. Genetic analyzes failed to separate (sub) populations of green discus along Amanã Lake, indicating that the study area is a single large panmictic population. Both animal and plant origin items were identified within the species diet, classified as omnivore. The feeding temporal variation observed to the species shows its ability to adapt its diet under changes on food items availability.The species has a long life cycle and intermediate growth rates typical of species with an "equilibrium" life strategy. It
reaches sexual maturity in its first year of life measuring around eleven centimeters long, the maximum longevity recorded was of more than eight years and the males are larger than the females. Spawning occurs at the end of the flooding season and it takes place probably in the flooded forest. The species spawns only once during a single hydrological cycle, when approximately 1000 oocytes are liberated. Characteristics of S. aequifasciatus populations life cycle at Amanã Lake indicate a tendency to classify it as a K-strategist species. Once it is a single population, all streams studied (10) can become potential areas for collection of green discus, nevertheless, a previous survey will be necessary in order to calculate the abundances of the species in each of these igarapés. As captivity does not cause green discus mortality neither changes animals‟ health conditions, it is recommended to choose fish catching and selling period according to commercial issues. Although, a breeding peak was identified between April and June, what makes the months of September and October proper for managed collection period. Observing S. aequifasciatus`s sexual maturation point it is suggested that the minimum catch size for managed fishery at Amanã Lake is 11.50 centimeters. The present study generated important information about S. aequifasciatus ecology which can be very useful to improve the management plan elaborated for the species at the Amanã Sustainable Development Reserve.A pesca ornamental é uma importante atividade econômica para o estado do Amazonas, onde o acará-disco Symphysodon aequifasciatus (Pelegrin, 1904) é uma das espécies mais importantes e representa a principal espécie comercializada na região do médio Solimões. Apesar de sua importância econômica, pouco se sabe sobre seus parâmetros biológicos e ecológicos. A autoecologia estuda as relações de uma espécie com seu meio, definindo essencialmente os limites de tolerância e as preferências da espécie em face dos diversos fatores ecológicos e examinando a ação do meio sobre a morfologia, a biologia, a fisiologia e o comportamento. Esses estudos são fundamentais para um maior entendimento das relações entre os peixes e seus ambientes naturais, gerando subsídios para elaboração de planos de manejo sustentáveis para estas espécies. O presente trabalho teve como objetivo analisar aspectos da ecologia do acará-disco S. aequifasciatus na RDS Amanã (Maraã - AM). Foram estudados: a estrutura genética das (sub) populações de S. aequifasciatus em igarapés tributários do lago Amanã, caracterizando as possíveis barreiras geográficas para o fluxo gênico; a dieta da espécie, avaliando os itens consumidos e sua variação temporal a categoria trófica que a espécie ocupa; a taxa de crescimento e a longevidade da espécie; a estrutura da população; o tamanho médio de primeira maturação gonadal; a época de reprodução; e o tipo de desova. Além disso, foi realizada uma revisão das normas de manejo descritas no Plano de manejo de peixes ornamentais vigente na área de estudo. As análises genéticas não conseguiram separar (sub) populações de acarás-disco ao longo do lago Amanã, indicando que a área de estudo uma única grande população panmítica. A espécie apresenta uma dieta diversificada, consumindo itens de origem vegetal e animal, sendo classificada como onívora. A variação temporal na alimentação demonstra que a espécie consegue adaptar sua dieta à disponibilidade temporal dos itens alimentares. A espécie possui um ciclo de vida longo e taxas de crescimento intermediárias típicas de espécies com estratégia de vida “em equilíbrio”. Atingindo a maturidade sexual no primeiro ano de vida, com cerca de onze centímetros de comprimento, possuindo uma longevidade máxima de mais de oito anos. O machos são maiores que as fêmeas. O período de desova ocorre no final da enchente, com a desova ocorrendo provavelmente no igapó. A espécie desova uma única vez ciclo hidrológico, com uma fecundidade em torno de 1000 oócitos. As populações de S. aequifasciatus