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Same Structure (same + structure)
Selected AbstractsFreeform Shape Representations for Efficient Geometry ProcessingCOMPUTER GRAPHICS FORUM, Issue 3 2003Leif Kobbelt The most important concepts for the handling and storage of freeform shapes in geometry processing applications are parametric representations and volumetric representations. Both have their specific advantages and drawbacks. While the algebraic complexity of volumetric representations is independent from the shape complexity, the domain of a parametric representation usually has to have the same structure as the surface itself (which sometimes makes it necessary to update the domain when the surface is modified). On the other hand, the topology of a parametrically defined surface can be controlled explicitly while in a volumetric representation, the surface topology can change accidentally during deformation. A volumetric representation reduces distance queries or inside/outside tests to mere function evaluations but the geodesic neighborhood relation between surface points is difficult to resolve. As a consequence, it seems promising to combine parametric and volumetric representations to effectively exploit both advantages. In this talk, a number of projects are presented and discussed in which such a combination leads to efficient and numerically stable algorithms for the solution of various geometry processing tasks. Applications include global error control for mesh decimation and smoothing, topology control for level-set surfaces, and shape modeling with unstructured point clouds. [source] Effect of different metal ions on structural, thermal, spectroscopic and optical properties of ATCC and ATMC single crystalsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 8 2007R. Perumal Abstract A novel metal-organic coordination complex nonlinear optical crystals, tri-allylthiourea cadmium chloride [(CdCl2(AT)3] and tri-allylthiourea mercury chloride [(HgCl2(AT)3] abbreviated as ATCC, ATMC (AT is Allylthiourea i.e.,CH2=CHCH2NHCSNH2) has been synthesized and grown as single crystals. It was synthesized in deionised water and further recrystallized to improve its purity. Single crystals of the allylthiourea co-ordination complex nonlinear optical crystals tri allylthiourea cadmium chloride (ATCC) with dimensions of 14x14x10 mm3 and tri allylthiourea mercury chloride (ATMC) with dimensions of 15x15x12 mm3 were grown successfully from aqueous solution by solvent evaporation as well as by temperature lowering method. It exhibits powder SHG efficiencies higher than that of a well known organic NLO crystal Urea. The solubility of the as grown crystals was estimated from the aqueous solution and the effect of different metal ions on the grown crystals, structural, thermal, spectral and optical properties were analyzed. XRD studies the reveals the same structure of both materials. Influence of the different central metal (Cd and Hg) atoms, changing the thermal properties of the materials when NLO complexes formed with the common ligand allylthiourea. The metal co-ordination was confirmed form the spectroscopic analysis. From the UV transmittance studies, red shift was from the transparency cut-off wavelengths. The value is 285nm for ATCC is and is 335nm ATMC, Non-linear an optical study confirms the suitabilities of the as grown crystals for the non linear optical applications. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] INTERPRETATION OF THE RESULTS OF COMMON PRINCIPAL COMPONENTS ANALYSESEVOLUTION, Issue 3 2002David Houle Abstract Common principal components (CPC) analysis is a new tool for the comparison of phenotypic and genetic variance-covariance matrices. CPC was developed as a method of data summarization, but frequently biologists would like to use the method to detect analogous patterns of trait correlation in multiple populations or species. To investigate the properties of CPC, we simulated data that reflect a set of causal factors. The CPC method performs as expected from a statistical point of view, but often gives results that are contrary to biological intuition. In general, CPC tends to underestimate the degree of structure that matrices share. Differences of trait variances and covariances due to a difference in a single causal factor in two otherwise identically structured datasets often cause CPC to declare the two datasets unrelated. Conversely, CPC could identify datasets as having the same structure when causal factors are different. Reordering of vectors before analysis can aid in the detection of patterns. We urge caution in the biological interpretation of CPC analysis