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121.
This report proposes a method for assessing resilience-building components in coastal social–ecological systems. Using the proposed model, the preferences of experts in Masan Bay (South Korea) and Puget Sound (USA) are compared. A total of 30 management objectives were determined and used to build a hierarchic tree designed using the principles of the Analytic Hierarchy Process (AHP). Surveys were performed with 35 Puget Sound experts using face-to-face interviews and with 28 Masan Bay experts by mail. The results demonstrate that the legal objective, which enables legislation, was the highest preferred component in both regions. The knowledge translation variable was also given a high preference score in both regions. An analysis of variance (ANOVA) showed that the Puget Sound experts significantly favored attention to education, habitat restoration and species protection objectives in comparison to the Masan Bay experts. The Masan Bay experts placed greater emphasis on legislation and the type of institutional design than did the Puget Sound experts. Using cluster analysis, four distinct groups of respondents were independently identified in Puget Sound and three groups were identified in Masan Bay. One unique subgroup in the Puget Sound experts group, which was characterized by its high preferences for habitat restoration and species protection, was not observed in Masan Bay. Demographic variables (length of career and role in coastal issue) failed to account for the differences in groupings and preferences in either region, except for the variable ‘favoring information source’ in the Puget Sound group. This finding implies that the demographic information was not related to differences in group opinions in both regions. The analysis framework presented here was effective in identifying expert preferences regarding the overall structure and emphasis in coastal management programs. Thus, this framework can be applied towards coastal policy development.  相似文献   
122.
American black bears frequently abandon their home ranges in late summer and move to feeding areas to fatten themselves for hibernation. We examined seasonal movements of 206 radio-collared bears in north-central Minnesota during 1981–1990. We exploited the variability in this long-term data set to test tradeoffs for animals leaving their home range. Late summer movements were common for both sexes and all ages (39% of females, 44% of males), but were variable from year-to-year in prevalence, timing, and destination. Bears typically left their summer home ranges in August and returned ~6 weeks later in September or October. Most traveled southward, where acorns were more plentiful (median = 10 km for females, 26 km for males; maximum = 168 km). These facultative migrations were most common when rich resources were available outside home ranges. Bears were least apt to leave when foods were scarce in their home range, possibly sensing a risk of migrating during a widespread food failure. Among females, those whose body mass was close to a reproductive threshold were most prone to migrate. Migrating bears were less likely to be killed by hunters, suggesting that they were especially vigilant.  相似文献   
123.
Contrary to much boundary spanning research, we examined the negative consequences of boundary spanning contact in multi‐organizational contexts. Results from a sample of 833 Dutch peacekeepers show that employees' boundary spanning contact with members of other organizations was associated with reports of negative relationships with external parties (e.g., work‐specific problems, culture‐specific problems). These negative relationships also had a spillover effect such that they mediated the effect of boundary spanning contact on boundary spanners' negative attitudes toward their own jobs and organization (e.g., job attractiveness and confidence in the organization). Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
124.
This article presents the geochemical characteristics and physicochemical properties of water and sediment from twelve semi-permanent, dryland pools in the upper Leichhardt River catchment, north-west Queensland, Australia. The pools were examined to better understand the quality of sediments and temporary waters in a dryland system with a well-established metal contamination problem. Water and sediment sampling was conducted at the beginning of the hydroperiod in May and September 2007. Water samples were analyzed for major solute compositions (Ca, Na, K, Mg, Cl, SO(4), HCO(3)) and water-soluble (operationally defined as the <0.45 μm fraction) metals (Cd, Cu, Pb, Zn). Sediment samples were analyzed for total extractable and bioaccessible metals (As, Cd, Cu, Pb, Zn), elemental composition and grain morphology. At the time of sampling a number of pools contained water and sediment with elevated concentrations, compared to Australian regulatory guidelines, of Cu (maximum: water 28 μg L(-1); sediment 770 mg kg(-1)), Pb (maximum: water 3.4 μg L(-1); sediment 630 mg kg(-1)) and Zn (maximum: water 150 μg L(-1); sediment 780 mg kg(-1)). Concentrations of Cd and As in pools were relatively low and generally within Australian regulatory guideline values. Localized factors, such as the interaction of waters with anthropogenic contaminants from modern and historic mine wastes (i.e. residual smelter and slag materials), exert influence on the quality of pool waters. Although the pools of the upper Leichhardt River catchment are contaminated, they do not appear to be the primary repository of water and sediment associated metals when compared to materials in the remainder channel and floodplain. Nevertheless, a precautionary approach should be adopted to mitigating human exposure to contaminated environments, which might include the installation of appropriate warning signs by local health and environmental authorities.  相似文献   
125.
