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1.
Abstract: In central Africa, where governments and funding agencies cover only a fraction of the recurrent expenditures needed to effectively manage the protected-areas network, it is essential to invest in the people who will be called on to participate in conservation efforts over the long term. In the Gamba Protected Areas Complex in southwestern Gabon, we analyzed the perseverance of all those who participated in training sessions, held since 1996, in ecological survey techniques and in participatory rural appraisal (socioeconomic studies). Of government agents who attended the respective training sessions, 7.7% continued ecological surveys and 0% continued participatory rural appraisal 2 years after training. However, 76.2% and 60.0% of the members of local communities who received training were still active in ecological surveys and participatory rural appraisal respectively after 2 years. Definitive conclusions regarding the participation of nongovernmental organization members cannot be drawn because of the low number of initial participants in the training programs. Based on our results, village collaborators seem to be a more "sustainable" human resource than government agents or of nongovernmental organizations members. Even though local communities cannot be solely responsible for managing protected areas, today's conservation professionals must acknowledge the strengths and limitations of village collaborators. Implementing a process involving the participation and the emulation of community members is a demanding task because protected-area managers must be based in the field to identify key individuals and to organize intensive training sessions. Also, constant support must be provided during the first years, and then the most capable and motivated collaborators will be able to pursue further training and work their way up through the ranks of the protected area's organizational structure.  相似文献   
2.
The purpose of this study was to validate the use of adenosine triphosphate (ATP) for evaluating hygiene intervention effectiveness in reducing viral dissemination in an office environment. The bacterial virus MS-2 was used to evaluate two scenarios, one where the hand of an individual was contaminated and another where a fomite was contaminated. MS-2 was selected as a model because its shape and size are similar to many human pathogenic viruses. Two separate experiments were conducted, one in which the entrance door push plate was inoculated and the other in which the hand of one selected employee was inoculated. In both scenarios, 54 selected surfaces in the office were tested to assess the dissemination of the virus within the office. Associated surface contamination was also measured employing an ATP meter. More than half of the tested hands and surfaces in the office were contaminated with MS-2 within 4 h. Next, an intervention was conducted, and each scenario was repeated. Half of the participating employees were provided hand sanitizer, facial tissues, and disinfecting wipes, and were instructed in their use. A significant (p < 0.05) reduction was observed in the number of surfaces contaminated with virus. This reduction in viral spread was evident from the results of both viral culture and the surface ATP measurements, although there was no direct correlation between ATP measurements with respect to viral concentration. Although ATP does not measure viruses, these results demonstrate that ATP measurements could be useful for evaluating the effectiveness of hygiene interventions aimed at preventing viral spread in the workplace.  相似文献   
3.
•ZnO/Perlite inactivated 72% of bioaerosols in continuous gas phase. •TiO2 triggered the highest level of cytotoxicity with 95% dead cells onto Poraver. •Inactivation mechanism occurred by membrane damage, morphological changes and lysis. •ZnO/Poraver showed null inactivation of bioaerosols. •Catalysts losses at the outlet of the photoreactor for all systems were negligible. Bioaerosols are airborne microorganisms that cause infectious sickness, respiratory and chronic health issues. They have become a latent threat, particularly in indoor environment. Photocatalysis is a promising process to inactivate completely bioaerosols from air. However, in systems treating a continuous air flow, catalysts can be partially lost in the gaseous effluent. To avoid such phenomenon, supporting materials can be used to fix catalysts. In the present work, four photocatalytic systems using Perlite or Poraver glass beads impregnated with ZnO or TiO2 were tested. The inactivation mechanism of bioaerosols and the cytotoxic effect of the catalysts to bioaerosols were studied. The plug flow photocatalytic reactor treated a bioaerosol flow of 460×1 06 cells/m3air with a residence time of 5.7 s. Flow Cytometry (FC) was used to quantify and characterize bioaerosols in terms of dead, injured and live cells. The most efficient system was ZnO/Perlite with 72% inactivation of bioaerosols, maintaining such inactivation during 7.5 h due to the higher water retention capacity of Perlite (2.8 mL/gPerlite) in comparison with Poraver (1.5 mL/gPerlite). However, a global balance showed that TiO2/Poraver system triggered the highest level of cytotoxicity to bioaerosols retained on the support after 96 h with 95% of dead cells. SEM and FC analyses showed that the mechanism of inactivation with ZnO was based on membrane damage, morphological cell changes and cell lysis; whereas only membrane damage and cell lysis were involved with TiO2. Overall, results highlighted that photocatalytic technologies can completely inactivate bioaerosols in indoor environments.  相似文献   
4.
