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741.
This research assesses the feasibility of degrading used disposable diapers, an important component (5-15% in weight) of urban solid waste in Mexico, by the activity of the fungus Pleurotus ostreatus, also known as oyster mushroom. Disposable diapers contain polyethylene, polypropylene and a super absorbent polymer. Nevertheless, its main component is cellulose, which degrades slowly. P. ostreatus has been utilized extensively to degrade cellulosic materials of agroindustrial sources, using in situ techniques. The practice has been extended to the commercial farming of the mushroom. This degradation capacity was assayed to reduce mass and volume of used disposable diapers. Pilot laboratory assays were performed to estimate the usefulness of the following variables on conditioning of used diapers before they act as substrate for P. ostreatus: (1) permanence vs removal of plastic cover; (2) shredding vs grinding; (3) addition of grape wastes to improve structure, nitrogen and trace elements content. Wheat straw was used as a positive control. After 68 days, decrease of the mass of diapers and productivity of fungus was measured. Weight and volume of degradable materials was reduced up to 90%. Cellulose content was diminished in 50% and lignine content in 47%. The highest efficiency for degradation of cellulosic materials corresponded to the substrates that showed highest biological efficiency, which varied from 0% to 34%. Harvested mushrooms had good appearance and protein content and were free of human disease pathogens. This research indicates that growing P. ostreatus on disposable diapers could be a good alternative for two current problems: reduction of urban solid waste and availability of high protein food sources.  相似文献   
742.
In this article, we analyse how the Internet is used to bring visibility to water affairs. We focus on the way different organisations exploit the Web in order to participate in the debates about water policy in Spain and to define the topics concerned. To do this, we have drawn up an issue network articulated around an alternative and sustainable water policy called ‘New Water Culture’. We examine the composition of this web structure, its hyperlinking styles, key nodes and political trajectories. The outcomes indicate that the ‘New Water Culture’ has become a main frame in Spanish environmental policy. Supported both by governmental and non-governmental players, the ‘New Water Culture’ struggles between two opposing trends: its expulsion from the public sphere and efforts to open it up to scrutiny from political outsiders.  相似文献   
743.

Introduction  

Complex organic compounds found in oil and sediments linked with a particular source (such as algae, bacteria or vascular plants) are defined as biomarkers and are useful dating indicators in organic geochemistry.  相似文献   
744.
Biodiversity conservation decisions are difficult, especially when they involve differing values, complex multidimensional objectives, scarce resources, urgency, and considerable uncertainty. Decision science embodies a theory about how to make difficult decisions and an extensive array of frameworks and tools that make that theory practical. We sought to improve conceptual clarity and practical application of decision science to help decision makers apply decision science to conservation problems. We addressed barriers to the uptake of decision science, including a lack of training and awareness of decision science; confusion over common terminology and which tools and frameworks to apply; and the mistaken impression that applying decision science must be time consuming, expensive, and complex. To aid in navigating the extensive and disparate decision science literature, we clarify meaning of common terms: decision science, decision theory, decision analysis, structured decision-making, and decision-support tools. Applying decision science does not have to be complex or time consuming; rather, it begins with knowing how to think through the components of a decision utilizing decision analysis (i.e., define the problem, elicit objectives, develop alternatives, estimate consequences, and perform trade-offs). This is best achieved by applying a rapid-prototyping approach. At each step, decision-support tools can provide additional insight and clarity, whereas decision-support frameworks (e.g., priority threat management and systematic conservation planning) can aid navigation of multiple steps of a decision analysis for particular contexts. We summarize key decision-support frameworks and tools and describe to which step of a decision analysis, and to which contexts, each is most useful to apply. Our introduction to decision science will aid in contextualizing current approaches and new developments, and help decision makers begin to apply decision science to conservation problems.  相似文献   
745.
The Biological Resource Centre for the Environment BRC4Env is a network of Biological Resource Centres (BRCs) and collections whose leading objectives are to improve the visibility of genetic and biological resources maintained by its BRCs and collections and to facilitate their use by a large research community, from agriculture research to life sciences and environmental sciences. Its added value relies on sharing skills, harmonizing practices, triggering projects in comparative biology, and ultimately proposing a single-entry portal to facilitate access to documented samples, taking into account the partnership policies of research institutions as well as the legal frame which varies with the biological nature of resources. BRC4Env currently includes three BRCs: the Centre for Soil Genetic Resources of the platform GenoSol, in partnership with the European Conservatory of Soil Samples; the Egg Parasitoids Collection (EP-Coll); and the collection of ichthyological samples, Colisa. BRC4Env is also associated to several biological collections: microbial consortia (entomopathogenic bacteria, freshwater microalgae…), terrestrial arthropods, nematodes (plant parasitic, entomopathogenic, animal parasitic...), and small mammals. The BRCs and collections of BRC4Env are involved in partnership with academic scientists, as well as private companies, in the fields of medicinal mining, biocontrol, sustainable agriculture, and additional sectors. Moreover, the staff of the BRCs is involved in many training courses for students from French licence degree to Ph.D, engineers, as well as ongoing training.  相似文献   
746.