Yucca Mountain is being considered as a geological repository for the USA’s spent nuclear fuel and high-level nuclear waste. Numerous groundwater seeps appeared during March 2005 within the exploratory studies facility (ESF), a tunnel excavated in the mountain. Because of the relevance to radionuclide transport and unsaturated zone-modeling studies, we analyzed the seep samples for major anions and cations, rare earth elements, and colloids. Major ion species and elemental concentrations in seep samples reflect interaction of the water with the volcanic rock and secondary calcites. Elemental fractograms from flow-injection field-flow fractionation ICP–MS scans detected Br, Ca, Cl, Cu, Fe, I, Mg, Si, Sr, W, and U at void fractions, suggesting they may be present in the form of dissolved anions. Colloids approximately 10 nm in hydrodynamic diameter, possibly calcite, were also present in the seepage samples. Geochemical calculations indicate, however, these may be an artifact (not present in the groundwater) which arose because of loss of CO2 during sample collection and storage.  相似文献   
126.
The Naval Facilities Engineering Service Center (NFESC), Arizona State University, and Equilon Enterprises LLC are partners in an innovative Environmental Security Technology Certification Program cleanup technology demonstration designed to contain dissolved MTBE groundwater plumes. This full‐scale demonstration is being performed to test the use of an oxygenated biobarrier at Naval Base Ventura County, in Port Hueneme, California. Surprisingly, few cost‐effective in‐situ remedies are known for the cleanup of MTBE‐impacted aquifers, and remediation by engineered in‐situ biodegradation was thought to be an unlikely candidate just a few years ago. This project demonstrates that MTBE‐impacted groundwater can be remediated in‐situ through engineered aerobic biodegradation under natural‐flow conditions. With respect to economics, the installation and operation costs associated with this innovative biobarrier system are at least 50 percent lower than those of a conventional pump and treat system. Furthermore, although it has been suggested that aerobic MTBE biodegradation will not occur in mixed MTBE‐BTEX dissolved plumes, this project demonstrates otherwise. The biobarrier system discussed in this article is the largest of its kind ever implemented, spanning a dissolved MTBE plume that is over 500 feet wide. This biobarrier system has achieved an in‐situ treatment efficiency of greater than 99.9 percent for dissolved MTBE and BTEX concentrations. Perhaps of greater importance is the fact that extensive performance data has been collected, which is being used to generate best‐practice design and cost information for this biobarrier technology. © 2001 John Wiley & Sons, Inc.  相似文献   
127.
ABSTRACT: Nutrient data from all available sources for the lower Mississippi River were examined for potential differences among sampling agencies and geographic locations for the period between 1960 and 1998. Monthly means grouped by parameter, sampling location and agency, were calculated and compared as paired sets, excluding those months where data were not available for both sets. Some significant differences were found between various agencies collecting nutrient data on the river, as well as between various stretches of river, especially in the case of phosphorus nutrient data. Results were used to synthesize data sets from which a history of nutrient loading in the Mississippi River was determined. General trends in nitrate+nitrite, total Kjeldahl nitrogen, orthophosphate, total phosphorus and silica loads, as well as changes in nutrient proportions and the specific limiting nutrient (by month) are reported. This study provides a useful summary of contemporary and historical nutrient data that may assist in the evaluation of Mississippi River water quality and its potential effect on the Gulf of Mexico.  相似文献   
128.
The decomposition of leaf litter is controlled by several factors. One factor that may play an important role is the content of condensed tannins (proanthocyanidins). Here we designed a combined method to isolate proanthocyanidins from leaf extracts, to convert them to anthocyanidins, and to quantify individual anthocyanidins exactly with a new, simple, but sensitive high-performance liquid chromatography method. We used this method to show composition of proanthocyanidins and to monitor degradation of proanthocyanidins and individual constituents in leaf litter in an aquatic environment over time. Despite the rapid decrease in the initial concentrations, a fraction of the proanthocyanidins remained detectable for several weeks.  相似文献   
129.
130.
Staszewski V  McCoy KD  Tveraa T  Boulinier T 《Ecology》2007,88(12):3183-3191
Little is known about the long-term persistence of specific antibodies (Ab) in natural host-parasite systems despite its potential epidemiological and ecological importance. In long-lived species, knowledge of the dynamics of individual immunological profiles can be important not only for interpreting serology results, but also for assessing transmission dynamics and the potential selective pressures acting on parasites. The aim of this paper was to investigate temporal variation in levels of specific Ab against the bacterium Borrelia burgdorferi sensu lato in adults of a long-lived colonial seabird, the Black-legged Kittiwake Rissa tridactyla. In wild populations, adults are naturally exposed each breeding season to a Borrelia vector, the tick Ixodes uriae. Breeding birds were captured during four consecutive breeding seasons, and parasite infestation quantified. Using enzyme-linked immunosorbent assay (ELISA) and immunoblots, we found that the immunological profiles of anti-Borrelia Ab were highly repeatable among years, reflecting the interannual persistence of Ab levels. We nevertheless also observed that year-to-year changes of Ab levels were related to exposure to ticks in the previous year. The long-term persistence of Ab levels may be an important mechanism of individual protection against future exposure to the microparasite. It will also affect the availability of susceptible hosts, and thus the transmission dynamics of the bacterium. These results illustrate the need to consider the dynamics of the immune response in order to better understand the evolutionary ecology of host-parasite interactions in natural populations.  相似文献   
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