results. [source] Calcite-specific coupling protein in barnacle underwater cementFEBS JOURNAL, Issue 24 2007Youichi Mori The barnacle relies for its attachment to underwater foreign substrata on the formation of a multiprotein complex called cement. The 20 kDa cement protein is a component of Megabalanus rosa cement, although its specific function in underwater attachment has not, until now, been known. The recombinant form of the protein expressed in bacteria was purified in soluble form under physiological conditions, and confirmed to retain almost the same structure as that of the native protein. Both the protein from the adhesive layer of the barnacle and the recombinant protein were characterized. This revealed that abundant Cys residues, which accounted for 17% of the total residues, were in the intramolecular disulfide form, and were essential for the proper folding of the monomeric protein structure. The recombinant protein was adsorbed to calcite and metal oxides in seawater, but not to glass and synthetic polymers. The adsorption isotherm for adsorption to calcite fitted the Langmuir model well, indicating that the protein is a calcite-specific adsorbent. An evaluation of the distribution of the molecular size in solution by analytical ultracentrifugation indicated that the recombinant protein exists as a monomer in 100 mm to 1 m NaCl solution; thus, the protein acts as a monomer when interacting with the calcite surface. cDNA encoding a homologous protein was isolated from Balanus albicostatus, and its derived amino acid sequence was compared with that from M. rosa. Calcite is the major constituent in both the shell of barnacle base and the periphery, which is also a possible target for the cement, due to the gregarious nature of the organisms. The specificity of the protein for calcite may be related to the fact that calcite is the most frequent material attached by the cement. [source] 5-Benzyl-3-methylimidazolidin-4-one-Derived Reactive Intermediates of Organocatalysis , A Comforting Resemblance of X-Ray, NMR, and DFT Solid-Phase, Liquid-Phase, and Gas-Phase StructuresHELVETICA CHIMICA ACTA, Issue 1 2009Abstract The X-ray crystal structures of three (E)-1-cinnamoylidene iminium PF6 salts of 5-benzyl-3-methylimidazolidin-4-ones (2,2-dimethyl-, cis -2-(tert -butyl)-, and cis -2-styryl-substituted; 2,4, resp.) are reported (Figs.,3,5). In the 2,2-dimethyl and in the cis -2-styryl derivative, 2 and 4, respectively, a CH bond of the cis -substituent in 2-position points to the center of the benzene ring of the benzyl group above the five-membered ring (Fig.,6,,a and b). NMR Measurements (Fig.,8) provide evidence that the same structure is present in solution, and that a fourth derivative of this type, 5 (Scheme), has (Z)- instead of (E)-configuration around the CN bond. In the cis -2-(tert -butyl) derivative 3, the benzyl group is located over the iminium , -system (Figs.,4 and 6,,c). Overlays with DFT-calculated crotonylidene analogs, A and B, show that the theoretical and experimental structures are almost superimposable (Fig.,9 and Table). The structures are discussed in view of their role as reactive intermediates in organocatalysis and in view of the help synthetic organic chemists may experience from theory. [source] Correlative 3D Microscopy: CLSM and FIB/SEM TomographyIMAGING & MICROSCOPY (ELECTRONIC), Issue 3 2008A Study of Cellular Entry of Vaccinia Virus Abstract Subcellular structural investigation on single cells or tissue samples requires the coupling of optimal structural preservation with detailed imaging at the light and electron microscopic level. To apply light microscopy (FLM, CLSM) and electron microscopy (SEM, FIB/SEM, TEM) imaging modes to the identical sample area has become available with the establishment of chemical preparation, or freeze-substitution protocols after high pressure freezing, adapted to retain fluorophores. One and the same structure can now be investigated at mm to nm range in 2D and 3D in a multimodal set-up [1, 2]. In combination with live cell imaging prior to immobilisation, this approach becomes a powerful tool in life science, e.g. in the development of new anti-viral strategies, as this requires detailed information on the replication cycle of viruses and their interaction with their host cells. [source] Consistent tangent matrices for density-dependent finite plasticity modelsINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 11 2001Agustí Pérez-Foguet Abstract The consistent tangent matrix for density-dependent plastic models within the theory of isotropic multiplicative hyperelastoplasticity is presented here. Plastic equations expressed as general functions of