Central and Eastern European countries are a hotspot area when analyzing the impacts of climate change on agricultural and environmental sectors. This paper conducts a socio-economic evaluation of climate risks on crop production in Hungary, using panel data models. The region has a special location in the Carpathian basin, where the spatial distribution of precipitation varies highly from humid conditions in the western part to semiarid conditions in eastern Hungary. Under current conditions, crop systems are mainly rainfed, and water licences are massively underexploited. However, water stress projected by climate change scenarios could completely change this situation. In the near future (2021–2050), most of the crops examined could have better climatic conditions, while at the end of the century (2071–2100), lower yields are expected. Adaptation strategies must be based on an integrated evaluation which links economic and climatic aspects, and since the results show important differences in the case of individual systems, it is clear that the response has to be crop and region specific.  相似文献   
5.
The concentration of elements Na through Pb, select ions, and organic carbon from fine (<2.5 µm) particles has been monitored at Shenandoah and Great Smoky Mountains National Parks from 1988 through 1995. The data obtained from 1988 through 1994 show that significant changes in the concentrations of many aerosol constituents occur on a seasonal basis. Particulate sulfate and organic carbon are shown to exhibit substantially higher concentrations during the summer, while sulfur dioxide and nitrate concentrations are highest during the winter.

A method for estimating the degree of neutralization of particulate sulfate is given. This method uses routinely measured aerosol elemental compositions because ammonium ion, the primary neutralizing species for sulfate, is not measured on a routine basis. Application of this method to the selected data set shows that sulfate aerosol is most acidic during summer with an average molar Hs (moles of hydrogen associated with sulfur) to S (moles of sulfur) ratio of approximately 4. This suggests the average sulfate particle during the summer has a molar coon slightly more acidic than ammonium bisulfate (NH4HSO4) which has a molar hydrogen to sulfur ratio of 5. Winter Hs to S ratios, however, are approximately 8, suggesting the aerosol is on average fully neutralized ammonium sulfate [(NH4)2SO4].  相似文献   
6.
Environmental Science and Pollution Research - In this work, it was analyzed the behavior of three commercial activated carbons with different textural and chemical properties to adsorb...  相似文献   
7.
The Ganges Delta in Bangladesh is an example of water‐related catastrophes in a major rural river basin where limitations in quantity, quality, and timing of available water are producing disastrous conditions. Water availability limitations are modifying the hydrologic characteristics especially when water allocation is controlled from the upstream Farakka Barrage. This study presents the changes and consequences in the hydrologic regime due to climate‐ and human‐induced stresses. Flow duration curves (FDCs), rainfall elasticity, and temperature sensitivity were used to assess the pre‐ and post‐barrage water flow patterns. Hydrologic and climate indices were computed to provide insight on hydro‐climatic variability and trend. Significant increases in temperature, evapotranspiration, hot days, heating, and cooling degree days indicate the region is heading toward a warmer climate. Moreover, increase in high‐intensity rainfall of short duration is making the region prone to extreme floods. FDCs depict a large reduction in river flows between pre‐ and post‐barrage periods, resulting in lower water storage capacity. The reduction in freshwater flow increased the extent and intensity of salinity intrusion. This freshwater scarcity is reducing livelihood options considerably and indirectly forcing population migration from the delta region. Understanding the causes and directions of hydrologic changes is essential to formulate improve water resources management in the region.  相似文献   
8.
