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211.
Marine Protected Areas (MPAs) have been hailed worldwide as vehicles toward sustainable development (SD) in coastal zones.
The prominent model by which MPAs operate is through a comanagement approach, a shift from traditional top-down management.
This paradigm shift must be reviewed continuously to evaluate its social and ecological impacts, thereby allowing adaptive
management. We evaluated the perceived impacts of the Cogtong Bay Mangrove Rehabilitation Project (CBMRP; Philippines) by
using 12 perception indicators categorized into 3 comanagement impact criteria (equity, efficiency, and sustainability). We
also collected 16 contextual attributes of each respondent to determine the correlates of perceived impacts. Our results showed
that there were significant improvements in all indicators under the efficiency criterion but mixed impacts in the equity
and sustainability criteria. Access to resource and household income (equity) and fisheries abundance (sustainability) were
perceived to have decreased during the last 15 years and were not expected to improve in the future. Stepwise multiple regression
analysis showed that the asymmetries of the perceived impacts of the CBMRP were principally caused by disparities in perceptions
by gender and by location (Candijay and Mabini). This highlighted the importance of cross-scale institutional linkages between
Cogtong Bay municipalities to systematically address baywide management issues. Our results further demonstrated the necessity
of integrating gender issues into the evaluation of MPA impacts to ensure a robust evaluation. Finally, we recommend that
a rigorous evaluation of MPAs using a common set of impact indicators should be encouraged to allow comparison of studies
both spatially and temporally. 相似文献
212.
The Seymour aquifer region of Texas has been identified as containing elevated levels of nitrate in ground water. Various state and federal agencies are currently studying policy options for the region by gathering more site-specific information. However, because of lack of sufficient information, cause and effect relationships between water quality and agricultural practices have not been well established for the region. Some recently available biophysical simulation models have impressive capabilities in generating large amounts of data on environmental pollution resulting from agricultural production practices. In this study, the data generated by a biophysical simulation model were used to estimate the nitrate percolation response functions for the Seymour aquifer region. Interestingly, nitrate percolation values obtained from simulation models often comprise acensoredsample because the non-zero percolation values are only observed under certain climatic events and input levels. It has been shown in the econometric literature that the use of Ordinary Least Squares (OLS) on censored sample data produces biased and inconsistent parameter estimates. Thus, a sample selection model was used in this study to estimate the response functions for nitrate percolation. The study provides some insight into the relationship between nitrate percolation and agricultural production practices. In particular, the study demonstrates the potential of selected design standards in minimizing agricultural nonpoint-source (NPS) pollution for the study area. 相似文献
213.
Ronald J. Burke 《组织行为杂志》1993,14(5):459-472
The introduction of a national health care system in Canada has resulted in regular and increasing conflict between the medical profession, government and other political actors. The present study utilizes a stressor–strain framework to understand physician militancy in Canada. Data were collected from 2087 men and women physicians using questionnaires completed anonymously. Four groups of predictor variables identified in previous research were considered: individual demographic characteristics, practice characteristics, work stressors, and work and professional satisfactions. Empirical support for the model was found. Each panel of predictor variables had significant and unique relationships with measures of physician militancy. 相似文献
214.
Matthew Wagner Ronald Kaiser Urs Kreuter Neal Wilkins 《Journal of the American Water Resources Association》2007,43(3):698-711
Abstract: As nearly all of Texas’ rural lands are privately owned, landowner associations for the management of white‐tailed deer and ground‐water have become increasingly popular. Deer are a common‐pool resource with transboundary characteristics, requiring landowner cooperation for effective management. Ground‐water reserves are economically important to landowners, but are governed by the “rule of capture” whereby property rights are not defined. One ground‐water association and four wildlife management associations (WMAs) were surveyed to characterize their member demographics, land use priorities, attitudes, and social capital. Members of the ground‐water cooperative were part of a much larger, more heterogeneous, and more recently formed group than members of WMAs. They also placed greater importance on utilitarian aspects of their properties, as opposed to land stewardship for conservation as practiced by members of WMAs. If ground‐water association members could be more locally organized with more frequent meetings, social capital and information sharing may be enhanced and lead to land stewardship practices for improved hydrologic functions and sustained ground‐water supply. This, coupled with pumping rules assigned by the local ground‐water district, could yield an effective strategy that is ecologically and hydrologicaly sound, and that allows rural provision of water supply to urban consumers. 相似文献
215.