the Kirchhoff stresses and density are considered. They include the Cauchy-based plastic models as a particular case. The standard exponential return-mapping algorithm is applied, with the density playing the role of a fixed parameter during the nonlinear plastic corrector problem. The consistent tangent matrix has the same structure as in the usual density-independent plastic models. A simple additional term takes into account the influence of the density on the plastic corrector problem. Quadratic convergence results are shown for several representative examples involving geomaterial and powder constitutive models. Copyright © 2001 John Wiley & Sons, Ltd. [source] A configuration for realizing floating, linear, voltage-controlled resistance, inductance and FDNC elementsINTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 5 2009R. Senani Abstract A configuration using current feedback amplifiers has been presented, which is capable of realizing linear, positive/negative voltage-controlled resistance, voltage-controlled inductance and voltage-controlled frequency-dependent negative conductance in floating form (and thereby, also in grounded form) from the same structure. The workability of the proposed configuration has been demonstrated by hardware implementation results using AD 844-type current feedback op-amps (CFOAs) and BFW-11-type JFETs and the workability in high-frequency range has been demonstrated by SPICE simulation using CMOS CFOAs. Copyright © 2008 John Wiley & Sons, Ltd. [source] An extension of the differential approach for Bayesian network inference to dynamic Bayesian networksINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 8 2004Boris Brandherm We extend Darwiche's differential approach to inference in Bayesian networks (BNs) to handle specific problems that arise in the context of dynamic Bayesian networks (DBNs). We first summarize Darwiche's approach for BNs, which involves the representation of a BN in terms of a multivariate polynomial. We then show how procedures for the computation of corresponding polynomials for DBNs can be derived. These procedures permit not only an exact roll-up of old time slices but also a constant-space evaluation of DBNs. The method is applicable to both forward and backward propagation, and it does not presuppose that each time slice of the DBN has the same structure. It is compatible with approximative methods for roll-up and evaluation of DBNs. Finally, we discuss further ways of improving efficiency, referring as an example to a mobile system in which the computation is distributed over a normal workstation and a resource-limited mobile device. © 2004 Wiley Periodicals, Inc. Int J Int Syst 19: 727,748, 2004. [source] Electronic and charge aspects of potential endocrine disruptors: Applications to pharmacological clusteringINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 4-5 2003James W. King Abstract Quantitative structure,activity relationships in a series of 37 substituted indoles with endocrine disruptor potential were performed using the structural indices FTe (electronic) and FTc (charge), in conjunction with a clustering technique, to relate substitution patterns to reported relative binding affinities for the calf estrogen receptor. Data clusters were generated by a primary numerically descending sort of the structure indices with a concurrent secondary numerically descending sort of the binding data. Reversal of the numerical descent of the latter served to delineate cluster boundaries. Analysis within the clusters defined the effect of substituents and their molecular positions on the pharmacological data. These results confirmed in detail a similar previous study in the same series using the more general FTm index and again suggested the same structure of a molecule with greater receptor binding ability than any in the database. The methodology used in these studies permits a rational presentation and subsequent interpretation of data that initially appear to be totally random and devoid of recoverable information content. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003 [source] Synthesis of liquid crystalline,amorphous block copolymers by the combination of atom transfer and promoted cationic polymerizationJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2007S. Demirhan Abstract Block copolymers of liquid crystalline 6-(4-cyanobiphenyl-4,-oxy) hexyl acrylate (LC6) and cyclohexene oxide (CHO) were obtained by the combination of atom transfer radical polymerization (ATRP) and promoted cationic polymerization (PCP). In the first part, a bifunctional initiator containing benzoin and halide groups in the same structure was used as an initiator in ATRP of LC6, in diphenyl ether in conjunction with CuBr/N,N,N,,N,,N,-pentamethyldiethylenetriamine as a catalyst. The obtained photoactive liquid crystalline polymers poly[6-(4-cyanobiphenyl-4,-oxy)hexyl acrylate] (PLC6), were used to induce polymerization of CHO through formation of electron donor polymeric radicals upon photolysis and subsequent oxidation to corresponding carbocations in the presence of onium salt. The spectral, thermal and optical measurements confirmed a full combination of ATRP and PCP, which resulted in the formation of AB-type block copolymers. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007 [source] Origins, uses of, and relations between goal programming and data envelopment analysisJOURNAL OF MULTI CRITERIA DECISION ANALYSIS, Issue 1 2005W.W. Cooper Abstract Origins and uses of ,goal programming' and ,data envelopment analysis' (DEA) are identified and discussed. The purpose of this paper is not only to review some of the history of these developments, but also to show some of their uses (e.g. in statistical regression formulations) in order to suggest paths for possible further developments. Turning to how the two types of models relate to each other, the ,additive model' of DEA is shown to have the same structure as a goal programming model in which only ,one-sided deviations' are permitted. A way for formally relating the two to each other is then provided. However, the objectives are differently oriented because goal programming is directed to future performances as part of the planning function whereas DEA is directed to evaluating past performances as part of the control function of management. Other possible ways of comparing and combining the two approaches are also noted including statistical regressions that utilize goal programming to ensure that the resulting estimates satisfy the multi-criteria conditions that are often encountered in managerial applications. Both goal programming and DEA originated in actual applications that were successfully addressed. The research was then generalized and published. This leads to what is referred to as an ,applications-driven theory' strategy for research that is also described in this paper. Copyright © 2006 John Wiley & Sons, Ltd. [source] ENDOMEMBRANE STRUCTURE AND THE CHLOROPLAST PROTEIN TARGETING PATHWAY IN HETEROSIGMA AKASHIWO (RAPHIDOPHYCEAE, CHROMISTA)JOURNAL OF PHYCOLOGY, Issue 6 2000Ken-ichiro Ishida Chloroplasts in heterokont algae are surrounded by four membranes and probably originated from a red algal endosymbiont that was engulfed and retained by eukaryotic host. Understanding how nuclear-encoded chloroplast proteins are translocated from the cytoplasm into the chloroplast across these membranes could give us some insights about how the endosymbiont was integrated into the host cell in the process of secondary symbiogenesis. In multiplastid heterokont algae such as raphidophytes, it has been unclear if the outermost of the four membranes surrounding the chloroplast (the chloroplast endoplasmic reticulum [CER] membrane) is continuous with the nuclear envelope and rough endoplasmic reticulum (ER). Here, we report detailed ultrastructural observations of the raphidophyte Heterosigma akashiwo (Hada) Hada ex Y. Hara et Chihara that show that the CER membranes were continuous with ER membranes that had attached ribosomes, implying that the chloroplast with three envelope membranes is located within the ER lumen, that is, topologically the same structure as that of monoplastid heterokont algae. However, the CER membrane of H. akashiwo had very few, if any, ribosomes attached, unlike the CER membranes in other heterokont algae. To verify that proteins are first targeted to the ER, we assayed protein import into canine microsomes using a precursor for a nuclear-encoded chloroplast protein, the fucoxanthin-chlorophyll a/c protein of H. akashiwo. This demonstrated that the precursor has a functional signal sequence for ER targeting and is cotranslationally translocated into the ER, where a signal sequence of about 17 amino acids is removed. Based on these data, we hypothesize that in H. akashiwo, nuclear-encoded chloroplast protein precursors that have been cotranslationally transported into the ER lumen are sorted in the ER and transported to the chloroplasts through the ER lumen. [source] Matching Inefficiencies, Regional Disparities, and UnemploymentLABOUR, Issue 3 2009Sanna-Mari Hynninen Our results suggest that there would be a substantial decline in aggregate unemployment if (i) all local labour offices operated with full efficiency or (ii) they shared the same structure of job seekers and vacant jobs as the