do lago Amanã, possuem características de seu ciclo de vida que permitem classificá-la com uma espécie K estrategista. Por se tratar de uma única população todos os 10 igarapés estudados podem virar áreas potenciais de coletas do acará-disco. Porém para que isto ocorra será necessário um levantamento prévio para calcular as abundâncias da espécie em cada um destes igarapés. O tempo de cativeiro não causa mortalidade, ou mesmo altera as condições de saúde dos animais, portanto para os acarás-disco recomenda-se que o melhor momento para a retirada e venda dos peixes esteja vinculada a questões comerciais. Foi identificado um pico de reprodução entre abril e junho, sendo recomendados como período de coleta manejada os meses de setembro e outubro. Os tamanhos mínimos de coleta estão relacionados com o ponto de maturação sexual de cada uma delas. Desta maneira fica sugerido que o tamanho mínimo de captura da pesca maneja de S. aequifasciatus no lago Amanã seja 11,50 centímetros. O presente estudo gerou importantes informações sobre as relaçõesentre o acará-disco e o seu ambiente natural, que servirão para o aprimoramento do plano de manejo elaborado para a espécie na Reserva de Desenvolvimento Sustentável Amanã
Diversidade e variabilidade espaço-temporal da ictiofauna da região estuarina do rio Curuçá município de Curuçá, Pará Brasil
No full textThe study of estuarine fish communities has called researchers’ attention due to the fact that these ecosystems present a great variety and abundance of fish, many of which have commercial importance. Such studies have become fundamental in the evaluation of fish stocks, and also contributed to the conservation of coastal and estuarine environments. Rio Curuçá’s estuary is located at the coastline in the northern part of the state of Para, although fishing is the main economic activity in towns of the region, there are a few studies on local ictiofauna. The main objective of this study was to characterize the demersal
ictiofauna of the main channels in the Curuçá River estuary, identifying annual and spatial variations in the composition, density and biomass of ictiofauna, as well as non-biotic factors that influence these variations. In order to this, data collection
trips were carried out once every two months, using trawl net, in two of the main estuary channels. At the end of the study, 18.989 individuals of 73 species were captured. Ophichthus cylindroideus, Hippocampus reidi, Sygnathus pelagicus and
Butis koilomatodon had not yet been registered in the state’s north coastline. Sciaenidae, Engraulidae and Ariidae families were the most representative in number of species, density and biomass. 20 species, classified as estuarine, were majority, and presented leading densities and biomass in all months and capture
stations. Average density (0,12 ind/m²) was significantly greater during the rainy season, but biomass (1,11 g/m²) did not present significant changes during the months of capture. The Curuçá area has presented greater richness of species, density and biomass. This difference is related mainly to a greater heterogeneity of
substrat in the area, and thus a greater availability of microhabitats. Physical and chemical composition of water was homogeneous in capture stations, and had little influence on the spatial distribution of ictiofauna. The registration of new species for the region enforces the importance of other studies for a greater comprehension of local ictiofauna, which is an important economic resource to the local human population.O estudo de comunidades de peixes estuarinos tem recebido a atenção de pesquisadores, pelo fato destes ecossistemas apresentarem uma grande variedade e abundância de peixes. Muitas destas espécies possuem interesse comercial, constituido-se numa ferramenta fundamental para a avaliação dos
estoques pesqueiros, contribuindo também para a conservação dos ambientes estuarinos e costeiros. O estuário do rio Curuçá localiza-se na costa norte, região do salgado paraense, apesar da pesca ser a principal atividade econômica das cidades da região, existem poucos estudos a respeito da ictiofauna local. O objetivo principal deste trabalho foi de caracterizar a ictiofauna demersal dos canais principais do estuário do rio Curuçá, identificando as variações anuais e espaciais na composição, densidade e biomassa, bem como os fatores abióticos que influenciam nestas variações. Para isto, foram realizadas coletas bimestrais, utilizando uma rede de arrasto de fundo, nos dois canais principais do estuário.
