136 research outputs found

    Dynamics of core and occasional species in the marine plankton: tintinnid ciliates in the north-west Mediterranean Sea

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    International audienceTo assess short-term variability in the community composition and community structure of tintinnid ciliates, herbivores of the microzooplankton. Location North-west Mediterranean Sea. We sampled on 18 dates over a 4-week period in 2004 at an openwater site. Species were classified as 'core species', found on every date, or 'occasional species', absent on one or more dates. Species abundance distributions of the entire community, and separately the core and occasional species, were compared with geometric, log-series and log-normal distributions. Core and occasional species were compared in terms of the shell or lorica oral diameter (LOD), analogous to gape size. We found 11 core and 49 occasional species. Diversity metrics were stable compared with shifts in abundances. Core species accounted for the majority of individuals in all samples. On each date, 9-22 occasional species, representing 10-15% of the population, were found. Species richness of the occasionals was positively related to population size. The identities of the occasional species found were unrelated to the time between sampling. The species abundance distribution of the occasional population was best fit by a log-series distribution, while that of the core species was best fit by a log-normal distribution. The species abundance distribution of the entire community was best fit by a log-series distribution. Most of the occasional species had LODs distinct from that of a core species and occupied size classes left empty by the core population. However, the most abundant and frequent of the occasional species had a LOD similar to that of a core species. Among tintinnids, which are planktonic protists, occasional species have a species abundance distribution pattern distinct from that of core species. Occasional species appeared to be composed of two groups, one of relatively abundant species and similar to core species, and a second group of ephemeral species with morphologies distinct from core species. The existence of two categories of occasional or rare species may be common: (1) those similar to, and thus perhaps able to replace, dominant species in the absence of a change in the environment; and (2) those distinct from dominant species and requiring different conditions to prosper

    Similar patterns of patterns of community organization characterize distinct groups of different trophic levels in the plankton of the NW Mediterranean Sea

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    International audiencePlanktonic populations were sampled over a 4 week period in the NW Mediterranean, at a site subject to little vertical advection during the Dynaproc 2 cruise in 2004. The characteristics of the phytoplankton, the tintinnid community and the zooplankton have recently been described in detail. Based on these studies, we compared the characteristics of 3 well-circumscribed assemblages of different trophic levels: Ceratium of the phytoplankton, herbivorous tintinnids of the microzooplankton, and large (>500μm) omnivorous and carnivorous copepods of the metazoan zooplankton. In all three groups, diversity as H' or species richness, wasless variable than concentration of organisms. Plotting time against species accumulation, the curves approached plateau values for Ceratium spp, tintinnids and large copepods but only a small number of species were consistently present (core species) and these accounted for most of the populations. or Ceratium core species numbered 10, for tintinnids 11 species, and for large copepods, core species numbered 4 during the day and 16 at night. Ceratium, tintinnids and large copepods showed some similar patterns of community structure in terms of species abundance distributions. Ceratium species were distributed in a log-normal pattern. Tintinnid species showed a log-series distribution. Large copepod assemblages were highly dominated with night samples showing much higher abundances and greater species richness than day samples. However, species abundance distributions were similar between day and night and were mostly log- normal. The paradox of the plankton, describing phytoplankton communities as super-saturated with species, extends to the microzooplankton and zooplankton

    Mapeamento de QTL para resistência a carrapatos no cromossomo 23 de bovinos (BTA23).

