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61.
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Irradiation of carboxin (1) with a 500 W UV lamp (filter Pyrex) in CH3CN leads to the products 3, 5-8, 12-14 depending upon the reaction conditions. All photo-products were isolated and characterized. Photooxidation occurred even if unsensitized, while photoalteration was very slow in the absence of oxygen. The main oxygenated-products 3 and 13 were also recovered under biomimetic conditions by exposure of an aqueous solution of 1 to sunlight.  相似文献   
63.
A home-modified atomic fluorescence detector (mAFS) has been employed for mercury and methylmercury determination in bivalves from the Andalusian coast (south Spain). This modification consists on the inclusion of a quartz flow cell into the detector, which increases the concentration of mercury atoms in the detector and therefore enhances sensitivity about two fold. Two analytical approaches for mercury speciation based on the coupling of gas chromatography on-line pyrolysis and mAFS (GC-Pyro-mAFS) have been tested. The first approach (Method 1) is based on aqueous ethylation followed by extraction into an organic solvent, and the second one (Method 2) in the extraction of monoalkylated mercury as chloride. Method 1 is a rapid procedure but not sensitive enough for the analysis of methylmercury in non-polluted sites (detection limit: 20 ng g(-1) as mercury, wet basis). The second one is quite more sensitive (detection limit: 0.2 ng g(-1), wet weight), but sample treatment is cumbersome and time-consuming. The optimum range for mercury determination for both methods are complementary and exhibit an overlapping measurable concentration range (OMCR) in which methylmercury can be indistinctly determined (75-100 ng g(-1) as mercury, wet basis). The suitability of both methods has been assayed with spiking experiences at levels within the OMCR with good recoveries. Both approaches have been validated with two certified reference materials (BCR-463, mercury and methylmercury in tuna fish; and NIST-2977, organic contaminants and trace metals in mussel tissue). Both procedures have been used for the analysis of three species of bivalve molluscs collected along the Andalusian coast (south Spain), all of them employed for human consumption (Chamelea gallina, Donax trunculus and Scrobicularia plana), and their potential use in routine analysis has been established.  相似文献   
64.
Packaging is strictly connected to environmental issues as it is a product characterised by high material consumption rate; it is often transported over long distances and has a short life. Providing environmental analysis is, therefore, urgent to identify energy and resources efficient solutions. The paper, taking advantage of a real case study, presents a life cycle-based comparative analysis among three different food packaging systems. The paper compares the life cycle of tin steel, polypropylene and glass-based packaging of an Italian preserves producer. The analysis leads to the conclusion that, for the baseline scenario, polypropylene packaging represents the greenest solution, whereas glass packaging is the worst choice. The paper presents a scenario analysis varying both the method used for accounting for recycling as well as the recycling rates of the packaging materials. Changes in overall results with parameters analysis changing are calculated and highlighted throughout the paper. The impact of a reuse policy of the glass-based solution is also analysed; a model for disposable glass packaging is proposed and the obtained results are compared with the single use polypropylene and tin steel-based packaging. In order to analyse the impact of different End of Life scenarios on the present case study, collecting as well as recycling rates of some European countries have been used. The results revealed a significant fluctuation both in energy consumption and in CO2 emission as the nation changes. Summing up, a methodology for packaging environmental impact analysis is applied to a real case study, some crucial aspects of the methodology have been analysed in depth in order to give a contribution in packaging environmental impact analysis.  相似文献   
65.
The vaquita (Phocoena sinus) is the world's most endangered marine mammal with approximately 245 individuals remaining in 2008. This species of porpoise is endemic to the northern Gulf of California, Mexico, and historically the population has declined because of unsustainable bycatch in gillnets. An illegal gillnet fishery for an endangered fish, the totoaba (Totoaba macdonaldi), has recently resurged throughout the vaquita's range. The secretive but lucrative wildlife trade with China for totoaba swim bladders has probably increased vaquita bycatch mortality by an unknown amount. Precise population monitoring by visual surveys is difficult because vaquitas are inherently hard to see and have now become so rare that sighting rates are very low. However, their echolocation clicks can be identified readily on specialized acoustic detectors. Acoustic detections on an array of 46 moored detectors indicated vaquita acoustic activity declined by 80% between 2011 and 2015 in the central part of the species’ range. Statistical models estimated an annual rate of decline of 34% (95% Bayesian credible interval –48% to –21%). Based on results from 2011 to 2014, the government of Mexico enacted and is enforcing an emergency 2‐year ban on gillnets throughout the species’ range to prevent extinction, at a cost of US$74 million to compensate fishers. Developing precise acoustic monitoring methods proved critical to exposing the severity of vaquitas’ decline and emphasizes the need for continual monitoring to effectively manage critically endangered species.  相似文献   
66.