Ao final do estudo foram capturados 18.989 indivíduos, pertecentes a 73 espécies, destas Ophichthus cylindroideus, Hippocampus reidi, Sygnathus pelagicus e Butis koilomatodon ainda não haviam sido registradas para a costa norte. As famílias Sciaenidae, Engraulidae e Ariidae, foram as mais representativas em número de espécies, densidade e biomassa, dominando as capturas. As 20 espécies classificadas como estuarinas foram a maioria, e apresentaram as maiores densidades e biomassa em todos os meses e estações de coleta. A densidade média (0,12 ind/m²) foi significativamente maior na estação chuvosa, já para a biomassa (1,11 g/m²) não houve diferenças significativas entre os meses de coleta. Entre os perfis, Curuçá apresentou uma maior riqueza de espécies, densidade e biomassa. Esta diferença está
relacionada principalmente a uma maior heterogenidade de substratos deste perfil, fazendo com que este possua uma maior disponibilidade de microhabitat. Os parâmetros físicos-químicos da água se apresentaram homogêneos ao longo dos pontos de coletas tendo pouca influência sobre a distribuição espacial da ictiofauna. O fato de encontrarmos novos registros de espécies para a região,
reforça a importância de novos estudos para uma maior compreensão da ictiofauna local, que é um importante recurso econômico para as populações locais
Homogeneidade genética de symphysodon tarzoo (perciformes: cichlidae) no lago amanã, amazonas, brasil
No full text
The hermetic logos : reading the "Corpus Hermeticum" as a reflection of Graeco-Egyptian mentality
No full textThis study analyses Hermetic literature and focuses on the seventeen treatises of the so-called Corpus Hermeticum. It takes as its starting point the assumption that what are nowadays known as the Philosophical Hermetica emerged as a product of a Graeco-Egyptian process of self-perception. As will be demonstrated, Hermetic literature helps our understanding of how reformulations of symbolic universes led to a specific Graeco-Egyptian mentality. The Hermetica will be treated as the result of cross-cultural exchange between Greek and Egyptian symbolic universes. Hermetic literature will therefore be analysed according to its historical context, i.e. as part of a Greek-Egyptian dialogue
Checklist of the ichthyofauna of Mamirauá Sustainable Development Reserve, Middle Solimões, Amazonas, Brazil: high richness in a large protected area of Western-Central Amazonia
No full textAbstract: The present study reviews the records of occurrences of fish species found in the Mamirauá Sustainable Development Reserve (MSDR). The reserve is located in a large section of the middle Solimões River basin, in its interflow with Japurá River. For the elaboration of the list of fish species occurring in Mamirauá Reserve, we used a database of different studies on fish communities carried out in the area over the last three decades, in addition to the material deposited in the ichthyological collections of three scientific institutions, the National Institute for Amazon Research - INPA, the Mamirauá Sustainable Development Institute - IDSM and the Science and Technology Museum of the Catholic University of Rio Grande do Sul - PUCRS. The ichthyofauna of the MSDR is composed of 541 species, encompassing 45 families and 15 orders. These correspond to 20% of all valid species known for the entire Amazonia so far. As observed in other studies in the Neotropical Region, the more represented orders were Siluriformes (209 species) and Characiformes (185 species), followed by the Gymnotiformes (78 species). The results presented here demonstrate a considerable increase (86%) in the knowledge about the fish diversity found in Mamirauá Reserve, in relation to its first list of fish species, published in the 90's. This increase reflects not only the growth in number of studies on fish diversity in the area, with new surveys, but also the continuous taxonomic work on the collections, and descriptions of twenty-eight new species, with one hundred and ten type series. Further surveys are expected to take place in the Northwestern, more isolated areas of the Reserve, and will allow the identification of new occurrences, and may even unveil new fish species yet to be described to Science..</div
Theodor W. Adorno: um crítico na era dourada do capitalismo
