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Additional Complexity (additional + complexity)
Selected AbstractsCommon-refinement-based data transfer between non-matching meshes in multiphysics simulationsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 14 2004Xiangmin Jiao Abstract In multiphysics simulations using a partitioned approach, each physics component solves on its own mesh, and the interfaces between these meshes are in general non-matching. Simulation data (e.g. jump conditions) must be exchanged across the interface meshes between physics components. It is highly desirable for such data transfers to be both numerically accurate and physically conservative. This paper presents accurate, conservative, and efficient data transfer algorithms utilizing a common refinement of two non-matching surface meshes. Our methods minimize errors in a certain norm while achieving strict conservation. Some traditional methods for data transfer and related problems are also reviewed and compared with our methods. Numerical results demonstrate significant advantages of common-refinement based methods, especially for repeated transfers. While the comparisons are performed with matching geometries, this paper also addresses additional complexities associated with non-matching surface meshes and presents some experimental results from 3-D simulations using our methods. Copyright © 2004 John Wiley & Sons, Ltd. [source] Extracellular interactome of the FGF receptor,ligand system: Complexities and the relative simplicity of the wormDEVELOPMENTAL DYNAMICS, Issue 2 2009Urszula M. Polanska Abstract Fibroblast growth factors (FGFs) and their receptors (FGFRs) regulate a multitude of biological functions in embryonic development and in adult. A major question is how does one family of growth factors and their receptors control such a variety of functions? Classically, specificity was thought to be imparted by alternative splicing of the FGFRs, resulting in isoforms that bind specifically to a subset of the FGFs, and by different saccharide sequences in the heparan sulfate proteoglycan (HSPG) co-receptor. A growing number of noncanonical co-receptors such as integrins and neural cell adhesion molecule (NCAM) are now recognized as imparting additional complexity to classic FGFR signaling. This review will discuss the noncanonical FGFR ligands and speculate on the possibility that they provide additional and alternative means to determining the functional specificity of FGFR signaling. We will also discuss how invertebrate models such as C. elegans may advance our understanding of noncanonical FGFR signaling. Developmental Dynamics 238:277,293, 2009. © 2008 Wiley-Liss, Inc. [source] Characterization of CC-chemokine receptor 7 expression on murine T cells in lymphoid tissuesIMMUNOLOGY, Issue 2 2003Olle Bjorkdahl Summary Expression of the lymph node homing and CC-chemokine receptor 7 (CCR7), with L-selectin (CD62L), has been shown to divide human memory T cells into two functionally distinct subsets. We generated a polyclonal antibody against murine CCR7 and used this antibody to study CCR7 expression on murine T-cell subsets. Using flow cytometric staining of T cells for visualisation expression of CCR7 in association with CD62L and CD44, a major population of CD4 or CD8 T cells expressing CCR7 were found to be CD62Lhigh CD44low, which would suggest a naïve cell phenotype. By analogy with human studies, memory cells could be subdivided into CCR7high CD62Lhigh CD44high (central memory) and CCR7low CD62Llow CD44high (effector memory). The proportions of these populations were different in lymph node, blood and spleen. Functional, short-term in vitro polyclonal stimulation of blood, spleen and lymph node cells from naive mice demonstrated that CCR7high CD4 T cells produced predominantly interleukin (IL)-2, whereas CCR7low CD4 T cells produced both IL-2 and interferon-, (IFN-,). However, in contrast to previously published reports, the CCR7high CD8 T-cell subpopulation produced both IFN-, and IL-2. Analysis of effector T cells, induced by immunization in vivo, showed that a proportion of activated naïve CD4 T cells down-regulated CCR7 only after multiple cell divisions, and this coincided with the down-regulation of CD62L and production of IL-4 and IFN-,. Finally, analysis of effector T cells during the phase of maximal clonal expansion of secondary immune responses in vivo indicated that the vast majority of both IL-2- and IFN-,-producing cells are CCR7low, while few cytokine-expressing CCR7high T cells were detected. Our results support the hypothesis, developed from studies with human cells, that CCR7 may separate functionally different murine memory T-cell subpopulations, but indicate additional complexity in that CCR7high CD8 T cells also may produce IFN-,. [source] Changing Pay Systems, Occupational Concentration and the Gender Pay Gap: Evidence from Australia and the UKINDUSTRIAL RELATIONS JOURNAL, Issue 3 2001Damian Grimshaw While aggregate level pay equity comparisons between Australia and the UK confirm expectations based on their different wage distributions and regulatory systems, observation of trends and occupational level analysis reveal additional complexity. Our analysis suggests the need for a multi-faceted approach to closing the average gender pay gap. [source] Bayesian approaches in evolutionary quantitative geneticsJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 4 2008R. B. O'HARA Abstract The study of evolutionary quantitative genetics has been advanced by the use of methods developed in animal and plant breeding. These methods have proved to be very useful, but they have some shortcomings when used in the study of wild populations and evolutionary questions. Problems arise from the small size of data sets typical of evolutionary studies, and the additional complexity of the questions asked by evolutionary biologists. Here, we advocate the use of Bayesian methods to overcome these and related problems. Bayesian methods naturally allow errors in parameter estimates to propagate through a model and can also be written as a graphical model, giving them an inherent flexibility. As packages for fitting Bayesian animal models are developed, we expect the application of Bayesian methods to evolutionary quantitative genetics to grow, particularly as genomic information becomes more and more associated with environmental data. [source] Central-local relations in the people's Republic of China: Trends, processes and impacts for policy implementationPUBLIC ADMINISTRATION & DEVELOPMENT, Issue 3 2010Linda Chelan Li Abstract Central,local relations are a matter of great importance to developmentalists because they highlight an intriguing puzzle in public administration especially in large states: how policies decided at higher echelons of the formal system can possibly be implemented by the multitude of intermediary and local actors across the system. In the case of China,the most populous nation in the world, the contrast between the authoritarian façade of the Chinese regime and yet the proliferation of implementation gaps over many policy arenas adds additional complexity to the puzzle. This article reviews changes in central,local relations in the 60 years of history of People's Republic of China (PRC) as the outcome of four co-evolving processes, and clarifies the roles of each process: state building and national integration, development efficiency, career advancement and external influences. It points out the continuous pre-dominance of administrative decentralization from 1950s to present time, and the new emphasis on institutionalized power sharing in the context of new state-market boundaries since 1980s. In conclusion, the article suggests going beyond the traditional reliance on the compliance model to understand central,local interactions and the abundant implementation gaps in a context of central,local co-agency, thereby improving policy implementation. Copyright © 2010 John Wiley & Sons, Ltd. [source] The persistent-access-caching algorithm,RANDOM STRUCTURES AND ALGORITHMS, Issue 2 2008Predrag R. Jelenkovi Abstract Caching is widely recognized as an effective mechanism for improving the performance of the World Wide Web. One of the key components in engineering the Web caching systems is designing document placement/replacement algorithms for updating the collection of cached documents. The main design objectives of such a policy are the high cache hit ratio, ease of implementation, low complexity and adaptability to the fluctuations in access patterns. These objectives are essentially satisfied by the widely used heuristic called the least-recently-used (LRU) cache replacement rule. However, in the context of the independent reference model, the LRU policy can significantly underperform the optimal least-frequently-used (LFU) algorithm that, on the other hand, has higher implementation complexity and lower adaptability to changes in access frequencies. To alleviate this problem, we introduce a new LRU-based rule, termed the persistent-access-caching (PAC), which essentially preserves all of the desirable attributes of the LRU scheme. For this new heuristic, under the independent reference model and generalized Zipf's law request probabilities, we prove that, for large cache sizes, its performance is arbitrarily close to the optimal LFU algorithm. Furthermore, this near-optimality of the PAC algorithm is achieved at the expense of a negligible additional complexity for large cache sizes when compared to the ordinary LRU policy, since the PAC algorithm makes the replacement decisions based on the references collected during the preceding interval of fixed length. © 2008 Wiley Periodicals, Inc. Random Struct. Alg., 2008 [source] | ||||||||||