most favourable office. In the former case an increase in hirings would lower the average unemployment rate by 2.4 percentage points. In the latter case the decrease would be 1.4 percentage points. Further, we find that fixed effects are positively correlated with both a more favourable structure and higher efficiency. This suggests that the fixed effects may capture some part of time-invariant features in the structure and inefficiency. Thus, the role of structural factors and inefficiency in regional unemployment disparities may be higher than estimated. [source] Structure elucidation of two new xanthone derivatives from the marine fungus Penicillium sp. (ZZF 32#) from the South China SeaMAGNETIC RESONANCE IN CHEMISTRY, Issue 11 2008Changlun Shao Abstract Two new xanthones, 8-(methoxycarbonyl)-1-hydroxy-9-oxo-9H-xanthene-3-carboxylic acid (1) and dimethyl 8-methoxy-9-oxo-9H-xanthene-1, 6-dicarboxylate (2) and one known xanthone methyl 8-hydroxy-6-methyl-9-oxo-9H-xanthene-1-carboxylate (3) were isolated from the culture broth of the mangrove fungus Penicillium sp. (ZZF 32#) collected from the South China Sea. Their structures were established by comprehensive analysis of one-dimensional (1D) and two-dimensional (2D) NMR data. The structure of compound 3 was confirmed by X-ray crystallography, which led to the suggestion that janthinone (4) might have the same structure as 3. Compounds 1,3 were inactive against KB or KBv200 cells during cytotoxicity evaluations. Copyright © 2008 John Wiley & Sons, Ltd. [source] Low on-resistance of GaN p-i-n vertical conducting diodes grown on 4H-SiC substratesPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7 2007Atsushi Nishikawa Abstract We investigated the resistance of conductive AlGaN buffer layers and the current-voltage characteristics of GaN p-i-n vertical conducting diodes on n -type 4H-SiC substrates grown by low-pressure metalorganic vapor-phase epitaxy. High Si doping of the AlGaN buffer layer at the AlGaN/SiC interface produces ohmic current-voltage characteristics in spite of the large band offset between AlGaN and 4H-SiC. Owing to the optimization of the AlGaN buffer layer, a low on-resistance (Ron) of 1.12 m, cm2 with high breakdown voltage (VB) of 300 V is obtained for a GaN p-i-n vertical conducting diode on a 4H-SiC substrate, leading to the figure of merit (VB2/Ron) of 80 MW/cm2, which is larger than that for the diode with the same structure on a 6H-SiC substrate (62 MW/cm2). This result indicates that 4H-SiC is preferable for fabricating GaN-based electronic devices with a low on-resistance and high breakdown voltage. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] HLA genes and surnames show a similar genetic structure in Lombardy: Does this reflect part of the history of the region?AMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 3 2007Antonella Lisa Lombardy, in northern Italy, is the most populated and industrialized Italian region. We attempt to study its genetic structure with two independent sets of data: HLA allele frequencies and surnames. According to our results, it is plausible to deduce that ancient history, more than genetic isolation and drift, may have contributed to the present genetic structure of Lombardy. The hypothesis seems to be confirmed by the results of the cluster analysis of the 11 provinces of the region, which was performed using two different types of markers. Both genes and surnames show approximately the same structure. Not only Celts but also ancient Ligurians (and Etruscans) probably shaped the region into the present three clusters in which the 11 provinces appear to be genetically structured. In particular, an ancient historic, archaeological, and linguistic boundary, along the Adda River, seems to be preserved in present-day Lombardy's population structure.Am. J.Hum. Biol. 19:311,318, 2007. © 2007 Wiley-Liss, Inc. [source] Material Modelling of Porous Media for Wave Propagation ProblemsPROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2003M. Schanz PD Dr.