bluuebunny/crossref_metadata_2025 huggingface dataset:
Eating together apart: patterns of segregation in a multi‐ethnic cafeteria
Authors: Clack Beverley , Dixon John , Tredoux Colin
Published: July 2004

Research on segregation has tended to focus on relations located at a macro‐spatial level of analysis and unfolding in contexts where boundaries to interaction are formally established. This research, by contrast, investigated segregation as a micro‐ecological process by observing patterns of seating in a multi‐ethnic cafeteria. A total of 3114 seating positions were coded over a 2‐week period and the resulting data were analysed using both adapted segregation indices (P and D) and loglinear and logistic regression techniques. The results suggested that ethnic segregation existed both at the level of interactional groups and in the form of broader patterns of racial clustering and dispersal in the cafeteria. Moreover, the magnitude of segregation was predicted by the gender composition of seating groups and by variations in the density of the cafeteria's population over time. Some implications of these results for social psychological research on contact and desegregation are considered. Copyright © 2004 John Wiley & Sons, Ltd.
Implementing peer support in schools: using a theoretical framework in action research
Authors: Visser Maretha J.
Published: July 2004

The 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

Neighbouring 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

Polarimetry 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

Rh2(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

BACKGROUND

Substantial 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).

METHODS

To 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.

RESULTS

Opposite 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.

CONCLUSIONS

These 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

In 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

The 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

Concurrent 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

The 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

Multiparty 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.
Determinants of adoption of third generation mobile multimedia services
Authors: Pagani Margherita
Published: July 2004

In this article, we review user information technology acceptance literature, formulate a model of consumer adoption of third generation mobile multimedia services, validate it through a qualitative exploratory study comprising 24 focus groups in six markets, and empirically test the proposed model on the Italian market. The results show that perceived usefulness, ease of use, price, and speed of use are the most important determinants of adoption of multimedia mobile services, in that order. They also show that the importance of determinants differs by age groups or segments. The results can help managers proactively design interventions (such as training and marketing activities) targeted at populations of users that may be less inclined to adopt and use new multimedia mobile services.
Customer lifetime value approaches and best practice applications
Authors: Kumar V. , Ramani Girish , Bohling Timothy
Published: July 2004

Each customer varies in his/her lifetime value to a firm. A firm would like to estimate the lifetime value of each customer and use this information in planning differential marketing initiatives targeted at each customer. Customer lifetime value computations require different approaches depending on the business application that a firm is looking at. The authors present two approaches of computing customer lifetime value and offer some best practice applications. The authors also address challenges that firms typically face in implementing the customer lifetime value approach to marketing.
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

We 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

IFN‐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

Two 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

The 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

Intact 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

The 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

An 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.
Improved capillary electrophoresis method for the determination of carbohydrate‐deficient transferrin in patient sera
Authors: Lanz Christian , Kuhn Martina , Deiss Veronika , Thormann Wolfgang
Published: July 2004

Capillary zone electrophoresis (CZE) with a dynamic double coating formed by charged polymeric reagents represents an effective tool for the separation of iron‐saturated transferrin (Tf) isoforms and thus the determination of carbohydrate‐deficient transferrin (CDT, sum of asialo‐, monosialo‐ and disialo‐Tf in relation to total Tf) in human serum. Using the CEofix‐CDT reagents, a 50 μm inner diameter (ID) capillary of 60 cm total length and the P/ACE MDQ under optimized instrumental conditions (20 kV and 30°C) is demonstrated to provide outstanding assay precision for the determination of CDT in human serum. For CDT levels of 1.0% and 4.5%, precision relative standard deviation (RSD) values (n = 8) were determined to be < 3.0% and < 1.5%, respectively. During the first year of operation under routine conditions, more than 600 patient samples were analyzed in a total of 62 sets of runs. Except for selected samples of patients with severe liver diseases, interference‐free Tf patterns were detected. Asialo‐Tf was not detected in control sera and in patient sera with a CDT level < 1.70%, but became detectable in 89.6% of sera with > 2.3% disialo‐Tf. Monosialo‐Tf was only detected in two sera containing > 13.3% CDT. The optimized CZE assay was applied to confirm positive CDT results produced by an immunoassay during long‐term monitoring of a patient which led to the determination of the elimination kinetics of asialo‐Tf, disialo‐Tf, and CDT after an episode of high alcohol consumption (estimated apparent half lifes of 4.86, 7.24, and 6.74 days, respectively). The optimized CZE assay with an upper reference limit for CDT of 1.70% represents an attractive alternative to high‐performance liquid chromatography (HPLC). It features simpler sample preparation, faster analysis time, and higher isoform resolution compared to the most recent HPLC approach and can thus be regarded as a new candidate of a reference method for CDT.
Mining the human cerebrospinal fluid proteome by immunodepletion and shotgun mass spectrometry
Authors: Maccarrone Giuseppina , Milfay Dale , Birg Isabel , Rosenhagen Marcus , Holsboer Florian , Grimm Rudolf , Bailey Jerome , Zolotarjova Nina , Turck Christoph W.
Published: July 2004

