bluuebunny/crossref_metadata_2025_split huggingface dataset:
Implementing peer support in schools: using a theoretical framework in action research
Authors: Visser Maretha J. 
Published: July 2004

AbstractThe implementation of a peer support project in 13 schools from a disadvantaged background is discussed using the social ecological, systems and social construction theory as a theoretical guide in action research. The goal was to establish an alternative helping system in schools that was sustainable within the school system. In the implementation of peer support attention was given to the integration of the project into the existing context; encouraging participation on all levels, facilitating change and creating shared meanings, supporting the process of reorganizing and restructuring and providing feedback to facilitate further change. From a process evaluation of the programme implementation challenges in the implementation process were identified and recommendations made that could contribute to the optimal functioning and sustainability of the project to address the needs of learners and enhance well being in the school community. Copyright © 2004 John Wiley & Sons, Ltd.
Hydrogen‐Bonding Cooperativity: Using an Intramolecular Hydrogen Bond To Design a Carbohydrate Derivative with a Cooperative Hydrogen‐Bond Donor Centre
Authors: Vicente Virginie , Martin Jason , Jiménez‐Barbero Jesús , Chiara José Luis , Vicent Cristina 
Published: July 2004

AbstractNeighbouring groups can be strategically located to polarise HO⋅⋅⋅OH intramolecular hydrogen bonds in an intended direction. A group with a unique hydrogen‐bond donor or acceptor character, located at hydrogen‐bonding distance to a particular OH group, has been used to initiate the hydrogen‐bond network and to polarise a HO⋅⋅⋅OH hydrogen bond in a predicted direction. This enhanced the donor character of a particular OH group and made it a cooperative hydrogen‐bond centre. We have proved that a five‐membered‐ring intramolecular hydrogen bond established between an amide NH group and a hydroxy group (1,2‐e,a), which is additionally located in a 1,3‐cis‐diaxial relationship to a second hydroxy group, can be used to select a unique direction on the six‐membered‐ring intramolecular hydrogen bond between the two axial OH groups, so that one of them behaves as an efficient cooperative donor. Talose derivative 3 was designed and synthesised to prove this hydrogen‐bonding network by NMR spectroscopy, and the mannopyranoside derivatives 1 and 2 were used as models to demonstrate the presence in solution of the 1,2‐(e,a)/five‐membered‐ring intramolecular hydrogen bond. Once a well‐defined hydrogen‐bond is formed between the OH and the amido groups of a pyranose ring, these hydrogen‐bonding groups no longer act as independent hydrogen‐bonding centres, but as hydrogen‐bonding arrays. This introduces a new perspective on the properties of carbohydrate OH groups and it is important for the de novo design of molecular recognition processes, at least in nonpolar media. Carbohydrates 1–3 have shown to be efficient phosphate binders in nonpolar solvents owing to the presence of cooperative hydroxy centres in the molecule.
Online monitoring of preferential crystallization of enantiomers
Authors: Alvarez Rodrigo Angela , Lorenz Heike , Seidel‐Morgenstern Andreas 
Published: July 2004

AbstractPolarimetry is used for continuous online monitoring of optical resolution by preferential crystallization. In combination with refractometry the liquid phase composition is determined, allowing one to follow the resolution progress quantitatively. The measurement techniques were calibrated up to relatively high solution concentrations and combined with the crystallizer. The resolution of DL‐threonine was performed by preferential crystallization experiments in aqueous solution varying several process parameters like supersaturation, seed amount, initial enantiomeric excess, and scale. The resolution progress can be conveniently described by profiles of the optical rotation (polarimetric signal) and the crystallization pathway in the corresponding ternary phase diagram. The method outlined is applicable for dynamic process optimization and control purposes in “quasi‐continuous” chiral separation processes. Chirality 16:499–508, 2004. © 2004 Wiley‐Liss, Inc.
Dirhodium‐catalyzed enantioselective C–H insertion of N‐(2‐benzyloxyethyl)‐N‐(tert‐butyl)diazoacetamide and its application for the synthesis of chiral GABOB
Authors: Du Zhenjun , Chen Zhenliang , Chen Zhiyong , Yu Xiaoqi , Hu WenHao 
Published: July 2004

AbstractRh2(4S‐MEOX)4 and ethereal solvent are the best catalytic system for the enantioselective intramolecular C–H insertion of N‐(2‐benzyloxyethyl)‐N‐(tert‐butyl)diazoacetamide 2. The highest enantiomeric excess obtained was 91%. A new route for the asymmetric synthesis of γ‐amino‐β‐hydroxybutyric acid (GABOB) has been developed. Chirality 16:516–519, 2004. © 2004 Wiley‐Liss, Inc.
Differential expression of Csk homologous kinase (CHK) in normal brain and brain tumors
Authors: Kim Sun‐Ok , Avraham Shalom , Jiang Shuxian , Zagozdzon Radoslaw , Fu Yigong , Avraham Hava Karsenty 
Published: July 2004

