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1.
Environment, Development and Sustainability - Environmental deterioration and global warming has created a substantial impact on international companies to incorporate eco-friendly, green supply...  相似文献   
2.
Environment, Development and Sustainability - Globally, the national and cultural resources of a country are major sources of attraction for tourism. Pakistan is gifted with abundant natural and...  相似文献   
3.
We investigated chlorinated hydrocarbon contaminants in aquatic mustelid species on the Fraser and Columbia Rivers of northwestern North America. Carcasses of river otter (Lutra canadensis) (N=24) and mink (Mustela vison) (N=34) were obtained from commercial trappers during the winters of 1990–91 and 1991–92. Pooled liver samples were analyzed for organochlorine pesticides, polychlorinated biphenyls (PCBs), including non-ortho congeners, polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Most samples contained detectable concentrations of DDE, PCBs, although there was substantial variability in patterns and trends among neighboring samples. Concentrations of DDE were in some mink and several otter samples from the lower Columbia River elevated (to 4700 g/kg wet weight); excluding one mink sample from the Wenatchee area, mean DDE levels generally decreased between 1978–79 and 1990–92. PCBs were present in all samples. PCB concentrations in otter livers collected from the lower Columbia were ten-fold lower than measured a decade previously; nevertheless, a sample taken near Portland had a mean concentration of 1500 g/kg, within a range of concentrations associated with reproductive effects in captive mink. Concentrations of 2,3,7,8-TCDD and TCDF were generally below detection limits, except for one otter collected near a pulp mill at Castlegar, on the upper Columbia, with 11 ng TCDD/kg in liver. Elevated concentrations of higher chlorinated PCDD/Fs, probably resulting from use of chlorophenolic wood preservatives, were found in both species; one otter sample from the lower Columbia had 2200 ng OCDD/kg. International TCDD toxic equivalent levels in mink (31 ng/kg) and otter (93 ng/kg) from the lower Columbia River approached toxicity thresholds for effects on reproduction in ranch mink.  相似文献   
4.
In Australasia (Australia and New Zealand) the use of health impact assessment (HIA) as a tool for improved policy development is comparatively new. The public health workforce do not routinely assess the potential health and equity impacts of proposed policies or programs. The Australasian Collaboration for Health Equity Impact Assessment was funded to develop a strategic framework for equity-focused HIA (EFHIA) with the intent of strengthening the ways in which equity is addressed in each step of HIA. The collaboration developed a draft framework for EFHIA that mirrored, but modified the commonly accepted steps of HIA; tested the draft framework in six different health service delivery settings; analysed the feedback about application of the draft EFHIA framework and modified it accordingly. The strategic framework shows promise in providing a systematic process for identifying potential differential health impacts and assessing the extent to which these are avoidable and unfair. This paper presents the EFHIA framework and discusses some of the issues that arose in the case study sites undertaking equity-focused HIA.  相似文献   
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6.
TWO STRATEGIES FOR LEARNING A ROUTE IN A DRIVING SIMULATOR   总被引:2,自引:0,他引:2  
The study of human navigation has long been dominated by the so-called stage theory, i.e. the notion that there are three distinct types of spatial knowledge (landmark, route, and survey knowledge), that are acquired sequentially during spatial learning and development. Based on the results of a route learning experiment in a driving simulator, an alternative to the stage theory is proposed. The authors suggest that subjects follow either a visually dominated or a spatially dominated strategy to solve a route-learning problem. In the visually dominated strategy, subjects base their wayfinding decisions on visually recognizing decision points along a route; the decision points are not integrated into any kind of survey representation. In the spatially dominated strategy, on the other hand, subjects represent the environment as a survey map right from the start; that is, they do not pass through a landmark or route stage. These strategies may be subserved by different cortical areas recently characterized in neurophysiological studies of animals solving maze problems.  相似文献   
7.
Starch-PVOH cast films were prepared with and without crosslinking agent (hexamethoxymethylmelamine) in the absence of plasticizer. Moisture absorption in films without crosslinking agent at a low relative humidity was similar to that of PVOH and increased as the relative humidity increased. Films with crosslinking agent showed moisture absorption linearly proportional to the relative humidity. Significant improvement in resistance to water disintegration for crosslinked starch-PVOH films was observed. While the tensile strength decreased with increased relative humidity, crosslinking significantly improved the tensile strength. Increased PVOH content improved elongation of films even when the relative humidity was 80% or higher. Biodegradation studies revealed that the degradation rate was negatively correlated with the PVOH content in films and crosslinking generated more converged degradation curves. Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also be suitable.  相似文献   
8.
Lightweight Concrete Containing an Alkaline Resistant Starch-Based Aquagel   总被引:1,自引:0,他引:1  
Starch aquagel-based lightweight concrete has properties similar to those of other lightweight concrete products. However, starch aquagels are unstable in the strongly alkaline conditions typical of Portland Cement-based concrete and may interfere with the setting process. The effect of alkali treatments on the physical, mechanical, and functional properties of starch aquagels and aquagels from starch/polymer blends was investigated. Starch was blended at 100–115°C in a twin-screw extruder with five different polymers to determine whether the blends improved alkaline resistance. Polymer blends containing 5%, 15%, and 30% of the polymer hydrated and formed aquagels when equilibrated in water for 24 h. However, equilibrium moisture content was lower for the blends compared to the starch control. Aquagels equilibrated in 0.15 N NaOH swelled, lost compressive strength and had greater than 90% moisture. The blend of starch and 30% PVOH absorbed less moisture and was more resistant to alkaline dissolution in 1 N NaOH than the other blends tested making it a more suitable material for aquagel-based concrete. The moisture content of starch-based aquagels and mixing time were critical factors in determining setting times. The size of aquagel blends had a minor effect on density and compressive strength.  相似文献   
9.
An exploration of place as a process: The case of Jackson Hole, WY   总被引:1,自引:1,他引:1  
A variety of theoretical positions and frameworks have been advanced to account for how places become “places”—in other words, how places become meaningful. Most existing frameworks share the idea that a place is a complex concept, given life by people attaching meaning to a physical setting in a variety of ways. This paper explores how places evolve as ever-shifting points of meaning that mark changes in people's lives in response to a variety of influences. Data collected from in-depth personal interviews in and around Jackson, Wyoming, are used to explore the conceptualization of place as a process, rather than a static entity. Three key themes or dimensions that were frequently described by interviewees are examined: (1) life stage/course, (2) searching for a feeling, and (3) commitment to a place. Not only did some respondents describe what made places important to them (the components, such as social ties, or favorite activities), they also described how these attributes worked together to create and maintain place meanings over the course of their lives. During the interviews, it was noted that these dimensions and processes were expressed explicitly as well as implicitly.  相似文献   
10.
Environmental Science and Pollution Research - Chromium (Cr) is a biologically non-essential, carcinogenic and toxic heavy metal. The cultivation of Cr-tolerant genotypes seems the most favorable...  相似文献   
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