Many tropical corals have declined in abundance in the last few decades, and evaluating the causal basis of these losses is critical to understanding how coral reefs will change in response to ongoing environmental challenges. Motivated by the likelihood that marine environments will become increasingly unfavorable for coral growth as they warm and become more acidic (i.e., ocean acidification), it is reasonable to evaluate whether specific phenotypic traits of the coral holobiont are associated with ecological success (or failure) under varying environmental conditions including those that are adverse to survival. Initially, we asked whether it was possible to identify corals that are resistant or sensitive to such conditions by compiling quantitative measures of their phenotypic traits determined through empirical studies, but we found only weak phenotypic discrimination between ecological winners and losers, or among taxa. To reconcile this outcome with ecological evidence demonstrating that coral taxa are functionally unequal, we looked beyond the notion that phenotypic homogeneity arose through limitations of empirical data. Instead, we examined the validity of contemporary means of categorizing corals based on ecological success. As an alternative means to distinguish among functional groups of corals, we present a demographic approach using integral projection models (IPMs) that link organismal performance to demographic outcomes, such as the rates of population growth and responses to environmental stress. We describe how IPMs can be applied to corals so that future research can evaluate within a quantitative framework the extent to which changes in physiological performance influence the demographic underpinnings of ecological performance.  相似文献   
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68.
The present article analyses the current situation of End-of-Life-of-Vehicles (ELVs) management in Europe, with particular attention on Italian condition. Similarly to other European countries, metal recycling is the main activity of the whole system, but such situation is evolving due to the 2000/53/EC Directive, which sets out targets for Reuse, Recycling and Recovery of ELVs. Due to the relevance of the ELVs problem, in 2008 Italian Ministry of Environment subscribed a framework agreement with competent stakeholders as carmakers, dismantlers, shredders. The main result is an industrial plan to promote (amongst other objectives) technological progress for residual waste (Automotive Shredder Residue – ASR) treatment. According with Italian Trial 2006 analysis about ELVs, Reuse and Recycling rate is currently estimated to be about 81%.At the present time, dismantling plants constitute the first collection points for ELVs; for this reason, during 2009 an investigation has been done over a number of ten Authorized Treatment Facilities (ATFs) operating in Italy. The first step of the analysis was aimed to find out major practices and methods through observations of ATFs activities and interviews to operators. Furthermore, the depollution and dismantling treatments of about 70 different ELVs have been observed and timed in detail over a period of three months. The results included the identification of most relevant critical issues in ELVs treatment, such as distortions between scrapping activities and Directive’s regulation, and the assessment of the time and of the resources needed to perform each operation.In the second step of the survey, a process simulation model has been built on the basis of such data. The model was aimed to include the real variability and all the uncertainties that are typical of dismantling activities; it is intended as a tool for process layout planning and for its management. Some control parameters have been introduced; these are able to dynamically modify process path depending on ELVs queues and priorities. The model can also be used for the economic assessments of single operations or of the whole treatment activity.  相似文献   
69.
A design-based strategy for estimating wildlife ungulate abundance in a Mediterranean protected area (Maremma Regional Park) is considered. The estimation is based on pellet group count (clearance count technique) in a set of plots, whose size and number is established on the basis of practical considerations and available resources. The sampling scheme involves a preliminary stratification and subsequent two-stage sampling. In the first stage, large strata (defined through habitat features) are partitioned into spatial units and a sample of units is selected by means of a sampling scheme ensuring inclusion probabilities proportional to unit size, but avoiding the selection of contiguous units. Then, the abundances of the selected units are estimated in a second stage, in which plots are located using a random scheme ensuring an even coverage of the units. In small strata, only the second stage is performed. Unbiased estimators of abundance and conservative estimators of their variances are derived for each strata and for the whole study area. The proposed strategy has been applied since the Summer of 2006 and the estimation results reveal substantial improvement with respect to the previous results obtained by means of an alternative strategy.  相似文献   
70.
In Europe, coastal dune systems with Juniperus spp. (Natura 2000 habitat code 2250) are a priority habitat for conservation according to the Natura 2000 policies. Currently, anthropogenic pressure is threatening the biodiversity of this habitat. While the impact of human pressure on animals and vascular plants is already documented, information is still scanty for other organisms such as epiphytic lichens. The main aim of this study is to test the effect of human disturbance on the occurrence and abundance of the red-listed macrolichen Seirophora villosa. We also tested the effect of human disturbance on the whole community of epiphytic lichens in terms of species richness and composition. The study was performed along the coast of Tuscany by comparing both disturbed and undisturbed Juniperus stands according to a stratified random sampling design. Our results provided evidence that in coastal systems the long-term conservation of the red-listed macrolichen S. villosa and its characteristic community composed by several Mediterranean species of conservation concern depends on the maintenance of undisturbed Juniperus habitats. Results also support the possibility of using S. villosa as an indicator species of habitat conservation importance and habitat integrity since its occurrence is predicted on nestedness in term of species composition, assemblages of species poor disturbed stands being subsets of those of richer undisturbed stands.  相似文献   
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