AbstractBACKGROUNDSubstantial evidence supports the suggestion that carboxyl‐terminal Src kinase (Csk) and Csk homologous kinase (CHK), two negative regulatory kinases of the Src tyrosine kinase family, play distinct roles during development of the central nervous system (CNS).METHODSTo further examine the individual roles of CHK and Csk in the CNS, the authors compared the expression patterns of Csk and CHK during differentiation of primary hippocampal neurons.RESULTSOpposite patterns of expression were observed for CHK and Csk. The authors observed an increase in CHK expression and a decline in Csk expression during differentiation of primary hippocampal neurons, but no difference in Src expression levels. CHK was also expressed in astrocytes and oligodendrocytes in a differentiation‐dependent manner. However, CHK expression was not detected in brain endothelial cells, transformed neuroblastoma or astrocytoma cell lines, nor in primary human neuroblastoma and glioblastoma tumors (10 cases), indicating that loss of CHK expression is associated with human brain tumors. Treatment with antisense CHK oligodeoxynucleotides blocked the neuronal process formation of primary hippocampal neurons and neuronal differentiation of PC12 cells. CHK overexpression in primary hippocampal neurons using recombinant adenovirus infection resulted both in increased CHK kinase activity and changes in neuronal morphology. In addition, CHK overexpression in neuroblastoma and astrocytoma cells inhibited their growth and proliferation.CONCLUSIONSThese findings strongly suggested that CHK may play a role in tumorigenesis and in the terminal differentiation of neurons within the CNS. Cancer 2004. © 2004 American Cancer Society.
A study of thickness optimization of golf club heads to maximize release velocity of balls
Authors: Nakai Kenji , Wu Zhiqiang , Sogabe Yuji , Arimitsu Yutaka 
Published: July 2004

AbstractIn the present study, the shape optimization of a golf club head is investigated. The problem of maximizing the release velocity of the ball after impact is treated under the constraint of a specified weight of club head. The thickness distribution of the clubface is chosen as the design variable for optimization. The basis vector method, which is an approximating method for optimization problems in which the sensitivity cannot be derived analytically, is employed. The basis vector represents a fundamental change of shape, and it is preferable to obtaining effective results that the basis vectors be mutually independent. A simple approach to create the basis vectors using eigenmodes is also presented. The theory of impedance matching is confirmed numerically by a two‐dimensional example. A three‐dimensional example is given to show that this approach is effective for optimal design of the golf club head. Copyright © 2004 John Wiley & Sons, Ltd.
Accuracy of Carrillo's formula for consolidation of soil with vertical and horizontal drainage under time‐dependent loading
Authors: Zhu Guofu , Yin Jian‐Hua 
Published: July 2004

AbstractThe accuracy of Carrillo's formula for consolidation of soil with vertical and horizontal drainage under time‐dependent loading is examined using the rigorous solutions in Zhu and Yin (Geotechnique 2001; 51: 361–367; Geotextiles and Geomembranes 2003) for two situations of free strain and equal strain assumptions. It is found from the examination that Carrillo's formula normally overestimates the overall average degree of consolidation. However, for the ranges of practical significance, the overestimate is less than 3% if the construction time factor Tc is less than 1.25. For the Tc up to 4, the overestimate is less than 9%. The comparison of free strain and equal strain solutions also shows that the difference between the two solutions under time‐dependent loading is small. Copyright © 2004 John Wiley & Sons, Ltd.
Finding stale‐value errors in concurrent programs
Authors: Burrows Michael , Leino K. Rustan M. 
Published: July 2004

AbstractConcurrent programs can suffer from many types of errors, not just the well‐studied problems of deadlocks and simple race conditions on variables. This paper addresses a kind of race condition that arises from reading a variable whose value is possibly out of date. The paper introduces a simple technique for detecting such stale values, and reports on the encouraging experience with a compile‐time checker that uses the technique. Copyright © 2004 John Wiley & Sons, Ltd.
A cache‐efficient implementation of the lattice Boltzmann method for the two‐dimensional diffusion equation
Authors: Velivelli A. C. , Bryden K. M. 
Published: July 2004

