940 research outputs found

    Mapping the Forms of Expressive Association

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    Freedom of expressive association is a relatively new right under the First Amendment, and as a result, its key definitional aspects are continually in flux. Scholarship to- date focuses on the Supreme Court’s treatment of expressive associations, but because the Court has never truly defined what an expressive association is, the Scholarship also fails to really define the boundaries and characteristics of an expressive association. This Article begins to fill this gap in the literature and takes on the task of “mapping” the forms of expressive association. Our goal is to begin the organizing, defining, and classifying task by identifying the essential forms of expressive associations and the boundaries that should attach to the various and often overlapping forms of collective First Amendment activity. By doing so, the First Amendment values associated with each typology begin to emerge and key patterns and characteristics are identified. With this map, we begin to see the landscape of expressive associations

    Caracterização da estrutura genética do pinhão manso (Jatropha curcas L.): isolamento de fragmentos de dna enriquecidos com sequências de microssatélites.

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    O pinhão manso (Jatropha curcas) é uma planta oleaginosa que vem se destacando por apresentar um alto potencial na produção de biocombustíveis. Por este motivo o interesse em sua exploração comercial vem aumentado consideravelmente. Assim, torna-se imprescindível o desenvolvimento de tecnologias moleculares de monitoramento e seleção de populações naturais e cultivares. Nesse contexto, marcadores moleculares como os microssatélites são amplamente utilizados. No entanto, os genomas de organismos eucariontes são muito amplos e, assim, o isolamento de seqüências de microssatélites específicas, que possam atuar como marcadores, torna-se uma tarefa complexa. O presente trabalho teve como objetivo estabelecer um protocolo para isolar fragmentos de DNA específicos contendo loci de microssatélites. Este procedimento tem por finalidade aumentar a incidência das seqüências alvo para futura clonagem. Foram testadas diferentes enzimas de restrição e sondas de DNA para o reconhecimento e captura de fragmentos contendo seqüências de microssatélites. Os resultados obtidos mostraram que a enzima RsaI apresentou o melhor padrão de digestão do DNA, enquanto as melhores sondas foram as compostas pelas repetições (AATG)6, (AAAC)6, (AATC)6 e (AAAG)6. Estes procedimentos constituem etapas fundamentais no processo de isolamento de microssatélites e contribuirão para a caracterização da estrutura genética do pinhão manso. Com isto, será possível avaliar quais os estoques mais adequados para seleção de linhagens viáveis para o cultivo, visando ganhos na produtividade

    Morphological consequences of hybridization between farm and wild Atlantic salmon Salmo salar under both wild and experimental conditions

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    The escape of Atlantic salmon Salmo salar from aquaculture has been identified as a significant threat to the persistence and stability of wild salmon populations. Yet the magnitude of phenotypic impacts due to hybridization remains largely unresolved. We evaluated the phenotypic consequences of hybridization using geometric morphometrics both under natural conditions in the wild and in the laboratory using common garden experiments. Juvenile Atlantic salmon field-collected in 2015 and 2016 from 18 southern Newfoundland rivers were classified as pure wild, pure farm, or F1 hybrids using genetic assignment. Overall size and shape differences between wild and farm, and wild and F1 hybrid individuals were small, largely size related, and present between pure farm and other crosses. Laboratory-reared pure wild, pure farm, and F1 hybrid salmon were grown in tank and semi-natural conditions. Wild fish were significantly larger than both farm and hybrid salmon at first feeding; these size differences remained at 80 d post first feeding under semi-natural conditions, but all crosses were the same size in tank conditions, and there were no differences between pure farm and hybrid individuals under either condition. Significant shape differences were present among all pairwise comparisons under tank conditions, and in semi-natural conditions, pure wild individuals differed significantly from pure farm and hybrid individuals. Our results suggest phenotypic differences observed under laboratory conditions between wild and farm×wild hybrid individuals may not be appreciable in the wild, and that significant genetic changes may occur in wild populations experiencing hybridization in the absence of obvious large phenotypic changes.publishedVersio

    Population connectivity and larval dispersal of the exploited mangrove crab Ucides cordatus along the Brazilian coast.