-Ing. Under the assumption of a linear geometry description and linear constitutive equations, the governing equations are derived for two poroelastic theories, Biot's theory and Theory of Porous Media (TPM), using solid displacements and pore pressure as unknowns. In both theories, this is only possible in the Laplace domain. Comparing the sets of differential equations of Biot's theory and of TPM, they show different constant coefficients but the same structure of coupled differential equations. Identifying these coefficients with the material data and correlating them leads to the known problem with Biot's ,apparent mass density'. Further, in trying to find a correlation between Biot's stress coefficient to parameters used in TPM yet unsolved inconsistencies are found. For studying the numerical effect of these differences, wave propagation results of a one-dimensional poroelastic column are analysed. Differences between both theories are resolved only for compressible constituents. [source] Prediction of the crystal structures of perovskites using the software program SPuDSACTA CRYSTALLOGRAPHICA SECTION B, Issue 6 2001Michael W. Lufaso The software program SPuDS has been developed to predict the crystal structures of perovskites, including those distorted by tilting of the octahedra. The user inputs the composition and SPuDS calculates the optimal structure in ten different Glazer tilt systems. This is performed by distorting the structure to minimize the global instability index, while maintaining rigid octahedra. The location of the A -site cation is chosen so as to maximize the symmetry of its coordination environment. In its current form SPuDS can handle up to four different A -site cations in the same structure, but only one octahedral ion. Structures predicted by SPuDS are compared with a number of previously determined structures to illustrate the accuracy of this approach. SPuDS is also used to examine the prospects for synthesizing new compounds in tilt systems with multiple A -site coordination geometries (a+a+a+, a0b+b+, a0b,c+). [source] The cocrystal nicotinamide,succinic acid (2/1)ACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2010Laura J. Thompson In the asymmetric unit of the crystal structure of nicotinamide,succinic acid (2/1), 2C6H6N2O·C4H6O4, there are two independent nicotinamide molecules in general positions and two half succinic acid molecules which lie about inversion centres. The structure contains acid,pyridine and amide,amide synthons with nicotinamide molecules forming ladders of alternating R22(8) and R42(8) rings linked through succinic acid to generate a corrugated hydrogen-bonded sheet. This sheet is a common supramolecular unit found in other 2:1 nicotinamide,dicarboxylic acid cocrystals, but the presence of two crystallographically distinct nicotinamides with anti and syn conformations, forming two distinct sheets within the same structure, is a novel packing feature in this type of material. [source] Two different one-dimensional structural motifs in [catena -{Cu(tacn)}2Pd(CN)4]Br2·[catena -Cu(tacn)Pd(CN)4]2·H2O (tacn is 1,4,7-triazacyclononane)ACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2009Juraj Kuchár The title compound, catena -poly[[bis[(triazacyclononane-,3N,N,,N,,)copper(II)]-di-,-cyanido-,4N:C -palladate(II)-di-,-cyanido-,4C:N] dibromide bis[[(triazacyclononane-,3N,N,,N,,)copper(II)]-,-cyanido-,2N:C -[dicyanidopalladate(II)]-,-cyanido-,2C:N] monohydrate], {[Cu2Pd(CN)4(C6H15N3)2]Br2·[Cu2Pd2(CN)8(C6H15N3)2]·H2O}n, (I), was isolated from an aqueous solution containing tacn·3HBr (tacn is 1,4,7-triazacyclononane), Cu2+ and tetracyanidopalladate(2,) anions. The crystal structure of (I) is essentially ionic and built up of 2,2-electroneutral chains, viz. [Cu(tacn)(NC),Pd(CN)2,(CN),], positively charged 2,4-ribbons exhibiting the composition {[Cu(tacn)(NC)2,Pd(CN)2,Cu(tacn)]2n+}n, bromide anions and one disordered water molecule of crystallization. The O atom of the water molecule occupies two unique crystallographic positions, one on a centre of symmetry, which is half occupied, and the other in a general position with one-quarter occupancy. One of the tacn ligands also exhibits disorder. The formation of two different types of one-dimensional structural motif within the same structure is a unique feature of this compound. [source] Autobiographical and event memories for surprising and unsurprising eventsAPPLIED COGNITIVE PSYCHOLOGY, Issue 2 2010Emanuele Coluccia Although research converges on the idea that surprise is not essential to form a ,flashbulb memory' (FBM), no study has explicitly shown that a FBM that develops from an unexpected event has the same structure as a FBM that develops from an expected event. In the present research, we explored whether there is any substantial difference on veridicality, consistency and confidence in both autobiographical and event memories for surprising and expected events. Two groups of participants were tested for their memories of a surprising (Study I) or an expected (Study II) event at different delays of indexing from the original news. All participants were then re-tested after 6 months and again after 1 year from the first interview. The same patterns of results were found for both events. Consistent with the ,narrative and rehearsal' hypothesis, our results