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    Uma população experimental F2 de bovinos, originada do cruzamento das raças Gir x Holandês, foi genotipada para o cromossomo 23 (BTA23) utilizando cinco marcadores microssatélites distribuídos ao longo dos cromossomos, com um espaçamento médio de 25 cM entre eles. Os marcadores utilizados foram BM1258, BM1818, BM1905, BB705 e CSSM24, com os quais foi construído um mapa de ligação para o BTA23. Dessa população F2, 263 animais foram submetidos a infestação artificial pelo carrapato Boophilus microplus. Vinte e um dias após a infestação, foi contado o número de carrapatos (larvas engurgitadas) presentes em cada animal. Dois modelos estatísticos foram desenvolvidos com o auxílio do programa SAS para análise da variância e para fins de mapeamento de QTL, o primeiro modelo incluía como efeitos fixos a avaliação dos animais quanto à cor da pelagem (100% branca, mais de 75%, entre 50 a 75% e entre 25 a 50%), tipo de pêlo (curto liso, curto lanado, longo liso e longo lanado) e sexo e como covariáveis idade à infestação e estação (águas e seca); no outro modelo a covariável estação foi eliminada. As medidas da contagem de carrapatos foram submetidas a várias transformações, entre elas a raiz quadrada e logaritmo, sendo que o logaritmo da contagem de carrapatos foi a mais adequada no sentido de remover a heterogeneidade das variâncias e promover normalidade. O mapeamento de QTL foi realizado pelo programa QTL Express (Seaton et al., 2002), considerando ou não as interações entre QTL e sexo, e entre QTL e estação. Foi encontrado, no cromossomo 23, um indício de QTL no modelo aditivo (p < 0,08) com interação com tipo de pelagem na posição de 24 cM, porém de pequeno efeito no aumento do numero de carrapatos (explicando 3,29% da variância fenotipica) e de origem na raça Holandês. Outro QTL sugestivo foi encontrado no modelo aditivo (p < 0,05) com interação com sexo na posição 89 cM, também de pequeno efeito (explicando 3,18% da variância fenotipica) com a mesma origem do anterior. Ambos QTL foram encontrados utilizando-se o modelo contendo a covariável estação. Isso mostra que o tipo de pelagem e o sexo do animal possuem influência em sua carga parasitária. Observou-se também uma melhora no poder do teste para detecção de QTL quando a covariável estação é retirada da análise no caso da interação do QTL com sexo, o mesmo não ocorre na interação com tipo de pelagem. Estes resultados preliminares justificam a realização de pesquisas adicionais no sentido de identificar os fatores relacionados a resistência genética de bovinos ao carrapato

    GIS-based detection of terraced landscape heritage: comparative tests using regional DEMs and UAV data

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    The analysis of terraced heritage has implications in many different fields of study, as it is shaped itself by natural, socioeconomic, and cultural dynamics. Given that their abandonment impoverishes territories and communities and raises natural, especially hydrogeological hazards, and that their deactivation leads to a loss of cultural identity, this paper aims to study rapid mapping systems for their detection. Since a deep relation between high land division and the use of terraces for the exploitation of territories has been recognized, a first detection method is based on cadastral maps. The joint use of regional-scale digital elevation models (DEMs) and cadastral dataset polygons, based on a model that typically uses GIS analyses, identifies areas with a high probability of terracing. A second method is based on the use of new technologies for very high-scale data collection. The DEM models derived from UAV (unmanned aerial vehicle) photogrammetry, given their ability to determine the micro-topographical characterization of the terrain as well as the most expensive on-site techniques, can be considered an excellent low-cost means by which to locate terraced heritage. The proposed work includes comparative testing between methods implying GIS-based analysis of slope models. It aims to highlight the effectiveness of using both methods: regional-scale DEMs and cadastral maps to detect a high probability of terrace localization, and DEMs derived from the use of low-altitude aerial data and structure from motion (SfM) algorithms, which have greatly and effectively increased the use of aerial drone photogrammetry

    Inclusão e Formação Profissional de mulheres em situação de vulnerabilidade social

