The sea-skater Halobates (Heteroptera: Gerridae) – probable cause for extinction in the Mediterranean and potential for re-colonisation following climate change

Sea-skaters in the genus Halobates Eschscholtz 1822 include some of the most specialised water striders and are found in tropical and subtropical seas around the world. Even though species of Halobates occur in both the Atlantic Ocean and the Red Sea, no extant sea-skater has been reported from the Mediterranean Sea. A fossil, Halobates ruffoi Andersen et al., 1994, described from Middle–Upper Eocene (45 Ma) Italy indicates that sea skaters were present in this part of the world in the past. Other geological evidence points to dramatic changes in the Mediterranean Sea during the Tertiary and Quaternary that may have led to their later extinction. In this paper we review briefly the distribution, systematics, evolution and ecology of Halobates, and discuss the potential for the Mediterranean to be recolonised following expected environmental changes due to global warming.     

生态意识及其主要特点

一、生态意识产生的时代背景生态意识作为人类思想的先进观念,产生于20世纪后半叶。产业革命以来二百多年,人类依据先进科学技术武装的强大生产力,无限制地向自然进     

医疗保险总额预付试点三级医院患者就医感受调查

目的 调查上海市实行医疗保险总额预付的三级医院中患者的就医感受。方法 经培训的调查员应用结构式调查问卷对上海市10家实行医疗保险总额预付的三级医院的699名患者进行面对面访谈，数据分析主要采用描述性统计。结果 城保患者对门诊医生明显减少处方金额（或处方天数）的感受强于非城保患者，城保和非城保患者的住院就医感受差异无显著统计学意义。结论 医疗保险总额预付对上海三级医院患者就医感受的总体效应似偏弱，而且有限的影响主要集中于门诊而非住院环节。     

When corridors collide: Road-related disturbance in commuting bats

As an increasingly dominant feature in the landscape, transportation corridors are becoming a major concern for bats. Although wildlife–vehicle collisions are considered to be a major source of mortality, other negative implications of roads on bat populations are just now being realized. Recent studies have revealed that bats, like many other wildlife species, will avoid roads rather than cross them. The consequence is that roads act as barriers or filters to movement, restricting bats from accessing critical resources. Our objective was to assess specific features along the commuting route, road, or surrounding landscape (alone or in combination) that exacerbated or alleviated the likelihood of a commuting bat exhibiting an avoidance behavior in response to an approaching vehicle. At 5 frequently used commuting routes bisected by roads, we collected data on vehicles travelling along the roads (such as visibility and audibility), commuting bats (such as height), and composition of the commuting route. We revealed that commuting route structure dictated the frequency at which bats turned back along their commuting routes and avoided the road. We found that gaps (>2 m) in commuting routes, such as the road itself, caused bats to turn away just before they reached the road. Furthermore, we found that turning frequencies of bats increased with vehicle noise levels and the locations at which bats responded to vehicles corresponded with areas where noise levels were greatest, including gaps <2 m. This suggested that bats had a disturbance threshold, and only reacted to vehicles when associated noise reached a certain level. We found that threshold levels for our study species were approximately 88 dB, but this value was likely to vary among species. Thus, our findings indicate that restoring (e.g., replanting native trees and shrubs in gaps) and establishing commuting routes (such as planting tree-lines and wooded hedgerows), as well as creating road-crossing opportunities (such as interlinking canopies) will improve the permeability of a road-dominated landscape to bats. Furthermore, our study highlights the influence of the soundscape. We recommend that effective management and mitigation strategies should take into account the ecological design of the acoustic environment. © 2012 The Wildlife Society.     

Recent increase in body size of the American marten Martes americana in Alaska

Using museum specimens, we studied recent changes in skull size of the American marten Martes americana , in continental Alaska. In Alaska, global warming has resulted in milder winters that may contribute to an improved food supply in the wild. In the present study, we tested the hypothesis that body size of the marten had increased during the second half of the 20th century, in response to global warming. We found that skull size, and by implication body size, increased significantly during the second half of the 20th century, possibly due to an improved food supply and/or lower metabolic demands in winter. Improved food availability in winter may result from the improved nutritional conditions for prey, and/or from increased access to prey resulting from a longer snow-free season. Longitude had a significant positive effect on skull size and a significant negative effect on teeth size. In Alaska, the climate is milder along the western coast and becomes harsher inland. Hence, the milder climate was associated with larger body size providing further support for our prediction that body size of the American marten was influenced by food availability and reduced energy expenditure. The negative relationship between longitude and teeth size may indicate a trend towards a larger prey in inland marten populations, but we have no data to support or refute this hypothesis.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 93 , 701–707.     

Evidence of stenotopy and anthropogenic influence on carbon source for two major riverine fishes of the Lake Victoria watershed

Stable isotope analysis was used to investigate the migratory status and to determine the relative contribution of allochthonous and autochthonous sources of carbon for the major riverine fish species ( Barbus altianalis and Labeo victorianus ) in rivers draining the Kenyan side of Lake Victoria. The two fish species derived carbon from both C4 and C3 plant sources, although L. victorianus exhibited less enriched isotopic carbon values. Fish samples from stations under direct influence of effluents from sugar factories exhibited enriched δ¹³C signals. Assuming that this reflects carbon sourcing from riparian C4 plants, it suggests that carbon from terrestrial sources can be a major energy source in some rivers. This heavy carbon enrichment associated with sugar factories was spatially restricted and occurred in all seasons, implying that sub-populations of the two fish species are non-migratory. The large migratory populations of these two species, for which Lake Victoria was once famous, may be no more.