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851.
This article examines the relationships between interpersonal attachment orientations, health, and social support. Four hypotheses specified relationships between three interpersonal attachment orientations (interdependent, counterdependent, and overdependent), physical and psychological symptoms, and social support. Data were collected from 297 students, the majority of whom were also full-time employees. An interdependent orientation was negatively related to social dysfunction. Counterdependent and overdependent orientations were negatively related to health. A counterdependent orientation was negatively related to social support, while an overdependent orientation was positively related to social support from co-workers and family. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
852.
Efforts to Reduce Mortality to Hydroelectric Turbine-Passed Fish: Locating and Quantifying Damaging Shear Stresses 总被引:1,自引:0,他引:1
Severe fluid forces are believed to be a source of injury and mortality to fish that pass through hydroelectric turbines.
A process is described by which laboratory bioassays, computational fluid dynamics models, and field studies can be integrated
to evaluate the significance of fluid shear stresses that occur in a turbine. Areas containing potentially lethal shear stresses
were identified near the stay vanes and wicket gates, runner, and in the draft tube of a large Kaplan turbine. However, under
typical operating conditions, computational models estimated that these dangerous areas comprise less than 2% of the flow
path through the modeled turbine. The predicted volumes of the damaging shear stress zones did not correlate well with observed
fish mortality at a field installation of this turbine, which ranged from less than 1% to nearly 12%. Possible reasons for
the poor correlation are discussed. Computational modeling is necessary to develop an understanding of the role of particular
fish injury mechanisms, to compare their effects with those of other sources of injury, and to minimize the trial and error
previously needed to mitigate those effects. The process we describe is being used to modify the design of hydroelectric
turbines to improve fish passage survival. 相似文献
853.
Hollamby S Afema-Azikuru J Waigo S Cameron K Gandolf AR Norris A Sikarskie JG 《Environmental monitoring and assessment》2006,118(1-3):13-20
An animal’s suitability as a biomonitor of environmental change can be determined by biological, reproductive and ecological
characteristics determined at the class, order and species level. The animal’s habitat where the research is to be performed
and the form, function and structure of the environmental change being studied within that habitat also determines suitability.
Non-threatened populations of large, non-migratory, long-lived, seasonally-breeding tertiary avian predators, whose dietary
preferences are narrow and known, can be useful as monitors of environmental chemical contaminants. If chemicals are being
monitored, a quantifiable endpoint effect must be demonstrated in the species, or a similar species under experimental laboratory
conditions. Logistical and economic issues as well as public and regulatory authority acceptance should also be considered
when assessing the suitability of a species as a biomonitor. 相似文献
854.
Vincent JH 《Journal of environmental monitoring : JEM》2006,8(1):53-62
In 2002 the Comité Européen Normalisation (CEN) published its document Workplace atmospheres-assessment of performance of instruments for measurement of airborne particle concentrations (EN 13205) that describes a standard protocol by which to carry out the testing and validation of personal aerosol samplers of the type widely used for occupational aerosol exposure assessment. It emerged from more than a decade of discussion and a large body of research experience involving several laboratories. The protocol that is described, however, still poses significant technical and economic challenges, not least because it involves laborious-and hence costly-procedures in large, specialized wind tunnel facilities. More recent research has identified a number of areas by which the protocol may be improved and made more accessible to testing laboratories, including a set of validated aerosol sampler scaling laws, a better understanding of the reduced role of the bluff body of the wearer on sampler performance, and the availability of new options for rapid sampler testing methods. Taking these into account, a dummy new protocol is offered for discussion. 相似文献
855.
Charlton AJ Donarski JA Jones SA May BD Clive Thompson K 《Journal of environmental monitoring : JEM》2006,8(11):1106-1110
The detection of trace levels of a range of organic contaminants (including pesticides, toxins and an explosive) in potable water, using cryoprobe NMR spectroscopy with limited sample preparation and rapid acquisition times, is described. Emphasis is placed on the applicability of NMR spectroscopy for use in emergency scenarios as the unbiased nature of the technique facilitates the detection and characterization of unknown compounds at levels as low as 50 microg L(-1). 相似文献
856.
JamesDMcCurry PaulZavitsanos 《环境化学》2004,23(1):113-116
利用气-质和液相/电喷雾-质谱联用仪对商用杀菌剂进行了分析.其中,气-质联用可用于分析杀菌剂中的挥发性化合物,但是对于活性化合物,如嗪氨灵,却不能分析.电喷雾/液质联用可以分析嗪氨灵和不挥发的表面活性剂及污染物.本文介绍了气-质和液相/电喷雾-质谱联用仪用于分析商用杀菌剂,结果表明,两种技术具有互补性. 相似文献
857.
Sean A. Woznicki George Kraynick James Wickham Maliha Nash Terry Sohl 《Journal of the American Water Resources Association》2023,59(4):726-742
Continued alteration of the nitrogen cycle exposes receiving waters to elevated nitrogen concentrations and forces drinking water treatment services to plan for such increases in the future. We developed four 2011–2050 land cover change scenarios and modeled the impact of projected land cover change on influent water quality to support long-term planning for the Minneapolis Water Treatment Distribution Service (MWTDS) using Soil Water and Assessment Tool. Projected land cover changes based on relatively unconstrained economic growth led to substantial increases in total nitrogen (TN) loads and modest increases in total phosphorus (TP) loads in spring. Changes in sediment, TN, and TP under two “constrained” growth scenarios were near zero or declined modestly. Longitudinal analysis suggested that the extant vegetation along the Mississippi River corridor upstream of the MWTDS may be a sediment (and phosphorus) trap. Autoregressive analysis of current (2008–2017) chemical treatment application rates (mass per water volume processed) and extant (2001–2011) land cover change revealed that statistically significant increases in chemical treatment rates were temporally congruent with urbanization and conversion of pasture to cropland. Using the current trend in chemical treatment application rates and their inferred relationship to extant land cover change as a bellwether, the unconstrained growth scenarios suggest that future land cover may present challenges to the production of potable water for MWTDS. 相似文献
858.
