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There is no consensus on a comprehensive classification for green infrastructure (GI). This is a consequence of the diversity of disciplines, application contexts, methods, terminologies, purposes and valuation criteria for which a GI typology is required. The aim of this systematic literature review is to evaluate the existing evidence on how GI is being categorised and characterised worldwide. We reviewed a total of 85 studies from 15 countries that were analysed for contextual trends, methods, parameters and typologies. Results show that relevant literature lacks a common terminology and that a universal typology for all scenarios is impractical. Analysis reveals that GI can be organised into four main GI categories: (a) tree canopy, (b) green open spaces, (c) green roofs and (d) vertical greenery systems (facades/walls). Green open spaces and tree canopy attracted the attention of researchers due to their complexity, variability and important roles in GI planning. Evidence suggests that a ternary approach in terms of the functional (purpose, use, services), structural (morphology) and configurational (spatial arrangements) attributes of GI should be applied for a more comprehensive classification. Although this approximation is inherently generic, since it can be used across different research disciplines, it is also sufficiently specific to be implemented for individual scopes, scenarios and settings. Further research is needed to develop a typology capable of responding to particular research aims and performance analyses based upon the findings discussed in this paper.  相似文献   
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Incomplete preferences over lotteries on a finite set of alternatives satisfying, besides independence and continuity, a property called bad outcome aversion are considered. These preferences are characterized in terms of their specific multi-expected utility representations (cf. Dubra et al., J Econ Theory, 115:118–133, 2004), and can be seen as generalized stochastic dominance preferences.  相似文献   
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Prior agency-theory research has presented conflicting findings regarding the importance of board monitoring in motivating R&D. We reinvestigate this literature by examining the value monitoring exerts in abating both the agency costs of underinvestment and overinvestment in R&D. We argue that monitoring that relies on board independence has both benefits and costs associated with promoting R&D. While we assert that intense monitoring by the board heightens underinvestment in the US context, it can also provide discipline over a firms free cash flows. We test our theory using a longitudinal panel data set consisting of a cross-section of S&P 1500 US-firms between 1997 and 2007. On average our study finds inside directors increase overinvestment in R&D, but facilitate better resource allocation when a firm has rich growth opportunities. Also, while too much emphasis on outside directors heightens underinvestment in R&D, a more independent board encourages better resource allocation when firms have high free cash flows that need to be paid back to owners. Thus, our results suggest a more inclusive perspective of agency-theory can help managers make better R&D investment decisions.  相似文献   
45.
Trees provide important ecological services in cities, yet the vulnerability of the urban forest to massive tree losses from pest outbreaks could threaten those services, with unknown environmental consequences. The outbreak of emerald ash borer is an imminent threat to the ash population in North America. In the Minneapolis?CSaint Paul, Minnesota, metropolitan area, ash trees are present in 50?% of residential landscapes in Ramsey and Anoka Counties. We used a large survey of household activities, a tree inventory, a Household Flux Calculator accounting tool, and a set of annual evapotranspiration measurements, to quantify the current carbon, nitrogen, and phosphorus storage in ash trees, the cycling of these elements, and the total evapotranspiration from ash trees in residential areas in the metropolitan region. Ash represented 6?% of the trees in residential areas and the removal of the entire ash population would correspondingly reduce net primary production and carbon sequestration by only a few percent and would have negligible effects on losses of nitrogen and phosphorus from residential landscapes. Similarly, the effects of ash loss on the hydrologic cycle would be minimal and would depend largely on management choices for the ground currently underneath ash tree canopies. Overall, the percentage change in biogeochemical and hydrological fluxes corresponded closely with the percent of the total urban tree population that was represented by ash, suggesting that areas with higher densities of ash would experience correspondingly larger effects. A hypothetical tree replacement scenario with similar broadleaf species was determined to be likely to re-establish the original biogeochemical and hydrological conditions once the replacement trees reach maturity.  相似文献   
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The great majority of families involved in the child welfare system are economically vulnerable, have limited incomes, and face a high risk of financial exploitation. Limited opportunities to participate meaningfully in the financial sector, along with poor decision making, can lead to overwhelming debt, eviction, and poverty that compromise child safety and wellbeing and can cripple efforts to reunify families. This article discusses the need to elevate financial capability–which scholars and practitioners define as knowledge of financial matters and means to exercise that knowledge. It addresses nascent research examining financial capability and asset building, the expanding role of the topic in human services, and efforts in Missouri to integrate an understanding of financial capability in work with families involved in the child welfare system. Such integration holds the promise of fulfilling the safety, permanence, and wellbeing goals of the child welfare system; involving a wider set of community partners; and achieving the federally mandated ‘normalcy’ in foster care.  相似文献   
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Influence of seasonality and vegetation type on suburban microclimates   总被引:2,自引:0,他引:2  
Urbanization is responsible for some of the fastest rates of land-use change around the world, with important consequences for local, regional, and global climate. Vegetation, which represents a significant proportion of many urban and suburban landscapes, can modify climate by altering local exchanges of heat, water vapor, and CO2. To determine how distinct urban forest communities vary in their microclimate effects over time, we measured stand-level leaf area index, soil temperature, infrared surface temperature, and soil water content over a complete growing season at 29 sites representing the five most common vegetation types in a suburban neighborhood of Minneapolis–Saint Paul, Minnesota. We found that seasonal patterns of soil and surface temperatures were controlled more by differences in stand-level leaf area index and tree cover than by plant functional type. Across the growing season, sites with high leaf area index had soil temperatures that were 7°C lower and surface temperatures that were 6°C lower than sites with low leaf area index. Site differences in mid-season soil temperature and turfgrass ground cover were best explained by leaf area index, whereas differences in mid-season surface temperature were best explained by percent tree cover. The significant cooling effects of urban tree canopies on soil temperature imply that seasonal changes in leaf area index may also modulate CO2 efflux from urban soils, a highly temperature-dependent process, and that this should be considered in calculations of total CO2 efflux for urban carbon budgets. Field-based estimates of percent tree cover were found to better predict mid-season leaf area index than satellite-derived estimates and consequently offer an approach to scale up urban biophysical properties.  相似文献   
50.
Self-report drug use data were collected from 282 female alternative school students surveyed through the Safer Choices 2 study in Houston, Texas. Data collection took place between October 2000 and March 2001 via audio-enabled laptop computers equipped with headphones. Logistic regression analyses indicated that sexual abuse history was significantly associated with lifetime use (OR = 1.9, p < or = 0.05). While the relationships tested in this study are exploratory, they provide evidence for an important connection between sexual abuse and substance use among female alternative school students.  相似文献   
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