Limited genetic variation and structure in softshell clams (Mya arenaria) across their native and introduced range

Author Posting. © Springer, 2009. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Conservation Genetics 10 (2009): 803-814, doi:10.1007/s10592-008-9641-y.To offset declines in commercial landings of the softshell clam, Mya arenaria, resource managers are engaged in extensive stocking of seed clams throughout its range in the northwest Atlantic. Because a mixture of native and introduced stocks can disrupt locally adapted genotypes, we investigated genetic structure in M. arenaria populations across its current distribution to test for patterns of regional differentiation. We sequenced mitochondrial cytochrome oxidase I (COI) for a total of 212 individuals from 12 sites in the northwest Atlantic (NW Atlantic), as well as two introduced sites, the northeast Pacific (NE Pacific) and the North Sea and Europe (NS Europe). Populations exhibited extremely low genetic variation, with one haplotype dominating (65-100%) at all sites sampled. Despite being introduced in the last 150-400 years, both NE Pacific and NS Europe populations had higher diversity measures than those in the NW Atlantic and both contained private haplotypes at frequencies of 10% to 27% consistent with their geographic isolation. While significant genetic structure (FST = 0.159, p<0.001) was observed between NW Atlantic and NS Europe, there was no evidence for genetic structure across the pronounced environmental clines of the NW Atlantic. Reduced genetic diversity in mtDNA combined with previous studies reporting reduced genetic diversity in nuclear markers strongly suggests a recent population expansion in the NW Atlantic, a pattern that may result from the retreat of ice sheets during Pleistocene glacial periods. Lack of genetic diversity and regional genetic differentiation suggests that present management strategies for the commercially important softshell clam are unlikely to have a significant impact on the regional distribution of genetic variation, although the possibility of disrupting locally adapted stocks cannot be excluded.This work was supported by NSF grants OCE-0326734 and OCE-0215905 to L. Mullineaux and OCE- 0349177 (Biological Oceanography) to PHB

Cefaléias em salvas: estudo das alterações autonômicas e outras manifestações associadas em 28 casos Cluster headache: study of autonomic alterations and other associated manifestations in 28 cases

As cefaléias de curta duração dividem-se entre aquelas com pouca ativação; autonômica e aquelas com importante ativação, este grupo inclui a cefaléia em salvas. Este trabalho tem por objetivo discutir a fisiopatologia da cefaléia em salvas, com maior enfoque nos fenômenos autonômicos, como injeção conjuntival, lacrimejamento, congestão nasal, rinorréia, semiptose e edema palpebral, mostrando o nítido envolvimento do núcleo salivatório superior com a propagação do estímulo doloroso, originado no nervo trigêmeo. As alterações autonômicas foram estudadas em 28 pacientes com cefaléia em salvas e as prevalentes foram o lacrimejamento e a hiperemia conjuntival.<br>The short lasting primary headaches are classified as those without autonomic activation and those with important activation, which includes the cluster headache. This study focuses on the pathophysiology of cluster headache mainly in its autonomic phenomenon (conjuntival injection, lacrimation, nasal congestion, rhinorrhoea, parcial ptosis and eyelid oedema) showing the involvement of superior salivatory nucleus with the pain stimulus propagation, which begins in the trigeminal nerve. The autonomic alterations were studied in 28 patients being lacrimation and conjuntival injection, the main features