provide direct evidence that surprise does not affect the structure of a FBM. Copyright © 2009 John Wiley & Sons, Ltd. [source] Multiferroicity in In-Containing PerovskitesCHEMPHYSCHEM, Issue 1 2010A new class of perovskite materials containing Indium at the A positions is Highlighted herein. New oxides of composition (In1,xMx)MO3 (x=0.112,0.176, M=Fe0.5Mn0.5), prepared at high pressures, exhibit the same structure as BiFeO3 (see picture) with TN close to RT and show multiferroic properties. This work shows that a polar distortion can be realized without the presence of a lone electron pair. [source] Influence of dynamic soil,structure interaction on the nonlinear response and seismic reliability of multistorey systemsEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 3 2007Armando Bárcena Abstract A set of reinforced concrete structures with gravitational loads and mechanical properties (strength and stiffness) representative of systems designed for earthquake resistance in accordance with current criteria and methods is selected to study the influence of dynamic soil,structure interaction on seismic response, ductility demands and reliability levels. The buildings are considered located at soft soil sites in the Valley of Mexico and subjected to ground motion time histories simulated in accordance with characteristic parameters of the maximum probable earthquake likely to occur during the system's expected life. For the near-resonance condition the effects of soil,structure interaction on the ductility demands depend mainly on radiation damping. According to the geometry of the structures studied this damping is strongly correlated with the aspect ratio, obtained by dividing the building height by its width. In this way, for structures with aspect ratio greater than 1.4 the storey and global ductility demands increase with respect to those obtained with the same structures but on rigid base, while for structures with aspect ratio less than 1.4 the ductility demands decrease with respect to those for the structures on rigid base. For the cases when the fundamental period of the structure has values very different from the dominant ground period, soil,structure interaction leads in all cases to a reduction of the ductility demands, independently of the aspect ratio. The reliability index , is obtained as a function of the base shear ratio and of the seismic intensity acting on the nonlinear systems subjected to the simulated motions. The resulting reliability functions are very similar for systems on rigid or on flexible foundation, provided that in the latter case the base rotation and the lateral displacement are removed from the total response of the system. Copyright © 2006 John Wiley & Sons, Ltd. [source] Correlation between gross anatomical topography, sectional sheet plastination, microscopic anatomy and endoanal sonography of the anal sphincter complex in human malesJOURNAL OF ANATOMY, Issue 2 2009S. Al-Ali Abstract This study elucidates the structure of the anal sphincter complex (ASC) and correlates the individual layers, namely the external anal sphincter (EAS), conjoint longitudinal muscle (CLM) and internal anal sphincter (IAS), with their ultrasonographic images. Eighteen male cadavers, with an average age of 72 years (range 62,82 years), were used in this study. Multiple methods were used including gross dissection, coronal and axial sheet plastination, different histological staining techniques and endoanal sonography. The EAS was a continuous layer but with different relations, an upper part (corresponding to the deep and superficial parts in the traditional description) and a lower (subcutaneous) part that was located distal to the IAS, and was the only muscle encircling the anal orifice below the IAS. The CLM was a fibro-fatty-muscular layer occupying the intersphincteric space and was continuous superiorly with the longitudinal muscle layer of the rectum. In its middle and lower parts it consisted of collagen and elastic fibres with fatty tissue filling the spaces between the fibrous septa. The IAS was a markedly thickened extension of the terminal circular smooth muscle layer of the rectum and it terminated proximal to the lower part of the EAS. On endoanal sonography, the EAS appeared as an irregular hyperechoic band; CLM was poorly represented by a thin irregular hyperechoic line and IAS was represented by a hypoechoic band. Data on the measurements of the thickness of the ASC layers are presented and vary between dissection and sonographic imaging. The layers of the ASC were precisely identified in situ, in sections, in isolated dissected specimens and the same structures were correlated with their