976 research outputs found

    The importance of predation by horseshoe crabs, Limulus polyphemus, to an intertidal sand flat community

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    Horseshoe crabs, Limulus polyphemus (L.), are abundant in the lower Delaware Bay during their spring spawning activity. The impact of predation on the benthic community of intertidal flats in the vicinity of breeding beaches was investigated using exclosures and enclosures. In 1978 and 1979, protected sediments contained significantly more individuals, biomass and species per core than unprotected sediments. In 1978, the bivalves Gemma gemma, Mulinia lateralis, and Mya arenaria were significantly more numerous within cages. At that time, unprotected sediments contained very few Mya or Mulinia over 4 mm, suggesting that predators “cropped off” these species as they attained a larger size. Changes in the benthic community were evident when the population of Limulus was at or near maximum. Alternative explanations for the changes seen in the exclusion experiment, including sedimentary modifications and the effects of alternative predators (crabs, fish, and shorebirds), were rejected. Sedimentary modifications were not observed, while the effects of predators besides Limulus were minor

    Isolated Trapezoid Fracture in a Boxer

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    BACKGROUND Trapezoid fractures are very uncommon, accounting for less than 1% of all wrist fractures. Isolated fractures of this bone are even more rare, with just a few reports in the literature. The trapezoid bone has a very stable position within the wrist, forming a relatively immobile joint with the second metacarpal base distally. It is also connected by very strong ligaments to the trapezium, capitate and, scaphoid. Trapezoid fractures occur when a strong bending or axial force is applied to the second metacarpal base. CASE REPORT We present a clinical case of an isolated, non-displaced, trapezoid fracture in a young white male, which was treated with cast immobilization for 4 weeks and physical therapy. Complete functional recovery was achieved 3 months after the injury, without any pain or tenderness. CONCLUSIONS Fractures of the trapezoid bone usually have a good clinical outcome. Nonetheless, we need to be very suspicious about this diagnosis since radiography is apparently normal in almost all such cases and clinical examination results may not be entirely clear.info:eu-repo/semantics/publishedVersio

    Prosomal-width-to-weight relationships in American horseshoe crabs (Limulus polyphemus): examining conversion factors used to estimate landings

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    Horseshoe crabs (Limulus polyphemus) are valued by many stakeholders, including the commercial fishing industry, biomedical companies, and environmental interest groups. We designed a study to test the accuracy of the conversion factors that were used by NOAA Fisheries and state agencies to estimate horseshoe crab landings before mandatory reporting that began in 1998. Our results indicate that the NOAA Fisheries conversion factor consistently overestimates the weight of male horseshoe crabs, particularly those from New England populations. Because of the inaccuracy of this and other conversion factors, states are now mandated to report the number (not biomass) and sex of landed horseshoe crabs. However, accurate estimates of biomass are still necessary for use in prediction models that are being developed to better manage the horseshoe crab fishery. We recommend that managers use the conversion factors presented in this study to convert current landing data from numbers to biomass of harvested horseshoe crabs for future assessments

    Proposta de construção de uma estrutura física aplicada a trabalhos com agrotóxicos em laboratórios de entomologia.

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    Esta circular técnica tem como objetivo apresentar uma proposta de construção e operação de uma Central de Experimentos Tóxicos, facilmente replicável nas diferentes Instituições de pesquisa e ensino, permitindo, assim, realizarem-se de forma segura experimentos com agrotóxicos em pequena escala.bitstream/item/48464/1/Circular-Tecnica-87.pd

    Manejo de Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) na cultura do morangueiro no Rio Grande do Sul.

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    Esta Circular Técnica tem como objetivo descrever a biologia de F. occidentalis na cultura do morangueiro, caracterizar o tipo de injúria causada pelo inseto em flores e frutos e fornecer informações para o monitoramento e o controle da espécie na cultura no Estado do Rio Grande do Sul.bitstream/item/73816/1/cir090.pd

    Avaliação das injúrias causadas por Anastrepha fraterculus (Wied.) sobre a incidência de podridões de cachos em videira da cv. ‘Itália’ em cultivo protegido.