AbstractThe lattice Boltzmann method is an important technique for the numerical solution of partial differential equations because it has nearly ideal scalability on parallel computers for many applications. However, to achieve the scalability and speed potential of the lattice Boltzmann technique, the issues of data reusability in cache‐based computer architectures must be addressed. Utilizing the two‐dimensional diffusion equation,$T_t=\mu(T_{xx}T_{yy})$, this paper examines cache optimization for the lattice Boltzmann method in both serial and parallel implementations. In this study, speedups due to cache optimization were found to be 1.9–2.5 for the serial implementation and 3.6–3.8 for the parallel case in which the domain decomposition was optimized for stride‐one access. In the parallel non‐cached implementation, the method of domain decomposition (horizontal or vertical) used for parallelization did not significantly affect the compute time. In contrast, the cache‐based implementation of the lattice Boltzmann method was significantly faster when the domain decomposition was optimized for stride‐one access. Additionally, the cache‐optimized lattice Boltzmann method in which the domain decomposition was optimized for stride‐one access displayed superlinear scalability on all problem sizes as the number of processors was increased. Copyright © 2004 John Wiley & Sons, Ltd.
An order‐based algorithm for implementing multiparty synchronization
Authors: Pérez José A. , Corchuelo Rafael , Toro Miguel 
Published: July 2004

AbstractMultiparty interactions are a powerful mechanism for coordinating several entities that need to cooperate in order to achieve a common goal. In this paper, we present an algorithm for implementing them that improves on previous results in that it does not require the whole set of entities or interactions to be known at compile‐ or run‐time, and it can deal with both terminating and non‐terminating systems. We also present a comprehensive simulation analysis that shows how sensitive to changes our algorithm is, and compare the results with well‐known proposals by other authors. This study proves that our algorithm still performs comparably to other proposals in which the set of entities and interactions is known beforehand, but outperforms them in some situations that are clearly identified. In addition, these results prove that our algorithm can be combined with a technique called synchrony loosening without having an effect on efficiency. Copyright © 2004 John Wiley & Sons, Ltd.
Frontline: Absence of functional STAT4 activation despite detectable tyrosine phosphorylation induced by murine IFN‐α
Authors: Berenson Lisa S. , Farrar J. David , Murphy Theresa L. , Murphy Kenneth M. 
Published: July 2004

AbstractWe previously reported that IL‐12, but not IFN‐αA/D, induces T helper type (Th) 1 development and STAT4 phosphorylation in murine CD4+ T cells. However, a recent study reported that IFN‐αA/D and recombinant murine IFN‐αA can induce STAT4 phosphorylation, although more weakly than IL‐12, largely in CD8+ rather than CD4+ T cells. That report did not examine Th1 development or directly demonstrate induction of IFN‐γ by IFN‐α. To address these differences, we compared IFN‐αA/D, murine IFN‐αA, and IL‐12 for STAT4 phosphorylation, formation of active nuclear DNA binding complexes, induction of Th1 development, and production of IFN‐γ in murine CD4+ T cells. IFN‐αA induced detectable STAT4 phosphorylation, although at significantly lower levels than induced by IL‐12. Furthermore, in contrast to IL‐12, IFN‐αA failed to induce Th1 development or the formation of DNA binding complexes or to synergize with IL‐18 for induction of IFN‐γ production. STAT1‐deficient CD4+ T cells showed increased IFN‐αA‐induced STAT4 phosphorylation but still exhibited significantly lower amounts of cytokine‐induced IFN‐γ compared to IL‐12. In summary, these results suggest that in contrast to IL‐12, IFN‐αA does not play a functionally significant role in meditating the STAT4‐dependent induction of Th1 development or IFN‐γ production in CD4+ T cells.
Depletion of NK cells results in disseminating lethal infection with Bordetella pertussis associated with a reduction of antigen‐specific Th1 and enhancement of Th2, but not Tr1 cells
Authors: Byrne Patricia , McGuirk Peter , Todryk Stephen , Mills Kingston H. G. 
Published: July 2004

