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131.
This paper examines the new Ontario guidelines for the clean-up of contaminated sites using Toronto as an empirical case. The contention of the paper is that Ontario's new soil clean-up policy is the product of a set of embedded understandings about the economy, about the environment and about deep interconnections between the environment and the economy. These understandings are, to a large degree, specifically local. We contextualise the new guidelines by arguing that they contribute to restructuring the political economy of Toronto from an industrial to a global city. The analysis is based on, among other sources, a series of interviews with policy makers, scientists, bankers, insurance representatives and other knowledgeable individuals in the debate on polluted soil clean-up. Substantively, the paper focuses on the introduction of various risk-assessment processes into the debate on contaminated sites. The paper concludes that these processes need to be made subject to democratic rather than purely technocratic processes of evaluation and decision making.  相似文献   
132.
The environmental structural change strategy claims that by shifting our expenditures to economic sectors with lower environmental intensity, absolute resource consumption and environmental impact can be lowered. Environmental Input-Output methodologies for computing these intensities attribute no resource consumption to labour or households because these are not classified as sectors. The suggestion that service sectors entail less environmental impact, however, loses force if a unit of labour contains embodied energy, and attributing these inputs to labour drastically reduces intensity variation between sectors. Relative growth of service sectors has furthermore not been accompanied by decreased resource consumption; thus models whose intensity computations cover not only inter-firm payments but also labour earnings and household expenditures may have superior predictive power. If moreover natural-resource and labour inputs to product are incommensurable, intensity ratios themselves have perhaps only monetary, rather than real, significance.  相似文献   
133.

Globally, hepatitis A virus (HAV) is one of the most common agents of acute viral hepatitis and causes approximately 1.4 million cases and 90,000 deaths annually despite the existence of an effective vaccine. In 2019, federal, state, and local partners investigated a multi-state outbreak of HAV infections linked to fresh blackberries sourced from multiple suppliers in Michoacán, Mexico. A total of 20 individuals with outbreak-related HAV infection were reported in seven states, including 11 hospitalizations, and no deaths. The Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC), and Nebraska State and Douglas County Health Departments conducted a traceback investigation for fresh blackberries reportedly purchased by 16 ill persons. These individuals reported purchasing fresh blackberries from 11 points of service from September 16 through 29, 2019 and their clinical isolates assessed through next-generation sequencing and phylogenetic analysis were genetically similar. The traceback investigation did not reveal convergence on a common grower or packing house within Mexico, but all of the blackberries were harvested from growers in Michoacán, Mexico. FDA did not detect the pathogen after analyzing fresh blackberry samples from four distributors, one consumer, and from nine importers at the port of entry as a result of increased screening. Challenges included gaps in traceability practices and the inability to recover the pathogen from sample testing, which prohibited investigators from determining the source of the implicated blackberries. This multi-state outbreak illustrated the importance of food safety practices for fresh produce that may contribute to foodborne illness outbreaks.

  相似文献   
134.
A highly significant second-order polynomial relation between SO(2) emissions and SO(4)(2-) concentrations during 1970-2000 (r(2)= 0.80, p= <0.001), and a linear relation between NO(x) and NO(3)(-) concentrations during 1991-2000 (r(2)= 0.67, p= 0.004) in bulk precipitation were found for the Hubbard Brook Experimental Forest, NH based on emissions from a 24 h, back-trajectory determined source area. Earlier periods (1965-1980) for SO(2)ratio SO(4)(2-) and longer periods (1965-2000) for NO(x)ratio NO(3)(-) had poorer linear relations, r(2)= 0.03, p= 0.51 and r(2)= 0.22, p= 0.004, respectively. Methodology by the US Environmental Protection Agency for calculating emissions data during this period has changed significantly and frequently, making trend analysis difficult. Given the large potential for errors in estimating emissions and to a lesser extent, deposition, the robust relations between SO(2) emissions and SO(4)(2-) concentrations in bulk precipitation at the Hubbard Brook Experimental Forest show that careful, long-term measurements from a single monitoring site can provide sound and reasonable data on trends in air pollution.  相似文献   
135.
Recent research on organizational identification has called for the consideration of an expanded model of identification, which would include a more thorough treatment of the ways an individual could derive his or her identity from the organization. This paper begins to answer that call by testing operationalizations of the four dimensions of the expanded model: identification, disidentification, ambivalent identification, and neutral identification. Survey results from 330 employed adults support the discriminability of the four dimensions. This exploratory study also begins to establish the criterion‐related validity of the model by examining organizational, job‐related, and individual difference variables associated with the four dimensions of the model, and suggests implications for the expanded model's strong potential for applications in organizational identification research. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
136.