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    Abstract: Background: The mangrove crab Ucides cordatus is considered a key species for the ecological balance of mangrove forests and a major source of employment and income for traditional crab collectors in Brazil. Several studies evidenced weak genetic variation among populations due to an efficient larval transport. However, gene flow patterns of the species is poorly understood, with no information about migration rates. The influence of the two main Brazilian currents in larval dispersion is also not clear. In order to provide baseline information for conservation, planning and management of this important fishery resource, the present study aimed to estimate and evaluate spatial distribution of genetic diversity, migration rates and gene flow directivity among populations of U. cordatus in Brazil. Methods:Nine microsatellites were used to resolve population structure of 319 crabs collected from six sites located along the Brazilian coast. The degree of geographical differentiation included estimates of genetic diversity, population structure and gene flow models, with spatial analysis of shared alleles (SAShA), isolation by distance tests, AMOVA, discriminant analysis of principal components (DAPC) and Bayesian clustering. We estimated the amount of ongoing gene flow between clusters using the coalescent-based method implemented in Migrate-N. Results:Loci were highly polymorphic (average of 12.4 alleles per locus) evidencing high genetic variability. There was significant differentiation among localities, despite of the low value of FST (= 0.019; P < 0.001). FST and Jost's D indexes were also estimated in pairwise comparisons and showed significant differences between most of the surveyed site pairs (P < 0.05). Structure evidenced a single genetic group among samples, however SAShA pointed to a non-panmictic condition (P = 0.011). AMOVA detected four statistical significant clusters with low level of differentiation (FCT = 0.037; P = 0.023). The gene flow model that best described the population connectivity was the island model, with ?24 crabs being exchanged among localities per generation.DIscussion:The high migration rates found among localities seem to be the main force acting to sustain the distribution of the genetic diversity of U. cordatus. Despite the high gene flow and the weak population structure among samples, the significant genetic differences found suggest that gene flow alone does not bypass the effects of genetic drift, natural selection and/or human exploitation. These findings are vital for the establishment of a database to be used in the development of conservation programs

    A uva de mesa do Vale do São Francisco no mercado de frutas nobres do Recife.

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    A pesquisa objetiva a sistematização do processo de comercialização de uvas de mesa produzidas na região semi-árida do Vale do São Francisco e comercializadas no mercado informal de frutas nobres, entendido como setor como setor isento de tributação, representado por comerciantes cadastrados na Prefeitura de Recife.Trabalho apresentado na Reunião de Projeto de Economia Rural da UFRPE em parceria com a Embrapa Semiárido

    Caracterização geral dos projetos irrigados do Vale do São Francisco com ênfase na fruticultura.

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    O estudo objetiva a sistematização de informações, enfatizando a fruticultura como fonte de geração de desenvolvimento do submédio do São Francisco pela implantação da agricultura irrigada, atuando como elemento catalisador do desenvolvimento regional pela transformação de um ambiente adverso caracterizado pela irregularidade das chuvas em polos de produção de culturas com elevado valor comercial. Levantamento de dados secundários, procedendo a seleção de informações de caráter de maior relevância ao objetivo do estudo e, posterior reflexão e análise. A implantação dos projetos de irrigação pela iniciativa pública gerou um novo desenho geográfico no semi-árido nordestino com a introdução da agricultura irrigada, em especial, a produção frutícola, pela melhoria dos níveis de renda, por ser uma atividade intensiva na utilização de mão de obra, promovendo a fixação do homem no campo através da interiorização do desenvolvimento regional.Trabalho apresentado na Reunião de Projeto de Economia Rural da UFRPE em parceria com a Embrapa Semiárido

    Application of a double-enrichment procedure for microsatellite isolation and the use tailed primers for high throughput genotyping.

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    The number of microsatellite loci and their allelic diversity contribute to increase accuracy and informativity of genetic estimates, however, the isolation of microsatellite loci is not only laborious but also quite expensive. We used (GATA)n and (GACA)n tetranucleotide probes and single- and double-enrichment hybridization to construct and screen a genomic library with an increased proportion of DNA fragments containing repeat motifs. Repeats were found using both types of hybridization but the double-enrichment procedure recovered sequences of which 100% contained (GATA)n and (GACA)n motifs. Microsatellite loci primers were then designed with an M13R-tail or CAG-tag to produce scorable PCR products with minimal stutter. The approach used in this study suggests that double-enrichment is a worthwhile strategy when isolating repeat motifs from eukaryotic genomes. Moreover, the use of tailed microsatellite primers provides increased resolution for compound microsatellite loci, with a significant decrease in costs
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