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41.
为了实现服务组合对环境的适应性,设计了能满足上下文动态集成的模型,并使用CC/PP的RDF创建P rofiles描述上下文。详细分析上下文集成中出现的冲突情况,定义优先级和效用因子,解决上下文集成中的冲突问题。结合原型系统进行测试,并给出了实验结果。研究结果表明:在不同的冲突策略情况下,该方法能在可接受的时间内解决冲突。 相似文献
42.
Snake envenomation is a socio-medical problem of considerable magnitude. About 2.5 million people are bitten by snakes annually,
more than 100,000 fatally. However, although bites can be deadly, snake venom is a natural biological resource that contains
several components of potential therapeutic value. Venom has been used in the treatment of a variety of pathophysiological
conditions in Ayurveda, homeopathy and folk medicine. With the advent of biotechnology, the efficacy of such treatments has
been substantiated by purifying components of venom and delineating their therapeutic properties. This review will focus on
certain snake venom components and their applications in health and disease.
Received 6 July 2006; received after revision 14 August 2006; accepted 28 September 2006 相似文献
43.
Expansion of amino acid homo-sequences, such as polyglutamines or polyalanines, in proteins has been directly implicated in
various degenerative diseases through a mechanism of protein misfolding and aggregation. However, it is still unclear how
the nature of the expansion and the protein context influence the tendency of a protein to aggregate. Here, we have addressed
these questions using spinocerebellar ataxia type-3 (ATX3) protein, the best characterised of the polyglutamine proteins,
chosen as a model system. Using a transfected mammalian cell line, we demonstrate that ATX3 aggregation is noticeably reduced
by deletion or replacement of regions other than the polyglutamine tract. The nature of the amino acid homo-sequences also
has a strong influence on aggregation. From our studies, we draw general conclusions on the effect of the protein architecture
and of the amino acid homo-sequence on pathology.
Received 3 March 2006; received after revision 19 April 2006; accepted 22 May 2006 相似文献
44.
Navarro S Aleu J Jiménez M Boix E Cuchillo CM Nogués MV 《Cellular and molecular life sciences : CMLS》2008,65(2):324-337
Human eosinophil cationic protein (ECP)/ ribonuclease 3 (RNase 3) is a protein secreted from the secondary granules of activated
eosinophils. Specific properties of ECP contribute to its cytotoxic activities associated with defense mechanisms. In this
work the ECP cytotoxic activity on eukaryotic cell lines is analyzed. The ECP effects begin with its binding and aggregation
to the cell surface, altering the cell membrane permeability and modifying the cell ionic equilibrium. No internalization
of the protein is observed. These signals induce cell-specific morphological and biochemical changes such as chromatin condensation,
reversion of membrane asymmetry, reactive oxygen species production and activation of caspase-3-like activity and, eventually,
cell death. However, the ribonuclease activity component of ECP is not involved in this process as no RNA degradation is observed.
In summary, the cytotoxic effect of ECP is attained through a mechanism different from that of other cytotoxic RNases and
may be related with the ECP accumulation associated with the inflammatory processes, in which eosinophils are present.
Received 26 October 2007; accepted 23 November 2007 相似文献
45.
We introduce a new strategy for the prediction of linear temporal aggregates; we call it ‘hybrid’ and study its performance using asymptotic theory. This scheme consists of carrying out model parameter estimation with data sampled at the highest available frequency and the subsequent prediction with data and models aggregated according to the forecasting horizon of interest. We develop explicit expressions that approximately quantify the mean square forecasting errors associated with the different prediction schemes and that take into account the estimation error component. These approximate estimates indicate that the hybrid forecasting scheme tends to outperform the so‐called ‘all‐aggregated’ approach and, in some instances, the ‘all‐disaggregated’ strategy that is known to be optimal when model selection and estimation errors are neglected. Unlike other related approximate formulas existing in the literature, those proposed in this paper are totally explicit and require neither assumptions on the second‐order stationarity of the sample nor Monte Carlo simulations for their evaluation. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
46.
在开关完全可靠的情况下,研究了由两个不同型、有优先权的部件和一个修理设备组成的冷贮备系统,建立了在部件工作寿命和修理时间均服从一般时间分布的可修模型,并利用Markov更新过程、LS变换、L变换推导出该模型的一些可靠性指标. 相似文献
47.
讨论了SR-SARV模型的时间聚合性和同期聚合性,比较了波动模型之间的关系,指出了SR-SARV模型研究的意义,并给出其参数估计方法,对上证指数进行了实证研究。 相似文献
48.
基于模糊语言评估的多属性决策方法 总被引:30,自引:0,他引:30
研究了属性权重确知,属性值以模糊语言形式给出的多属性决策问题,定义了一种模糊语言评估标度并给出其相应的区间数表达方式,利用区间数运算法则对各方案的属性值进行集结。基于区间数之间两两比较的可能度公式,构造可能变矩阵,并利用已有的排序公式求出其相应的排序向量。进而对决策方案进行排序和择优,最后进行了实例分析,数值结果表明:该方法可行且有效。 相似文献
49.
针对异构多部件系统内部存在部件维修地位不均等的问题,提出了一种基于寿命分布的非集中式维修策略.考虑多部件系统由两类部件构成:功能复杂的高维修优先级部件和功能简单的低维修优先级部件.前者的故障需要立即进行紧急维修,同时维修次数是有限的;而后者的故障可被暂且搁置,以等待成组维修.考虑维修工作由两个维修团队共同竞争完成,团队之间的竞争关系符合斯坦克尔伯格竞争模型.在此基础上,通过建立起部件的故障次序统计量,以多部件系统总体期望费用率的最小化为目标,建立了一种非集中式维修策略的优化模型,并通过数值仿真进行验证. 相似文献
50.