bluuebunny/crossref_metadata_2025_split huggingface dataset:
Data Analysis of Multi‐Angle Photon Correlation measurements without and with prior knowledge
Authors: Finsy Robert , de Groen Pieter , Deriemaeker Luc , Geladé Eric , Joosten Jacques 
Published: June 2005

AbstractThe application of the singular value analysis and reconstruction method (SVR) and of the Contin method for the collective analysis of multi‐angle noisy photon correlation data sets was investigated. Provided the data are sampled equidistant in time and by proper tuning of the sampling time to the scattering angle, a collective multi‐angle SVR analysis is feasible. For homogeneous spherical particles such an analysis does not require any prior knowledge of the angular dependence of particle scattering power (e.g. Mie scattering). SVR allows the information content to be separated from noisy intensity autocorrelation data. It is illustrated that the multi‐angle SVR analysis enhances the recovery of the information content. Moreover, SVR can be used as a fast and accurate preprocessor for extracting the field autocorrelation function for a subsequent Contin analysis whereby prior knowledge of particle scattering power as a function of scattering angle is used as a constraint. Compared with the data analysis of multi‐angle time‐averaged scattered intensity measurements, the information that can be extracted from multi‐angle PCS data in comparable accumulation times is poorer.
Application of Precision Transparent Sieves to the determination of low number concentrations of oversize particles in powders
Authors: Allen Terry 
Published: June 2005

AbstractPowders are often added to film coatings in order to improve handling or end‐use properties. The presence of oversize particles at the level of less than one in a trillion can lead to substandard or reject products. Using current methods of testing it is difficult to detect such low levels of oversize particles until after the final product is made. Sieving techniques have been tried but these are generally unreliable due to the difficulty of controlling cross contamination. A filtration technique is described here for determining low levels of oversize particle in powders and suspensions, in which cross‐contamination is minimized by using a single container for the particle separation and the subsequent number concentration measurement. Precision Transparent Sieves are used in a holder, specially designed to minimize contamination, for use with a Coulter Counter. The method permits the determination of number concentration (oversize particles per gram or ml) with reasonable accuracy at levels not previously possible.
Outlaw locked particles – 3rd order locking criteria
Authors: Meloy Thomas P. , Preti Ugo 
Published: June 2005

AbstractAn unexpectedly large additional three phase locking region, the outlaw area has been found where three phase, locked particle may be formed. This implies that in some ores, the number of three phase locked particles may be an order of magnitude larger than expected. The size of this outlaw region is sensitive to the angle at which the three phases meet. Since these higher order locked particles behave differently in separation circuits, it is proposed that in characterizing a solid or ore rock, these angles between the interfacial planes be both measured and included in a Textural Transform.
Structure and energy landscape of a photoswitchable peptide: A replica exchange molecular dynamics study
Authors: Nguyen Phuong H. , Mu Yuguang , Stock Gerhard 
Published: June 2005

AbstractA replica exchange molecular dynamics (REMD) simulation of a bicyclic azobenzene peptide in explicit dimethyl sulfoxide solution is presented in order to characterize the conformational structures and energy landscape of a photoswitchable peptide. It is shown that an enhanced‐sampling technique such as the REMD method is essential to obtain a converged conformational sampling of the peptide at room temperature. This is because conventional MD simulations of less than ∼100‐ns length are either trapped in local minima (at 295 K) or—if run at high temperature—do not resemble the room‐temperature REMD results. Calculating various nuclear Overhauser effects (NOEs) and 3J‐couplings, a good overall agreement between the REMD simulations and the NMR experiments of Renner et al. (Biopolymers 2000;54:501–514) is found. In particular, the REMD study confirms the general picture drawn by Renner et al. that the trans‐isomer of the azobenzene peptide exhibits a well‐defined structure, while the cis‐isomer is a conformational heterogeneous system; that is, the trans‐isomer occurs in 2 well‐defined conformers, while the cis‐isomer represents an energetically frustrated system that leads to an ensemble of conformational structures. Employing a principal component analysis of the REMD data, the free energy landscape of the systems is studied at various temperatures. The implications for the folding and unfolding pathways of the system are discussed. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Ligand‐induced fit in mycobacterial MabA: The sequence‐specific C‐terminus locks the conformational change
Authors: Cohen‐Gonsaud Martin , Ducasse‐Cabanot Stéphanie , Quemard Annaïk , Labesse Gilles 
Published: June 2005

