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41.
《Journal of Great Lakes research》2020,46(4):899-909
Gmelinoides fasciatus is a successful invasive amphipod (Amphipoda, Crustacea) that dispersed from Lake Baikal to various waterbodies. Here we studied whether Baikal conditions are optimal for G. fasciatus in terms of thermotolerance and investigated lethal temperatures, 70 kDa heat shock protein level, energy metabolism, and antioxidant defense of animals from three geographically distant waterbodies under changing temperatures. We used acute heat exposure to 28 °C to assess the median lethal times and gradual temperature increase from 6 °C to determine the lethal temperatures. Mortality under heat shock was explainable by the baseline content of Hsp70 that correlated with thermal history. But it was not the case under gradual temperature increase where Hsp70 levels became similar and the mortality pattern changed. The most thermotolerant amphipods from the Gulf of Finland demonstrated a higher amount of free glucose during the temperature increase that may be related to the higher salinity of this waterbody and less energy required for ion regulation. Even though concentrations of major physiological ions in Lake Baikal are lower than in Lake Ladoga, G. fasciatus from Ladoga was slightly more sensitive to the gradual temperature increase. This difference could be explained by the influence of high levels of humic and other potentially toxic substances in Lake Ladoga indicated by increased activities of catalase and glutathione S-transferase. Importantly, all G. fasciatus populations accumulated relatively low levels of lactate during the temperature increase, which may reflect the ability of this invasive species to effectively maintain aerobic metabolism under various conditions. 相似文献
42.
Feng Guo 《Review of Financial Economics》2019,37(2):297-321
Following the approach of interpolation, this paper proposes the multiple exponential decay model to fit yield curves for both the U.S. TIPS market and the conventional Treasury security market. Several estimation methods, including the unconstrained/constrained nonlinear minimization, quadratic programming, and the iterative linear least squares, are applied to estimate the unknown parameters according to different curve‐fitting purposes. Comparisons between the proposed model and the alternatives show that the multiple exponential decay successfully (1) adapts to a variety of shapes associated with yield curves, (2) (partially) keeps in line with the economic interpretations of Nelson–Siegel summarized by Diebold and Li ( 2006 ), and (3) dominates the competing models in curve‐fitting performance measured by mean fitted‐price errors over the sample period. In addition, the exact specification of a nonparametric interpolation model is pinned down by applying three statistical tools, which enable us to jointly take into account validity, optimality, and parsimoniousness of the proposed model. 相似文献
43.
The advertising and marketing literature have established that celebrity endorsements constitute an effective way to enhance attitudes toward brands and increase purchase intents. However, there are no relevant studies on digital influencers. This study addresses the research gap by examining the effect of digital influencers' attractiveness and the effect of the congruence between a digital influencer and a brand on consumer attitudes and purchase intentions. By applying structural equation modeling to a sample of 307 followers of digital influencers, a model was tested and group analysis was performed for two categories (“entertainment & video games” and “fashion & beauty”). The results show that both brand attitudes and purchase intentions are influenced by the digital influencer's attractiveness (which includes both likeability and familiarity) and by the congruence between the digital influencer and the brand. This study makes several contributions to both theory and practice, which are highlighted in this paper. 相似文献
44.
45.
大坝运行监测易受自然环境和监测条件影响,存在时间和空间上的变异性,监测数据具有不确定性。以云理论的随机性和不确定性分析方法为基础,并与空间数据辐射思想相结合,建立了云滴概率密度分布估计模型,然后导出云概率密度分布函数,依据样本监测数据推求母体空间数据的分布特征,并设计了基于逆向云算法云变换的计算程序。分析陆浑水库1979~1999年测压管监测数据和位移变形数据的云概率密度分布特征和云数字特征,得出了20 a来大坝的数据分布特征和运行状态。监测数据分析结果表明,云概率密度分布估计不仅能有效合理地分析大坝的运行状态,而且能够依据云数字特征来判断监测状态和监测环境的异常变化。
相似文献
46.