AbstractIFN‐γ plays a critical role in protection against Bordetella pertussis, but Th1 cells are only detectable after the infection has started to resolve, suggesting a protective role for innate IFN‐γ early in infection. Here, we demonstrate significant recruitment of NK cells and NKT cells into the lungs following respiratory challenge with B. pertussis. Furthermore, NK cells are the primary source of IFN‐γ in the lungs during the acute stage of infection. Stimulation of IFN‐γ production by NK cells was indirect through B. pertussis‐activated IL‐12 or IL‐23 production by dendritic cells. Depletion of NK cells with anti‐asialo ganglio‐N‐tetraosylceramide antibody resulted in a lethal infection, with enhancement of bacterial load in the lungs and dissemination of the bacteria to the liver via the blood. NK cell‐depleted mice had significantly reduced B. pertussis‐specific IFN‐γ and enhanced IgG1 and IL‐5, but not IL‐10 production, suggesting that regulatory T cells are induced simultaneously with Th1 cells, but the absence of NK cells resulted in enhancement of Th2‐type responses. These findings suggest that NK cells confer resistance to B. pertussis by activating IL‐12‐mediated production of IFN‐γ, which enhances the anti‐bacterial activity of macrophages, but also promotes the differentiation of Th1 cells.
Syntheses and Characterizations of Metal‐Organic Frameworks with Unusual Topologies Derived from Flexible Dipyridyl Ligands
Authors: Wang Ruihu , Han Lei , Xu Lijin , Gong Yaqiong , Zhou Youfu , Hong Maochun , Chan Albert S. C. 
Published: July 2004

AbstractTwo flexible exo‐bidentate ligands, 2,2′‐bis(3‐pyridylmethyleneoxy)‐1,1′‐biphenylene (3,3′‐bpp) and 2,2′‐bis(4‐pyridylmethyleneoxy)‐1,1′‐biphenylene (4,4′‐bpp), were synthesized and employed for the preparation of coordination polymers. Seven metal‐organic complexes, [Zn2(3,3′‐bpp)2Cl4] (1), [Zn2(3,3′‐bpp)2Br4] (2), [Zn(4,4′‐bpp)Cl2]n (3), [Zn(4,4′‐bpp)Br2]n (4), [Co(4,4′‐bpp)2(SCN)2]n (5), {[Cd(4,4′‐bpp)2(SCN)2]·2H2O}n (6) and [Cd(4,4′‐bpp)(dca)2]n (7) (dca− = dicyanamide), have been obtained through self‐assembly reactions of 3,3′‐bpp or 4,4′‐bpp with the divalent metal ions ZnII, CoII and CdII. Crystal structure analyses reveal that 1 and 2 are dinuclear metallomacrocycles, are isomorphous and possess a layer network built from metallomacrocycles through π−π interactions. In drastic contrast, 3 and 4 exhibit a three‐dimensional structure consisting of one‐dimensional polymeric chains held together through π−π interactions between adjacent pyridyl rings. The metal‐organic frameworks of 5, 6, and 7 possess unusual topologies: Complex 5 is a two‐dimensional polymer based on folded rectangular boxes and zigzag chains, whereas 6 is a polycatenated species consisting of inclined interpenetrating two‐dimensional layers, and each layer is constructed by the alternating assembly of left‐hand (M) and right‐hand (P) cylindrical 21 helices. In 7, dca− connects CdII centers forming a two‐dimensional {Cd(dca)2}n layer, which is fused with (M)‐ and (P)‐Cd‐(4,4′‐bpp) helical chains into a three‐dimensional structure. The results suggest that the nature of organic ligands and the coordination preferences of transitional metal ions have a great influence on the structures of metal‐organic complexes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Syntheses and Crystal Structures of Two Cobalt Carboxylate−Phosphonates with 4,4′‐Bipyridine as a Secondary Metal Linker
Authors: Song Jun‐Ling , Prosvirin Andrey V. , Zhao Han‐Hua , Mao Jiang‐Gao 
Published: July 2004

AbstractThe hydrothermal syntheses and crystal structures of two novel cobalt carboxylate−phosphonates with 4,4′‐bipyridine (4,4′‐bipy) as the secondary metal linker are reported. Compound 1, [Co3(H2L)2(H2O)4(4,4′‐bipy)], where H5L = 4‐HO2CC6H4CH2N(CH2PO3H2)2, crystallizes in the monoclinic space group C2/c with a = 25.9281(5), b = 9.76310(10), c = 17.3671(5) Å, β = 103.290(2)°, V = 4278.6(2) Å3, and Z = 4. Its structure contains a pillar‐layered architecture in which CoII octahedra are linked by carboxylate−phosphonate ligands to form a 2D layer and these layers are crosslinked further by 4,4′‐bipy ligands to form a porous 3D network. Compound 2, [Co2(PMIDA)(H2O)5(4,4′‐bipy)]·4H2O, where H4PMIDA = H2O3PCH2N(CH2CO2H)2, crystallizes in the triclinic space group P$\bar 1$
with a = 7.8009(7), b = 13.4560(12), c = 13.5453(12) Å, α = 65.207(2), β = 88.035(2), γ = 77.135(2)°, V = 1255.57(19) Å3, and Z = 2. The crystal structure of compound 2 contains 1D zigzag chains in which two cobalt(II) ions are bridged by PMIDA ligand to form dimeric units, and these dimeric units are connected further by bridging 4,4′‐bipy ligands. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Effect of pH on the Hydrogenase Activity of Desulfovibrio vulgaris
Authors: Sakaguchi Seiya , Kano Kenji , Ikeda Tokuji 
Published: July 2004