AbstractThe protein MabA of Mycobacterium tuberculosis is a β‐ketoacyl reductase (KAR) and catalyses one of the four steps of the fatty acid elongation system FAS‐II. The crystal structures of different KARs revealed a significant rearrangements of the active site between a “closed” inactive conformation and an “open” and active form in presence of the cofactor. MabA is a potential therapeutic target. However, only the structure of the “closed” form was obtained and rational drug design requires the structure of the active form. Here we described the sequences and structures analysis of the KARs to stabilize the “open form” in MabA. The crystal structure of a mutated MabA protein was then solved in both inactive and active form. The crystal structure of the wild‐type MabA in the presence of NADP was also solved and showing a mixture of the two mutually exclusive conformations. This new structure of MabA is analyzed in view of its distinctive enzymatic and structural properties and those of related enzymes. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Data‐driven docking: HADDOCK's adventures in CAPRI
Authors: van Dijk A. D. J. , de Vries S. J. , Dominguez C. , Chen H. , Zhou H.‐X. , Bonvin A. M. J. J. 
Published: June 2005

AbstractWe have shown previously that given high‐resolution structures of the unbound molecules, structure determination of protein complexes is possible by including biochemical and/or biophysical data as highly ambiguous distance restraints in a docking approach. We applied this method, implemented in the HADDOCK (High Ambiguity Driven DOCKing) package (Dominguez et al., J Am Chem Soc 2003;125:1731–1737), to the targets in the fourth and fifth rounds of CAPRI. Here we describe our results and analyze them in detail. Special attention is given to the role of flexibility in our docking method and the way in which this improves the docking results. We describe extensions to our approach that were developed as a direct result of our participation in CAPRI. In addition to experimental information, we also included interface residue predictions from PPISP (Protein–Protein Interaction Site Predictor; Zhou and Shan, Proteins 2001;44:336–343), a neural network method. Using HADDOCK we were able to generate acceptable structures for 6 of the 8 targets, and to submit at least 1 acceptable structure for 5 of them. Of these 5 submissions, 3 were of medium quality (Targets 10, 11, and 15) and 2 of high quality (Targets 13 and 14). In all cases, predictions were obtained containing at least 40% of the correct epitope at the interface for both ligand and receptor simultaneously. Proteins 2005;60:232–238. © 2005 Wiley‐Liss, Inc.
Searching for protein–protein interaction sites and docking by the methods of molecular dynamics, grid scoring, and the pairwise interaction potential of amino acid residues
Authors: Terashi Genki , Takeda‐Shitaka Mayuko , Takaya Daisuke , Komatsu Katsuichiro , Umeyama Hideaki 
Published: June 2005

AbstractIn CAPRI Rounds 1 and 2, we assumed that because there are many ionic charges that weaken electrostatic interaction forces in living cells, the hydrophobic interaction force might be important entropically. As a result of Rounds 1 and 2, the predictions for binding sites and geometric centers were acceptable, but those of the binding axes were poor, because only the largest benzene cluster was used for generating the initial docking structures. These were generated by fitting of benzene clusters formed on the surface of receptor and ligand. In CAPRI Rounds 3–5, the grid‐scoring sum on the protein–protein interaction surface and the pairwise potential of the amino acid residues, which were indicated as coming easily into the protein–protein interaction regions, were used as the calculation methods, along with the smaller benzene clusters that participated in benzene cluster fitting. Good predicted models were obtained for Targets 11 and 12. When the modeled receptor proteins were superimposed on the experimental structures, the smallest ligand root‐mean‐square deviation (RMSD) values corresponding to the RMSD between the model and experimental structures were 6.2 Å and 7.3 Å, respectively. Proteins 2005;60:289–295. © 2005 Wiley‐Liss, Inc.
Research on historic structures in seismic areas in Italy
Authors: Binda Luigia , Saisi Antonella 
Published: June 2005

