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This paper estimates the value of green belt land by assessing its output: agricultural; amenity; recreational; and savings in costs, by restricting the size of urban areas. These outputs are valued in social terms by the application of welfare economics. Some types of agriculture are shown to impose net social cost rather than benefits. Hedonic price models and contingent valuation are used to assess amenity benefits which are revealed as the most important justification for green belts. These benefits are set against the opportunity cost of the land in terms of foregone housing and industrial development. Uncertainty and irreversibility of a land-use change, from green belt, suggests that the benefits of housing or industry should substantially exceed the value of green belt land before a land-use change is sanctioned.  相似文献   
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Breeding bird communities in Berlin were investigated at five study sites, which represent an structural urban-rural gradient, from densely built-up areas with sealed ground to green areas such as large parks. In this paper, we tested the Hasse Diagram Technique (HDT), an approach belonging to partial order theory, for its appropriateness to extract information about changes in species composition from our data set. As expected, the overall number of bird species was positively correlated with the urban-rural gradient, increasing from 12 found in the city center to 28 in an urban park. By HDT analysis, four different sub-groups of birds could be identified, contributing differentially to the increase in species number: (1) ubiquists, i.e., species found at each study site, (2) a sub-group, the species’ number of which was positively correlated with the urban-rural gradient, increasing with increasingly green areas, (3) a sub-group, the species’ number of which was negatively correlated with the urban-rural gradient, decreasing with a declining density of buildings, and (4) species, the distribution of which did not show any correlation with the urban-rural gradient. The results show that HDT is a suitable tool for formalized analysis of the pattern of species’ communities along an environmental gradient.  相似文献   
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1. Brief planned and crisis admissions to an inpatient psychiatric unit are presented as a component supportive of outpatient care and case management for chronically mentally ill patients. 2. Typical patients admitted to this inpatient short-term program are those experiencing a life stress or temporary crisis; chronically mentally ill patients who cycle and experience exacerbations of their illness; and those who need to make the transition from an acute inpatient unit to community living. 3. The Brief Admission Program treats the individual's response to and the consequences of a lifelong illness and enables the patient to return to his previous level of functioning and continue necessary outpatient treatment.  相似文献   
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This study investigated significant relationships between youth assets and youth alcohol, tobacco, and drug use that differ according to family structure (one- or two-parent households). Data were collected from a randomly sampled inner-city population (n=1,256 teenagers and 1,256 parents of the teenagers) using in-home, in-person interviews. Logistic regression analyses, stratifying by one- and two-parent household status, were conducted with nine youth assets as the independent variables and youth alcohol, tobacco, and drug use as the dependent variables. Results indicated that the associations between assets and risk behaviors varied depending upon whether the youth lived in one- or two-parent households. Continued research is warranted to further investigate associations among family structure, youth assets, and youth risk behaviors.  相似文献   
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This paper suggests that the concept of the muse in relation to the creative process is more than a myth or cultural artifact. It is argued that the muse is a psychic recollection of our memories of the female who presided over our first experiences of consciousness as we traversed the borders of inner and outer reality—that is, the mother. The shift of consciousness required in creative activity triggers recall of this figure. Object relations theory, recent findings from infant research, and the intuitive observations of several authors are used to support this thesis. Clinical examples illustrate the application of this concept in treatment.  相似文献   
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SUMMARY Families of joint distributions for describing the lifetimes of a system of components that operate under an unknown environment, when the environment follows a Weibull distribution, are derived. The reliability function for this system is calculated and several properties of the aforementioned joint distributions are investigated.  相似文献   
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