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61.
This study examined protégé characteristics that mentors reported were most influential when choosing a protégé. Based on existing research, two variables were identified related to protégé selection: perceptions regarding the protégé's potential/ability and perceptions regarding the protégé's need for help. The relationships of these two factors with perceived barriers to mentoring others, mentor advancement aspirations, and mentor gender were investigated. Data from 282 mentors revealed that mentors were more likely to choose a protégé based on perceptions regarding the protégé's ability/potential than based on perceptions regarding the protégé's need for help. Additionally, women were more likely to choose a protégé based on the protégé's perceived ability than were men. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   
62.
The purpose of this investigation was to analyze the relationship between four interviewer‐related factors and the validity of the employment interview. Using a regression approach to meta‐analysis, an analysis of 120 interview studies with a total sample size of 18,158 suggested that: (1) training should be provided to interviewers regardless of whether the interview itself (i.e. the questions and rating scales) is structured; (2) the same interviewer should be used across all applicants, especially when the interview itself is not highly structured; and (3) using a panel of interviewers does not contribute to validity, and may actually have a detrimental effect. Results for the fourth interviewer factor, taking notes during the interview, were inconclusive. Limitations and directions for future research are noted. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   
63.
This study applied theory from the employee learning and development literature to examine factors related to employees' perceptions of being job content plateaued and hierarchically plateaued. Results indicated that both types of plateauing were related to support from top management, career planning, job involvement, and education level. Furthermore, career exploration, motivation to learn, organizational tenure, and job tenure were related to perceptions of hierarchical plateauing, while supervisor support was related to job content plateauing. Additionally, the two types of plateauing differed in the relative strength of their relationship with the variables studied. Implications and future research suggestions are provided. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   
64.
Two important contributions to the understanding of voluntary turnover are the ideas that employees become embedded in a net or web of restraining forces on- and off-the-job and that they experience varying degrees of control and desire that yield proximal withdrawal states explaining turnover motivations. We build on these ideas in two multi-wave studies to study job insecurity, one of the most common work stressors and top concerns among employees around the world. Study 1 demonstrates that job search mediates the positive relationship between job insecurity and voluntary turnover, and that employees higher in on-the-job embeddedness are less likely to search for jobs despite job insecurity. Study 2 demonstrates that turnover intention mediates the positive relationship between job insecurity and voluntary turnover, and that employees higher in on-the-job embeddedness are less likely to contemplate quitting despite job insecurity. However, off-the-job embeddedness had opposite interactive effects, exacerbating the relationship of job insecurity with turnover.  相似文献   
65.
Male sexually selected traits can evolve through different mechanisms: conspicuous and colorful ornaments usually evolve through intersexual selection, while weapons usually evolve through intra-sexual selection. Male ornaments are rare among mammals in comparison to birds, leading to the notion that female mate choice generally plays little role in trait evolution in this taxon. Supporting this view, when ornaments are present in mammals, they typically indicate social status and are products of male-male competition. This general mammalian pattern, however, may not apply to rhesus macaques (Macaca mulatta). Males of this species display conspicuous skin coloration, but this expression is not correlated to dominance rank and is therefore unlikely to have evolved due to male-male competition. Here, we investigate whether male color expression influences female proceptivity toward males in the Cayo Santiago free-ranging rhesus macaque population. We collected face images of 24 adult males varying in dominance rank and age at the peak of the mating season and modeled these to rhesus macaque visual perception. We also recorded female sociosexual behaviors toward these males. Results show that dark red males received more sexual solicitations, by more females, than pale pink ones. Together with previous results, our study suggests that male color ornaments are more likely to be a product of inter- rather than intra-sexual selection. This may especially be the case in rhesus macaques due to the particular characteristics of male-male competition in this species.  相似文献   
66.
Centrality metrics evaluate paths between all possible pairwise combinations of sites on a landscape to rank the contribution of each site to facilitating ecological flows across the network of sites. Computational advances now allow application of centrality metrics to landscapes represented as continuous gradients of habitat quality. This avoids the binary classification of landscapes into patch and matrix required by patch-based graph analyses of connectivity. It also avoids the focus on delineating paths between individual pairs of core areas characteristic of most corridor- or linkage-mapping methods of connectivity analysis. Conservation of regional habitat connectivity has the potential to facilitate recovery of the gray wolf (Canis lupus), a species currently recolonizing portions of its historic range in the western United States. We applied 3 contrasting linkage-mapping methods (shortest path, current flow, and minimum-cost-maximum-flow) to spatial data representing wolf habitat to analyze connectivity between wolf populations in central Idaho and Yellowstone National Park (Wyoming). We then applied 3 analogous betweenness centrality metrics to analyze connectivity of wolf habitat throughout the northwestern United States and southwestern Canada to determine where it might be possible to facilitate range expansion and interpopulation dispersal. We developed software to facilitate application of centrality metrics. Shortest-path betweenness centrality identified a minimal network of linkages analogous to those identified by least-cost-path corridor mapping. Current flow and minimum-cost-maximum-flow betweenness centrality identified diffuse networks that included alternative linkages, which will allow greater flexibility in planning. Minimum-cost-maximum-flow betweenness centrality, by integrating both land cost and habitat capacity, allows connectivity to be considered within planning processes that seek to maximize species protection at minimum cost. Centrality analysis is relevant to conservation and landscape genetics at a range of spatial extents, but it may be most broadly applicable within single- and multispecies planning efforts to conserve regional habitat connectivity.  相似文献   
67.