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    Este trabalho teve como objetivo avaliar o efeito da associação entre as injúrias causadas pela mosca-das-frutas sul-americana (MFSA) A. fraterculus com Botrytis cinerea e Glomerella cingulata na cultura da videira.Resumo

    Mitefauna (Arachnida: Acari) associated to grapevine, Vitis vinifera L. (Vitaceae), in the municipalities of Bento Gonçalves and Candiota, Rio Grande do Sul, Brazil.

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    The mitefauna associated to Merlot and Chardonnay grapevine cultivars and associated plants in the municipalities of Bento Gonçalves and Candiota, Rio Grande do Sul was investigated. The study was developed between October 2006 and September 2007, where 20 grapevine plants were randomly chosen from each municipality and monthly sampled. Three leaves of each plant were taken. A total of 11,598 mites belonging to 14 families and to 52 species were found. Fifty-nine percent of the total specimens were collected in Candiota, being 93% associated to the Merlot cultivar. Higher species richness was observed on associated plants. Phytoseiidae showed the highest species richness, with ten species, and Eriophyidae showed the highest abundance, with 8,675 specimens. Calepitrimerus vitis (Nalepa, 1905) and polyphagotarsonemus latus (Banks, 1904) were the most common phytophagous mites, while Neoseiulus californicus (McGregor, 1954) and Pronematus anconai (Baker, 1943) were the most common predators

    Atividade de forrageamento de Linepithema micans (Hymenoptera: Formicidae) em videira.

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    Neste trabalho, foi estudado a preferência alimentar (tipo de alimento) e os períodos de atividade de forrageamento de L.micans durante o dia em diferentes épocas do ano.Resumo

    Diagnóstico da área cultivada com uva fina de mesa (Vitis vinifera L.) sob cobertura plástica e do manejo de pragas.

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    Neste trabalho, foi realizado o censo das áreas cultivadas com uvas finas de mesa sob cultivo protegido e a identificação das principais espécies de pragas e estratégias de controle empregadas pelos produtores, no município de Caxias do Sul-RS. Na safra de 2007/2008, foram identificados os produtores envolvidos com a atividade no município e através de entrevista presencial e semiestruturada ao estabelecimento produtivo, registrou-se a área cultivada e variedades. Para produtores com cultivo de áreas superiores a 2.000m2 da cultivar Itália, com dois anos ou mais de produção, foi aplicado outro questionário na safra de 2008/2009 com o objetivo de levantar as informações referentes: a) espécies de insetos e ácarospraga que danificam as uvas finas de mesa na propriedade, segundo o viticultor; b) conhecer a realidade do manejo de insetos e ácaros-praga na cultura; c) verificar os parâmetros que o produtor utiliza para a aplicação de inseticidas; d) conhecer os produtos aplicados, e e) identificar o tipo de assistência técnica recebida pelo viticultor. Foram identificados 43 produtores de uvas finas de mesa sob cultivo protegido com área total cultivada de 30,36 ha, sendo 70,31% desta área da cultivar Itália. As pragas mais importantes mencionadas pelos produtores foram tripes - Frankliniella rodeos Moulton e a mosca-das-frutas-sul-americana Anastrepha fraterculus (Wied). O manejo realizado para controle destas pragas é através da aplicação de inseticidas com os ingredientes ativos acefato e fentiona, respectivamente, com base em calendário. Os principais problemas enfrentados para implementar estratégias de manejo de pragas no cultivo são a falta de assistência técnica, a ausência de metodologias confiáveis para o monitoramento e o reduzido número de inseticidas autorizados para a cultura

    Horseshoe Crab Research in Urban Estuaries: Challenges and Opportunities

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    Horseshoe crabs rely on estuaries for food resources, places to spawn and for larvae and juveniles to develop and grow. Many of these estuaries are becoming increasingly urbanized and dominated by human activity. An urban estuary is characterized by armored shorelines, high nutrient loads, large fluctuations in algal and bacteria populations, increased levels of pollutants like heavy metals and pesticides, and seasonally low oxygen levels and pH. While urban estuaries are challenging for horseshoe crab survival and to researchers trying to study them, there are also opportunities for involving the public in research and increasing public awareness of the importance of the conservation and survival of horseshoe crabs. Two recent studies in New York and Connecticut have involved citizen scientists to tag and gather valuable data on horseshoe crab population dynamics. It has been discovered that there is very low recruitment of new adults into the two urban estuaries studied and that spawning populations of horseshoe crabs are relatively low when compared to less disturbed more rural estuaries
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