We have analyzed the proteome of human cerebrospinal fluid with the help of shotgun mass spectrometry. In order to identify low‐abundant proteins in these fluids, we have found it necessary to remove the abundant protein components from the mixture. Immunodepletion of the abundant proteins has allowed us to identify more than 100 proteins in cerebrospinal fluids from a patient suffering from normal pressure hydrocephalus. The identified proteins belong to a variety of different classes ranging from serum proteins to intracellular mediators that are involved in signal transduction and transcription. This work establishes a platform for future studies aimed at the comparative proteome analysis of cerebrospinal fluids from different groups of patients suffering from various psychiatric and neurological disorders.
Optimization of the electrokinetic supercharging preconcentration for high‐sensitivity microchip gel electrophoresis on a cross‐geometry microchip
Authors: Xu Zhongqi , Hirokawa Takeshi
Published: July 2004

We developed a novel on‐line preconcentration procedure for microchip gel electrophoresis (MCGE), which enables application of electrokinetic supercharging (EKS) for highly sensitive detection of DNA fragments on a cross‐geometry microchip. In comparison with conventional pinched injection using the cross microchip, the present approach allows loading a much larger amount of the sample by taking advantage of a newly developed operational mode. In order to obtain high preconcentration effect and prevent splitting of an enriched sample into subchannels, i.e., off the detector range, effects of the voltage applied on the reservoirs and the time of isotachophoretic preconcentration were examined. The optimal balance between the voltage and time was found for a high‐sensitivity analysis of DNA fragments. After experimental optimization the detection limit of a 150 bp fragment was as low as 0.22 mg/L (S/N = 3) that is 10 times better than using the conventional pinched injection.
Automated carbohydrate profiling by capillary electrophoresis: A bioindustrial approach
Authors: Khandurina Julia , Blum David L. , Stege Justin T. , Guttman András
Published: July 2004

Automated, high‐resolution, quantitative, high‐throughput analysis of mono‐ and oligosaccharides, produced by enzymatic digestion of cellohexaose (model substrate) and lignocellulosic biomass, is demonstrated using high‐performance capillary electrophoresis in conjunction with a single‐step fluorophore labeling strategy for sensitive laser‐induced fluorescence detection. Unattended batch sample processing from 96‐well plates enabled reliable industrial‐scale carbohydrate analysis. Excellent resolution of mono‐ and oligosaccharides was achieved under suppressed electroosmotic flow conditions, using either covalently or dynamically coated fused‐silica capillary columns. The proposed approach readily supports the demands of bioindustrial operation environments with respect to high‐throughput carbohydrate profiling.
Alkali‐stable high‐pI isoelectric membranes for isoelectric trapping separations
Authors: Lalwani Sanjiv , Shave Evan , Fleisher Helen C. , Nzeadibe Kingsley , Busby M. Brent , Vigh Gyula
Published: July 2004

Alkali‐stable, high‐pI isoelectric membranes have been synthesized from quaternary ammonium derivatives of cyclodextrins and poly(vinyl alcohol), and bifunctional cross‐linkers, such as glycerol‐1,3‐diglycidyl ether. The new, high‐pI isoelectric membranes were successfully applied as cathodic membranes in isoelectric trapping separations in place of the hydrolytically more labile, polyacrylamide‐based cathodic isoelectric membranes, and permitted the use of catholytes as alkaline as 1 M NaOH. The new high‐pI isoelectric membranes have shown excellent mechanical stability, low electric resistance and long life times, even when subjected to electrophoresis with current densities as high as 80 mA/cm2.
A column gel electrophoresis‐coupled genomic DNA subtractive hybridization technique
Authors: Ozawa Kazuo , McElgunn Cathal J. , Yasukochi Takanori , Shibanaka Yasuhiko
Published: July 2004