AbstractThe paper analyses the most recent research carried out in Italy concerning the seismic behaviour of historic buildings. The last Umbria (Italy) earthquake in 1997 was an interesting on site test for the evaluation of the repair and prevention techniques applied to masonry building of historic centres in seismic areas, but also of the structural modelling. Most of the situations examined made important contributions to a general re‐thinking of masonry evaluation and strengthening. The great importance in the mechanical behaviour of a building of building rules and of structural details, as well as transformation phases has been demonstrated.
Luminescent characteristics of pure and Ce doped K2LaCl5 phase in KCl host
Authors: Voloshinovskii A. , Stryganyuk G. , Zimmerer G. , Rodnyi P. , Antonyak O. , Myagkota S. , Savchyn P. 
Published: June 2005

AbstractThe formation of Ce3+ doped K2LaCl5 microphase has been revealed for the KCl–LaCl3–CeCl3 system. Luminescent characteristics of pure and Ce3+ doped K2LaCl5 microcrystals, embedded in KCl matrix, are studied in comparison with those of bulk K2LaCl5:Ce(0.1%) crystal. For both the micro‐ and bulk K2LaCl5:Ce crystals the bands peaked at 344 and 373 nm are attributed to Ce3+ emission revealing a 24 ns time constant for the main decay component upon the excitation within the Ce3+ f–d absorption range. The method elaborated for the synthesis of the activated K2LaCl5 microphase in the KCl–LaCl3–CeCl3 system provides the possibility of producing large‐size homogeneous scintillation elements possessing efficient emission of rare earth doped A2LaX5 micro‐ and nano‐phases embedded in AX matrices (A = Cs, K, Rb; X = F, Cl, Br, I). (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electric field gradients at indium sites in spinels measured by perturbed angular correlations
Authors: Pasquevich A. F. 
Published: June 2005

AbstractThe Electric Field Gradient (EFG) at 111Cd isotope (produced by the Electron Capture (EC) decay of 111In) has been measured using Perturbed Angular Correlations (PAC) technique in many spinels. In the present work, data arising from such experiments were collected. The experimental EFG values, obtained at room temperature, at the B site of normal spinels are compared with those calculated considering the monopole moment of the ions and the dipole polarization of the anions. This comparison allows the determination of the u‐parameter, which gives the anion position in the lattice. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of PZT (54/46) ferroelectric ceramics under the influence of a ‘soft’ double modification with La and Nb
Authors: Suárez‐Gómez A. , Calderón‐Piñar F. , Durruthy M. D. , Peláiz‐Barranco A. , Saniger‐Blesa J. , de Frutos J. 
Published: June 2005

AbstractIn the present work, a ‘soft‐doped’ PZT ceramic system with a near MPB Zr/Ti ratio of about 54/46, is characterized when simultaneously modified with Lanthanum (La) and Niobium (Nb) at the same doping level, x = 0.4, 1.0 and 1.4 mol%. X‐rays diffraction patterns showed the rombohedral/tetragonal perovskite phase coexistence as reported for Zr/Ti ratios near the Morphotropic Phase Boundary (MPB). Scanning Electron Microscopy (SEM) showed a decrease of the mean grain size when increasing the doping level. On the other hand, permittivity and AC conductivity were analysed in the ferro‐ and paraelectric phases. Samples showed a lower Curie temperature for higher doping levels as well as normal ferroelectric/paraelectric transitions. The piezoelectric response of thin polarized cylinder‐shaped samples was measured for a near‐saturation poling field. The behaviour of some electromechanical parameters and possible applications for these materials are also discussed herein. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Density of electronic states in impurity‐doped quantum well wires
Authors: Betancur F. J. , Orozco E. A. , Gonzalez J. D. , Mikhailov I. D. 
Published: June 2005

