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21.
There is growing awareness in today’s society regarding the potential of sustainable farming practices to decrease soil degradation processes. This paper analyses the financial, environmental and social aspects of durum wheat cultivation practices linked to soil degradation processes in Southern Tuscany. The analysis has been conducted within a Social Multi-Criteria Evaluation (SMCE) framework and utilizing NAIADE (Novel Approach to Imprecise Assessment and Decision Environments) as a software tool. Conventional, integrated and organic durum wheat cultivation practices have been compared. One key outcome of the analysis is that organic practices represent a good compromise solution in relation to the environmental and socio-economic evaluation criteria chosen. Finally, the paper also offers some considerations regarding the influence of Agricultural European Policies (such as the CAP-Common Agricultural Policy) on the management of farming systems and as a consequence on the soil degradation phenomena.  相似文献   
22.
The results obtained in the four seasonal cruises planned in the PRISMA II project are reported. These concern dissolved and colloidal organic carbon, free amino acids and total dissolved carbohydrates and heterotrophic activity. Main factors controlling organic matter degradation, resulting from laboratory tests not planned in the above project, are also discussed. Dissolved organic matter shows seasonal accumulation, which may be markedly different from year to year, and large contributions by colloidal and saccharide components. Heterotrophic activities play an important role in the carbon cycle, although laboratory runs highlight limitations caused by aging of organic matter and phosphorus deficiency.  相似文献   
23.
Food Community Networks as Leverage for Social Embeddedness   总被引:1,自引:0,他引:1  
Social embeddedness, defined as the interaction of economic activities and social behavior, is used in this study as a conceptual tool to describe the growing phenomenon of food community networks (FCNs). The aim in this paper was to map the system of relations which the FCNs develop both inside and outside the network and, from the number of relations, it was inferred the influence of each FCN upon the formation of new socially embedded economic realities. A particular form of FCN was taken under consideration: solidarity purchase groups (SPGs). Performed with the aid of social network analysis on a sample of SPGs in Sicily (a region in southern Italy), the study allowed us to identify a relational (internal) social embeddedness, in which groups of consumers and farmers are directly influenced by reciprocal interactions, giving rise to more or less numerous links of reciprocity and trust depending on the number of interactions. It was also identified a structural (external) social embeddedness, generated by the nature of relations that the SPGs undertake with the various social actors. From the results of our analysis it emerges that SPGs lie at the intersection of many social realities, influencing them and in turn being influenced by such realities. We highlight the major role played by consumer and environmental associations in affecting the phenomenon of social embeddedness.  相似文献   
24.
The prevalence and genetic diversity of human bocaviruses (HBoVs) in sewage water samples are largely unknown. In this study, 134 raw sewage samples from 25 wastewater treatment plants (WTPs) in Italy were analyzed by nested PCR and sequencing using species-specific primer pairs and broad-range primer pairs targeting the capsid proteins VP1/VP2. A large number of samples (106, 79.1 %) were positive for HBoV. Out of these, 49 were classified as HBoV species 2, and 27 as species 3. For the remaining 30 samples, sequencing results showed mixed electropherograms. By cloning PCR amplicons and sequencing, we confirmed the copresence of species 2 and 3 in 29 samples and species 2 and 4 in only one sample. A real-time PCR assay was also performed, using a newly designed TaqMan assay, for quantification of HBoVs in sewage water samples. Viral load quantification ranged from 5.51E+03 to 1.84E+05 GC/L (mean value 4.70E+04 GC/L) for bocavirus 2 and from 1.89E+03 to 1.02E+05 GC/L (mean value 2.27E+04 GC/L) for bocavirus 3. The wide distribution of HBoV in sewages suggests that this virus is common in the population, and the most prevalent are the species 2 and 3. HBoV-4 was also found, representing the first detection of this species in Italy. Although there is no indication of waterborne transmission for HBoV, the significant presence in sewage waters suggests that HBoV may spread to other water environments, and therefore, a potential role of water in the HBoV transmission should not be neglected.  相似文献   
25.
The potential of high pressure processing to inactivate hepatitis A virus (HAV) within Mediterranean mussels (Mytilus galloprovincialis) and blue mussels (Mytilus edulis) was evaluated. HAV was bioaccumulated within mussels to approximately 6-log10 PFU by exposure of mussels to HAV-contaminated seawater. After shucking, 5 min pressure treatments of 300, 325, 350, 375, and 400 MegaPascals (MPa) were performed at room temperature (18–22°C). For blue mussels, log10 PFU reductions of HAV averaged 2.1 and 3.6 for treatments of 350 and 400 MPa, while for Mediterranean mussels reductions of 1.7 and 2.9 log10 PFU MPa were observed for equivalent treatments. These results demonstrate that high pressure processing is capable of inactivating HAV within mussels.  相似文献   
26.
