征兵情境下社会期许性量表的编制

本研究根据Paulhus1998年提出的双成分模型为理论基础,结合已有问卷,编制征兵心理检测情境下社会期许性量表。对某军校2010级的1224名新生分别在"应征心理检测情境"和"非应征情境"下,进行两次施测,前后测试间隔7个月,并对调查数据进行探索性因素分析和验证性因素分析。根据探索性因子分析提取的印象管理和自我欺骗两因子模型,符合理论构想,经验证性因子分析表明量表的结构效度良好;前后测试结果具有显著性差异,且效应值较大;内部一致性信度和重测信度均符合预期设想,自编征兵情境下社会期许性量表的信、效度均达到心理测量学的要求。     

Cycles of <Emphasis Type="Italic">Euphausia superba</Emphasis> recruitment evident in the diet of Pygoscelid penguins and net trawls in the South Shetland Islands,Antarctica

Size and sex of Antarctic krill taken from chinstrap and gentoo penguin diet were compared to those from scientific net surveys in the South Shetland Islands from 1998 to 2006 in order to evaluate penguin diet as a sampling mechanism and to look at trends in krill populations. Both penguin diet and net samples revealed a 4–5 year cycle in krill recruitment with one or two strong cohorts sustaining the population during each cycle. Penguin diet samples contained adult krill of similar lengths to those caught in nets; however, penguins rarely took juvenile krill. Penguin diet samples contained proportionately more females when the krill population was dominated by large adults at the end of the cycles; net samples showed greater proportions of males in these years. These patterns are comparable to those reported elsewhere in the region and are likely driven by the availability of different sizes and sexes of krill in relation to the colony.     

机械通气治疗急性呼吸窘迫综合征的肺复张策略研究

目的:探讨机械通气治疗急性呼吸窘迫综合征(Acute respiratory distress syndrome,ARDS)的肺复张策略的作用。方法:选择2012年1月~2012年12月我院收治的采用机械通气并进行肺复张治疗的ARDS患者94例,根据肺复张方法不同,将所有患者分为对照组和实验组,并比较两组患者的不同时点的氧合指数、肺顺应性及两组出现的并发症。结果:对照组肺复张成功率为72.34%,实验组肺复张成功率为95.75%,X2=38.928,P0.05,两组患者肺复张成功率差异具有统计学意义。两组患者氧合指数、肺顺应性和PaCO2在肺复张实施前比较,差异无统计学意义。肺复张策略实施后24h、48h和72h的氧合指数和PaCO2比较,这三个时点的氧合指数和PaCO2差异具有统计学意义。两组患者肺顺应性在肺复张策略实施后1h、2h和6h比较,t分别=4.939,5.391和5.999,P0.05,此三个时点的肺顺应性差异同样具有统计学意义。对照组气压伤发生率为82.98%,实验组气压伤发生率为59.57%,两组患者气压伤发生率差异具有统计学意义。结论:ARDS的患者在机械通气治疗的过程中上采用肺复张策略,不但可以提高肺复张成功率,改善肺部通气效果,且安全性好,适合临床使用。     

Variable reproductive success in fragmented populations

Marine habitats are naturally patchy and anthropogenic disturbance can further fragment them. Many marine animals are sessile as adults or obligate inhabitants of particular habitats, so populations living in isolated patches of habitat are linked largely by dispersal of planktonic larvae. Theoretically, larvae are more likely to find and settle into large patches of habitat than small patches, thus small habitat patches may experience a more discontinuous supply of recruits resulting in small populations with unusual size- or age-structures or odd sex ratios — conditions where Allee effects on reproductive success are likely. We tested this hypothesis for the Caribbean spotted spiny lobster (Panulirus guttatus), an obligate inhabitant of coral patch reefs whose mating dynamics are size-dependent. We found that P. guttatus were less abundant on small reefs where their size structure and per capita reproductive success were significantly more variable, particularly among large females that are susceptible to sperm limitation that diminishes fertilization rates. These results are indicative of Allee effects and provide a mechanistic understanding of how size-dependent mating dynamics influence reproductive success in ways that alter population dynamics in patchy habitats.     

