Genetic diversity and the history of pacific island house geckos (Hemidactylus and Lepidodactylus)

Patterns of variation in chromosomes, mitochondrial DNA and allozymes were assessed for two parthenogenetic (Lepidodactylus lugubris and Hemidactylus garnotii ) and one sexual (H. frenatus) species of house gecko that have colonized remote Pacific Ocean islands. The aims were to test the assumed recency of colonization and to provide information on the amount and distribution of genetic variation. Lepidodactylus lugubris was found to have diploid and triploid clones, high heterozygosity and moderate diversity for allozymes, and only two common types of mtDNA. The common clones distinguished by genetic analysis were geographically widespread. Together the genetic data suggest multiple origins of L. lugubris, with multiple recent invasions of the Pacific Ocean islands. Hemidactylus garnotii had low genetic diversity for chromosomes, mtDNA and allozymes. In contrast, its sexual congener, H. frenatus, had unusually high levels of mtDNA diversity, with some widespread variants. The low level of mtDNA diversity in the parthogenetic species provides strong support for the assumption that these are recent colonists of Pacific islands

Treatment of venous thromboembolism with low-molecular-weight heparin: a synthesis of the evidence published in systematic literature reviews

Objective: To evaluate the methodology and cumulative evidence presented in systematic reviews of clinical trials comparing low-molecular-weight heparin (LMWH) with unfractionated heparin (UFH) for the treatment of venous thromboembolism. Methods: We reviewed all systematic reviews of clinical trials published until March 2002. Fourteen systematic literature reviews were published between 1994 and 2000. Deficiencies in methodological quality were common, particularly in the description of search strategies, assessment of clinical trial quality, and methods used to combine results. Results: Results of reviews indicate that LMWH is superior to UFH for the treatment of venous thromboembolism, particularly in reducing mortality. Patients with isolated deep venous thrombosis or deep venous thrombosis with concomitant pulmonary embolism seemed to have similar benefit. However, the benefits of LMWH over UFH were smaller in magnitude in reviews that included more recent clinical trials

Abundance patterns of terrestrial isopods along an urbanization gradient

The abundance of terrestrial isopods (Isopoda: Oniscidea) was evaluated along an urban-suburban-rural gradient. We tested two hypotheses regarding the response of species: (i) habitat specialist hypothesis, according to which the abundance of the forest specialists would increase, while the abundance of the urban environment specialist isopods would decrease along the urban-rural gradient, and (ii) opportunistic species hypothesis (abundance of the generalist species would increase by increasing level of urbanization). The abundance of the forest specialist isopod Trachelipus ratzeburgii increased significantly along the studied gradient. An opposite tendency was observed for the abundance of the urban environment specialist isopod Porcellio scaber , as it was significantly higher in the urban area than in the suburban and rural sites. One generalist species (Trachelipus rathkii) gained dominance in the urban area, while other two generalists (Armadillidium vulgare and Porcellium collicola) showed no significant changes in abundance along the gradient