27.
This paper presents an empirical research in a protected area of northern Nicaragua, aimed at: (a) classifying predominant narratives surrounding present and future pathways of the local rural system, drivers of change, features of livelihoods’ vulnerability; (b) understanding current functioning of local metabolic patterns of rural systems by developing a typology of farms and (c) comparing types’ vulnerability to current drivers of change. To achieve these objectives, we integrated qualitative and quantitative analytical approaches. The different visions of rural spaces, which emerge from the analysis of the narratives, and the five types of farms, characterized by specific land-time budget and energy and monetary flows, suggest two emerging dynamics of local restructuration in protected areas: (1) a dominant land re-concentration process which is generating increasing inequality in access to resources and a progressive marginalization of the self-sufficient economy of landless and subsistence households; (2) an emergence of a paradigm of ‘environmentalization’ of rural spaces together with a valorization of small and medium-scale diversified economies. Moreover, the vulnerability assessment focuses on multidimensional features of types’ sensitivity to crisis, i.e. risk unacceptability, production instability, economic inefficiency, food and exosomatic energy dependency, as well as capacity to buffer and adapt to change, i.e. access to assets, including labour for men and women, social safety nets and degrees of economic diversification. The discussion highlights the occurrence of trade-off between the solutions adopted by farms within different development paths, suggesting the relevance of the proposed framework of analysis at the interface between science and policy.  相似文献   
28.
The pesticides originally designed to kill target organisms are dangerous for many other wild species. Since they are applied directly to the environment, they can easily reach the water basins and the topsoil. A dataset of 125 aromatic pesticides with well-expressed aquatic toxicity towards trout was subjected to quantitative structure activity relationships (QSAR) analysis aimed to establish the relationship between their molecular structure and biological activity. A literature data for LC50 concentration killing 50% of fish was used. In addition to the standard 2D-QSAR analysis, a comparative molecular field analysis (CoMFA) analysis considering the electrostatic and steric properties of the molecules was also performed. The CoMFA analysis helped the recognition of the steric interactions as playing an important role for aquatic toxicity. In addition, the transport properties and the stability of the compounds studied were also identified as important for their biological activity.  相似文献   
29.
Control of rainfall-runoff particulate matter (PM) and PM-bound chemical loads is challenging; in part due to the wide gradation of PM complex geometries of many unit operations and variable flow rates. Such challenges and the expense associated with resolving such challenges have led to the relatively common examination of a spectrum of unit operations and processes. This study applies the principles of computational fluid dynamics (CFD) to predict the particle and pollutant clarification behavior of these systems subject to dilute multiphase flows, typical of rainfall-runoff, within computationally reasonable limits, to a scientifically acceptable degree of accuracy. The Navier-Stokes (NS) system of nonlinear partial differential equations for multiphase hydrodynamics and separation of entrained particles are solved numerically over the unit operation control volume with the boundary and initial conditions defined and then solved numerically until the desired convergence criteria are met. Flow rates examined are scaled based on sizing of common unit operations such as hydrodynamic separators (HS), wet basins, or filters, and are examined from 1 to 100 percent of the system maximum hydraulic operating flow rate. A standard turbulence model is used to resolve flow, and a discrete phase model (DPM) is utilized to examine the particle clarification response. CFD results closely follow physical model results across the entire range of flow rates. Post-processing the CFD predictions provides an in-depth insight into the mechanistic behavior of unit operations by means of three dimensional (3-D) hydraulic profiles and particle trajectories. Results demonstrate the role of scour in the rapid degradation of unit operations that are not maintained. Comparisons are provided between measured and CFD modeled results and a mass balance error is identified. CFD is arguably the most powerful tool available for our profession since continuous simulation modeling.  相似文献   
30.
European society, with its steadily increasing welfare levels, is not only concerned with food (safety, prices), but also with other aspects such as biodiversity loss, landscape degradation, and pollution of water, soil, and atmosphere. To a great extent these concerns can be translated into a larger concept named sustainable development, which can be defined as a normative concept by). Sustainability in the food chain means creating a new sustainable agro-food system while taking the institutional element into account. While different concepts of sustainability abound, in recent years, spontaneous groups of consumers called solidarity purchase groups (SPG) have been developing. In short, they are characterized by an economy that is not necessarily local, but ethical and equitable, where social and economic territorial relations tend to develop districts and networks. One of the main characteristics of a SPG is the direct relationships between small farms and their customers; a relationship that is characterized by consumer participation and farmer specialization. This study aims to address issues related to organizational frameworks, at farm and chain level, and to assess those elements that lead to consumer choice and satisfaction.  相似文献   
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