AbstractWe analyze the effect of the mixing of the 1s and 2px,y subbands on the ground state binding energy of the off‐axis donors in cylindrical nanotubes by using the recently developed fractal dimension method. Curves of the D0 ground state binding energies as a function of the donor distance from axis are presented and compared with those obtained previously without consideration of the effect of the subband mixing. Also, we analyze the density impurity states in nanotubes with randomly distributed donors. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetic viscosity and activation volume in chromium substituted Pb–M hexaferrite
Authors: Faloh‐Gandarilla J. C. , Díaz Castañón S. , Leccabue F. 
Published: June 2005

AbstractPbFe11CrO19 polycrystalline samples were prepared by the chemical coprecipitation method. X‐ray diffraction and Mössbauer spectroscopy confirm the formation of the M‐type hexagonal structure. Time dependence of the magnetization was recorded on the demagnetization curve of the hysteresis loop. It is well described by a simple logarithmic law but also non‐logarithmic behavior was detected. A two‐peak dependence of the viscosity coefficient S with the applied field was encountered. Considering reversible susceptibility measurements and a M(H) curve at constant dM/dt in the irreversible susceptibility determination, the calculated activation volume as a function of the applied field shows two well defined zones. The zones observed in the activation volumes are related to the two local maxima that the total susceptibility exhibits. It points to the fact that the viscosity study is sensible enough to characterize this system, encountering two apparent activation volumes. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Self‐Assembly and Crystallization Behavior of Mesoporous, Crystalline HfO2 Thin Films: A Model System for the Generation of Mesostructured Transition‐Metal Oxides
Authors: Brezesinski Torsten , Smarsly Bernd , Iimura Ken‐ichi , Grosso David , Boissière Cédric , Amenitsch Heinz , Antonietti Markus , Sanchez Clément 
Published: June 2005

AbstractMesoporous thin films of crystalline hafnium oxide were fabricated by evaporation‐induced self‐assembly in combination with sol–gel processing, followed by a suitable post heat‐treatment procedure to initiate the crystallization. A novel type of block‐copolymer template was used as structure‐directing agent, which generated a distorted cubic arrangement of spherical mesopores, the size of which could be quantified by suitable techniques, such as ellipsometry–porosimetry, small‐angle X‐ray scattering, and atomic force microscopy. Detailed insights into the nature of the crystallization process of mesostructured hafnium oxide were obtained by temperature‐dependent, in situ X‐ray scattering experiments. These investigations revealed that crystallization takes place, within the confinement of the mesostructure, as a solid–solid transition from a dehydrated, amorphous form of hafnium oxide. The study suggests that one main benefit of the novel template results from the ability of the polymer to stabilize the mesostructure of amorphous hafnium oxide up to 400–450 °C.
The MyProxy online credential repository
Authors: Basney Jim , Humphrey Marty , Welch Von 
Published: June 2005

AbstractThe MyProxy online credential repository has been used by the Grid computing community for over four years for managing security credentials in the Grid public key infrastructure. MyProxy improves usability by giving users access to their credentials over the network using password authentication, allowing users to delegate their credentials via Web browser interfaces to the Grid, and supporting credential renewal for long‐running jobs. MyProxy helps administrators secure users' private keys by providing an online service from which users retrieve short‐lived credentials without distributing long‐lived keys to potentially vulnerable end‐systems. This paper describes the MyProxy system and its use. Copyright © 2005 John Wiley & Sons, Ltd.
The case for using Bridge Certificate Authorities for Grid computing
Authors: Humphrey Marty , Basney Jim , Jokl Jim 
Published: June 2005

AbstractAs Grid deployments increase, the challenge remains to create a scalable, multi‐organizational authentication infrastructure. Public key infrastructures (PKIs) are widely used for authentication in Grids, due in large part to the success of the Globus toolkit, despite the challenges and difficulties both for PKI administrators and users. The Bridge Certificate Authority (CA) is a compromise between a strictly hierarchical PKI and a mesh PKI and achieves many of the benefits of the hierarchical PKI and mesh PKI but has been untested for use with Grid software. This paper reports on the use of a Bridge CA with two representative Grid software packages: the Globus Toolkit v2 and WSRF.NET. We find that both packages support Bridge CAs sufficiently today to be usable in Grid software architectures, although not without limitations. In this paper, and through these experiments, we build the case for using Bridge CAs for Grid computing. Copyright © 2005 John Wiley & Sons, Ltd.
The GridSite Web/Grid security system
Authors: McNab Andrew 
Published: June 2005