Ronald Parker J.G. Arnold Michael Barrett Lawrence Burns Lee Carrubba S.L. Neitsch N.J. Snyder R. Srinivasan 《Journal of the American Water Resources Association》2007,43(6):1424-1443
Abstract: The U.S. Environmental Protection Agency (USEPA) Office of Pesticide Programs (OPP) has completed an evaluation of three watershed‐scale simulation models for potential use in Food Quality Protection Act pesticide drinking water exposure assessments. The evaluation may also guide OPP in identifying computer simulation tools that can be used in performing aquatic ecological exposure assessments. Models selected for evaluation were the Soil Water Assessment Tool (SWAT), the Nonpoint Source Model (NPSM), a modified version of the Hydrologic Simulation Program‐Fortran (HSPF), and the Pesticide Root Zone Model‐Riverine Water Quality (PRZM‐RIVWQ) model. Simulated concentrations of the pesticides atrazine, metolachlor, and trifluralin in surface water were compared with field data monitored in the Sugar Creek watershed of Indiana’s White River basin by the National Water Quality Assessment (NAWQA) program. The evaluation not only provided USEPA with experience in using watershed models for estimating pesticide concentration in flowing water but also led to the development of improved statistical techniques for assessing model accuracy. Further, it demonstrated the difficulty of representing spatially and temporally variable soil, weather, and pesticide applications with relatively infrequent, spatially fixed, point estimates. It also demonstrated the value of using monitoring and modeling as mutually supporting tools and pointed to the need to design monitoring programs that support modeling. 相似文献
216.
We have conducted a series of simulations in order to compare the relative diversification effects of disturbance and intransitive (i.e., A > B, B > C but C > A) competition on a hypothetical set of clonal organisms. We found large significant differences between these two effects only when disturbance levels were low or absent. We suggest that natural assemblages should be examined for the frequency of intransitive interactions along disturbance gradients in order to assess the significance of these competitive relationships. We also argue that intransitive competition ought to be incorporated into nonequilibrium disturbance models; diversification effects of disturbance and intransitive competition need not be mutually exclusive. 相似文献
217.
A sex-linked recessive lethal test was performed on male fruit flies of the species Drosophila melanogaster, (Oregon-R strain), exposed to an approximate five-fold dilution of exhaust from a diesel engine. The eight hour exposure was achieved by drawing diluted diesel exhaust from a three cubic meter stainless steel exposure chamber housing laboratory animals through a two liter reaction flask modified for use with Drosophila. A preconditioned sampling bag was used to collect the emissions after passing through the exposure chamber containing the flies. Results of analyses performed on the diesel exhaust mixture showed the following: carbon dioxide—0.17%, carbon monoxide—12.2 ppm, hydrocarbons—11.6 ppm, nitrogen oxide—3.8 ppm, nitrogen dioxide—2.9 ppm, sulphur dioxide—1.0 ppm, and particulates—2.18 mg/m3. Two broods of the F2 generation were investigated for the occurrence of recessive lethal events. These broods approximated the developing gametogenic stages of mature sperm (P1 matings on days 2 and 3 postexposure) and spermatocytes (P1 matings on days 8 and 9). Additionally, the F3 generation was evaluated for the occurrence of mosaic recessive lethal events which might escape detection in the F2 generation. An equal number of F2 and F3 flies for both broods served as concurrent controls. Results indicate that, under the conditions tested, the diesel exhaust did not increase the mutation frequency of the exposed flies (F2 rate = 0.30%, F3 rate = 0%) when compared to the concurrent controls (F2 rate = 0.37%, F3 rate = 0.15%). 相似文献
218.
Ronald L. Moomaw Larkin Warner 《Journal of the American Water Resources Association》1981,17(6):1029-1034
ABSTRACT: It is contended that water conservation measures that reduce a water system's net revenues are unlikely to be adopted. Pricing policies that induce conservation can be designed to increase net revenues. Management practices that lead to conservation and pure conservation measures may reduce net revenues; consequently, they are unlikely to be adopted. Recent experience in five southwestern cities supports these contentions. It is argued that the managers of a municipal water enterprise are particularly sensitive to short term variation in revenues. Consequently, to increase the likelihood of the adoption of measures that reduce net revenues it is necessary to remove either the decision to adopt measures that reduce net revenue or the adverse revenue effect from the water enterprise. Finally, to make higher rates for conservation palatable, imaginative use for the funds generated must be developed. 相似文献
219.
A program has been initiated to assess an SO2 removal method wherein dry powdered sodium compounds are injected into the gas stream ahead of the baghouse filter. The compounds are collected on the surface of the filter bags for reaction with the gaseous SO2. Initial program efforts include a survey of suitable and available sodium compounds, methods of preparing the compounds for injection, and an invistigation of environmentally acceptable methods of disposal. 相似文献
220.