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Original Structure (original + structure)
Selected AbstractsStatic reanalysis of structures with added degrees of freedomINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 4 2006Baisheng Wu Abstract This paper deals with static reanalysis of a structure with added degrees of freedom where the nodes of the original structure form a subset of the nodes of the modified structure. A preconditioned conjugate-gradient approach is developed. The preconditioner is constructed, and the implementation of the approach involves only decomposition of the stiffness matrix corresponding to the newly added degrees of freedom. In particular, the approach can adaptively monitor the accuracy of approximate solutions. The approach is applicable to the reanalysis of the structural layout modifications for the case of addition of some nodes, deletion and addition of elements and further changes in the geometry as well as to the local mesh refinements. Numerical examples show that the condition number of the selected preconditioned matrix is largely reduced. Therefore, the fast convergence and accurate results can be achieved by the approach. Copyright © 2005 John Wiley & Sons, Ltd. [source] Sequence-dependent proton-transfer reaction in stacked GC pair III: The influence of proton transfer to conductivityINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 12 2010Yasuyuki Nakanishi Abstract We have computed current,voltage character of natural DNA and its proton-transferred structure by scattering theory based on density functional theory. The current is not observed if the electron path contains only hydrogen bonding such as one base pair. The current becomes larger if the electron path contains ,,, stacking molecule such as two base pairs. We also found that the conductivity of pseudo-ion pair (C+G,/G,C+), which is derived from proton-transfer reaction in CG/GC, differs from that of the original structure. On the other hand, the current changes dramatically if the electrode connects to guanine or cytosine, which can be explained by the difference of electron affinities. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010 [source] The Learning Transfer System Inventory (LTSI) translated into French: internal structure and predictive validityINTERNATIONAL JOURNAL OF TRAINING AND DEVELOPMENT, Issue 3 2007Christelle Devos The Learning Transfer System Inventory (LTSI, Holton et al., 2000) considers 16 factors likely to influence the transfer of training to the workplace. The purpose of this study is to translate the Learning Transfer System Inventory into French and to examine (1) the internal structure of the translated instrument; and (2) its predictive validity. The Learning Transfer System Inventory was administered to 328 participants from six companies during the week following the end of a training program. The transfer questionnaire was filled in by 106 of those participants 1,3 months later. The results showed that a principal component analysis reveals a factor structure very similar to the original structure: the 16 original factors are replicated. Second, seven factors display statistically significant correlations with transfer: learner readiness, motivation to transfer, transfer design, opportunity to use, transfer-performance expectations, performance-outcomes expectations and performance self-efficacy. Comparisons with four similar previous studies allow us to draw directions for future research on the instrument. [source] Virtual passive control of flexible arms with collocated and noncollocated feedbackJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 11 2001Shang-Teh Wu A novel approach to the control of flexible manipulators is proposed. The controller includes both joint-variable and tip-deflection feedback. It is shown that tip-deflection feedback transforms the original structure into new system in which the structure parameters are virtually scaled up or down. The new system can hence be easily stabilized via a strictly passive feedback law. A co-hub, lumped-parameter structure with multiple massless links is first investigated and stability conditions are developed. The results are then applied to a distributed-parameter flexible arm, which is decomposed into an equivalent lumped-parameter structure via a set of modal functions normalized in a particular way. Tip-deflection feedback is shown to be capable of enhancing control performance on a flexible arm, and stability is ensured as long as the gain associated with the noncollocated feedback satisfies a simple inequality. The stability criteria re valid independent of high-order flexible modes. © 2001 John Wiley & Sons, Inc. [source] A shorted square-ring slot antenna with a branched slot for the 1575 MHz and 2.4 GHz dual-band operationsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2009Chin-Long Tsai Abstract A shorted square-ring slot antenna with a branched slot is presented for the 1575 MHz and 2.4 GHz dual-band operations. This proposed antenna can be designed by two steps. First, the shorted square-ring slot antenna is designed for circular polarization in the GPS band. Then, a branched slot is added to the original structure to result linear polarization in the 2.4 GHz band. Because the added branched slot almost has no influence in the GPS band's characteristics, the design rule is very simple. The impedance and axial ratio bandwidths for the GPS band is 23.3% and 4.2%, respectively. Besides, the AR and antenna gain is 1.23 dB and 2.3 dBic at the frequency of 1575 MHz. The impedance bandwidth for the 2.4 GHz band is 4.5% and antenna gain at the center frequency of 2.445 GHz is 2.8 dBi. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 402,405, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24073 [source] A comparison of the electron ionization and electrospray behaviour of some N,N,-disubstituted hexahydropyrimidinesRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 5 2006Liliana R. Orelli The behaviour of some N,N,-disubstituted hexahydropyrimidines, a class of naturally occurring compounds of biological and biomedical interest, has been studied in both electron ionization (EI) and electrospray ionization (ESI) modes coupled with collisional experiments (ESI-MSn). In both techniques, the [M,H]+ ions are highly abundant, even if their formation is generated by two different mechanisms, i.e. H. loss from the M+. species in the case of EI and hydride (H,) abstraction from the molecules in the case of ESI. Furthermore, due to the low, step-by-step internal energy deposition typical of collisional experiments performed in an ion trap mass spectrometer, different fragment ions were observed in EI and ESI-MSn collisions. In both cases, the ions can be related to the original structure and allow us to identify the positions in which the different substituents are present. Copyright © 2006 John Wiley & Sons, Ltd. [source] Fusarium oxysporum trypsin at atomic resolution at 100 and 283,K: a study of ligand bindingACTA CRYSTALLOGRAPHICA SECTION D, Issue 1 2001Wojciech R. Rypniewski The X-ray structure of F. oxysporum trypsin has been determined at atomic resolution, revealing electron density in the binding site which was interpreted as a peptide bound in the sites S1, S2 and S3. The structure, which was initially determined at 1.07,Å resolution and 283,K, has an Arg in the S1 specificity pocket. The study was extended to 0.81,Å resolution at 100,K using crystals soaked in Arg, Lys and Gln to study in greater detail the binding at the S1 site. The electron density in the binding site was compared between the different structures and analysed in terms of partially occupied and overlapping components of peptide, solvent water and possibly other chemical moieties. Arg-soaked crystals reveal a density more detailed but similar to the original structure, with the Arg side chain visible in the S1 pocket and residual peptide density in the S2 and S3 sites. The density in the active site is complex and not fully interpreted. Lys at high concentrations displaces Arg in the S1 pocket, while some main-chain density remains in sites S2 and S3. Gln has been shown not to bind. The free peptide in the S1,S3 sites binds in a similar way to the binding loop of BPTI or the inhibitory domain of the Alzheimer's ,-protein precursor, with some differences in the S1 site. [source] Chromatin dynamics of unfolding and refolding controlled by the nucleosome repeat length and the linker and core histonesBIOPOLYMERS, Issue 4 2007Toshiro Kobori Abstract Chromatin is composed of genomic DNA and histones, forming a hierarchical architecture in the nucleus. The chromatin hierarchy is common among eukaryotes despite different intrinsic properties of the genome. To investigate an effect of the differences in genome organization, chromatin unfolding processes were comparatively analyzed using Schizosaccaromyces pombe, Saccharomyces cerevisiae, and chicken erythrocyte. NaCl titration showed dynamic changes of the chromatin. 400,1000 mM NaCl facilitated beads with ,115 nm in diameter in S. pombe chromatin. A similar transition was also observed in S. cerevisiae chromatin. This process did not involve core histone dissociation from the chromatin, and the persistence length after the transition was ,26 nm for S. pombe and ,28 nm for S. cerevisiae, indicating a salt-induced unfolding to "beads-on-a-string" fibers. Reduced salt concentration recovered the original structure, suggesting that electrostatic interaction would regulate this discrete folding-unfolding process. On the other hand, the linker histone was extracted from chicken chromatin at 400 mM NaCl, and AFM observed the "beads-on-a-string" fibers around a nucleus. Unlike yeast chromatin, therefore, this unfolding was irreversible because of linker histone dissociation. These results indicate that the chromatin unfolding and refolding depend on the presence and absence of the linker histone, and the length of the linker DNA. © 2007 Wiley Periodicals, Inc. Biopolymers 85:295,307, 2007. This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source] Structural and functional growth in self-reproducing cellular automata,COMPLEXITY, Issue 6 2006Eleonora Bilotta Abstract In this article, we analyze the dynamics