sonographic appearance. The results of the measurements of ASC components in this study on male cadavers were variable, suggesting that these should be used with caution in diagnostic and management settings. [source] Spatially and temporally resolved thermal imaging of cyclically heated interconnects by use of scanning thermal microscopy,,MICROSCOPY RESEARCH AND TECHNIQUE, Issue 8 2008Nicholas Barbosa III Abstract A scanning thermal microscope with a Wollaston probe was used to investigate the spatial distribution and temporal variation of temperature in interconnect structures subjected to thermal cycling. The probe, utilized in passive temperature sensing mode, was calibrated from 20°C to 200°C using a single-layer aluminum microdevice. Spatial measurements were performed on nonpassivated aluminum interconnects sinusoidally heated by a 6 MA/cm2 current at 200 Hz. The interconnects were determined to have temperatures that decreased with position from a maximum located at the center of both the interconnect length and width. Time-resolved temperature measurements were performed on the same structures sinusoidally heated by a 6 MA/cm2 current at 2 Hz. Both the peak-cycle temperature and average-cycle temperature were found to decrease with increasing distance from the center of the width of the interconnects. Microsc. Res. Tech., 2008. Published 2008 Wiley-Liss, Inc. [source] The reliability of crown,root ratio, linear and angular measurements on panoramic radiographsORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 4 2000Steve Stramotas The aim of this study was to evaluate the reliability of crown and root length, crown,root ratio and angular measurements of teeth relative to constructed reference lines and to other teeth in the same region on consecutive (T1 and T2) panoramic radiographs (OPGs). This retrospective study employed 20 cases; ten with five implants in each jaw (age range between 20 and 60 years) and ten with a full permanent dentition (age range between 12 and 16 years). The consecutive pairs of OPGs ranged from 6 months to 3 years apart. Four variables were measured and compared: 1) the crown or coronal segment length and the root or apical segment length; 2) the crown,root ratio; 3) the angulations of teeth and implants relative to specific reference lines in each jaw; 4) the angle between teeth and implants in the same sextant. The results revealed that comparisons of measurements taken of the same structures at T1 and T2, there were no statistically significant differences (p>0.05) between vertical linear measurements. The crown,root ratios and coronal,apical segment ratios too, showed no significant differences (p>0.05). Whereas, angulations of teeth or implants relative to respective reference lines showed significant differences (p=0.001) for some of the teeth. These differences, however, were less than 5°; a clinically acceptable range. Angles measured between teeth or implants in the same sextant showed no significant differences (p>0.05). These results seem to support the hypothesis, therefore, that the linear vertical measurements, ratio calculations and angular measurements can be used to compare crown and root lengths, crown,root ratios and tooth angulations on OPGs taken of the same patient at different times with consistent accuracy. [source] Early neural activity in Necker-cube reversal: Evidence for low-level processing of a gestalt phenomenonPSYCHOPHYSIOLOGY, Issue 1 2004Jürgen Kornmeier Abstract Normally we experience the visual world as stable. Ambiguous figures provide a fascinating exception: On prolonged inspection, the "Necker cube" undergoes a sudden, unavoidable reversal of its perceived front-back orientation. What happens in the brain when spontaneously switching between these equally likely interpretations? Does neural processing differ between an endogenously perceived reversal of a physically unchanged ambiguous stimulus and an exogenously caused reversal of an unambiguous stimulus? A refined EEG paradigm to measure such endogenous events uncovered an early electrophysiological correlate of this spontaneous reversal, a negativity beginning at 160 ms. Comparing across nine electrode locations suggests that this component originates in early visual areas. An EEG component of similar shape and scalp distribution, but 50 ms earlier, was evoked by an external reversal of unambiguous figures. Perceptual disambiguation seems to be accomplished by the same structures that represent objects per se, and to occur early in the visual stream. This suggests that low-level mechanisms play a crucial role in resolving perceptual ambiguity. [source] | |||||||||||||||||||||||||||||||