The Interstitial Interface within the Renal Stem/Progenitor Cell Niche Exhibits an Unique Microheterogeneous Composition

Repair of parenchyma by stem/progenitor cells is seen as a possible alternative to cure acute and chronic renal failure in future. To learn about this therapeutic purpose, the formation of nephrons during organ growth is under focus of present research. This process is triggered by numerous morphogenetic interactions between epithelial and mesenchymal cells within the renal stem/progenitor cell niche. Recent data demonstrate that an astonishingly wide interstitial interface separates both types of stem/progenitor cells probably controlling coordinated cell-to-cell communication. Since conventional fixation by glutaraldehyde (GA) does not declare in transmission electron microscopy the spatial separation, improved contrasting procedures were applied. As a consequence, the embryonic cortex of neonatal rabbit kidneys was fixed in solutions containing glutaraldehyde in combination with cupromeronic blue, ruthenium red or tannic acid. To obtain a comparable view to the renal stem/progenitor cell niche, the specimens had to be orientated along the cortico-medullary axis of lining collecting ducts. Analysis of tissue samples fixed with GA, in combination with cupromeronic blue, demonstrates demasked extracellular matrix. Numerous braces of proteoglycans cover, as well, the basal lamina of epithelial stem/progenitor cells as projections of mesenchymal stem/progenitor cells crossing the interstitial interface. Fixation with GA containing ruthenium red or tannic acid illustrates strands of extracellular matrix that originate from the basal lamina of epithelial stem/progenitor cells and line through the interstitial interface. Thus, for the first time, improved contrasting techniques make it possible to analyze in detail a microheterogeneous composition of the interstitial interface within the renal stem/progenitor cell niche.     

Optimization of Rolling Force Distribution Based on Niche Genetic Algorithm in Continuous Hot Rolling Mills

Based on the niche genetic algorithm, the intelligent and optimizing model for the rolling force distribution in hot strip mills was put forward. The research showed that the model had many advantages such as fast searching speed, high calculating pre- cision and suiting for on-line calculation. A good strip shape could be achieved by using the model and it is appropriate and practica-ble for rolling producing.     

Assessing the validity of a niche strategy model in predicting the potential and success of niche markets and products

Companies can increase market share and profitability through the use of a niche market strategy. Parrish examined how companies use a niche market strategy and developed the Parrish Niche Strategy Model. This paper presents results of a study testing the model in terms of: (1) predicting the potential of a niche market and/or product and (2) predicting the success of a niche market and/or product. In order to test the model, deductive logic was used to develop questions that would gather quantitative data related to market potential strategies and success variables. In order to determine the importance of variables in relation to predicting the potential and success of a niche market and/or product, instrument questions were developed that utilized rank order scales. In addition, three-point Likert scales were used in order to determine the level of importance for each of the market potential and success variables. The sample consisted of fiber and yarn manufacturers, fabric manufacturers, apparel manufacturers and marketers, and retailers. Results indicate that the Parrish Niche Strategy Model was useful for gaging the potential and success of niche strategies, in terms of both product and market. This research was significant in that it tested the only existing model of niche strategies developed specifically for the textile industry. In addition, this study focused on bottomweights, which represents a significant domestic consumption market for the US textile supply chain.     

Emergence and the Forms of Metabolism

Earlier this year, Michael Weinstock published a seminal book, The Architecture of Emergence: The Evolution of Form in Nature and Civilisation, which challenges established cultural and architectural histories. The conventional worldview is expanded by placing human development alongside ecological development: the history of cultural evolution and the production of cities are set in the context of processes and forms of the natural world. As well as providing a far-reaching thesis, Weinstock's book gives lucid and accessible explanations of the complex systems of the physical world. In this abridged extract from Chapter 5, Weinstock explains the dynamics of individual and collective metabolisms from which intelligence and social and spatial orders emerge. Copyright © 2010 John Wiley & Sons, Ltd.     

基于泊松碟采样的小生境遗传算法剩余静校正

针对线性剩余静校正容易陷入局部解,导致复杂山地地震资料成像效果不佳的难题,本文提出一种基于泊松碟采样的小生境遗传算法剩余静校正方法。在常规遗传算法剩余静校正基础上,应用泊松碟采样对求解的静校正量实数编码,增加初始解空间的均匀度;采用多线程构建多种群小生境,种群内采用“精英+赌轮”选择、余下个体与精英两两交叉、小扰动变异策略进行遗传进化;种群间进行“联姻”操作,优选几个种群中适应度最大个体并与其他种群联姻,充分利用计算机多核并行运算功能以快速搜索到最优剩余静校正量。理论模型及实际资料应用结果均表明,该方法能增强同相轴的连续性,显著提高山前带低信噪比资料成像品质。     

基于遗传算法的过程辨识方法实现与应用

简单遗传算法存在着收敛速度慢和容易早熟的缺点,针对这种情况,通过合理选择编码方式,改进初始种群选择策略、复制、交叉和变异策略提出一种综合的改进遗传算法,并将其应用于系统模型辨识。用基于排序法的新的选择算子和多个交叉、变异概率,能有效维持种群的多样性,克服算法早熟现象。在改进的算法中,同时用到精英保留策略和模拟小生境方法,保护优良个体,使算法的引导性增强。在系统辨识的过程中,结合系统先验知识,对模型的阶次辨识进行指导。最后通过几个系统辨识的实例验证了该算法的有效性。     

牙嵌离合器的可靠性遗传优化设计

将标准遗传算法用于最优化问题时存在早熟收敛和后期收敛速度缓慢的现象。这里扼要分析了遗传算法的运行机制,提出了一种基于小生镜技术的改进遗传算法,根据牙嵌离合器的可靠性设计原理,建立了遗传优化的模型,并给出了应用改进的遗传算法进行优化设计的实例和计算结果。     

Photovoltaic deployment strategy in Japan and the USA—an institutional appraisal

Photovoltaic (PV) is a renewable energy technology, along side with other modular energy generation technologies such as micro-turbines, fuel cells, etc., which will enable the alternative distributed generation paradigm compared to the incumbent fossil fuel based centralized generation paradigm. Distributed generation utilizing renewable energy resources offers opportunities for significant carbon dioxide and emissions reductions thus contributing solutions to broader climate change issues.     

小生境遗传算法在井间走时地震层析成像中的应用

采用旅行时线性/二次联合插值射线追踪算法(QLTI算法)对包括直达波、折射波、透射波在内的多种射线进行追踪,得到井间层析成像的旅行时,它的突出优点是精度高。反演则引入了小生境遗传算法,对每个种群内的速度个体进行QLTI射线追踪后,通过目标函数的反馈信息,采用自适应控制交配概率和变异概率,搜索最优速度分布,最终得到若干个全局峰或局部峰,然后利用先验知识进行判断,得到满意解。数值模拟显示,这种方法可以处理复杂的介质模型,而且在复杂情况下反演解的稳定性、可靠性强。     

一种多染色体交叉的小生境遗传算法

生物进化一般只在两个个体间进行交配,传统的遗传算法也仅在两个染色体之间进行交叉操作。使用在三个以上的染色体进行交叉操作,并设计了多染色体交叉的算子。多染色体交叉算法可显著提高算法局部寻优能力和收敛速度,但由于收敛速度过快容易产生早熟现象。因此,设计了一种带子种群淘汰策略的小生境算法,可避免算法产生早熟现象。通过几种遗传算法的实验结果比较,证明多染色体交叉算法在多峰优化中的效果要优于传统遗传算法。