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas, Programa de Pós-Graduação em Filosofia, Florianópolis, 2015.A presente tese apresenta a teoria crítica tardia de Theodor W. Adorno por meio da análise dos diversos elementos que a compõe: sua dimensão política; seu público-alvo; seu objeto de crítica; suas críticas ao capitalismo, à racionalidade predominante na modernidade, à dominação da natureza e à vida danificada; seu projeto de emancipação e sua justificação normativa. Argumenta-se que, ao contrário do que defende a interpretação predominante, não houve uma substituição do objeto da crítica ao longo do percurso teórico do pensador frankfurtiano, da economia política à razão instrumental ou à dominação da natureza, mas sim uma complementação: de forma que a crítica ao capitalismo seguia sendo necessária, mas já não era mais suficiente como análise dos obstáculos que impedem a emancipação. O trabalho visa tanto expor o procedimento teórico crítico adorniano, a dialética negativa, como também questionar o diagnóstico de época e as tendências sociais observadas pelo autor frankfurtiano, e, na medida em que obtiver sucesso nessa dupla empreitada, almeja conseguir, ainda, estabelecer um diálogo crítico entre o autor, o seu tempo e o nosso.Abstract : This Doctoral Dissertation aims to present the late critical theory of Theodor W. Adorno by analyzing the various elements that compose it: its political dimension; its target audience; its object of criticism; its criticism of capitalism, of the prevailing rationality in modernity, of nature?s domination and of the damaged life; its emancipation project and its normative justification. It is argued that, contrary to the predominant interpretation defends, there was not a replacement of the object of criticism during the theoretical trajectory of the Frankfurtian thinker, from political economy to instrumental reason or to nature?s domination, but rather a complement: so the critique of capitalism was still necessary, but it was no longer sufficient as analysis of the obstacles to emancipation. The work aims to expose both the critical theoretical procedure, the negative dialectics, as well as to question the diagnosis of the time and social trends observed by the Frankfurtian author, and, in the extent that succeeds in this double endeavor, seeks also to be able to establish a critical dialogue between the author, his time and ours
Spatial and temporal heterogeneity foster high fish biodiversity in an Amazonian floodplain
No full textFunding: Instituto de Desenvolvimento Sustentável Mamirauá, FUNDREF 10.13039/501100005387; Fundação de Amparo à Pesquisa do Estado do Amazonas, FUNDREF 10.13039/501100004916; Petrobras Ambiental; Ministério da Ciência, Tecnologia e Inovação, FUNDREF 10.13039/501100003545; Natural Environment Research Council, FUNDREF 10.13039/501100000270, GRANT #(s) NE/T004487/1; European Commission Directorate-General for Research and Innovation, FUNDREF 10.13039/100004431, GRANT #(s) 10002799.The high biodiversity of tropical ecosystems was one of the earliest ecological patterns to be reported, but the ecological processes that maintain this diversity remain unresolved. Here, we revisit Pianka’s 1966 hypothesis that spatial heterogeneity contributes to tropical biodiversity. Using a comprehensive survey of a fish community in a central Amazonian floodplain, conducted over the 2003, 2012, and 2022 hydrological cycles, we ask if the high levels of environmental heterogeneity (both temporal and spatial) that characterize this ecosystem constrain the capacity of species to dominate local assemblages. We find rapid replacement of dominant species, with local species richness inversely related to dominance. Marked turnover in fish community structure and composition is also present, with different functional groups favored under changing environmental conditions. By showing that turnover in dominant species fuels species coexistence, we identify an ecological mechanism that helps explain how environmental heterogeneity can foster tropical biodiversity.Peer reviewe
Eyewitness accounts of 'the Indies' in the Later Medieval West: reading, reception, and re-use (c. 1300-1500)
No full textDespite increased mercantile and missionary contact between the Latin West and India and China between the thirteenth and fifteenth centuries, scholars have often
noted that Western Europe's knowledge of India, as judged by geographical texts from the period, changed surprisingly little during this time. This thesis employs
some of the methodologies of reception studies in order to investigate the role played by first-hand travel accounts in the construction and change of concepts of the Indies
during the fourteenth and fifteenth centuries. It investigates in particular the reception in Italy, France and England of the information about the area known as
India or the 'three Indies' presented in the texts produced by two Italian travellers to the East: the Divisament dou monde of the Venetian merchant Marco Polo (c. 1298),
and the Relatio of the Franciscan missionary Odorico da Pordenone (1330).
