The morphology of the grooming limbs, the 5th pair of pereiopods, was studied by scanning electron microscopy in six species of porcellanid crabs, Petrolisthes cabrilloi, P. cinctipes, P. armatus, P. galathinus, Pachycheles monilifer, and Pachycheles rudis, and their function was inferred by comparison with findings from previous studies. Grooming limb morphology was almost identical among the four Petrolisthes species and differed little compared to that of the two Pachycheles species. The 5th pereiopods bore a basal tuft of mechanoreceptive setae, three different types of grooming setae armed with setules or denticles, two types of smooth sensilla for location and identification of fouling objects, and a terminal, toothed chela for picking firmly attached objects off the gills and body. The grooming limb was extremely flexible and could reach most parts of the body, including the gill chamber on the opposite side. The grooming limb morphology in Petrolisthes cabrilloi is consistent with its wellknown effectiveness in preventing parasitism by the rhizocephalan Lernaeodiscus porcellanae. Grooming setae remove recently attached cyprids, while the chela can grip and remove the much smaller, firmly attached kentrogons. Porcellanid crabs not known to host rhizocephalans, however, had grooming limbs almost identical to those of Petrolisthes cabrilloi despite their previously demonstrated failure to prevent settlement and infestation by L. porcellanae larvae. The effectiveness of P. cabrilloi in removing kentrogons, therefore, seems also to depend on behavioral adaptations whereby this species recognizes the parasite larvae as high-threat objects. 相似文献
We report three cases of Turner's syndrome with cystic hygromata, which were diagnosed by routine ultrasound scanning before amniocentesis in the second trimester of pregnancy. Maternal and amniotic level of alpha-fetoprotein were normal. Karyotyping carried out afterwards showed a 45,X karyotype. Our data indicate, that cystic hygromata in Turner's syndrome may coexist with a normal amniotic fluid AFP, thus questioning the theory of leakage from the hygroma. It remains to be investigated if all cases of Turner's syndrome present a cystic hygroma in utero. 相似文献
Objective: This study aligns to the body of research dedicated to estimating the underreporting of road crash injuries and adds the perspective of understanding individual and crash factors contributing to the decision to report a crash to the police, the hospital, or both.
Method: This study focuses on road crash injuries that occurred in the province of Funen, Denmark, between 2003 and 2007 and were registered in the police, the hospital, or both authorities. Underreporting rates are computed with the capture–recapture method, and the probability for road crash injuries in police records to appear in hospital records (and vice versa) is estimated with joint binary logit models.
Results: The capture–recapture analysis shows high underreporting rates of road crash injuries in Denmark and the growth of underreporting not only with the decrease in injury severity but also with the involvement of cyclists (reporting rates of about 14% for serious injuries and 7% for slight injuries) and motorcyclists (reporting rates of about 35% for serious injuries and 10% for slight injuries). Model estimates show that the likelihood of appearing in both data sets is positively related to helmet and seat belt use, number of motor vehicles involved, alcohol involvement, higher speed limit, and females being injured.
Conclusions: This study adds significantly to the literature about underreporting by recognizing that understanding the heterogeneity in the reporting rate of road crashes may lead to devising policy measures aimed at increasing the reporting rate by targeting specific road user groups (e.g., males, young road users) or specific situational factors (e.g., slight injuries, arm injuries, leg injuries, weekend). 相似文献
Stopping declines in biodiversity is critically important, but it is only a first step toward achieving more ambitious conservation goals. The absence of an objective and practical definition of species recovery that is applicable across taxonomic groups leads to inconsistent targets in recovery plans and frustrates reporting and maximization of conservation impact. We devised a framework for comprehensively assessing species recovery and conservation success. We propose a definition of a fully recovered species that emphasizes viability, ecological functionality, and representation; and use counterfactual approaches to quantify degree of recovery. This allowed us to calculate a set of 4 conservation metrics that demonstrate impacts of conservation efforts to date (conservation legacy); identify dependence of a species on conservation actions (conservation dependence); quantify expected gains resulting from conservation action in the medium term (conservation gain); and specify requirements to achieve maximum plausible recovery over the long term (recovery potential). These metrics can incentivize the establishment and achievement of ambitious conservation targets. We illustrate their use by applying the framework to a vertebrate, an invertebrate, and a woody and an herbaceous plant. Our approach is a preliminary framework for an International Union for Conservation of Nature (IUCN) Green List of Species, which was mandated by a resolution of IUCN members in 2012. Although there are several challenges in applying our proposed framework to a wide range of species, we believe its further development, implementation, and integration with the IUCN Red List of Threatened Species will help catalyze a positive and ambitious vision for conservation that will drive sustained conservation action. 相似文献
Today, as Greenland focuses on more economic and cultural autonomy, the continued development of societal infrastructure systems is vital. At the same time, pressure is put on the systems by a lack of financial resources and locally based professional competences as well as new market-based forms of organization. Against this background, the article discusses the challenges facing Greenland’s self-rule in relation to further develop the existing water and wastewater systems so that they can contribute to the sustainable development of Greenland. The article reviews the historical development of the water supply and wastewater system. This leads to an analysis of the sectorisation, which in recent decades has reorganized the Greenlandic infrastructures, and of how this process is influencing local sustainable development. The article discusses the socio-economic and human impacts and points to the need for developing the water and sanitation system to support not only hygiene and health, but also local sustainable development. 相似文献