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    RESUMO O presente trabalho busca analisar a inclusão de mulheres em situação de vulnerabilidade social através da formação profissional oferecida por escolas técnicas que desenvolvem o Programa Mulheres Mil. O referido programa foi inicialmente estruturado no país no ano de 2007, tinha como objetivo a formação educacional, profissional e cidadã de mulheres economicamente desfavorecidas nas regiões Norte e Nordeste do país. A partir de 2011, foi instituído e desenvolvido pelo Ministério da Educação através da Secretaria de Educação Profissional e Tecnológica (SETEC), inserindo-se em um conjunto de prioridades do Governo Federal. Apesar desta oferta não ser exclusiva dos Institutos Federais, é nela que prioritariamente o programa se desenvolveu. De acordo com os princípios e diretrizes preconizadas pelo Programa Mulheres Mil, torna-se um desafio atingir e executar todas as ações programadas com os recursos humanos e financeiros disponíveis. O objetivo geral da pesquisa é avaliar a eficácia das políticas de inclusão de mulheres em situação de vulnerabilidade no Programa Mulheres Mil através de um estudo de caso realizado no Instituto Federal de Educação, Ciência e Tecnologia do Rio de Janeiro – campus Volta Redonda (IFRJ-CVR). Os resultados obtidos foram interpretados pelo viés da etnografia crítica que leva em consideração os aspectos culturais, políticos e econômicos para a conclusão do trabalho. Espera-se que o leitor ao se aproximar do conteúdo do artigo compreenda o histórico do programa, a construção e execução do programa mulheres mil no IFRJ-CVR, assim como os resultados obtidos por ele enquanto uma política de inclusão. Palavras-Chave: Políticas de Inclusão; Programa Mulheres Mil; Institutos Federais de Educação.  ABSTRACT  The following paper tries to analyze the inclusion of women at social risk through professional qualification offered by vocational-technical schools that manage a program called Mulheres Mil (A thousand women). Such program was firstly established in Brazil in 2007 and it aimed educational and professional qualification, as well as citizenship awareness, of northern and northeastern underprivileged women. Afterwards, staring from 2011, it was stablished and developed by the Department of Education, through the Technological and Professional Office, and became part of the Federal government priorities. It was not exclusively offered by Technical Schools, which where it was primarily developed. According to the principles and directives recommended by the Mulheres Mil program, reaching and executing all programed deeds with the human and financial resources available is quite a challenge. The study general objective is to evaluate the underprivileged women inclusion policies efficiency through a case study performed by the Instituto Federal de Educação, Ciência e Tecnologia do Rio de Janeiro – campus Volta Redonda (IFRJ-CVR). The results were interpreted through critical ethnography, which considered cultural, political and economic aspects to conclude the study. It is expected when the reader is acquainted with the study content he/she understands the program background, the construction and execution of the IFRJ-CVR mulheres mil project as well as the results it obtained as an inclusion policy. Keywords: Inclusion Policies; Mulheres Mil program; Institutos Federais de Educação (Technical Schools).

    POLÍTICAS DE DIFUSÃO DAS TECNOLOGIAS DA INFORMAÇÃO E COMUNICAÇÃO NA EDUCAÇÃO: REFLEXÕES A PARTIR DE UM RESGATE HISTÓRICO

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    Seguindo uma tendência internacional e com intuito de atender a demanda pela disseminação de um conhecimento mais científico-tecnológico para uma sociedade em desenvolvimento, foi que surgiram as primeiras experiências,ainda na década de 1970, do uso do computador na educação brasileira. Desde essa época até agora, ocorreram mudanças significativas na nossa forma de se comunicar, interagir e aprender. Não obstante, muitos foram os programas e projetos desenvolvidos a fim de levar parte dessas mudanças para as escolas públicas. Opresente artigo tem como objetivo apresentar um breve resgate histórico das principais iniciativas que ocorreram no país para incentivar a introdução das tecnologias da informação e comunicação no cenário educacional. O texto pretende trazer ao leitor uma reflexão crítica a respeito do processo de democratização do uso das tecnologias na educação, levando em consideração os interesses do capital. Como resultado, destacamos a necessidade de superar a ideia de que apenas o acesso às tecnologias garante avanços e melhorias no ambiente educacional

    Pulseless Electrical Activity as the Initial Cardiac Arrest Rhythm: Importance of Preexisting Left Ventricular Function

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    Background Pulseless electrical activity (PEA) is a common initial rhythm in cardiac arrest. A substantial number of PEA arrests are caused by coronary ischemia in the setting of acute coronary occlusion, but the underlying mechanism is not well understood. We hypothesized that the initial rhythm in patients with acute coronary occlusion is more likely to be PEA than ventricular fibrillation in those with prearrest severe left ventricular dysfunction. Methods and Results We studied the initial cardiac arrest rhythm induced by acute left anterior descending coronary occlusion in swine without and with preexisting severe left ventricular dysfunction induced by prior infarcts in non-left anterior descending coronary territories. Balloon occlusion resulted in ventricular fibrillation in 18 of 34 naive animals, occurring 23.5 +/- 9.0 minutes following occlusion, and PEA in 1 animal. However, all 18 animals with severe prearrest left ventricular dysfunction (ejection fraction 15 +/- 5%) developed PEA 1.7 +/- 1.1 minutes after occlusion. Conclusions Acute coronary ischemia in the setting of severe left ventricular dysfunction produces PEA because of acute pump failure, which occurs almost immediately after coronary occlusion. After the onset of coronary ischemia, PEA occurred significantly earlier than ventricular fibrillation (&lt;2 minutes versus 20 minutes). These findings support the notion that patients with baseline left ventricular dysfunction and suspected coronary disease who develop PEA should be evaluated for acute coronary occlusion
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