隔代抚育会对延迟退休年龄政策在促进劳动力供给上产生挤出效应。为了对此进行验证,本文在工资收入随机性的假定及延迟退休5年的情景下,模拟了面临孙辈照护需求的女性临近退休者提前退休所产生的福利变化。进一步,本文采用CHIP和CHARLS的微观调查数据,对不同群组的收入增长率和收入风险进行了估计,继而分析了当面临孙辈照护需求时这些收入特征对退休决策者制度退休和退休后劳动参与抉择产生的影响。总体上,在延迟退休年龄政策下,隔代抚育将对女性劳动力供给产生挤出效应。当面临孙辈照护需求时,女性临近退休者的制度退休抉择主要受自身收入增长率和收入风险的影响,收入增长率越低,或收入风险越高,她们提前退休的意愿就越强烈;制度退休后的劳动参与则更多地受子女收入增长率的影响,子女收入增长率越高,劳动参与的概率越低。 相似文献
47.
《Business Horizons》2019,62(5):603-613
This study integrates insights from Self-Determination Theory and Boundary Theory to present scenarios on how flexible workplace designs can trigger multiple motivational processes underlying gendered work/nonwork integration behaviors, and how these affect work/life conflict. We disentangle processes underlying work engagement and work/life conflict, explaining the paradoxical outcomes found with regard to gender inequality in terms of work/life performance, satisfaction, and health. Policy makers and organizations need an increased understanding and a reconceptualization of these issues, realizing that the ideal worker does not exist. Instead, a long-term perspective is needed in order to truly realize the potential benefits of flexible workplace designs for all stakeholders. Organizations need to take responsibility for preventing individual workers’ depletion and stimulating the regeneration of workers’ resources. 相似文献
48.
HUBERTO M. ENNIS 《Journal of Money, Credit and Banking》2019,51(7):1737-1764
I study the implications for central bank discount window stigma of a workhorse model of adverse selection in financial markets. In the model, firms (banks) need to borrow to finance a productive project. There is limited liability and firms have private information about their ability to repay their debts, which gives rise to the possibility of adverse selection. The central bank can ameliorate the impact of adverse selection by lending to firms. Discount window borrowing is observable and it may be taken as a signal of firms' credit worthiness. Under some conditions, firms borrowing from the discount window may pay higher interest rates to borrow in the market, a phenomenon often associated with the presence of stigma. I discuss these and other outcomes in detail and what they suggest about the relevance of stigma as an empirical phenomenon. 相似文献
49.
高科技社会衍生“人为风险”,西方发达高科技国家倡导新型风险沟通,而后发场域由于系统落差,呈现出迟滞型风险沟通。通过构建全球化高科技风险社会、全球本地化风险沟通的新分析框架,发现高科技社会我国风险沟通面临着风险的社会放大、气泡结构、路径互动阙如、手段叠加、目标战略缺失、过程碎片化等迟滞困境。通过创新理念、吸纳型风险沟通、复合式路径、平衡化手段、连续统、政府学习和政府职能的“七位一体”再造,可有效重塑高科技社会我国风险沟通,推进国家风险治理体系和治理能力现代化。 相似文献
50.
New technologies enable practitioners to communicate scents in advertisements on various media. The current research examines the importance of matching scent cues to the advertised product, and the joint effect of scent and other cues such as colour on consumer responses to advertising. A 4 × 2 experimental design was conducted, where participants (N = 603) were presented with scented colour print advertisements. Three hierarchical responses were measured: emotional response, attitude, and purchase intention. Findings reveal that higher congruence between scent and the advertised product heightens positive consumer response. Furthermore, this research stresses the significant joint effect of scent and colour cues, and supports the incongruence approach, suggesting that combining scents that are poorly congruent with other sensory cues enhance consumer response. Practical and theoretical implications are discussed. 相似文献