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1.
Considerable empirical evidence supports recovery of reef fish populations with fishery closures. In countries where full exclusion of people from fishing may be perceived as inequitable, fishing‐gear restrictions on nonselective and destructive gears may offer socially relevant management alternatives to build recovery of fish biomass. Even so, few researchers have statistically compared the responses of tropical reef fisheries to alternative management strategies. We tested for the effects of fishery closures and fishing gear restrictions on tropical reef fish biomass at the community and family level. We conducted 1,396 underwater surveys at 617 unique sites across a spatial hierarchy within 22 global marine ecoregions that represented 5 realms. We compared total biomass across local fish assemblages and among 20 families of reef fishes inside marine protected areas (MPAs) with different fishing restrictions: no‐take, hook‐and‐line fishing only, several fishing gears allowed, and sites open to all fishing gears. We included a further category representing remote sites, where fishing pressure is low. As expected, full fishery closures, (i.e., no‐take zones) most benefited community‐ and family‐level fish biomass in comparison with restrictions on fishing gears and openly fished sites. Although biomass responses to fishery closures were highly variable across families, some fishery targets (e.g., Carcharhinidae and Lutjanidae) responded positively to multiple restrictions on fishing gears (i.e., where gears other than hook and line were not permitted). Remoteness also positively affected the response of community‐level fish biomass and many fish families. Our findings provide strong support for the role of fishing restrictions in building recovery of fish biomass and indicate important interactions among fishing‐gear types that affect biomass of a diverse set of reef fish families.  相似文献   
2.
A facile, scalable, and solution-based technique is used to fabricate Al and Ni-doped (LiAl0.1Mn1.9O4 and LiAl0.1Ni0.1Mn1.8O4) microspheres of lithium manganese oxide (LMO) spinels for use as reversible cathode materials for lithium ion batteries (LIBs). The spheres of the two samples exhibit different porosities. Cells with these LMO-based cathodes are then cycled between 4.5 V and 2 V to study their stabilities while simultaneously being subjected to the undesirable Jahn-Teller distortion that occurs around the ~3 V regime. The LiAl0.1Mn1.9O4 (LAMO) and the LiAl0.1Ni0.1Mn1.8O4 (LANMO) cells exhibit comparable open circuit voltages (OCV) of 2.94 V and 2.97 V, respectively. During cell cycling, the LAMO cell exhibits a maximum specific capacity of 122.51 mAh g?1 with a capacity fade of 65.35% after 75 cycles. The LiAl0.1Ni0.1Mn1.8O4 (LAMO) sample fares better and exhibits a maximum of 140.49 mAh g?1 and a capacity drop of 52.59%. Detailed structural studies indicate that Ni doping and the greater degree of porosity of the LANMO sample to be a stabilizing factor. This is further confirmed by cyclic voltammetry (CV) and AC impedance spectra analysis.  相似文献   
3.
Organic aerosol chemical markers from normalized concentrations of independent measurements of mass fragments (using Aerosol Mass Spectrometry, AMS) are compared to bond-based functional groups (from Fourier Transform Infrared spectroscopy, FTIR) during eight field projects in the western hemisphere. Several field projects show weak correlations between alcohol group fractions and m/z 60 fractions, consistent with the organic hydroxyl groups and the fragmentation of saccharides, but the weakness of the correlations indicate chemical differences among the relationships for ambient aerosols in different regions. Carboxylic acid group fractions and m/z 44 fractions are correlated weakly for three projects, with correlations expected for aerosols dominated by di-acid compounds since their fragmentation is typically dominated by m/z 44. Despite differences for three projects with ratios of m/z 44 to m/z 57 fragments less than 10, five projects showed a linear trend between the project-average m/z 44 to m/z 57 ratio and the ratio of acid and alkane functional groups. While this correlation explains only a fraction of the fragment and bond variability measured, the consistency of this relationship at multiple sites indicates a general agreement with the interpretation of the relative amount of m/z 44 as a carboxylic acid group marker and m/z 57 as an alkane group marker.  相似文献   
4.
