Short‐chain fatty acids affect cell‐association and invasion of HEp‐2 cells by Salmonella typhimurium

Abstract

This study demonstrates that the growth of S. typhimurium in Luria Bertani broth supplemented with acetate, propionate, butyrate, or a mixture of the three SCFA, affected cell‐association and the ability to invade cultured HEp‐2 cells. Cell‐association and invasion was determined after growth for 4 h of growth in the presence of the SCFA at pH 6 and 7. The results suggest that the growth rate of the culture may have affected cell‐association and invasion since accompanying the significant decrease in growth rate in the presence of SCFA at pH 6 was a decrease in cell‐association and invasion. However, the results also suggest that the individual SCFA may play a role in modulating cell‐association and the invasion phenotype and the regulation of cell‐association and invasion by the SCFA was dependent on the concentration and the pH of the medium. Although the growth rates were similar for S. typhimurium in the SCFA mixture, butyrate (100 mM) and propionate (50 mM) at pH 6, differences in cell‐association and invasion were observed among these cultures. Also, at pH 7, differences were observed among the SCFA treatments even though the growth rates were similar.     

Cities vs. agriculture: A review of intersectoral water re-allocation

Water demand management, or making better use of the water we have — as opposed to augmenting supply — is increasingly proposed as a way of mitigating water-scarcity problems. Moving water away from agriculture to uses with higher economic value is one of the main measures widely seen as desirable. Sectoral "allocation stress" is seen as resulting from the disproportionate share, and inefficient use of water in the agricultural sector. This apparent misallocation is often attributed to the failure of government to allocate water rationally.
This paper revisits this commonly-accepted wisdom and examines the nature of urban water scarcity, showing the importance of economic and political factors, shaped by incentives to decision-makers, and sometimes compounded by climatic conditions. It shows that cities' growth is not generally constrained by competition with agriculture. In general, rather than using a narrow financial criterion, cities select options that go along the "path of least resistance," whereby economic, social and political costs are considered in conjunction. The question of allocation stress is thus reframed into an inquiry of how transfers effectively occur and can be made more effective.     

Water Mass Balances for the Solaire and the 2020 Tower: Implications for Closing the Water Loop in High‐Rise Buildings1

Abstract: Building water mass balances were performed for one 150‐story conventional building scenario for comparison with three scenarios of the 2020 Tower, a hypothetical 150‐story high‐rise building with on‐site wastewater treatment and reuse. To ensure that the assumptions for the hypothetical building are appropriate, a one‐year water balance was also conducted of the existing 27‐story Solaire building that partly closes the water/wastewater loop, meters major water flows and implements low‐flow/water conserving fixtures and appliances. For comparison, a conventional 27‐story building scenario with the same low‐flow/water conserving fixtures as the Solaire but no water reuse was also assessed. The mean daily indoor water use in the Solaire was 246 l/(d cap) which exceeds mean daily water use found in the literature. The water mass balances showed that an urban high‐rise building needs another source of water even when potable reuse water is produced because of losses during water end use and treatment (i.e., evaporation, water in treatment residues). Therefore, water conservation (i.e., modification of human behavior) and water efficiency improvements (i.e., equipment, appliances and fixtures) are important major factors in reducing the municipal water needed in all scenarios.     

Optimal planning for the sustainable utilization of municipal solid waste

The increasing generation of municipal solid waste (MSW) is a major problem particularly for large urban areas with insufficient landfill capacities and inefficient waste management systems. Several options associated to the supply chain for implementing a MSW management system are available, however to determine the optimal solution several technical, economic, environmental and social aspects must be considered. Therefore, this paper proposes a mathematical programming model for the optimal planning of the supply chain associated to the MSW management system to maximize the economic benefit while accounting for technical and environmental issues. The optimization model simultaneously selects the processing technologies and their location, the distribution of wastes from cities as well as the distribution of products to markets. The problem was formulated as a multi-objective mixed-integer linear programing problem to maximize the profit of the supply chain and the amount of recycled wastes, where the results are showed through Pareto curves that tradeoff economic and environmental aspects. The proposed approach is applied to a case study for the west-central part of Mexico to consider the integration of MSW from several cities to yield useful products. The results show that an integrated utilization of MSW can provide economic, environmental and social benefits.     