Early post-hurricane stand development in Fringe mangrove forests of contrasting productivity

We examined the immediate effects of a hurricane (Hurricane Andrew, August 1992) in a coastal landscape in sub-tropical Florida, and then monitored stand recovery in Fringe mangrove sites of different productive capacity for 9 years after the disturbance. Structural impacts of the hurricane were confined almost entirely to forests within 200–300 m of the coast. Mortality and damage were concentrated on canopy individuals. Following the hurricane, rapid canopy recovery and the early onset of competition among Fringe forest stems, as evidenced by relatively high mortality of smaller individuals, magnified the initial dominance of hurricane survivors and early-established seedlings over later cohorts, and limited recruitment to the brief period prior to canopy closure. Changes in the relative abundance of the two dominant mangrove species following disturbance varied strongly along the productivity gradient. The shade-tolerant Rhizophora mangle L. generally became the overwhelming canopy dominant in the competitive environment of the recovering Coastal Fringe forest following hurricane, but the shade-intolerant Laguncularia racemosa (L.) C.F. Gaertn was better represented in less productive Interior Fringe sites, where canopy closure was delayed. Site productivity is an important determinant of the success of mangrove species during post-hurricane stand development, and consequently of the zonation of communities in the coastal landscape.     

The role of the perch effect on the nucleation process in Mediterranean semi-arid oldfields

Oldfield succession in Mediterranean ecosystems has been studied extensively in mesic conditions. However, this phenomenon is still poorly understood in semi-arid Mediterranean areas, where reduced plant cover, the importance of facilitation processes and the role of abiotic factors make these environments distinct. We first test whether the carob tree (Ceratonia siliqua) generates nucleation patterns in semi-arid oldfields, and to what extent such patterns change with abandonment age. Then we test to what extent nucleation can be explained by the perch effect. And finally, we test whether the nucleated pattern around carob trees is a source of diversity in the oldfields studied. To answer these questions we located oldfields abandoned 25 and 50 years ago (20 in each case) in the Alacant Province (SE Spain, Iberian Peninsula) on the basis of aerial photographs and personal interviews with local landowners and managers. In each oldfield woody plant density and richness were sampled on two microsites: under the carob tree and in the open field. Analysis was performed on all woody plants and by separating the species in two functional groups: fleshy-fruited (with fleshy mesocarp) and non-fleshy-fruited species. The results suggest that woody vegetation colonising abandoned C. siliqua fields in SE Spain is not randomly distributed but follows a nucleation pattern with higher plant density under the trees. However, the nucleation pattern is only significant for fleshy-fruited species, suggesting that facilitative interactions alone cannot explain the nucleation pattern and that the perch effect plays an important role. The results also show that the nucleation pattern (total plant density and density of non-fleshy-fruited plants) did not increase with abandonment age, while the perch effect (density of fleshy-fruited plants) did increase significantly. Furthermore, the results also show that the nucleation pattern is not only a loci of high plant density but also a loci of high species richness. Thus we can conclude that the nucleation pattern found in oldfield succession is best explained by the perch effect, while facilitation has a secondary importance. This emphasises the key role that dispersal mode has on the dynamics of vegetation recovery in formerly cropped areas.     

Fluorescence census techniques for the early detection of coral recruits

Many coral recruits are very small and often cryptic at settlement making them difficult to detect with normal census techniques. Here we show that fluorescence census techniques can increase the accuracy of juvenile coral counts in highly fluorescent taxa. Using fluorescent filters at night, counts of coral recruits were 20–50% higher than during the day. Acropora abundances were up to 300% higher, the difference being made up of cryptic individuals, and individuals that were too small to see during the day. Fluorescence techniques will be particularly useful in regions where fluorescent taxa are dominant, such as most Indo-Pacific reefs. The technique offers particular promise to determine the influence of early post-settlement mortality on the ecology of fluorescent taxa, because corals can be detected at the size at which they settle.