As part of the Russian FIRE BEAR (Fire Effects in the Boreal Eurasia Region) Project, replicated 4-ha experimental fires were conducted on a dry Scotch pine (Pinus sylvestris)/lichen (Cladonia sp.)/feathermoss (Pleurozeum schreberi) forest site in central Siberia. Observations from the initial seven surface fires (2000-2001) ignited under a range of burning conditions quantified the different fuel consumption and fire behavior characteristics (e.g., rate of spread, fireline intensity, etc.) possible in this particular forest fuel type. Experimental results and dendrochronological study of local fire history both support the dominance of local fire regimes by low to moderate-intensity surface fires. Carbon released by the experimental fires ranged from 4.8 to 15.4 t C ha− 1 depending on fuel conditions and fire severity. Preliminary emission data show a strong correlation between carbon dioxide (CO2) and carbon monoxide (CO) emissions, which should facilitate accurate estimates of fire impacts on atmospheric chemistry. Carbon concentration in smoke samples was related to fire severity. The short landscape-scale fire-return interval (50 years), combined with typically low fire severity, in pine ecosystems of central Siberia is often associated with low tree mortality and relatively rapid buildup of litter and understory fuels after a fire.  相似文献   
137.
Division of labor during honey bee colony defense   总被引:5,自引:0,他引:5  
Summary Some worker honey bees respond to major disturbances of the colony by flying around the assailant and possibly stinging; they are a subset of the bees involved in colony defense. These defenders have an open-ended age distribution similar to that of foragers, but defensive behavior is initiated at a younger age than foraging is. Behavioral and genetic evidence shows that defenders and foragers are distinct groups of older workers. Behaviorally, defenders have less worn wings than foragers, suggesting less flight activity. Genetically, defenders differ in allozyme frequencies, demonstrating different subfamily composition from foragers in the same colony. They also differ in allozyme frequencies from guards in the same colony, providing further evidence for division of labor associated with colony defense. We use this information to develop a model for honey bee colony defense involving at least two distinct groups of workers and we propose that the non-guard defenders be called soldiers, due to their important role in colony defense.Offprint requests to: M.D. Breed  相似文献   
138.
Summary Three experiments were performed to determine whether brood care in honey bee colonies is influenced by colony genetic structure and by social context. In experiment 1, there were significant genotypic biases in the relative likelihood of rearing queens or workers, based on observations of individually labeled workers of known age belonging to two visually distinguishable subfamilies. In experiment 2, no genotypic biases in the relative likelihood of rearing drones or workers was detected, in the same colonies that were used in experiment 1. In experiment 3, there again were significant genotypic differences in the likelihood of rearing queens or workers, based on electrophoretic analyses of workers from a set of colonies with allozyme subfamily markers. There also was an overall significant trend for colonies to show greater subfamily differences in queen rearing when the queens were sisters (half- and super-sisters) rather than unrelated, but these differences were not consistent from trial to trial for some colonies. Results of experiments 1 and 3 demonstrate genotypic differences in queen rearing, which has been reported previously based on more limited behavioral observations. Results from all three experiments suggest that genotypic differences in brood care are influenced by social context and may be more pronounced when workers have a theoretical opportunity to practice nepotism. Finally, we failed to detect persistent interindividual differences in bees from either subfamily in the tendency to rear queen brood, using two different statistical tests. This indicates that the probability of queen rearing was influenced by genotypic differences but not by the effect of prior queen-rearing experience. These results suggest that subfamilies within a colony can specialize on a particular task, such as queen rearing, without individual workers performing that task for extended periods of time.  相似文献   
139.
140.
A comparison of mussels (Perna viridis) and semi-permeable membrane devices (SPMDs) was carried out at five sites, representing a gradient of contaminant concentrations, in Hong Kong coastal waters. Mussels, originally collected from a “clean” location, were deployed along with SPMDs at each site for 30 days. Analyses for chlorinated pesticides and polychlorinated biphenyls (PCBs) indicated that SPMDs have potential as monitoring tools, and to some extent can overcome the problems associated with mussels, such as natural variability, differing age, sex, and physical condition. However, in most cases, SPMDs failed to rank the sites in the same order as mussels in terms of contaminant concentrations. Nonetheless, in localities where mussels cannot survive – as shown at Kwun Tong in the present experiment – SPMDs may be valuable in providing an indication of potentially bio-available lipophilic pollutants.  相似文献   
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