AbstractThis paper describes the architecture of the GridSite system, which adds support for several Grid security protocols to the Apache Web server platform. These include the Globus GSI authentication system, Grid Access Control Language (GACL) access policy files, and Distinguished Name (DN) List and Virtual Organization Membership Service (VOMS) group memberships. Particular emphasis is placed on how the architecture of GridSite has evolved during the past 3 years, how this has been influenced by operational experience with production systems, and how the project has led to new developments, such as GACL. Finally, a description is given of how GridSite has been made to interoperate with other deployed security systems, both as producers and consumers of GridSite's authorization information. Copyright © 2005 John Wiley & Sons, Ltd.
‘R‐What?’ Development of a role‐based access control policy‐writing tool for e‐Scientists
Authors: Brostoff Sacha , Sasse M. Angela , Chadwick David , Cunningham James , Mbanaso Uche , Otenko Sassa 
Published: June 2005

AbstractA lightweight role‐based access control policy authoring tool was developed for e‐Scientists, a community for which access policies have to be implemented for an increasingly heterogeneous group of local and remote users. Two fundamental problems were identified: (1) lack of understanding of what the policy components are (i.e. how authorization policies are structured), and (2) lack of understanding of the underlying policy paradigm (i.e. what should go into the policy, and what should be left out). Conceptual design (CD) techniques were used to revise the user interface (UI) labels so that e‐Scientists and developers were better able to describe access policy components from labels, and match labels with components (t = 6.28, df = 7, p = 0.000 two‐tailed). CD, instructional text, bubble help, UI behaviour and alert boxes were used to shape users' models of the policy paradigm. The final prototype improved users' efficiency and effectiveness by more than doubling the speed with which expert users could write authorization policies, and facilitating users without specialist security knowledge to overcome the policy paradigm and components problems, enabling them to complete 80% of basic and 75% of advanced authorization policy‐writing tasks in a usability trial. Copyright © 2005 John Wiley & Sons, Ltd.
Towards secure Grid‐enabled healthcare
Authors: Power D. J. , Politou E. A. , Slaymaker M. A. , Simpson A. C. 
Published: June 2005

AbstractThe primary focus of the UK e‐Science Programme is the development of software architectures, middleware and applications to support the end‐user scientific community in the undertaking of large‐scale research. A significant subset of e‐Science projects is concerned with the healthcare domain: as well as satisfying the needs of the end users, such projects have to consider the legal, ethical and security constraints associated with the use of sensitive patient data—these concerns are particularly relevant within the context of the U.K.'s National Health Service (NHS). In this paper we present a vision for Grid‐enabled healthcare that is sensitive to the information security requirements both of the NHS and the projects themselves. Although our motivation is principally derived from U.K.‐based e‐Health projects, this paper should be of interest to the worldwide health Grid community. By restricting ourselves to information security, we do not consider, for example, physical security or audit trail capabilities, which are outside the scope of this paper. The vision we describe is grounded in terms of experience, and reflects the challenges faced by the e‐DiaMoND project team. Copyright © 2005 John Wiley & Sons, Ltd.
Applying Security Design Analysis to a service‐based system
Authors: Chivers Howard , Fletcher Martyn 
Published: June 2005

AbstractRisk analysis is the only effective way of making value judgments about the need for security. Established analysis methods apply to whole operational systems, taking a necessarily holistic view of security, but this makes them difficult to integrate into the design process for service‐based applications, where design and implementation are independent of operational deployment. However, the most costly mistakes occur early in the development lifecycle, and effective security can be difficult to retrofit, motivating the need for early security analysis. This paper describes SeDAn (Security Design Analysis), a security risk analysis framework that is adapted for use in the design phase of service‐based systems, and its application to a significant Grid‐based project (Distributed Aircraft Maintenance Environment—DAME). The complete lifecycle of the risk analysis is described, and the effectiveness of the process in identifying design defects validates both the need for, and the effectiveness of, this type of analysis. Copyright © 2005 John Wiley & Sons, Ltd.