We have developed a DNA subtractive hybridization technique especially designed for mammalian genome comparison. The core of this protocol is a newly devised denaturant‐containing polyacrylamide gel formed in a glass‐column. In this gel system, the following DNA manipulation steps are carried out sequentially: size separation by electrophoresis, heat‐denaturation, renaturation, and recovery. In the first step, a mixture of tester and driver DNA fragments are segregated according to their size whilst keeping their double‐stranded forms. This reduces the complexity of the original genomic DNA fragments and also segregates DNA fragments having closely related sequences. In the second step, fractionated DNA fragments are quickly denatured and subjected to successive subtractive hybridization in situ by controlling gel temperature in a water bath. In the third step, DNA fragments are recovered by electrophoresis towards the reverse‐orientation and are adsorbed onto ion‐exchange beads. Two lines of experiments show that our protocol is able to highly enrich or directly extract differences among genomic DNA samples.
On‐line capillary electrophoresis‐mass spectrometry for the analysis of biomolecules
Authors: Hernández‐Borges Javier , Neusüß Christian , Cifuentes Alejandro , Pelzing Matthias
Published: July 2004

Mass spectrometry (MS) has become a key tool for the characterization of biologically relevant molecules in the last decade. Due to the complexity of most biological samples an upstream separation is essential. Capillary electrophoresis (CE) has gained much interest due to its high separation efficiency, speed, and often complementary selectivity to liquid chromatography. We describe the state‐of‐the‐art of on‐line CE‐MS for the analysis of molecules of biological origin. The characterization of peptides, including the study of post‐translational modifications, intact proteins, oligonucleotides, and related interaction studies are reviewed. Relevant publications are summarized in tables, including some important method parameters. Key applications are discussed with respect to the advantages and limitations of CE‐MS. Coupling interfaces, preconcentration techniques, capillary coatings, and the different CE techniques, e.g., capillary zone electrophoresis, capillary isoelectric focusing, capillary gel electrophoresis, etc. are briefly discussed against the background of their bioanalytical applications.
Virtual two‐dimensional gel electrophoresis of high‐density lipoproteins
Authors: Ogorzalek Loo Rachel R. , Yam Lang , Loo Joseph A. , Schumaker Verne N.
Published: July 2004

High‐density lipoproteins (HDLs) isolated by immunoaffinity chromatography and separated by immobilized pH gradient‐isoelectric focusing (IPG‐IEF) were examined by mass spectrometry directly, applying a new proteomics technology, virtual two‐dimensional (2‐D) gel electrophoresis. A preliminary examination of HDL particles has revealed at least 42 unique masses for protein species with isoelectric points between pH 5.47–5.04, some of which have not been observed previously. By delivering masses of intact proteins from complex cellular mixtures in a format that correlates directly to classical 2‐D gel analyses, virtual 2‐D gel electrophoresis constitutes a general discovery tool to expose and monitor protein isoforms and post‐translational modifications. Furthermore, its general ability to deliver ions from sub‐picomole level proteins enmeshed in complex cellular mixtures potentially fulfills the need of top‐down proteomics to obtain intact protein ions from microscale samples. Additional comparison of such data to 2‐D gel analyses and their identified proteins may elucidate the functions of the individual apolipoprotein components and the cardioprotective effects of HDL.
An integrated method for mutation detection using on‐chip sample preparation, single‐stranded conformation polymorphism, and heteroduplex analysis
Authors: Vahedi Golnaz , Kaler Karan , Backhouse Christopher J.
Published: July 2004

This work integrates rapid techniques for mutation detection by producing single‐stranded DNA and (renatured) double‐stranded DNA on‐chip, labeling these with fluorescent DNA stains and then performing two complementary methods of mutation detection‐single stranded conformation polymorphism (SSCP) analysis and heteroduplex analysis (HA). This involves the denaturation of double‐stranded polymerase chain reaction (PCR) product into single‐stranded DNA, the mutation analysis of the single‐stranded DNA by SSCP and the rehybridized double‐stranded DNA by HA. These steps were performed entirely on‐chip within several minutes of operation. The combination of these two mutation detection methods on‐chip provides a highly sensitive method of mutation detection for either genotyping or screening. Many mutation analysis methods rely upon fluorescently labeled samples from a PCR with fluorescently labeled primers. By labeling on‐chip we not only attain improved signal strength, but the method is considerably more versatile. Although we used PCR products in this work, this method could be used to analyze DNA from any source. We believe that this combination of several procedures on a single chip represents a significant step in the development of higher levels of integration upon microfluidic devices.
Sensitive and simultaneous analysis of five transgenic maizes using multiplex polymerase chain reaction, capillary gel electrophoresis, and laser‐induced fluorescence
Authors: García‐Cañas Virginia , González Ramón , Cifuentes Alejandro
Published: July 2004

