Urban cultivation in Accra: an examination of the nature, practices, problems, potentials and urban planning implications

The literature on urban farming in Sub-Saharan African cities reveals that most studies have been conducted in Eastern, Southern and Central African cities. A few have focused on West Africa, including Sierra Leone, Guinea Bissau, and Cameroon. In Ghana there is a paucity of information on urban farming. The purpose of this paper is to examine the status of urban cultivation in Accra, Ghana's capital, reviewing existing research, and to present new empirical findings on urban cultivation emphasizing on its history, nature, practices, problems, potentials and urban planning implications.     

三代领导人城市布局思想与政策绩效分析

城市作为社会、经济、文化活动空间集聚面形成了社会景观, 其产生和发展是各种社会经济要素的空间流动和地理集中的结果。城市不但是人口集聚地, 而且成为各种产业的集聚中心。本文所及的城市布局、规范的范围始于新中国建立。20世纪50年来, 三代领导人在城市布局理论、方法和实践上的特色有许多值得总结的东西     

美国城市化经验对江苏城市化战略的启示

美国城市化经历了发生、发展、成熟的完整过程 ,具体表现为集中和分散两个显著特征 ;我国江苏城市化进程中的独特现象与美国城市化形成鲜明对比 ,通过比较、借鉴 ,江苏必须走出一条符合省情的城市化道路。     

Urban Housing as an Issue of Redistribution through Planning? The Case of Dhaka City

The rapid growth of population, the mushrooming of poor settlements and unplanned urbanization have crucial implications for the efficiency and equity of urban services. The resultant infringements of critical human rights throw into focus the importance of housing as a social policy issue. Urban services are strained in Dhaka city. Urban management has been disrupted as a result of spatial encroachment and environmental degradation. In addition to land scarcity, land speculation and endemic corruption, the high price of land is also a product of the system of land registration. The dearth of valuable urban land, together with delays in urban planning and its implementation, have made the acquisition of land for housing prohibitively expensive for middle and low‐income households. Consequently, the quality of the housing environment is deteriorating. The problem of housing finance is intrinsically linked to its affordability, being currently the prerogative only of the affluent. This article delineates the inherent lack of integrated urban planning, the lacunae within institutions responsible for urban management – and, contextually, the nature of housing as a social policy issue, where reinforced, coordinated planning and administration could ensure distributive benefits even to the poor.     

西部大开发中新疆城镇发展的对策研究

实施西部大开发是国家提出的一项重大战略决策。城市是社会经济发展的一个重要组成部分 ,如何对待城市的发展问题 ,关系到西部地区开发成败的关键。本文首先分析了新疆城镇发展的主导因素 ,指出以政府为主导的发展模式是新疆城镇发展缺乏内在动力的原因。然后从城镇空间分布及城镇体系等方面分析了目前新疆城镇发展的主要特征及存在的问题。最后在以上分析的基础上 ,提出了今后城镇发展的对策与建议     

Tree health mapping with multispectral remote sensing data at UC Davis, California

Tree health is a critical parameter for evaluating urban ecosystem health and sustainability. Traditionally, this parameter has been derived from field surveys. We used multispectral remote sensing data and GIS techniques to determine tree health at the University of California, Davis. The study area (363 ha) contained 8,962 trees of 215 species. Tree health conditions were mapped for each physiognomic type at two scales: pixel and whole tree. At the pixel scale, each tree pixel within the tree crown was classified as either healthy or unhealthy based on vegetation index values. At the whole tree scale, raster based statistical analysis was used to calculate tree health index which is the ratio of healthy pixels to entire tree pixels within the tree crown. The tree was classified as healthy if the index was greater than 70%. Accuracy was checked against a random sample of 1,186 trees. At the whole tree level, 86% of campus trees were classified as healthy with 88% mapping accuracy. At the pixel level, 86% of the campus tree cover was classified as healthy. This tree health evaluation approach allows managers to identify the location of unhealthy trees for further diagnosis and treatment. It can be used to track the spread of disease and monitor seasonal or annual changes in tree health. Also, it provides tree health information that is fundamental to modeling and analysis of the environmental, social, and economic services produced by urban forests.     

价值哲学的认识论转换--乌尔班价值理论研究

从乌尔班的《评价 :其性质及其法则》开始 ,价值哲学的研究主题发生了一种根本性的转变 :由新世界图景的价值哲学建构 ,转向对价值哲学理论的研究。换言之 ,在此之后价值哲学研究结束了形而上学阶段 ,而进入了认识论阶段。在认识论阶段 ,评价问题成为最为重要的研究课题。在对评价问题的研究中 ,乌尔班开创了一种以心理学为基础的经验论研究理路。我国近 2 0年的价值哲学的研究范式与乌尔班开始的美国价值哲学的研究范式十分相似。     

实施乡村振兴战略要防止的几种倾向

乡村振兴战略是要服务于中国建设社会主义现代化强国的目标,是要为建设中国社会主义现代化强国提供稳定的农村基础。 在不同阶段,乡村振兴战略的任务是不同的,尤其是 2035 年之前和2035—2050 年的乡村振兴战略应该是差异极大的。 2035—2050 年的目标是全面乡村振兴,2035 年之前则是为乡村全面振兴打基础的阶段。 没有中国现代化的基本实现,就没有全面振兴乡村的物质基础。乡村振兴战略必须分阶段实施。 当前学界、政策部门、地方实践部门在解读乡村振兴战略时普遍误解了乡村振兴战略的实施阶段性特征,有急于求成的倾向。     

Governing Deviance in Public Space through Mayoral Orders: Fields Mismatch and Metropolitan Turbulence

This article addresses the issue of policy change and its consequences on the organizational field and institutional context, looking at the role of an instrument transfer process. We adopt a political sociology approach to policy instruments to account for the impact that the introduction of a securitarian instrument, the mayoral order, had on the implementation process of a social policy. Through a genealogy of the instrument we identify a constitutive, normative and cognitive dimension. Our aim is to explain the interaction between these institutional dimensions, the re‐definition of the organizational field of the policy, and the dynamics of metropolitan politics. Following a synthesis of the policy process and the institutional arrangements where the policy is implemented, we show how the instrument transfer triggered a division within the organizational field, and the rise of institutional tensions amongst local authorities. In the conclusion, we identify the institutional dimensions of the instruments and the policy implementation scale as elements that are to interact with public‐private relationships and institutional arrangements, and that have an impact on implementation process and policy outcome.     

Measuring conflict management,emotional self-efficacy,and problem solving confidence in an evaluation of outdoor programs for inner-city youth in Baltimore,Maryland

Substantial evidence supports the value of outdoor education programs for promoting healthy adolescent development, yet measurement of program outcomes often lacks rigor. Accurately assessing the impacts of programs that seek to promote positive youth development is critical for determining whether youth are benefitting as intended, identifying best practices and areas for improvement, and informing decisions about which programs to invest in.We generated brief, customized instruments for measuring three outcomes among youth participants in Baltimore City Outward Bound programs: conflict management, emotional self-efficacy, and problem solving confidence. Measures were validated through exploratory and confirmatory factor analyses of pilot-testing data from two groups of program participants. We describe our process of identifying outcomes for measurement, developing and adapting measurement instruments, and validating these instruments.The finalized measures support evaluations of outdoor education programs serving urban adolescent youth. Such evaluations enhance accountability by determining if youth are benefiting from programs as intended, and strengthen the case for investment in programs with demonstrated success.