The body of information presented in this paper is directed toward those individuals involved with handling hazardous materials, whether in actual use of such chemicals, or in monitoring atmospheric emissions. Although specifically relating experience in the design and testing of phosgene emission control equipment, it attempts to establish general guidelines for effectively dealing with emissions of hazardous materials. An approach for handling chemical pollutants having no established air quality emission standards is developed. The paper presents a technique for establishing process emissions at acceptably low levels to insure the health and safety of the general population as well as that of the process workers themselves. Methods, suitable for measuring phosgene at these low levels, have been investigated, and problems associated with such an investigation are discussed. While complete theoretical scrubber design criteria are beyond the scope of this paper, many of the "real world" problems which affected scrubber performance are presented. Finally, the practical aspects of process emissions control are illustrated by actual results from the system test.  相似文献   
5.
Airports represent highly complex organisations, incorporating such interdependent operations as airlines, ground transport, flight services, ground services, refueling, maintenance, customer services, catering, administration and security. Airports, and especially International Airports, must ensure that their operations are conducted in a safe and efficient manner, as the consequence of any error or failure during operations has the potential for catastrophic outcomes. The international governing body for air transportation, ICAO, requires that airports must implement a Safety Management System as a means of ensuring safe operations and eliminating or reducing the likelihood of low frequency/high consequence incidents. This research project sought to determine the extent to which the implementation of a Safety Management System (SMS) influenced the attitudes of airport employees toward unsafe acts. The hypothesis tested was that the implementation of an SMS into an airport will result in an improvement in attitudes toward safety. A Safety Culture Survey was utilized to measure these attitudes. Two International Airports were chosen to measure the extent to which the introduction of an SMS at one airport would influence the safety attitude and culture of those employees. Sharjah International Airport, UAE, was used as the experimental group, as it did not have a formal SMS in operation, with another English-speaking International Airport (the Second Airport) being used as a control group, as it already had an SMS in operation. A Safety Culture Survey was used as the pre and post-test measure over a 12-month period to determine the extent of influence of the introduction of the SMS at Sharjah Airport. The results of Phase 1 of the survey (June 2008) were compared against the results of Phase 2 of the survey (June 2009). The average score reported by participants at Sharjah Airport increased significantly from pre-test measure to post-test measure in relation to communication, safety rules, supportive environment, personal risk appreciation, work environment, and involvement. At the same time, the average score for personal priorities decreased significantly from Phases 1 to 2. Results indicate that participants at Sharjah Airport recorded a significant positive shift in attitude to the safety factors covered in the Safety Culture Survey, whilst at the same time responses from the Second Airport showed no such shift in attitude. The Second Airport showed neither decline nor improvement in responses. Whilst some methodological issues were identified, the results were of sufficient strength as to conclude that the outcomes reported support the hypothesis that the introduction of an SMS at Sharjah Airport has effected positive changes not observed at the Second Airport. Recommendations for ongoing research were made to further explore the strength of relationship between SMS and safety attitudes, as well as the relationship between safe attitude and safe behaviour.  相似文献   
6.
Information on flood inundation extent is important for understanding societal exposure, water storage volumes, flood wave attenuation, future flood hazard, and other variables. A number of organizations now provide flood inundation maps based on satellite remote sensing. These data products can efficiently and accurately provide the areal extent of a flood event, but do not provide floodwater depth, an important attribute for first responders and damage assessment. Here we present a new methodology and a GIS‐based tool, the Floodwater Depth Estimation Tool (FwDET), for estimating floodwater depth based solely on an inundation map and a digital elevation model (DEM). We compare the FwDET results against water depth maps derived from hydraulic simulation of two flood events, a large‐scale event for which we use medium resolution input layer (10 m) and a small‐scale event for which we use a high‐resolution (LiDAR; 1 m) input. Further testing is performed for two inundation maps with a number of challenging features that include a narrow valley, a large reservoir, and an urban setting. The results show FwDET can accurately calculate floodwater depth for diverse flooding scenarios but also leads to considerable bias in locations where the inundation extent does not align well with the DEM. In these locations, manual adjustment or higher spatial resolution input is required.  相似文献   
7.
Organic farming is a whole-farm management approach believed to encourage biodiversity by excluding the input of agrochemicals and introducing specific management regimes for non-crop habitats. We examined the impact of the hedgerow management regime encouraged for organic farms on small mammal populations, since small mammal numbers influence a range of species at higher trophic levels and, in particular, are key to the conservation of a range of mammalian and avian predators. We compared differences in management and structure of non-crop habitats at the farm-scale between organic and conventional farms, and used within-farm variations in hedgerow size to predict the effect of hedgerow size on small mammals on both farm types. There were no significant differences in the proportion of non-crop habitats between organic and conventional farms, although management differences produced larger hedgerows on organic farms and greater diversity of hedgerow growth stages. However, a difference in hedgerow size between the farm types did not have a significant effect on small mammal abundance or diversity. We conclude that increased hedgerow size is not benefiting small mammal populations on organic farms: significant gains in small mammal numbers may be more effectively achieved by increasing the area of non-crop habitats rather than by improving management regimes.  相似文献   
8.