Sleeping with a broken promise: The moderating role of generativity concerns in the relationship between psychological contract breach and insomnia among older workers
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Patrick Raymund James M. Garcia Prashant Bordia Simon Lloyd D. Restubog Valerie Caines 《组织行为杂志》2018,39(3):326-338
This paper examines the relationship between psychological contract breach and insomnia among older workers (aged 40 years and up). Drawing upon the conservation of resources theory, we conceptualize breach as a stressful event characterized by a perceived threat, failure to gain, or actual loss of valued resources, which increases psychological distress and insomnia. Moreover, we hypothesized that older workers' generativity concerns would act as a personal resource that would buffer the negative impact of breach. We tested our proposed model in 2 studies (Study 1 = 123; Study 2 = 168) of employee–spouse dyads. Results revealed that psychological distress mediated the relationship between psychological contract breach and insomnia. These mediated relationships were significant for those with low, but not for those with high levels of generativity concerns. These effects remained significant even after controlling for perceived organizational support (i.e., a social exchange mechanism). Theoretical and practical implications are discussed. 相似文献
859.
James R. Beebe Maria Baghramian Luke Drury Finnur Dellsén 《Environmental Communication: A Journal of Nature and Culture》2019,13(1):35-50
We report the results of an exploratory study that examines the judgments of climate scientists, climate policy experts, astrophysicists, and non-experts (N?=?3367) about the factors that contribute to the creation and persistence of disagreement within climate science and astrophysics and about how one should respond to expert disagreement. We found that, as compared to non-experts, climate experts believe that within climate science (i) there is less disagreement about climate change, (ii) methodological factors play less of a role in generating disagreements, (iii) fewer personal or institutional biases influence climate research, and (iv) there is more agreement about which methods should be used to examine relevant phenomena we also observed that the uniquely American political context predicted experts’ judgments about some of these factors. We also found that, in regard to disagreements concerning cosmic ray physics, and commensurate with the greater inherent uncertainty and data lacunae in their field, astrophysicists working on cosmic rays were generally more willing to acknowledge expert disagreement, more open to the idea that a set of data can have multiple valid interpretations, and generally less quick to dismiss someone articulating a non-standard view as non-expert, than climate scientists were in regard to climate science. 相似文献
860.
Computational modeling and analysis of thoracolumbar spine fractures in frontal crash reconstruction
Xin Ye James P. Gaewsky Derek A. Jones Logan E. Miller Joel D. Stitzel 《Traffic injury prevention》2018,19(8):S32-S39
AbstractObjective: This study aimed to reconstruct 11 motor vehicle crashes (6 with thoracolumbar fractures and 5 without thoracolumbar fractures) and analyze the fracture mechanism, fracture predictors, and associated parameters affecting thoracolumbar spine response.Methods: Eleven frontal crashes were reconstructed with a finite element simplified vehicle model (SVM). The SVM was tuned to each case vehicle and the Total HUman Model for Safety (THUMS) Ver. 4.01 was scaled and positioned in a baseline configuration to mimic the documented precrash driver posture. The event data recorder crash pulse was applied as a boundary condition. For the 6 thoracolumbar fracture cases, 120 simulations to quantify uncertainty and response variation were performed using a Latin hypercube design of experiments (DOE) to vary seat track position, seatback angle, steering column angle, steering column position, and D-ring height. Vertebral loads and bending moments were analyzed, and lumbar spine indices (unadjusted and age-adjusted) were developed to quantify the combined loading effect. Maximum principal strain and stress data were collected in the vertebral cortical and trabecular bone. DOE data were fit to regression models to examine occupant positioning and thoracolumbar response correlations.Results: Of the 11 cases, both the vertebral compression force and bending moment progressively increased from superior to inferior vertebrae. Two thoracic spine fracture cases had higher average compression force and bending moment across all thoracic vertebral levels, compared to 9 cases without thoracic spine fractures (force: 1,200.6 vs. 640.8 N; moment: 13.7 vs. 9.2?Nm). Though there was no apparent difference in bending moment at the L1–L2 vertebrae, lumbar fracture cases exhibited higher vertebral bending moments in L3–L4 (fracture/nonfracture: 45.7 vs. 33.8?Nm). The unadjusted lumbar spine index correctly predicted thoracolumbar fracture occurrence for 9 of the 11 cases (sensitivity?=?1.0; specificity?=?0.6). The age-adjusted lumbar spine index correctly predicted thoracolumbar fracture occurrence for 10 of the 11 cases (sensitivity?=?1.0; specificity?=?0.8). The age-adjusted principal stress in the trabecular bone was an excellent indicator of fracture occurrence (sensitivity?=?1.0; specificity?=?1.0). A rearward seat track position and reclined seatback increased the thoracic spine bending moment by 111–329%. A more reclined seatback increased the lumbar force and bending moment by 16–165% and 67–172%, respectively.Conclusions: This study provided a computational framework for assessing thoracolumbar fractures and also quantified the effect of precrash driver posture on thoracolumbar response. Results aid in the evaluation of motor vehicle crash–induced vertebral fractures and the understanding of factors contributing to fracture risk. 相似文献