36 research outputs found

    The Effects of Warming-Shifted Plant Phenology on Ecosystem Carbon Exchange Are Regulated by Precipitation in a Semi-Arid Grassland

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    BACKGROUND: The longer growing season under climate warming has served as a crucial mechanism for the enhancement of terrestrial carbon (C) sink over the past decades. A better understanding of this mechanism is critical for projection of changes in C cycling of terrestrial ecosystems. METHODOLOGY/PRINCIPAL FINDINGS: A 4-year field experiment with day and night warming was conducted to examine the responses of plant phenology and their influences on plant coverage and ecosystem C cycling in a temperate steppe in northern China. Greater phenological responses were observed under night than day warming. Both day and night warming prolonged the growing season by advancing phenology of early-blooming species but without changing that of late-blooming species. However, no warming response of vegetation coverage was found for any of the eight species. The variances in species-level coverage and ecosystem C fluxes under different treatments were positively dependent upon the accumulated precipitation within phenological duration but not the length of phenological duration. CONCLUSIONS/SIGNIFICANCE: These plants' phenology is more sensitive to night than day warming, and the warming effects on ecosystem C exchange via shifting plant phenology could be mediated by precipitation patterns in semi-arid grasslands

    Global Assessment of Extinction Risk to Populations of Sockeye Salmon Oncorhynchus nerka

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    BACKGROUND: Concern about the decline of wild salmon has attracted the attention of the International Union for the Conservation of Nature (IUCN). The IUCN applies quantitative criteria to assess risk of extinction and publishes its results on the Red List of Threatened Species. However, the focus is on the species level and thus may fail to show the risk to populations. The IUCN has adapted their criteria to apply to populations but there exist few examples of this type of assessment. We assessed the status of sockeye salmon Oncorhynchus nerka as a model for application of the IUCN population-level assessments and to provide the first global assessment of the status of an anadromous Pacific salmon. METHODS/PRINCIPAL FINDINGS: We found from demographic data that the sockeye salmon species is not presently at risk of extinction. We identified 98 independent populations with varying levels of risk within the species' range. Of these, 5 (5%) are already extinct. We analyzed the risk for 62 out of 93 extant populations (67%) and found that 17 of these (27%) are at risk of extinction. The greatest number and concentration of extinct and threatened populations is in the southern part of the North American range, primarily due to overfishing, freshwater habitat loss, dams, hatcheries, and changing ocean conditions. CONCLUSIONS/SIGNIFICANCE: Although sockeye salmon are not at risk at the species-level, about one-third of the populations that we analyzed are at risk or already extinct. Without an understanding of risk to biodiversity at the level of populations, the biodiversity loss in salmon would be greatly underrepresented on the Red List. We urge government, conservation organizations, scientists and the public to recognize this limitation of the Red List. We also urge recognition that about one-third of sockeye salmon global population diversity is at risk of extinction or already extinct

    Perfectionism, depression, loneliness, and life satisfaction: A study of high school students in Hong Kong

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    This study investigates the cross-cultural construct validity of perfectionism using the Chinese translation of the Almost Perfect Scale-Revised (APS-R; Slaney, Mobley, Trippi, Ashby, & Johnson, 1996) with 509 Chinese high school students from Hong Kong. The factor structure of the Chinese APS-R and correlations between the APS-R subscales and measures of Depression, Satisfaction with Life, and Loneliness are examined. Participants are grouped into three clusters-adaptive and maladaptive perfectionists and nonperfectionists. A comparison of group means revealed that adaptive perfectionists reported higher Satisfaction with Life scores and lower Depression scores than the other two groups. This sample of Chinese students also reported higher Discrepancy scores compared to U.S. students' scores in previous studies. Similarities and differences in comparison to previous studies using U.S. participants are examined. Finally, the limitations of this study and implications for future research with Chinese participants are discussed. © 2009 Sage Publications.link_to_subscribed_fulltex

    Affect intensity contributes to perfectionistic self-presentation in adolescents beyond perfectionism

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    Perfectionistic self-presentation in adolescents is associated with psychological maladjustment and distress. Yet, no study so far has investigated what personality characteristics contribute to perfectionistic self-presentation in adolescence. Using a cross-sectional correlational design with 119 adolescents aged 11-16 years, this study investigated how perfectionism (self-oriented and socially prescribed perfectionism) and affect intensity (positive affectivity, negative intensity, and negative reactivity) predicted individual differences in three modes of perfectionistic self-presentation: perfectionistic self-promotion, nondisplay of imperfection, and nondisclosure of imperfection. Results showed a unique prediction pattern for all three modes of perfectionistic self-presentation. Moreover, affect intensity contributed to perfectionistic self-presentation beyond perfectionism in two of the three modes: Perfectionistic self-promotion was predicted by high self-oriented perfectionism, high socially prescribed perfectionism, high positive affectivity, and low negative reactivity. In contrast, nondisplay of imperfection was predicted by high self-oriented perfectionism, high negative reactivity, and low positive affectivity. Nondisclosure of perfectionism was predicted by high socially prescribed perfectionism only. The findings suggest that affect intensity is a personality characteristic contributing to perfectionistic self-presentation in adolescence beyond perfectionism

    White Paper: functionality and efficacy of wrist protectors in snowboarding—towards a harmonized international standard

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    The wrist is the most frequently injured body region among snowboarders. Studies have shown that the risk of sustaining a wrist injury can be reduced by wearing wrist protection. Currently, there are a wide variety of wrist protection products for snowboarding on the market that offer a range of protective features. However, there are no minimum performance standards for snowboarding wrist protectors worldwide. The International Society for Skiing Safety convened a task force to develop a White Paper to evaluate the importance and necessity of a minimum performance for all wrist protectors used in snowboarding. The White Paper outlines the need for a general framework for a harmonized international standard and reviews the existing evidence. Therefore, this White Paper may serve as a common base for future discussions. The broader goal of developing and implementing such a standard is to reduce the incidence and the severity of wrist injuries in snowboarding without increasing the risk of adverse events, such as upper arm or shoulder injury. The European standard for inline skating wrist protectors (EN 14120) can serve as a starting point for efforts related to a standard for snowboard wrist protectors, but certain modifications to the standard would be required. It is hypothesized that implementation of a snowboarding wrist protector standard would result in fewer and less severe wrist injuries in the sport and could translate into more riding days for healthy snowboarders and significant health-care costs savings
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