An animal movement model incorporating home range and habitat selection

Wildlife biologists are often interested in how an animal uses space and the habitat resources within that space. We propose a single model that estimates an animal’s home range and habitat selection parameters within that range while accounting for the inherent autocorrelation in frequently sampled telemetry data. The model is applied to brown bear telemetry data in southeast Alaska. This article is based on a portion of this author’s Ph.D. dissertation completed in 2003 at the University of Iowa.     

湖南省汨罗市再生资源产业集群升级研究

随着我国经济快速增长。生态建设和环境保护的形势日益严峻，再生资源产业作为根本解决资源枯竭、能源短缺、环境污染等问题的有效途径，对我国资源节约型、环境友好型社会建设具有重要战略意义。汨罗市再生资源产业历史悠久，已经初步建立起再生资源回收系统、再生资源加工利用系统和废弃物资无害化处置系统．呈现出产业集群发展雏形。针对目前汨罗市再生资源产业集群存在的产业链条短、产品加工度不高、附加值低等问题。必须通过再生资源产业价值链技术创新、链核延伸和链条辐射。实现汨罗市再生资源产业集群的动态升级。加速汨罗市再生资源产业集群区域品牌的形成。为其他地区和城市再生资源产业发展提供重要经验借鉴和发展启示。     

A Simple Discussion on the Supply and Demand of Water Resources in the Western Region of China

Abstract

We are accustomed to solve the problem of the water scarcity in the western region by the thought of increasing the effective supply of water to meet the needs of Go-west Campaign. After introducing the dynamic equilibrium principle on supply and demand in economy, we find that we should solve the problem of the water scarcity in the western region through reducing total demand to achieve the dynamic equilibrium of supply and demand. Finally water resources in the western region can be enlarged by an accumulated way.     

Issues in reverse supply chain,part III: classification and simple analysis

Due to growing environmental concern and increasing awareness among customers, reverse supply chain (RSC) has received much attention among researchers and practitioners. Therefore it is necessary to provide a comprehensive list of references for other researchers (or readers), who are interested in RSC research to help stimulate further interest. In this paper, we present classification schemes and a simple analysis for the reverse supply chain. This literature review was mainly based on journal articles but also included web based documents, conference materials, working papers, etc. A total of 543 articles were reviewed, of which 506 were published between 1967 and 2008 from 100 reputed international journals. Based on the literature review carried out and the nature of research observed in RSC, we have introduced two classification schemes to systematically organise the published articles. The first classification scheme is based on the content related issues on RSC and the second one is based on the solution methodology followed by the researchers. These classification schemes indicate that there is considerable research potential for RSC. The results also show that there is strong growth in RSC research.     

Development of composite sustainable supply chain performance index for the automobile industry

The automobile companies are becoming increasingly aware about the importance of sustainability and its challenges. In order to compete in the global market, the industry has responded to these challenges by identifying the sustainability indicators. It is quite difficult to evaluate the performance of the company on the basis of large number of sustainability indicators. Integration of key sustainability indicators is quite essential for effective decision-making. This article presents an integrated method by accommodating both qualitative and quantitative approaches for the development of composite sustainable supply chain (SC) performance index. We applied an integration of fuzzy analytical hierarchy process, Liberatore score and signal-to-noise ratio approaches to compute the index. The proposed methodology demonstrates how quantitative statistical inputs can be combined with expert opinion to construct an overall index of sustainability. The index can be extensively used by SC managers to measure their organization's contribution towards SC sustainability. An application of an integrated methodology is demonstrated for an automobile SC.     

基于图论的海洋平台连锁风险评价

为控制海洋平台连锁风险,基于图论(GT),提出一种新型定性风险评价方法,将分析对象的复杂风险分析转化为图形分析运算。该方法综合考虑研究对象的风险,重点考虑事故可能的发展模式,建立并转换可能发生的事故的连锁图,用图论算法进行图形运算,得到造成结果事故发生的关键路径、最短路径和点割集,设置并优化安全屏障,防止初始事故发生。最后,结合墨西哥湾事故,建立事故连锁图,通过图形变换与运算得到2条最短路径、3条关键路径和2个点割集,并提出风险控制措施。