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41.
42.
Shang TQ  Gordon MP 《Chemosphere》2002,47(9):957-962
Trichloroethylene (TCE) is one of the most prevalent environmental contaminants, and it poses an expensive remediation problem. Phytoremediation has been investigated as a potential tool for the removal of TCE from ground water and soil, and has shown promise in preliminary trials. However, the fate of TCE in plants is largely unknown. Radiolabel studies showed that once taken up and transformed, most of the TCE is incorporated into plant tissue as a non-volatile, un-extractable residue. We describe here an assay for TCE transformation by poplar suspension cells. Using this assay, it was shown that two different activities contribute to the fixation of TCE by poplar cells, one associated with cell walls and insoluble residues, the other associated with a high molecular weight, heat labile fraction of the cell extract. It appears that plant enzymes catalyze some of the transformations.  相似文献   
43.
ABSTRACT: This paper pursues more specifically the recommendations of a recent National Research Council report recommending greater attention to research on institutions in the field of water resource management. The important challenge for the future in institutional research lies in going beyond the observation that institutions are important and in explaining instead how institutions actually affect management options and outcomes. It is possible to illuminate the relationships between institutional features and water management through comparative institutional research. This paper offers recommendations for studying water institutions in a comparative context, including methodological recommendations concerning approaches to comparative institutional research, and topics for comparative institutional research that appear especially fruitful at this time. The example of conjunctive management is used to illustrate the importance of institutional factors in water management, drawing to some extent on the authors’ recent experience with a comparative study of conjunctive management institutions.  相似文献   
44.
We examined whether the quality (concentration) of incoming sucrose solutions returned by foraging honey bees affected the response thresholds of pre-foraging members of the colony. Six pairs of colonies were given ad libitum access to sucrose solution feeders. A colony from each pair was switched from 20–50% sugar concentration feeders while the other continued to have access to 20% sucrose feeders. Proboscis extension response (PER) scores to an increasing series of sucrose concentrations were significantly higher in pre-foragers of colonies foraging on 20% sucrose throughout compared to pre-foragers in colonies where foraging was switched to 50% sucrose. Although all colonies had honey stores, the concentration of sugar solution in non-foraging bees crops were significantly lower in bees from colonies foraging on 20% sucrose compared to those from colonies foraging on 50% sucrose. Because response thresholds to sugar of young bees were modulated by the concentration of sucrose solution returned to colonies, we repeated the 2000 study of Pankiw and Page that potentially confounded baseline response thresholds with modulated scores due to experience in the colony. Here, we examined PER scores to sucrose in bees within 6 h of emergence, prior to feeding experience, and their forage choice 2 to 3 weeks later. Pollen foragers had higher PER scores as newly emerged bees compared to bees that eventually became nectar foragers. These results confirm those of the 2000 study by Pankiw and Page. Combined, these experiments demonstrate that variation in pre-forager sucrose response thresholds are established prior to emerging as adults but may be modulated by incoming resources later on. Whether this modulation has long-term effects on foraging behavior is unknown but modulation has short-term effects and the potential to act as a means of communication among all bees in the colony.Communicated by M. Giurfa  相似文献   
45.
ABSTRACT

In 2014 an Australia public servant was killed in a confrontation over illegal land clearing. The perpetrator was a land holder with a history of non-compliance with environmental regulations and had been subject to a series of prosecutions. Political suggestions that the crime was somehow justified drew attention to the growing prevalence of law breaking linked to environmental law and policy in rural Australia. This paper investigated the social construction of both the crime and the community response through a qualitative media content analysis. Utilising the “Recipe for Criminalisation” framework developed by Amnesty International, the analysis identified a contest between media discourses of legitimacy in regards to the actions taken by the perpetrator, the public servant and ultimately, the regulatory framework itself. The analysis revealed that the link between media references to illegitimate legislation, excessive regulation, over-zealous compliance and strong social norms of rural independence and economic survival created a persuasive story of justified resistance to unwelcome environmental legislation in this case. Understanding how affected communities respond to instances of policy failure, civil and criminal law breaking and environmental compliance is a crucial factor in designing more legitimate and effective governance regimes. How media narratives are constructed, by whom and in whose interests remains an important analytic question for the study of resistance to environmental law and policy around the world.  相似文献   
46.

Introduction  

Increasing demand for water has stimulated efforts to treat wastewater for reuse in agriculture. Decentralized facilities for wastewater treatment became popular as a solution to remote and small communities. These systems mimic natural wetlands, cleaning wastewater as they flow through a complex of filter media, microbial fauna, and vegetation. The function of plants in constructed wetlands (CWs) has not been fully elucidated yet.  相似文献   
47.
Abstract

Objective: Some drivers involved in motor vehicle crashes across the United States may be identified as at risk of subsequent injury by a similar mechanism. The purpose of this study was to perform a national review of the risk factors for hospitalization for a new injury due to a subsequent motor vehicle crash. It was hypothesized that presenting to a different hospital after subsequent injury would result in worse patient outcomes when compared to presentation at the same hospital.