This paper provides an overview of the impacts of rural land use on lowland streamwater phosphorus (P) and nitrogen (N) concentrations and P loads and sources in lowland streams. Based on weekly water quality monitoring, the impacts of agriculture on streamwater P and N hydrochemistry were examined along a gradient of rural–agricultural land use, by monitoring three sets of ‘paired’ (near-adjacent) rural headwater streams, draining catchments which are representative of the major geology, soil types and rural/agricultural land use types of large areas of lowland Britain. The magnitude and timing of P and N inputs were assessed and the load apportionment model (LAM) was applied to quantify ‘continuous’ (point) source and ‘flow-dependent’ (diffuse) source contributions of P to these headwater streams. The results show that intensive arable farming had only a comparatively small impact on streamwater total phosphorus (TP loads), with highly consistent stream diffuse-source TP yields of ca. 0.5 kg-P ha?1 year?1 for the predominantly arable catchments with both clay and loam soils, compared with 0.4 kg-P ha?1 year?1 for low agricultural intensity grassland/woodland on similar soil types. In contrast, intensive livestock farming on heavy clay soils resulted in dramatically higher stream diffuse-source TP yields of 2 kg-P ha?1 year?1. The streamwater hydrochemistry of the livestock-dominated catchment was characterised by high concentrations of organic P, C and N fractions, associated with manure and slurry sources. Across the study sites, the impacts of human settlement were clearly identifiable with effluent inputs from septic tanks and sewage treatment works resulting in large-scale increases in soluble reactive phosphorus (SRP) loads and concentrations. At sites heavily impacted by rural settlements, SRP concentrations under baseflow conditions reached several hundred μg-P L?1. Load apportionment modelling demonstrated significant ‘point-source’ P inputs to the streams even where there were no sewage treatment works within the upstream catchment. This indicates that, even in sparsely populated rural headwater catchments, small settlements and even isolated groups of houses are sufficient to cause significant nutrient pollution and that septic tank systems serving these rural communities are actually operating as multiple point sources, rather than a diffuse input.  相似文献   
9.
Many VOC represent hazards to human health through chronic exposure. Recent European and world-wide legislation proposes limit values for ambient concentrations of these compounds. However, very little experimental data exists for true population exposure. In 1996, the European MACBETH initiative set out to measure population exposure to benzene in six European cities. This study details the French contribution to this program. Six campaigns were carried out, each comprising measurements at 100 outdoor sites and the participation of 50 non-smoking volunteers who wore personal samplers and had passive monitors installed in their homes. Iso-concentration maps were drawn for each campaign and the results showed that outdoor concentrations were significantly lower than indoors. Almost 75% of the volunteers were exposed to mean concentrations higher than the limit value of 5µgm3. It is demonstrated that personal exposure levels cannot be deduced simply by combining indoor and outdoor background concentrations. It is also shown that there is need for better knowledge of the contributions to overall exposure of outdoor microenvironments and the authors hope that future European directives will take this into account.  相似文献   
10.
The technique of thermal desorption (TD)–GC/MS was evaluated for measuring airborne, 4–6 ring polycyclic aromatic hydrocarbons (PAHs) collected onto quartz filters. TD provides a more readily automated and sensitive alternative to traditional solvent extraction, decreasing the time/cost of analysis and reducing the risk of analyte loss or sample contamination. The developed method was successfully applied to the analysis of PAH standard solutions loaded on sorbent tubes packed with quartz wool and the graphitized carbon black sorbent Carbograph2. The optimized method showed high desorption efficiency over the whole range of target PAHs with good precision, linearity and sensitivity. The proposed method was verified on an urban dust Standard Reference Material (SRM 1649a); the experimentally determined concentrations agreed with the certified ranges (95% confidence limit) for all target compounds except benzo[a]anthracene, which fell just outside the narrow certified range. The desorption efficiency and the reproducibility of the method was evaluated by analysing pieces of real sample filters sampled from urban air for a period of 24 h. The results confirmed the homogeneity of the filter and showed high recovery efficiencies for all target PAHs.  相似文献   
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