The benefits of using multiplex polymerase chain reaction (PCR) followed by capillary gel electrophoresis with laser‐induced fluorescence (CGE‐LIF) for the simultaneous detection of five transgenic maizes (Bt11, T25, MON810, GA21, and Bt176) are demonstrated. The method uses a hexaplex PCR protocol to amplify the five mentioned transgenic amplicons plus the zein gene used as reference, followed by a CGE‐LIF method to analyze the six DNA fragments. CGE‐LIF was demonstrated very useful and informative for optimizing multiplex PCR parameters such as time extension, PCR buffer concentration and primers concentration. The method developed is highly sensitive and allows the simultaneous detection in a single run of percentages of transgenic maize as low as 0.054% of Bt11, 0.057% of T25, 0.036% of MON810, 0.064% of GA21, and 0.018% of Bt176 in flour obtaining signals still far from the detection limit (namely, the signal/noise ratios for the corresponding DNA peaks were 41, 124, 98, 250, 252, and 473, respectively). These percentages are well below the minimum threshold marked by the European Regulation for transgenic food labeling (i.e., 0.5–0.9%). A study on the reproducibility of the multiplex PCR‐CGE‐LIF procedure was also performed. Thus, values of RSD lower than 0.67 and 6.80% were obtained for migration times and corrected peak areas, respectively, for the same sample and three different days (n = 12). On the other hand, the reproducibility of the whole procedure, including four different multiplex PCR amplifications, was determined to be better than 0.66 and 23.3% for migration times and corrected peak areas, respectively. Agarose gel electrophoresis (AGE) and CGE‐LIF were compared in terms of resolution and sensitivity for detecting PCR products, demonstrating that CGE‐LIF can solve false positives induced by artifacts from the multiplex PCR reaction that could not be addressed by AGE. Moreover, CGE‐LIF provides better resolution and sensitivity. To our knowledge, these results demonstrate for the first time that multiplex PCR‐CGE‐LIF is a solid alternative to determine multiple genetically modified organisms in maize flours in a single run.
Call for papers: Electrophoresis 14/2004
Authors: Schmitt‐Kopplin Philippe
Published: July 2004

No abstracts.
Factorial structure of the Sociocultural Attitudes Towards Appearance Questionnaire among Italian and Australian girls
Authors: Bagnara Sabina , Huon Gail , Donazzolo Sabina
Published: July 2004

This study compared the factorial structure of the self‐report inventory SATAQ (Sociocultural Attitudes Towards Appearance Questionnnaire) (Heinberg, Thompson, & Stormer, 1995) when administered to two samples of girls, one in Italy and a second in Australia. The measure was translated into Italian and its back‐translation carefully checked to ensure equivalence of meaning. Participants were 172 Australian and 171 Italian female undergraduate students. Their responses were scored according to the authors' instructions. Following Heinberg et al. (1995), a principal components factor analysis with promax oblique rotation was conducted. A two‐factor solution that essentially replicates that of Heinberg et al. was produced for the Australian data. However, a more clearly interpretable solution for the Italian responses involved three factors. We discuss the significance of the findings in terms of the utility of the instrument for research and for clinical intervention. Copyright © 2004 John Wiley & Sons, Ltd and Eating Disorders Association.
Relations between aerodynamic and surface roughness in a hyper‐arid cold desert: McMurdo Dry Valleys, Antarctica
Authors: Lancaster Nicholas
Published: July 2004

Studies of boundary‐layer winds and surface roughness characteristics of unvegetated rocky desert surfaces provide new insights into the relations between aerodynamic roughness and surface roughness, as described by the roughness density (λ). The description of non‐erodible roughness by the roughness density (λ) is shown to be valid for rocky surfaces as well as sparsely vegetated surfaces and simulated surfaces in a wind tunnel. There is a good relation (r2 = 0·71) between aerodynamic roughness and roughness density (λ), allowing use of the threshold friction velocity ratio to predict sediment transport rates on these surfaces. Copyright © 2004 John Wiley & Sons, Ltd.
Numerical calculations of erosion in an abrupt pipe contraction of different contraction ratios
Authors: Habib M. A. , Badr H. M. , Ben‐Mansour R. , Said S. A. M.
Published: July 2004

