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1.
Abstract

Recently, a literature has emerged using empirical techniques to study the evolution of international cities over many centuries; however, few studies examine long-run change within cities. Conventional models and concepts are not always appropriate and data issues make long-run neighbourhood analysis particularly problematic. This paper addresses some of these points. First, it discusses why the analysis of long-run urban change is important for modern urban policy and considers the most important concepts. Second, it constructs a novel data set at the micro level, which allows consistent comparisons of London neighbourhoods in 1881 and 2001. Third, the paper models some of the key factors that affected long-run change, including the role of housing. There is evidence that the relative social positions of local urban areas persist over time but, nevertheless, at fine spatial scales, local areas still exhibit change, arising from aggregate population dynamics, from advances in technology, and also from the effects of shocks, such as wars. In general, where small areas are considered, long-run changes are likely to be greater, because individuals are more mobile over short than long distances. Finally, the paper considers the implications for policy.  相似文献   
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Rats given medial frontal lesions on Postnatal Day 1 or Day 10 were trained on the Morris water task on Days 19–21 or Days 56–58. The operated groups were equally impaired at the water task on Days 19–21, but the Day 10 rats had recovered by 56 days. Dendritic arborization and spine density were analyzed in parietal layer II–III pyramidal cells. At Day 60, but not at Day 22, the Day 10 animals had more dendritic spines per unit dendritic length than did the controls or Day 1 rats. Thus, there was functional recovery rather than sparing after frontal lesions at 10 days, and the recovery was correlated with an increase in dendritic spines. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
3.
The present study describes the development of an enzyme-linked immunosorbent assay capable of quantifying serum antibody of all four canine IgG subclasses. A panel of subclass-restricted and subclass-specific monoclonal antibodies was used to measure IgG subclasses in the serum of healthy dogs, as well as in dogs with a range of clinical diseases. The subclasses have been redefined as IgG1, IgG2, IgG3 and IgG4 based on a comparison with the relative concentration and electrophoretic mobilities of human IgG subclasses. In serum samples from healthy dogs, the concentration of IgG1 (mean, 8.17 +/- 0.95 mg ml-1) and IgG2 (mean, 8.15 +/- 3.16 mg ml-1) were very similar and considerably higher than the levels of IgG3 (mean, 0.36 +/- 0.43 mg ml-1) and IgG4 (mean, 0.95 +/- 0.45 mg ml-1). There was no apparent difference in the level of subclasses between the different breeds comprising this normal population. Sera from dogs with a range of immune-mediated or inflammatory diseases all had markedly elevated levels of IgG2 (more than 13 mg ml-1), but IgG1 decreased (less than 4 mg ml-1) to levels below the normal range.  相似文献   
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This paper discusses the need for interface management within construction, with particular reference to building facade interfaces. It categorizes the three different types of interface management—physical, contractual, and organizational. The implication of interface management in construction contracting is discussed; it is explained how the U.K. procurement trends have changed, affecting the interface management within projects. U.K. cladding procurement is very fragmented, and the paper maps the development of a typical cladding system showing the complexities of interface management. Finally, the paper discusses CladdISS, a U.K. government funded research project to develop a standardized strategy for the design and management of window and cladding interfaces. It explains the principles of CladdISS with reference to process maps, action plans, management strategy, bibliography, advice on standards, materials, maintenance, joints, movement, and tolerances. This will enable strategies to be developed to avoid the endemic interface problems occurring on-site. It will also guide the management of the interfaces throughout the project.  相似文献   
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Evaluating to what extent a component or building system should be produced off‐site is inadequate within the industry. The potential benefits of off‐site production (OSP) are commonly cited when justifying an OSP approach, yet holistic and methodical assessments of the applicability and overall benefit of these solutions, to a particular project, have been found to be deficient. Common methods of evaluation simply take material, labour and transportation costs into account when comparing various options, often disregarding other cost‐related items such as site facilities, crane use and rectification of works. These cost factors are usually buried within the nebulous preliminaries figure, with little reference to the building approach taken. Further, softer issues such as health and safety, effects on management and process benefits are either implicit or disregarded within these comparison exercises. Yet it is demonstrated that these issues are some of the most significant benefits of OSP. A series of case studies demonstrated that evaluation focus is almost solely on direct material and labour costs of components, without explicit regard for the wider cost or soft issue implications of OSP on a project. The paper argues that until evaluation is more holistic and value‐based rather than cost‐based, OSP uptake in construction will be slow.  相似文献   
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Standardization and pre-assembly (S&P) are not new, but their application and their drivers, pragmatism and perception, need to be considered in the light of current technology and management practice. There are lessons to be learned from a historical review, but there are also numerous myths that must be dispelled: houses are not cars; maximum standardization is not always the answer; and, S&P do not have to cost more. Steven Groák worked with the author on the research project ‘Adding value to construction projects through standardisation and pre-assembly’ funded by CIRIA (Construction Industry Research and Information Association). The CIRIA project, which forms the basis of this paper, aimed to produce a review of the subject and guidance for clients and project teams through a comprehensive literature review, expert work5 shops and case study research. The paper defines S&P, discusses past, present and future applications (providing case study evidence) and presents the key benefits and implications of the optimized use of standardization and pre-assembly.  相似文献   
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