Methods: The Nationwide Readmissions Database for 2010–2014 was queried for all inpatient hospitalizations with injury related to motor vehicle traffic. The primary patient outcome of interest was subsequent motor vehicle crash–related injury within 1 year. The secondary patient outcomes were different hospital subsequent injury presentation, higher Injury Severity Score (ISS), longer length of stay (LOS), and in-hospital death after subsequent injury. The analysis of secondary patient outcomes was performed only on patients who were reinjured. Univariable analysis was performed for each outcome using all variables during the index admission. Multivariable logistic regression was performed using all significant (P < .05) variables on univariate analysis. Results were weighted for national estimates.

Results: During the study period, 1,008,991 patients were admitted for motor vehicle–related injury; 12,474 patients (1.2%) suffered a subsequent injury within 1 year. From the reinjured patients, 32.9% presented to a different hospital, 48.9% had a higher ISS, and 22.1% had a longer LOS. The in-hospital mortality rate after subsequent injury was 1.1%. Presentation to a different hospital for subsequent injury was associated with a longer LOS (odds ratio [OR]?=?1.32; 95% confidence interval [CI], 1.20–1.45; P < .01) and a higher ISS (OR?=?1.38; 95% CI, 1.27–1.49; P < .01). Motorcyclists were more likely to suffer subsequent injury (OR?=?1.39; 95% CI, 1.32–1.46; P < .01) and motorcycle passengers were more likely to present to a different hospital with a subsequent injury (OR?=?2.49; 95% CI, 1.73–3.59; P < .01). Alcohol abuse was associated with subsequent injury (OR?=?1.12; 95% CI, 1.07–1.18; P < .01).

Conclusions: Nearly a third of patients suffering subsequent motor vehicle crash–related injury after an initial motor vehicle crash in the United States present to a different hospital. These patients are more likely to suffer more severe injuries and longer hospitalizations due to their subsequent injury. Future efforts to prevent these injuries must consider the impact of this fragmentation of care and the implications for quality and cost improvements.  相似文献   
48.
Conservation organizations rely increasingly on integrated planning approaches that explicitly address social and economic goals while pursuing ecological conservation. Moreover, the spatial and temporal scale at which these organizations operate is growing. The Sierra Nevada Conservancy, established as a new state agency by California legislation in 2004 to pursue social, economic and ecological sustainability across a 25 million acre region, exemplifies this large-scale, integrated approach. Therefore, the new agency faces a complex set of policy objectives that must be pursued across a widely varying geography of social, economic and ecological conditions. Using the Conservancy's fire management program area as an example, the paper illustrates how application of an analytic framework from complex adaptive systems theory can guide the Conservancy to deploy its resources more effectively than broader-scale application of a single, agency-wide strategy relying on a more static model. Therefore, the complex adaptive systems framework offers promise in strategic planning. The paper illustrates how the model's four-stage cycle can be applied at the sub-regional and programmatic level to identify opportunities for agency intervention that address varying local conditions. This approach is likely to increase the effectiveness of programs for agencies facing similar complexities and challenges.  相似文献   
49.
Pollen is the sole source of protein for honey bees, most importantly used to rear young. Honey bees are adept at regulating pollen stores in the colonies based on the needs of the colony. Mechanisms for regulation of pollen foraging in honey bee are complex and remain controversial. In this study, we used a novel approach to test the two competing hypothesis of pollen foraging regulation. We manipulated nurse bee biosynthesis of brood food using a protease inhibitor that interferes with midgut protein digestion, significantly decreasing the amount of protein extractable from hypopharyngeal glands. Experimental colonies were given equal amounts of protease inhibitor-treated and untreated pollen. Colonies receiving protease inhibitor treatment had significantly lower hypopharyngeal gland protein content than controls. There was no significant difference in the ratio of pollen to nonpollen foragers between the treatments. Pollen load weights were also not significantly different between treatments. Our results supported the pollen foraging effort predictions generated from the direct independent effects of pollen on the regulation of pollen foraging and did not support the prediction that nurse bees regulate pollen foraging through amount of hypopharyngeal gland protein biosynthesis.  相似文献   
50.
13C-labelled cyprodinil was applied on 13C-depleted wheat plants with 27-fold field application rate. A control experiment applying same amounts of 14C-cyprodinil showed that main portions of the residues were detected in the cellulose (15% NER), hemicellulose (28.3% NER), and lignin fraction (23.3% NER). 16.7% were detected in water soluble polymers, 6% in both, pectin and protein fraction, and 4% in the starch containing fraction. Free cyprodinil was detectable by TLC in all fractions except lignin. A direct characterization of the residues in vivo by CP-MAS was not successful. Cell wall fractions were further analysed by liquid state NMR to determine the structure of the mobilized highly polymer/polar residues: Within lignin, where most of the residues were located at field application rate, neither intact cyprodinil nor its metabolites could not be detected. The 13C-label introduced was probably incorporated in the polymer as natural lignin monomers and thus are not considered as bound residues according to IUPAC definition.  相似文献   
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