24 research outputs found

    Microsatellite markers: what they mean and why they are so useful

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    Experimental evidence of inbreeding avoidance in the hermaphroditic snail Physa acuta

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    Inbreeding depression should select for inbreeding avoidance behaviours. Here we test this hypothesis in two populations of the simultaneous hermaphroditic freshwater snail Physa acuta. We recorded the copulatory behaviour of 288 pairs of sib-mates, non-kin mates from the same population, or non-kin mates from two different populations. We find that kin discriminatory behaviours exist in this species, exclusively expressed by individuals playing the female role. We discuss the relevance of our finding in the context of the evolution of recognition systems and the consequences of such a behaviour in natural populations

    Ocorrência de acidente de trabalho por materiais perfurocortantes e fluidos biológicos em estudantes e trabalhadores da saúde de um hospital escola de Brasília Frecuencia de accidentes del trabajo causados por instrumentos puntiagudo-cortantes y fluidos biológicos entre estudiantes y personal de un hospital escuela de la ciudad de Brasilia Occurrence of work accidents caused by sharp-edged hollow-pointed equipment and biological fluids among medical students and health personnel in a Brasília university hospital

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    estudo teve por objetivo verificar e analisar a ocorrência de acidentes de trabalho causados por materiais perfurocortantes e fluidos biológicos em estudantes e trabalhadores da área da saúde. Foi realizado em um hospital-escola de Brasilia. A coleta de dados foi feita a partir dos registros de acidentes de trabalho mantidos pela Comissão de Controle de Infecção Hospitalar e referentes ao período de agosto de 1998 a junho de 2000. Verificou-se que 117 pessoas sofreram acidentes de trabalho, em sua grande maioria causados por agulhas. Concluiu-se que existe a necessidade de melhoria nos sistemas de prevenção de acidentes na instituição.<br>El objetivo del estudio fue el de verificar y analizar la frecuencia de accidentes del trabajo causados por instrumentos puntiagudo-cortantes entre estudiantes y personal de un hospital escuela de la ciudad de Brasilia. Los datos, recogidos de los registros de accidentes del trabajo de la Comisión de Control de Infección Hospitalaria, corresponden al periodo entre agosto de 1998 y junio de 2000. Se verifico que 117 personas sufrieron accidentes del trabajo, en su gran mayoría causados por agujas. Se llegó a la conclusión de que es necesario mejorar el sistema de prevención de accidentes en dicha institución.<br>The objective of the study was to check and analyze the occurrence of work accidents caused by sharp-edged hollow-pointed equipment and biological fluids among medical students and health personnel. It was carried out in a Brasilia university hospital. The data were collected from records of work accidents kept by the Hospital Infection Control Committee, from August 1998 to June 2000. It has turned out that 117 persons were victims of work accidents, the vast majority of them caused by needles. The study has reached the conclusion that the accident prevention system must be improved at the above mentioned hospital

    Field and experimental evidence of preferential selfing in the freshwater mollusc Lymnaea truncatula (Gastropoda, Pulmonata)

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    International audienceWe have conducted a thorough study of the mating system of Lymnaea truncatula, the intermediate host of the liver fluke, using three approaches: (i) a population genetics study, (ii) controlled pairings in the laboratory and (iii) a progeny-array analysis. The population genetics study revealed high levels of inbreeding in the studied populations, with strong clues that the extensive heterozygote deficiencies observed are due to selfing. However, Wahlund effects may also arise due to recolonisations from different source populations after bottleneck events. A breeding experiment helped to disentangle the mating system and the Wahlund effects, and showed that high levels of selfing occurred in isolation and in controlled pairings. However, the progeny-array analysis performed after a high-density culturing of the snails suggests that substantial outcrossing may also occur

    Host race formation in the Acari

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    Host race formation generates diversity within species and may even lead to speciation. This phenomenon could be particularly prevalent in the Acari due to the often intimate interaction these species have with their hosts. In this review, we explore the process of host race formation, whether it is likely to occur in this group and what features may favour its evolution. Although few studies are currently available and tend to be biased toward two model species, results suggest that host races are indeed common in this group, and more likely to occur when hosts are long-lived. We discuss future directions for research on host-associated adaptations in this group of organisms and the potential relevance of host race formation for the biodiversity of mites and ticks
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