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排序方式: 共有327条查询结果,搜索用时 31 毫秒
271.
Katherina A. Pietsch Kiona Ogle Johannes H. C. Cornelissen William K. Cornwell Gerhard Bönisch Joseph M. Craine Benjamin G. Jackson Jens Kattge Duane A. Peltzer Josep Penuelas Peter B. Reich David A. Wardle James T. Weedon Ian J. Wright Amy E. Zanne Christian Wirth 《Global Ecology and Biogeography》2014,23(9):1046-1057
272.
This article argues that policies aimed at sustainability need to address the spatial dimensions of environmental problems and their solutions. In particular, spatial configurations of economic activities deserve attention, which means addressing land use, infrastructure, trade, and transport. Unfortunately, good theory and indicators to support the analysis and design of spatial‐environmental policies are not fully developed. One approach that has become very popular in the last decade is the ecological footprint (EF). It is both an environmental accounting tool and aggregate indicator, which is used by scientists, environmental organizations, and popular media. Despite criticisms of the EF method in the past, its popularity has only increased. In fact, an increasing number of publications with an application of the EF appear in scientific journals. We review the EF approach from indicator‐methodology and welfare angles and assess its policy relevance. Our conclusion is that it does not offer any meaningful information for public policy. 相似文献
273.
274.
Integrated continuous bioprocessing: Economic,operational, and environmental feasibility for clinical and commercial antibody manufacture 下载免费PDF全文
This paper presents a systems approach to evaluating the potential of integrated continuous bioprocessing for monoclonal antibody (mAb) manufacture across a product's lifecycle from preclinical to commercial manufacture. The economic, operational, and environmental feasibility of alternative continuous manufacturing strategies were evaluated holistically using a prototype UCL decisional tool that integrated process economics, discrete‐event simulation, environmental impact analysis, operational risk analysis, and multiattribute decision‐making. The case study focused on comparing whole bioprocesses that used either batch, continuous or a hybrid combination of batch and continuous technologies for cell culture, capture chromatography, and polishing chromatography steps. The cost of goods per gram (COG/g), E‐factor, and operational risk scores of each strategy were established across a matrix of scenarios with differing combinations of clinical development phase and company portfolio size. The tool outputs predict that the optimal strategy for early phase production and small/medium‐sized companies is the integrated continuous strategy (alternating tangential flow filtration (ATF) perfusion, continuous capture, continuous polishing). However, the top ranking strategy changes for commercial production and companies with large portfolios to the hybrid strategy with fed‐batch culture, continuous capture and batch polishing from a COG/g perspective. The multiattribute decision‐making analysis highlighted that if the operational feasibility was considered more important than the economic benefits, the hybrid strategy would be preferred for all company scales. Further considerations outside the scope of this work include the process development costs required to adopt continuous processing. © 2017 The Authors Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers Biotechnol. Prog., 33:854–866, 2017 相似文献
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以漓江水陆交错带为研究区,分两个条带分别量测了适生植物的5个叶性状指标:最大净光合速率(A_(max))、比叶重(LMA)、单位质量叶片全氮含量(N_(mass))、单位质量叶片全磷含量(P_(mass))、单位质量叶片全钾含量(K_(mass))。研究重度淹没带与微度淹没带不同功能型植物叶性状间的差异,分析并讨论重度淹没带叶性状间的关系与全球尺度是否存在差异,探究重度淹没带植物对水淹生境的生理响应机制。结果如下:(1)重度淹没带植物叶片的A_(mass)、N_(mass)、P_(mass)显著高于微度淹没带。(2)乔木、灌木叶片的LMA均显著高于草本植物,而A_(mass)、PPUE均显著低于草本植物。(3)重度淹没带草本叶性状指标的N_(mass)、P_(mass)、PNUE均显著高于微度微度淹没带,而乔木、灌木的叶性状在两个条带的差异则不显著。(4)重度淹没带植物叶性状关系与全球尺度基本一致,其植物叶片具有低LMA,高A_(mass)、Nmas s、P_(mass)。分析可知,重度淹没带植物在出露期提高叶片光合效率及相关营养水平可能是其适应水淹胁迫特殊生境的关键策略之一;不同功能型植物对同一环境的适应能力存在一定的差异,草本对于水淹环境的响应更为积极,适应能力更好;重度淹没带也存在叶经济谱,其植物在经济谱中属于"快速投资-收益"型物种。 相似文献
277.
中国大陆省际生态-经济效率的时空格局及其驱动因素 总被引:2,自引:0,他引:2
在参考和借鉴有关生态系统服务价值理论研究成果的基础上,提出生态-经济产出效率概念及其内涵、表征方法,结合有关统计数据计算了2001—2013年中国大陆31省区生态-经济产出效率并就其时空分布及重心移动方向、移动距离等进行分析,在此基础上应用探索性空间数据分析方法及偏最小二乘回归模型对其空间集聚特征和驱动因素进行实证分析。研究结果表明:考察时段内中国大陆省际生态-经济产出效率自西向东依次提高的三级梯度分布格局趋于形成;省区之间生态-经济产出效率具有全局空间依赖性和空间正相关特征,显著高-高集聚和显著低-高集聚表现相对稳定、高-低集聚区的生态效率溢出效应促使显著低-低集聚区逐步消失;人均国民生产总值、单位面积内的道路交通里程数、科研资金投入占GDP的比重等三因素显著驱动了中国大陆省际生态-经济产出效率溢出,但东、中、西部地区的制约因素不尽相同。 相似文献
278.
Nicole Olynk Widmar Emily Lord 《Journal of applied animal welfare science : JAAWS》2013,16(3):209-221
Streamlining purchasing in nonhuman animal shelters can provide multiple financial benefits. Streamlining shelter inputs and thus reducing shelter costs can include trading paid labor and management for fewer, more involved volunteers or purchasing large quantities of medical supplies from fewer vendors to take advantage of bulk-purchasing discounts. Beyond direct savings, time and energy spent on purchasing and inventory control can be reduced through careful management. Although cost-cutting measures may seem attractive, shelter managers are cautioned to consider the potential unintended consequences of short-term cost reduction measures that could limit revenues or increase costs in the future. This analysis illustrates an example of the impact of cost reductions in specific expense categories and the impact on shelter net revenue, as well as the share of expenses across categories. An in-depth discussion of labor and purchasing cost-reducing strategies in the real world of animal shelter management is provided. 相似文献
279.
Integrating Urbanization into Landscape-level Ecological Assessments 总被引:31,自引:0,他引:31
Economists and ecologists are often asked to collaborate on landscape-level analyses designed to jointly assess economic and
ecological conditions resulting from environmental policy scenarios. This trend toward multidisciplinary projects, coupled
with the growing use of geographic information systems, has led to the development of spatially explicit models that can be
used to examine and project land-use change. Although spatial land-use models are still evolving, most published efforts have
modeled the conversion of nonurban land to urban uses as a function of explanatory variables based on population density and
the spatial proximity of land to roads, markets, and population centers. In this paper, we use a gravity model to describe
the urbanization potential of forest and agricultural land as a combination of population and proximity. We develop an empirical
model that describes the probability that forests and agricultural land in western Oregon and western Washington were transformed
to residential, commercial, or industrial uses over a 30-year period as a function of urbanization potential, other socioeconomic
factors, and geographic and physical land characteristics. Land-use data were provided by the USDA Forest Service's Forest
Inventory and Analysis program. We use this empirical model to generate geographic information system maps depicting the probability
of future land-use change that can be integrated with landscape-level ecological models developed for western Oregon's Coast
Range.
Received 14 April 2000; accepted 17 August 2000. 相似文献
280.