of change in two-dimensional self-reproducers, identifying the processes that drive their evolution. We show that changes in self-reproducers structure and behavior depend on their genetic memory. This consists of distinct yet interlinked components determining their form and function. In some cases these components degrade gracefully, changing only slightly; in others the changes destroy the original structure and function of the self-reproducer. We sketch these processes at the genotype and the phenotype level,showing that they follow distinct trajectories within mutation space and quantifying the degree of change produced by different trajectories. We show that changes in structure and behavior depend on the interplay between the genotype and the phenotype. This determines universal structures, from which it is possible to construct a great number of self-reproducing systems, as we observe in biology. Creative processes of change produce divergent and/or convergent methods for the generation of self-reproducers. Divergence involves the creation of completely new information convergence involves local change and specialization of the structures concerned. © 2006 Wiley Periodicals, Inc. Complexity 11: 12,29, 2006 [source] Coarse-graining of protein structures for the normal mode studiesJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 8 2007Kilho Eom Abstract The coarse-grained structural model such as Gaussian network has played a vital role in the normal mode studies for understanding protein dynamics related to biological functions. However, for the large proteins, the Gaussian network model is computationally unfavorable for diagonalization of Hessian (stiffness) matrix for the normal mode studies. In this article, we provide the coarse-graining method, referred to as "dynamic model condensation," which enables the further coarse-graining of protein structures consisting of small number of residues. It is shown that the coarser-grained structures reconstructed by dynamic model condensation exhibit the dynamic characteristics, such as low-frequency normal modes, qualitatively comparable to original structures. This sheds light on that dynamic model condensation and may enable one to study the large protein dynamics for gaining insight into biological functions of proteins. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007 [source] Confirmatory Factor Analysis of the Way of Coping Checklist-Revised (WCCL-R) in the Asian ContextAPPLIED PSYCHOLOGY, Issue 2 2010Sukanlaya Sawang Industrial employment growth has been one of the most dynamic areas of expansion in Asia; however, current trends in industrialised working environments have resulted in greater employee stress. Despite research showing that cultural values affect the way people cope with stress, there is a dearth of psychometrically established tools for use in non-Western countries to measure these constructs. Studies of the "Way of Coping Checklist-Revised" (WCCL-R) in the West suggest that the WCCL-R has good psychometric properties, but its applicability in the East is still understudied. A confirmatory factor analysis (CFA) is used to validate the WCCL-R constructs in an Asian population. This study used 1,314 participants from Indonesia, Sri Lanka, Singapore, and Thailand. An initial exploratory factor analysis revealed that original structures were not confirmed; however, a subsequent EFA and CFA showed that a 38-item, five-factor structure model was confirmed. The revised WCCL-R in the Asian sample was also found to have good reliability and sound construct and concurrent validity. The 38-item structure of the WCCL-R has considerable potential in future occupational stress-related research in Asian countries. La croissance de l'emploi dans l'industrie a été l'un des aspects les plus dynamiques de l'expansion en Asie, mais l'évolution actuelle des environnements de travail industriels a accru le stress des salariés. Malgré les recherches qui ont souligné que les valeurs culturelles affectaient la façon dont les gens faisaient face au stress, on ne peut que regretter la pénurie d'outils psychométriquement valides pour mesurer ces dimensions dans les pays non occidentaux. Les travaux occidentaux sur la "liste révisée des stratégies de faire-face" (WCCL-R) laissent entendre que cette échelle présentent des propriétés psychométriques positives, mais ses possibilités d'application en Asie n'ont pas été suffisamment étudiées. On a mis à l'épreuve par analyse factorielle les concepts de la WCCL-R sur une population asiatique. L'échantillon comprenait 1,314 sujets en provenance d'Indonésie, du Sri Lanka, de Singapour et de Thaïlande. Une première analyse factorielle exploratoire n'a pas confirmé la structure originelle. Toutefois, les analyses ultérieures débouchèrent sur un modèle à cinq facteurs et 38 items. On a aussi pu constater que la WCCL-R présentait une bonne fidélité, des concepts pertinents et une validité concurrente satisfaisante. La structure en 38 items de la WCCL-R recèle un potentiel considérable pour les recherches sur le stress professionnel dans les pays asiatiques. [source] | |||||||||||||