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71.
There is no simple recipe for success in implementing environmental accounting. Day-to-day needs and strategic objectives will determine how an organization can benefit from environmental accounting. Our previous article listed many potential applications of environmental accounting and discussed common environmental accounting objectives.1 This article is geared toward organizations that want to start implementing environmental accounting and create a foundation of success on which to build. In this context, the questions are (1) What are some logical starting points? and (2) Where do companies go from there? This article first describes some paradigms that may guide companies as they think about how to implement environmental accounting, then it presents a series of critical activities that are needed to make environmental accounting an integral part of ongoing business management functions.  相似文献   
72.
In September and October 1980 we examined the relationships between food availability, depth, and chemical composition among 12 midwater fish species, from three adjacent areas of the eastern North Pacific: the eastern gyre, the California Current, and the transitional region between them. By comparing trends in chemical composition across a geographical productivity gradient, the influence of food availability could be examined both with and without depth as a dependent variable. In general, caloric density, lipids, and water content showed consistent trends along both vertical and horizontal gradients of food availability. Lipids and caloric contents were lowest among bathypelagic species and among fishes from the gyre. Water content was highest in the gyre and among deeper-living species. While protein content as a percentage of the total wet weight declined with depth, there was no clear trend among mesopelagic species between stations. Protein as percent of the total organic content showed no decrease with depth, but was significantly higher in the gyre among mesopelagic species. These findings suggest that compositional trends in water, lipids, and caloric content are correlated with food availability, regardless of any depth-related factors. In contrast, protein did not vary consistently with food availability and thus may be linked to other factors.  相似文献   
73.
A large body of literature addresses the role of science in environmental impact assessment (EIA) but less attention has been given to the views of practitioners themselves. In this research a survey of 31 EIA practitioners in Western Australia was undertaken to determine their perceptions of the quality and importance of science in EIA. The survey results are compared with previous theoretical, empirical, and survey studies of the role of science in EIA. Interview questions addressed the role of science in impact prediction, monitoring activities, mitigation and management, and EIA decision-making. It was clear from the interviews that many practitioners are satisfied with the quality of science currently used in EIA, but do not believe that it is given sufficient importance in the process. The quality and importance of science in the predecision stages of EIA was rated higher than in the postdecision stages. While science was perceived to provide the basis for baseline data collection, impact prediction, and mitigation design, it was seen to be less important during decision-making and ongoing project management. Science was seen to be just one input to decision-makers along with other factors such as sociopolitical and economic considerations. While time and budget constraints were seen to limit the scientific integrity of EIA activities, pressure from the public and regulatory authorities increased it. Improving the scientific component of EIA will require consideration of all these factors, not just the technical issues.  相似文献   
74.
Delineation of ecosystem regions   总被引:4,自引:0,他引:4  
As a means of developing reliable estimates of ecosystem productivity, ecosystem classification needs to be placed within a geographical framework of regions or zones. This paper explains the basis for the regions delineated on the 1976 mapEcoregions of the United States. Four ecological levels are discussed—domain, division, province, and section—based on climatic and vegetational criteria. Statistical tests are needed to verify and refine map units.  相似文献   
75.
Objectives: Understanding how lower extremity injuries from automotive intrusion and underbody blast (UBB) differ is of key importance when determining whether automotive injury criteria can be applied to blast rate scenarios. This article provides a review of existing injury risk analyses and outlines an approach to improve injury prediction for an expanded range of loading rates. This analysis will address issues with existing injury risk functions including inaccuracies due to inertial and potential viscous resistance at higher loading rates.

Methods: This survival analysis attempts to minimize these errors by considering injury location statistics and a predictor variable selection process dependent upon failure mechanisms of bone. Distribution of foot/ankle/leg injuries induced by axial impact loading at rates characteristic of UBB as well as automotive intrusion was studied and calcaneus injuries were found to be the most common injury; thus, footplate force was chosen as the main predictor variable because of its proximity to injury location to prevent inaccuracies associated with inertial differences due to loading rate. A survival analysis was then performed with age, sex, dorsiflexion angle, and mass as covariates. This statistical analysis uses data from previous axial postmortem human surrogate (PMHS) component leg tests to provide perspectives on how proximal boundary conditions and loading rate affect injury probability in the foot/ankle/leg (n = 82).

Results: Tibia force-at-fracture proved to be up to 20% inaccurate in previous analyses because of viscous resistance and inertial effects within the data set used, suggesting that previous injury criteria are accurate only for specific rates of loading and boundary conditions. The statistical model presented in this article predicts 50% probability of injury for a plantar force of 10.2 kN for a 50th percentile male with a neutral ankle position. Force rate was found to be an insignificant covariate because of the limited range of loading rate differences within the data set; however, compensation for inertial effects caused by measuring the force-at-fracture in a location closer to expected injury location improved the model's predictive capabilities for the entire data set.