The thesis falls into three distinct parts. In the first section, I contextualise the project with a broad survey of the Latin European ideas of India in the late thirteenth
and early fourteenth centuries and with an outline of the travellers' journeys and their contexts. The second part of the thesis provides a broad overview of the
circumstances of diffusion of the two travel accounts in England, France and Italy over the fourteenth and fifteenth centuries, before conducting a detailed, manuscriptbased
investigation of the ways in which the two accounts of India were approached by their early readers. This investigation focuses principally upon the presentation
and possible modes of reception of the texts' geographical and ethnographic details and relies heavily on the evidence of presentation, paratext and the traces of reading
present in the physical texts of the accounts.
The third and final part of the thesis considers the evidence of the reception of elements from first-hand travel accounts in other textual and cartographic
productions. Proceeding on the basis of case studies, it demonstrates that first-hand accounts of 'the Indies' were used by the authors and compilers of cosmo graphical
texts in this period in a variety of ways. It suggests, however, that the manner and context of the deployment of elements from such accounts often tended to assimilate
these with, rather than distinguish them from, the writings of accepted authorities. This section also contrasts the way that details from travel accounts were re-used in
texts with the way the same information was handled in the composition of maps. Finally, by analysis of the ways eyewitness accounts of the Indies were re-used in
certain ambiguous and comic texts produced in this period, the thesis sheds light on an underexplored aspect of the reception both of eyewitness information and of the
genres in which it appeared. The appendices contain tables presenting information relative to the manuscripts discussed that support the arguments presented in section
two
Recombinant expression of fungal oxidases for industrial application
No full textLaccases catalyse the oxidation of a range of organic substrates coupled to the
reduction of molecular oxygen to water. They are members of the ubiquitous blue multi-copper oxidase family. These enzymes are implicated in a wide variety of biological activities. Most of the laccases studied thus far are of fungal origin. Large variety of potential substrates has raised interest in the use of laccases in several industrial applications, such as pulp delignification, textile dye bleaching, effluent detoxification, biopolymer modification and bioremediation. Cloning of the laccase genes followed by heterologous expression may provide higher enzyme yields and may permit to produce laccases with desired properties (different substrate specificities and improved stabilities) for industrial applications.
Heterologous expression of Pleurotus ostreatus laccases POXC and POXA1b in two yeasts and a first approach of directed evolution experiments are reported. The yeasts of choice were Saccharomyces cerevisiae, proven to be success-full in recombinant laccase expression and directed-evolution experiments, and Kluyveromyces lactis, a non-conventional yeast offering significant advantages, such as high-level secretion of non-hyperglycosylated recombinant proteins. Expression vectors were set up cloning the cDNAs under the control of different promoters. Furthermore, the laccase leader peptides (poxc and poxa1b), as well as the yeast derived signal peptides (S. cerevisiae invertase and K. lactis killer toxin), were alternatively used to direct the secretion of active laccase into the culture medium. The laccase signals proved to be more effective to drive the secretion of recombinant proteins in both hosts.
Levels of laccase secreted activity were markedly different: rPOXA1b transformants always gave much higher activity than rPOXC transformants, and production of both laccases in S. cerevisiae was significantly lower than that in K. lactis.
Recombinant laccases from K. lactis were purified to electrophoretic homogeneity and characterized. rPOXA1b specific activity was similar to that of the native protein, whilst rPOXC specific activity was much lower than that of the native POXC. Mass spectrometry analyses of the recombinant proteins allowed to verify their primary structures and to identify post-translational modifications. Our data confirm that K. lactis has a lower tendency, respect to S. cerevisiae, to hyperglycosylate recombinant proteins. The S. cerevisiae laccase expression systems were further used to set off directed evolution experiments. Mutated cDNAs libraries with different mutation rate were created, and homologous recombination experiments were performed, giving rise to libraries of mutated laccase secreting yeasts. Moreover a screening procedure to isolate clones exhibiting desired property was realized.
As a result, this work allowed obtaining the heterologous expression of two P. ostreatus laccases in yeasts, and their purification and characterisation. Moreover, this research work broadened the potentiality of the developed expression system addressing enzymes to such large markets and different industrial application such as pulp and textile bleaching, and enzymatic remediation of waste streams. A new laccase host (K. lactis) has been built on, and its promising performances will lead to further investigate its utilization for further structure-activities studies, as well as for directed evolution. Results obtained demonstrate the potential of the recombinant expression for the study of potential industrial interest