Erosion predictions in a pipe with abrupt contraction of different contraction ratios for the special case of two‐phase (liquid and solid) turbulent flow with low particle concentration are presented. A mathematical model based on the time‐averaged governing equations of 2‐D axi‐symmetric turbulent flow is used for the calculations of the fluid velocity field (continuous phase). The particle‐tracking model of the solid particles is based on the solution of the governing equation of each particle motion taking into consideration the effect of particle rebound behaviour. Models of erosion were used to predict the erosion rate in mg/g. The effect of Reynolds number and flow direction with respect to the gravity was investigated for three contraction geometries considering water flow in a carbon steel pipe. The results show that the influence of the contraction ratio on local erosion is very significant. However, this influence becomes insignificant when the average erosion rates over the sudden contraction area are considered. The results also indicate the significant influence of inlet velocity variations. The influence of buoyancy is significant for the cases of low velocity of the continuous flow. A threshold velocity below which erosion may be neglected was indicated. Copyright © 2004 John Wiley & Sons, Ltd.
A γ‐model BGK scheme for compressible multifluids
Authors: Jiang Song , Ni Guoxi
Published: July 2004

We present a γ‐model BGK scheme for the numerical simulation of compressible multifluids. The scheme is based on the incorporation of a conservative γ‐model scheme given in (J. Comput. Phys. 1996; 125:150–160) into the gas kinetic BGK scheme (J. Comput. Phys. 1993; 109:53–66, J. Comput. Phys. 1994; 114:9–17), and is simple to implement. Several numerical examples presented in this paper validate the scheme in the application of compressible multimaterial flows. Copyright © 2004 John Wiley & Sons, Ltd.
Numerical study of physiological turbulent flows through series arterial stenoses
Authors: Lee T. S. , Liao Wei , Low H. T.
Published: July 2004

A numerical investigation on the characteristics of transitional turbulent flow over series bell‐shape stenoses for a physiological pulsatile flow is presented in the present study. The flow behaviours for the physiological pulsatile flow are studied by considering the effects of the Reynolds number, Womersley number, constriction ratio and spacing ratio of the stenoses on the pulsatile turbulent flow fields. Especially, the mutual influences between the double stenoses under different flow conditions are considered. The numerical results show that the variation of these flow parameters puts significant impacts on the flow developments in the arteries with series stenoses. The double stenoses lead to the higher peak turbulence disturbance and the greater area with comparatively high turbulence intensity distal to the stenoses in comparison with the single stenosis. The analysis shows that for the physiological pulsatile flow, the downstream stenosis usually does not have perceptible influences on the upstream flow fields. Copyright © 2004 John Wiley & Sons, Ltd.
A finite element model for the simulation of lost foam casting
Authors: Houzeaux G. , Codina R.
Published: July 2004

In this paper, we present a numerical model to simulate the lost foam casting process. We introduce this particular casting first in order to capture the different physical processes in play during a casting. We briefly comment on the possible physical and numerical models used to envisage the numerical simulation. Next we present a model which aims to solve ‘part of’ the complexities of the casting, together with a simple energy budget that enables us to obtain an equation for the velocity of the metal front advance. Once the physical model is established we develop a finite element method to solve the governing equations. The numerical and physical methodologies are then validated through the solution of a two‐ and a three‐dimensional example. Finally, we discuss briefly some possible improvements of the numerical model in order to capture more physical phenomena. Copyright © 2004 John Wiley & Sons, Ltd.
Efficient temporally controlled targeted somatic mutagenesis in hepatocytes of the mouse
Authors: Schuler Michael , Dierich Andrée , Chambon Pierre , Metzger Daniel
Published: July 2004

To generate temporally controlled targeted somatic mutations selectively and efficiently in hepatocytes, we established SA+/CreERT2 mice in which the tamoxifen‐dependent Cre‐ERT2 recombinase coding sequence preceded by an internal ribosomal entry site was inserted in the 3′ untranslated region of the serum albumin (SA) gene. Whereas the wildtype SA allele was strongly expressed in the liver and at lower levels in some extrahepatic tissues, SA‐Cre‐ERT2 fusion transcripts were only detected in the liver. The Cre‐ERT2 protein was expressed in most if not all hepatocytes, and tamoxifen (Tam) treatments of adult mice at various ages efficiently induced Cre‐mediated recombination of LoxP flanked (floxed) alleles in these cells, but none in other cell types or tissues. Thus, SA+/CreERT2 mice should be of great value to analyze gene function in the liver and to establish animal models of human diseases. genesis 39:167–172, 2004. © 2004 Wiley‐Liss, Inc.