Conclusions: This study provides better injury prediction capabilities for both automotive and blast rates because of reduced sensitivity to inertial effects and tibia–fibula load sharing. Further, a framework is provided for future injury criteria generation for high rate loading scenarios. This analysis also suggests key improvements to be made to existing anthropomorphic test device (ATD) lower extremities to provide accurate injury prediction for high rate applications such as UBB.  相似文献   
76.
The water resources of the atolls of the Republic of Maldives are under continual threat from climatic and anthropogenic stresses, including land surface pollution, increasing population, drought, and sea‐level rise (SLR). These threats are particularly acute for groundwater resources due to the small land surface area and low elevation of each island. In this study, the groundwater resources, in terms of freshwater lens thickness, total volume of fresh groundwater, and safe yield are estimated for the 52 most populous islands of the Maldives for current conditions and for the year 2030, with the latter accounting for projected SLR and associated shoreline recession. An algebraic model, designed in previous studies to estimate the lens thickness of atoll islands, is expanded in this study to also estimate volume of groundwater. Results indicate that average current lens thickness, groundwater volume, and per capita safe yield are approximately 4.6 m, 1,300 million liters, and 300 l/day, and that these values will decrease by approximately 10, 11, and 34%, respectively, by the year 2030. Based on results, it is demonstrated that groundwater, in terms of quantity, is a viable source of water for the islands of the Maldives both now and in coming decades, particularly for islands with large surface area and low population. Study results can provide water resource managers and government officials with valuable data for consideration in water security measures.  相似文献   
77.
High volume air sampling in the Canadian Prairies was used to characterize atmospheric concentrations for 10 herbicides (alachlor, atrazine, ethalfluralin, metolachlor, 2,4-D, dicamba, bromoxynil, MCPA, trifluralin, and triallate) along a 500-km north-south transect. Atmospheric concentration measurements at various altitudes identified that of the six herbicides present in the highest concentrations, triallate was strongly influenced by local sources, while 2,4-D, dicamba, bromoxynil, MCPA and trifluralin were dominated by regional atmospheric transport. Concentrations of the herbicides measured at various altitudes were compared with dry deposition rates measured using a dry/wet deposition sampler and used to calculate deposition velocities V(d). The primary atmospheric transport mechanism for MCPA and bromoxynil was shown to be adsorption to particles dispersed in the atmosphere, with the same mechanism also confirmed for 2,4-D and dicamba, while trifluralin was shown to be transported mainly in the gas phase. This method of calculation indicated that transportation of triallate was influenced by particle adsorption. Weekly maximum atmospheric loadings of the major herbicides present in the Prairies were estimated to range from 73 kg for trifluralin to 541 kg for 2,4-D.  相似文献   
78.
Rates of predation by the invertebrates Aurelia aurita, Thysanoessa raschi and Euchaeta norvegica on larval stages of cod (Gadus morhua L.), flunder (Platichthys flesus L.), plaice (Pleuronectes platessa L.), herring (Clupea harengus L.), and turbot (Scophthalmus maximus L.) were determined. Experiments were conducted in late winter and early spring 1982 with predators collected in Loch Etive, Scotland and prey obtained from several locations in Great Britain. Early stages of the smallest species, cod, flounder and turbot, tended to be most vulnerable to all three predators, while the early stages of the larger species, plaice and herring, and older stages of all species, were less vulnerable. For all stages and species of larvae, predation rates by the three predators were most closely related to larval length and escape swimming speed. Larval length itself was closely correlated to indices of larval escape ability. Low predation rates on large larvae by E. norvegica could be due to handling difficulties, whereas for A. aurita and T. raschi these low rates were due to escape abilities of the larger larvae. Prey movement is an important stimulus eliciting predation in E. norvegica but not in A. aurita or T. raschi.  相似文献   
79.
Growth rate and hatch date distributions were estimated for juvenile walleye pollock Theragra chalcogramma (Pallas, 1814) collected in autumn 1987 from the western Gulf of Alaska. Mean juvenile growth rates varied geographically by as much as 45%. A trend for slower growth around Unimak Pass and the Shumagin Islands and faster growth upstream in the Alaska Coastal Current towards Kodiak Island was noted; the fastest growth did not occur in the main habitat region. Juvenile hatch date distributions were compared to identify regional differences that might reflect stock structure. Juvenile hatch dates were compared with hatch dates of the same cohort sampled as larvae to test for selective mortality. Regional differences in hatch dates, along with other information, indicated several minor spawning populations located around Kodiak Island and near Unimak Pass. For the main aggregation of pollock in the Shumagin Island region, hatch date distributions were not significantly different among the early larval cohort sampled in late May, the late larvae sampled in mid-June to early July, and the juveniles sampled in autumn. Neither growth-rate nor size-dependent mortality of pollock between the larval and juvenile stages appears to be a dominant factor in determining survival patterns. An alternative test was attempted, by which lengths-at-age during larval life were back-calculated from juvenile otoliths and compared with lengths-at-age of the population sampled as larvae in May and June. Pollock surviving as juveniles in autumn were not larger as larvae than the general larval population. This result is an example of the observation that back-calculated lengths are almost always smaller than the lengths of fish sampled at age (Lee's phenomenon). Problems in determining survival patterns based on otolith back-calculations and comparison of hatch date distributions are discussed.  相似文献   
80.
Several recent studies have found important differences between behavior in the laboratory and the field. We explore two possible causes for the divergence: social concerns and unfamiliarity with the traded good. Consistent with our conceptual model, we find that people overstated their preferences for relatively familiar goods with normative attributes and understated their preferences for a relatively unfamiliar good with low normative motivations in the laboratory as compared to the field. We also find that for goods with a normative dimension, a new method we refer to as inferred valuation has the potential to narrow the lab–field gap. In some cases, willingness-to-pay obtained from a conventional valuation elicitation method is more than twice the value from the new inferred valuation approach.  相似文献   
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