As declines in biodiversity accelerate, there is an urgent imperative to ensure that every dollar spent on conservation counts toward species protection. Systematic conservation planning is a widely used approach to achieve this, but there is growing concern that it must better integrate the human social dimensions of conservation to be effective. Yet, fundamental insights about when social data are most critical to inform conservation planning decisions are lacking. To address this problem, we derived novel principles to guide strategic investment in social network information for systematic conservation planning. We considered the common conservation problem of identifying which social actors, in a social network, to engage with to incentivize conservation behavior that maximizes the number of species protected. We used simulations of social networks and species distributed across network nodes to identify the optimal state-dependent strategies and the value of social network information. We did this for a range of motif network structures and species distributions and applied the approach to a small-scale fishery in Kenya. The value of social network information depended strongly on both the distribution of species and social network structure. When species distributions were highly nested (i.e., when species-poor sites are subsets of species-rich sites), the value of social network information was almost always low. This suggests that information on how species are distributed across a network is critical for determining whether to invest in collecting social network data. In contrast, the value of social network information was greatest when social networks were highly centralized. Results for the small-scale fishery were consistent with the simulations. Our results suggest that strategic collection of social network data should be prioritized when species distributions are un-nested and when social networks are likely to be centralized.  相似文献   
747.
Conservation of the marine environment mainly focuses on threatened elements and more precisely on vulnerable and endangered species like birds and mammals. When dealing with the conservation of marine habitats, the scientific community is mainly interested in hot spots of diversity, like seagrass beds in Europe, or hot spots of endemism, like coral reefs in tropical areas. Nevertheless, using the example of a common and widespread marine invertebrate, the sandmason worm (Lanice conchilega, Polychaeta, Terebellidae), we show that vulnerability and rarity are not the only criteria to take into account in order to select the best natural element for conservation. This species can form dense beds that increase biodiversity, are attractive feeding grounds for birds and fishes, and have a high socioeconomic value. In consequence, they have a high functional value that should be considered as an important conservation stake. Through the example of the Chausey archipelago and the Bay of the Mont Saint-Michel (France), we propose a synthetic interdisciplinary approach to evaluate the conservation needs of these beds. The issue is even more pressing when one considers that these natural elements and many similar ones still do not benefit from any legal protection in Europe despite their high heritage value.  相似文献   
748.
The reactivity of paclobutrazol (PBZ, a plant growth retardant) with a Yellow Ultisol and a Vertisol from the semiarid northeast region of Brazil was evaluated through batch sorption experiments and modeling. Although not instantaneous, the sorption kinetic of PBZ (pure and formulated) was fast (a few hours) in both soils. The sorption kinetics were well described by a second-order (dS(t)/dt=k(2)(S(e2)-S(t))(2)) but not by a first-order model. The sorption isotherms were found to be linear and the calculated K(D) values were 8.8 +/- 0.11 and 7.4 +/- 0.2 L kg(-1) for pure PBZ in the Ultisol and the Vertisol, respectively. The corresponding K(OC) values were 1275 +/- 34 (logK(OC) = 3.11) and 1156 +/- 49 (logK(OC) = 3.06) L kg(-1), respectively. Considering the very different texture of the two soils and the similar K(OC) values determined, these results showed that in both soils, the sorption of PBZ is dominantly controlled by organic matter, although some interactions of PBZ with iron oxides (goethite) were observed in the Ultisol. Based on these sorption parameters a low leachability potential of PBZ in soils is anticipated, as they correspond to a groundwater ubiquity score (GUS) ranging from 2.0 to 2.7, i.e., moderately to not mobile, in contradiction with the actual groundwater situation in Brazil. This work stresses the need to evaluate and predict the risk associated with aquifer contamination by this widely used plant growth regulator.  相似文献   
749.
Copper can affect essential processes in soils, often for long periods. Enzyme activity is considered a sensitive indicator to evaluate soil health and the potential toxic impact of a soil contaminant. Nevertheless, there is heterogeneity in the responses from enzyme activity assays because of the influence of pH and other physicochemical parameters on both enzyme activity and metal speciation. This leads to complications when comparing soils and limits the validity of the results. To overcome these problems, this paper evaluates resistance and recovery, quantified by using a relative soil stability index (RSSI), of the beta-glucosidase and protease activities towards an additional heat disturbance (17 h at 60 degrees C) in soils where soil organic matter, pH and Cu content were modified in a factorial setup. Chemical analyses (dissolved Cu, pCu(2+), dissolved organic carbon, pH) were performed both before the heat-perturbation and after the enzyme activity monitoring period. Results show that soil pH did not interfere with the RSSI scores of both enzymes. beta-glucosidase RSSI scores were scarcely affected by copper, making it inappropriate for evaluating copper-induced stress to soils. Protease activity shows stimulations of up to 2.5 times the activity of the unperturbed control in uncontaminated samples only. Thus, the protease RSSI score seems a good indicator for soil health relative to copper contamination given that all samples were affected by the presence of copper and high correlations were observed between RSSI scores and the different copper forms.  相似文献   
750.
A greenhouse study was undertaken to determine the suitability of adding papermill sludge to neutral/alkaline gold mine tailings to improve the establishment of Festuca rubra, Agropyron trachycaulum and Medicago sativa. Festuca rubra root and shoot biomass and A. Trachycaulum shoot biomass were increased with papermill sludge amendment. The addition of papermill sludge and fertilizer drastically increased the shoot and root biomass of M. sativa (20-30 times) while A. trachycaulum and F. rubra showed a more moderate increase in growth. Photosynthetic pigment content of the leaves was higher in papermill sludge treatments than in the treatments without papermill sludge. The organic carbon content, macro-aggregate content and field capacity of the gold mine tailings were increased while the bulk density was decreased by the addition of papermill sludge. This study suggests that addition of papermill sludge and adequate fertilization can alleviate some of the adverse conditions of neutral/alkaline gold mine tailings.  相似文献   
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