Phenological tracking enables positive species responses to climate change   总被引:1,自引:0,他引:1  
Earlier spring phenology observed in many plant species in recent decades provides compelling evidence that species are already responding to the rising global temperatures associated with anthropogenic climate change. There is great variability among species, however, in their phenological sensitivity to temperature. Species that do not phenologically "track" climate change may be at a disadvantage if their growth becomes limited by missed interactions with mutualists, or a shorter growing season relative to earlier-active competitors. Here, we set out to test the hypothesis that phenological sensitivity could be used to predict species performance in a warming climate, by synthesizing results across terrestrial warming experiments. We assembled data for 57 species across 24 studies where flowering or vegetative phenology was matched with a measure of species performance. Performance metrics included biomass, percent cover, number of flowers, or individual growth. We found that species that advanced their phenology with warming also increased their performance, whereas those that did not advance tended to decline in performance with warming. This indicates that species that cannot phenologically "track" climate may be at increased risk with future climate change, and it suggests that phenological monitoring may provide an important tool for setting future conservation priorities.  相似文献   
68.
Sublethal predation can be a significant trophic pathway in sediment communities, and the regeneration of damaged tissue affects the activity, growth, and reproduction of prey. A field experiment was conducted 12–18 July 2010 in the Tijuana Estuary, California (+32.56617°, −117.13152°), to measure in situ rates of body growth and palp regeneration of the polychaete Polydora cornuta after simulating sublethal predation by removing 2, 1, or 0 palps from labeled individuals. After 3 days in the field, individuals that had 2 palps removed grew significantly slower than worms that had 0 palps removed; 1-palp worms had intermediate growth. After 6 days in the field, rates of body growth were faster than those of worms recovered after 3 days, with similar trends among the three palp treatments. During the 3-day transplantation, removed palps regenerated to half the initial length of unmanipulated palps. After 6 days, palp lengths did not differ significantly among treatment groups, indicating complete regeneration. The regeneration rate of removed palps was significantly faster than the growth rate of undamaged palps, and palp regeneration rate did not differ significantly between worms that had 1 or 2 palps removed.  相似文献   
69.
Aedes albopictus has been the fastest spreading invasive animal species in the world from the mid-1980s until the mid-2000s. In areas it infests, it disrupts native mosquito ecology and can potentially vector up to 21 viruses. To better understand the population dynamics of this species, we created a temperature dependent population model. A stage-structured model was chosen to allow each life-stage to have different temperature dependent mortality and development rates, and each stage was modeled with an ordinary differential equation. Model parameters and distributions were based upon literature values. Initially, a basic model was constructed. This model then had parameters that were forced based upon daily average temperatures. Several criteria were used to evaluate the model, including a comparison to field data from Lubbock, TX. In a stochastic version of the model, a 95% confidence limit contained 70.7% of the field data points. Based upon these results, we feel reasonably confident that we have captured the role of temperature in driving the population dynamics of Ae. albopictus.  相似文献   
70.
We compared two methods of estimating crop water consumption to assess whether remote sensing techniques provide consumptive use (CU) estimates commensurate with conventional methods. Using available historical satellite and meteorological data, we applied Mapping EvapoTranspiration at high Resolution using Internalized Calibration (METRIC) to 317,455 ha in the South Platte basin, in northeastern Colorado, for the 2001 irrigation season. We then compared these derived CU estimates with values calculated by using the Colorado Water Conservation Board's South Platte Decision Support System StateCU model. Evaluating the data by irrigation ditch service area, we disaggregated the output to allow for comparison by service area size, crop type, irrigation method, water supply source, and water availability. We concluded that METRIC is a suitable alternative to StateCU in the South Platte basin and could help to identify areas with inhibited crop growth or deficit irrigation practices. In addition, METRIC could be used as a complement to StateCU to refine StateCU model parameters, allowing for more accurate estimates of crop water shortages and groundwater recharge associated with irrigation delivery and application.  相似文献   
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