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91.
    
ABSTRACT: Successful restoration of declining anadromous species is dependent upon effective riparian buffer zone management. Natural resource managers, policy developers and local conservation groups require science‐based information concerning the width at which a given buffer will be effective for its stated purpose. This paper summarizes a method developed in 1999 to determine effective riparian buffer widths for Atlantic salmon habitat protection as part of the Atlantic Salmon Conservation Plan for Seven Maine Rivers. A major assumption of the method is that no two buffers are alike with respect to their effectiveness and that various buffer characteristics dictate the required width for a given level of effectiveness. The method uses a predictive model that generates suggested riparian buffer widths as a function of specific, measurable buffer characteristics (such as slope, soil characteristics, and plant community structure and density) that affect buffer function. The method utilizes a variable‐width, two‐zone approach and specifies land uses that are consistent with desired buffer function within the two zones.  相似文献   
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Wasps robbing food from ants: a frequent behavior?   总被引:1,自引:0,他引:1  
Food robbing, or cleptobiosis, has been well documented throughout the animal kingdom. For insects, intrafamilial food robbing is known among ants, but social wasps (Vespidae; Polistinae) taking food from ants has, to the best of our knowledge, never been reported. In this paper, we present two cases involving social wasps robbing food from ants associated with myrmecophytes. (1) Polybioides tabida F. (Ropalidiini) rob pieces of prey from Tetraponera aethiops Smith (Formicidae; Pseudomyrmecinae) specifically associated with Barteria fistulosa Mast. (Passifloraceae). (2) Charterginus spp. (Epiponini) rob food bodies from myrmecophytic Cecropia (Cecropiaceae) exploited by their Azteca mutualists (Formicidae; Dolichoderinae) or by opportunistic ants (that also attack cleptobiotic wasps). We note here that wasps gather food bodies (1) when ants are not yet active; (2) when ants are active, but avoiding any contact with them by flying off when attacked; and (3) through the coordinated efforts of two to five wasps, wherein one of them prevents the ants from leaving their nest, while the other wasps freely gather the food bodies. We suggest that these interactions are more common than previously thought.  相似文献   
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The health impacts of tobacco consumption are well documented and have gained acceptance worldwide. Today, a substantial, preventable burden of tobacco attributable diseases exists in most countries, though in most of the cases, unknown. Smoking accounts for almost half of the deaths in middle age in some regions. In Uganda, translating findings into policy action is slow and involves several stakeholders. It will continue to require support from tobacco control campaign groups. This paper analyses secondar...  相似文献   
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Abstract

River Nile is one of the longest transboundery rivers and it is shared and used by Burundi, Democratic Republic of Congo, Egypt, Ethiopia, Eritrea, Kenya, Rwanda, Sudan, Tanzania and Uganda. As of today, the Nile is a crucial resource for the economic development of the Nile Basin countries and a vital source of livelihood for 160 million inhabitants as well as 300 million people living in the 10 riparian countries. The Nile Basin Initiative (NBI) is one of the international cooperative river basin management program and regional partnership where all the Nile Basin countries except Eritrea unite to pursue long-term sustainable development, improved land use practices and management. This review therefore focused on the challenges not faced on NBI in terms of integrated use of the river and conducted analysis of strengths, weaknesses, opportunities and threats (SWOT) based on secondary data. The result of the review revealed that for decades, the Nile Basin people have been facing many complex environmental, social, economic and political challenges that have made it difficult for the proper management and sustainability of Nile water. The initiative provides training to develop skills in government ministries, non-governmental organizations and local communities in each country. It is also working to raise awareness of critical environmental issues by strengthening networks of environmental education practitioners; developing curriculum in the education sector. The challenges of NBI include the involvement and funding of World Bank, lack of sufficient staff, procedural and policies conflicts, lack of coordination and linkage with other regional institutions and lack of recognition as river basin organization. Considering the complex nature of the project, it is recommended that the NBI should come up with a strong multi-disciplinary monitoring and evaluation team to follow up all implemented projects. The NBI should carry out participatory land use planning in communities along the river basin. Moreover, livelihood analysis should be carried out especially in communities along the Nile to come up with poverty eradication projects which are socially acceptable, applicable, economically viable and affordable.  相似文献   
99.
Jacques Henry 《Disasters》2013,37(2):293-316
This paper proposes an inductive analysis of the decision as to whether to return or to relocate by persons in the State of Louisiana, United States, who evacuated after Hurricanes Katrina and Rita in August and September 2005, respectively. Drawing on interviews with evacuees in these events and extensive fieldwork in the impacted area, the paper seeks to identify the folk dimensions of the decision‐making process, assess their arrangements, and situate the process in the larger context of risk and resilience in an advanced society. It suggests that, despite the material and emotional upheaval experienced by affected persons, the decision‐making process is a rational endeavour combining a definite set of tightly interconnected factors, involving material dimensions and substantive values that can act in concert or in conflict. In addition, it indicates that there are significant variations by geographic areas, homeownership, and kind of decision. Some theoretical implications, practical measures, and suggestions for future research are examined.  相似文献   
100.
    
Groundwater contamination due to pesticide applications on agricultural lands is of great environmental concern. The mathematicalmodels help to understand the mechanism of pesticide leaching in soils towards groundwater. We developed a user-friendly modelcalled ArcPRZM-3 by integrating widely used Pesticide Root Zone Model version 3 (PRZM-3) using Visual Basic and GeographicInformation System (GIS) based Avenue programming. ArcPRZM-3 could be used to simulate pesticide leaching towards groundwaterwith user-friendly input interfaces coupled with databases of crops, soils and pesticides. The outputs from ArcPRZM-3 could bevisualized in user-friendly formats of tables, charts and maps. In this study we evaluated ArcPRZM-3 model by simulating bentazonleaching in soil towards groundwater. ArcPRZM-3 was applied to 37 sites in Woodru County, Arkansas, USA to observe the dailyaverage dissolved bentazon concentration for soybean, sorghum and rice at a depth of 1.8 m for a period of two years. Nineteen ranksof bentazon leaching potential were obtained using ArcPRZM-3 for all sites having di erent soil and crop combinations. ArcPRZM-3simulation results for bentazon were compatible with the field monitored data in term of relative ranking and trend, although someuncertainties exist. This study indicated that macropore flow mechanism would be important in analyzing the e ect of irrigation ongroundwater contamination due to pesticides. Overall, ArcPRZM-3 could be used to simulate pesticide leaching towards groundwatermore e ciently and e ectively as compared to PRZM-3.  相似文献   
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