Rural areas represent approximately 95% of the 14000 km(2) Alabama Black Belt, an area of widespread Vertisols dominated by clayey, smectitic, shrink-swell soils. These soils are unsuitable for conventional onsite wastewater treatment systems (OWTS) which are nevertheless widely used in this region. In order to provide an alternative wastewater dosing system, an experimental field moisture controlled subsurface drip irrigation (SDI) system was designed and installed as a field trial. The experimental system that integrates a seasonal cropping system was evaluated for two years on a 500-m(2) Houston clay site in west central Alabama from August 2006 to June 2008. The SDI system was designed to start hydraulic dosing only when field moisture was below field capacity. Hydraulic dosing rates fluctuated as expected with higher dosing rates during warm seasons with near zero or zero dosing rates during cold seasons. Lower hydraulic dosing in winter creates the need for at least a two-month waste storage structure which is an insurmountable challenge for rural homeowners. An estimated 30% of dosed water percolated below 45-cm depth during the first summer which included a 30-year historic drought. This massive volume of percolation was presumably the result of preferential flow stimulated by dry weather clay soil cracking. Although water percolation is necessary for OWTS, this massive water percolation loss indicated that this experimental system is not able to effective control soil moisture within its monitoring zone as designed. Overall findings of this study indicated that soil moisture controlled SDI wastewater dosing is not suitable as a standalone system in these Vertisols. However, the experimental soil moisture control system functioned as designed, demonstrating that soil moisture controlled SDI wastewater dosing may find application as a supplement to other wastewater disposal methods that can function during cold seasons.  相似文献   
9.
This article reviews the existing models of corporate social responsiveness and develops a theoretical framework with which to examine corporations' discretionary performance with respect to one social issue, that of the environment. Discretionary indicators of corporate response to environmental issues are developed and tested within this framework. Twelve companies from five different sectors were selected for the survey, based on prior knowledge of their commitment to environmental concerns. Primary data was collected from personal interviews, and secondary data was obtained from company documents, annual reports, and other forms of publically disclosed information. Empirical results varied, but certain voluntary indicators, such as composition of the board of directors, the environmental affairs function, community support, and the annual report are considered to provide strong indications of discretionary corporate performance. Philanthropy and company products proved to be less satisfactory indicators of corporate commitment to the environment. The aggregated results revealed a correlation between the final rankings of firms' discretionary environmental performance and whether those companies are process or product oriented. Linkages between discretionary elements and those of economic and legal requirements were not explored.  相似文献   
10.
Polybromodiphenyl ethers (PBDEs) are one of the many toxic chemicals present in the environment and in the food we eat every day, being fish one of the main sources of persistent organic pollutants in our diet; like other lipid-related contaminants, they are of concern since they can bioaccumulate and biomagnify through the trophic chain. We published a study focused on the dietary uptake of dioxins and furans (PCDD/Fs) and dioxin-like polychlorobiphenyls (dl-PCBs) in a set of samples of Spanish farmed turbot (Blanco et al., 2007). In the present paper, we extend the study to PBDEs to provide more information about the uptake and transfer from feed to fish of halogenated contaminants. PBDEs in the feeds (2.35-4.76 ng g(-1)) were reflected in turbot fillets (0.54-2.05 ng g(-1)): predominant congeners were tetra-BDE 47, penta-BDEs 99 and 100. It is remarkable that tetra-BDE 49, accounting for only 2% in the feed, contributed to 15% of total PBDEs in turbot fillets. Dietary net accumulation values, 30-45%, showed that tri-, tetra-, penta- and hexa-BDEs were as efficiently transferred into turbot as dl-PCBs and tetra- and penta-chlorinated PCDD/Fs. Lipid-normalized biomagnification factors relating concentration in fish and in feed, BMFs>1 were obtained, except for BDE 209. BDE 49 accumulation, 90%, was possibly contributed by metabolism of higher brominated BDEs. Implication in aquaculture management is a need for uncontaminated fish feed to offer safe products.  相似文献   
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