Ecologia da pesca e biologia reprodutiva do acará-disco (Symphysodon aequifasciatus, Pellegrin 1904) (Perciformes: Cichilidae) na RDS Piagaçu-Purus, Amazônia Central: subsídios para o manejo sustentável de um recurso natural

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

Frequência de pós-larvas e juvenis do mexilhão dourado, Limnoperna fortunei (Dunker, 1857), durante o ano na bacia do Guaíba, RS (Mollusca, Bivalvia, Mytilidae)

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Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Quali-quantitative first data of golden mussel, Limnoperna fortunei (Dunker), in Jacuí Delta, Guaíba Lake and Patos Lagoon and some invasion aspects

At the end of 1998 and the beginning of 1999, the golden mussel Limnoperna fortunei (Dunker, 1857), Mytilidae, originating from Southeast Asia, was registered for the first time in the Guaíba Lake Basin, Rio Grande do Sul State, Brazil. Quantitative samples were taken since the first register and for two years at various localities in the Jacuí Delta, northern limit of Guaíba Lake, and in the south limit of the later where it empties into Patos Lagoon. Samplings in Patos Lagoon revealed the presence of L. fortunei in October 2000 at Arambaré (30º54’S, 51º30’W) and in January 2001 at São Lourenço do Sul (31º20’S, 51º58’W). Quantitative samplings on roots of water hyacinths Eichhornia azurea (Sw.) Kunth and E. crassipes (Mart.) Solms-Laubach, on rhizomes of rushes Scirpus californicus (C.A. Mey.) Steud. and on trunks of Cephalanthus glabratus (Spreng.) K. Schum, were made in Jacuí Delta and on the beaches of Vila de Itapuã and Pombas camping area, in the Municipality of Viamão. Limnoperna fortunei encreased in number to a maximum density of 27,275 individuals/m2 one year and five months after the first register and 62,100 individuals/m2 two years later. In November 2000, i.e., two years after the appearance of the species in Guaíba Lake, it was recorded the first macrofouling in the pipes catching water for the city of Porto Alegre and in filters and pipelines of the cellulose industry Riocell-Klabin, Municipality of Guaíba (30º06’S, 51º20’W). Limnoperna fortunei preferentially occur on rhizomes of rushes, initially forming flat clusters that grow to large mass. It also fix on the shells and soft parts of native bivalves and on shells and operculum of gastropods, prevening full closure of these mollusks. The recent decrease of rushy areas on the shores of Guaíba Lake is attributed to invasion of L. fortunei.Facultad de Ciencias Naturales y Muse

Biofilms of Candida albicans serotypes A and B differ in their sensitivity to photodynamic therapy

Candida albicans is classified into different serotypes according to cell wall mannan composition and cell surface hydrophobicity. Since the effectiveness of photodynamic therapy (PDT) depends on the cell wall structure of microorganisms, the objective of this study was to compare the sensitivity of in vitro biofilms of C. albicans serotypes A and B to antimicrobial PDT. Reference strains of C. albicans serotype A (ATCC 36801) and serotype B (ATCC 36802) were used for the assays. A gallium-aluminum-arsenide laser (660 nm) was used as the light source and methylene blue (300 mu M) as the photosensitizer. After biofilm formation on the bottom of a 96-well microplate for 48 h, each Candida strain was submitted to assays: PDT consisting of laser and photosensitizer application (L + P+), laser application alone (L + P-), photosensitizer application alone (L-P+), and application of saline as control (L-P-). After treatment, biofilm cells were scraped off and transferred to tubes containing PBS. The content of the tubes was homogenized, diluted, and seeded onto Sabouraud agar plates to determine the number of colony-forming units (CFU/mL). The results were compared by analysis of variance and Tukey test (p < 0.05). The two strains studied were sensitive to PDT (L + P+), with a log reduction of 0.49 for serotype A and of 2.34 for serotype B. Laser application alone only reduced serotype B cells (0.53 log), and the use of the photosensitizer alone had no effect on the strains tested. It can be concluded that in vitro biofilms of C. albicans serotype B were more sensitive to PDT