AbstractIntact hydrogenase in Desulfovibrio vulgaris (Hildenborough) cells exhibits catalytic activity for the reaction H2+Mox⇔︁2H++Mred (here Mox/Mred is a redox couple serving as an electron acceptor/donor). Dependence on pH of the catalytic activity was studied in view of the expected pH dependence of the substrate concentration [H+] and the standard free energy change of the overall reaction ΔG°. It has been revealed that the conventional Michaelis‐Menten type analysis for the H2 evolution reaction leads an erroneous conclusion with respect to the dependence of the reaction rate on [H+] and that the pH dependence of the hydrogenae‐catalyzed H2 evolution and consumption reactions reflect the pH‐dependent change of ΔG°.
A Systematic Study of the Influence of Peptide Modification of a Gold Electrode on the Cyclic Voltammetry of Pseudoazurin from Alcaligenes faecalis Strain S‐6
Authors: Astier Yann , Bond Alan M. , Wijma Hein J. , Canters Gerard W. , Hill H. Allen O. , Davis Jason J. 
Published: July 2004

AbstractThe influence of peptide‐protein interactions on the electrochemistry of copper‐containing pseudoazurin from Alcaligenes faecalis strain S‐6 has been investigated by covalently binding cysteine‐containing hexapeptides to a gold electrode surface. The hexapeptides contain three cysteines in the same positions with the remaining amino acids varied to give mixed charge (lysine, threonine, alanine), positive (lysine), overall neutral (alanine), and negative (glutamate) chemically modified electrode surfaces. These systematic variations in the amino acid sequence lead to large variations in voltammetric behavior for the Cu(II)→Cu(I) heterogeneous pseudoazurin redox process encompassing fully reversible and diffusional, transitionally adsorbed, or strongly adsorbed forms of voltammetry. The variations in voltammetric behavior may be related to electrostatic interactions between the charges from the hexapeptide electrode modifiers and surface charges of pseudoazurin. A possible description of the pseudoazurin‐electrode surface interaction is given.
Bioanalysis: Its past, present, and some future
Authors: Righetti Pier Giorgio 
Published: July 2004

AbstractAn overview of about 100 years of bioanalysis is here disastrously attempted. The beginning of rigorous analytical systems can perhaps be traced back to the building and testing of the analytical ultracentrifuge by Svedberg and the apparatus for moving‐boundary electrophoresis of Tiselius, both systems relying on expensive and hard to operate machines. In the sixties, Porath discovered porous beads for the determination of relative molecular mass (Mr) of proteins, based on the principle of molecular sieving. Concomitantly, Svensson and his pupil Vesterberg described a revolutionary principle for fractionating proteins in a nonisocratic environment, based on generation of stable pH gradients in an electric field, a technique that went down to history as isoelectric focusing (IEF). Polyacrylamide gel electrophoresis (PAGE), with the brilliant idea of discontinuous buffers, was brought to the limelight and in 1967, sodium dodecyl sulfate (SDS)‐PAGE was described, permitting easy assessment of protein purity and reasonable measurements of Mr values of denatured polypeptide chains. By the mid seventies, another explosive concept was realized: orthogonal combination of two unrelated techniques, based on surface charge and mass fractionation, namely, two‐dimensional (2‐D) PAGE already in the very first papers by O'Farrell elaborated to its utmost sophistication. The eighties saw the systematic growth of 2‐D PAGE, accompanied by systematic efforts to develop instrumentation for large‐scale production of 2‐D maps and computer evaluation for 2‐D map analysis, based on the sophisticated algorithms adopted by astronomers for mapping stars in the sky. Another fundamental innovation in the field of IEF was the discovery of immobilized pH gradients (IPGs) that brought the much needed reproducibility in 2‐D maps while allowing exquisite resolution in very narrow pH ranges. The nineties were definitely the decade of capillary zone electrophoresis, with the concomitant concept of automation and miniaturization in electrokinetic methodologies. Also 2‐D map analysis witnessed a big revival, thanks to the adoption of IPGs for the first dimension. The enormous progress of mass spectrometry resulted in first reports on the analysis of macromolecules and the building of data bases on gene and protein banks. The third millennium is, perhaps, exasperating the concept of miniaturization at all costs, while not disdaining increasingly larger maps for 2‐D analysis of complex protein mixtures.