bluuebunny/crossref_metadata_2025 huggingface dataset:
Greedy mixture learning for multiple motif discovery
in biological sequences
Authors: Blekas Konstantinos , Fotiadis Dimitrios I. , Likas Aristidis
Published: March 2003

Motivation: This paper studies the problem of discovering subsequences, known as motifs, that are common to a given collection of related biosequences, by proposing a greedy algorithm for learning a mixture of motifs model through likelihood maximization. The approach adds sequentially a new motif to a mixture model by performing a combined scheme of global and local search for appropriately initializing its parameters. In addition, a hierarchical partitioning scheme based on kd-trees is presented for partitioning the input dataset in order to speed-up the global searching procedure. The proposed method compares favorably over the well-known MEME approach and treats successfully several drawbacks of MEME.

Results: Experimental results indicate that the algorithm is advantageous in identifying larger groups of motifs characteristic of biological families with significant conservation. In addition, it offers better diagnostic capabilities by building more powerful statistical motif-models with improved classification accuracy.

Availability: Source code in Matlab is available at http://www.cs.uoi.gr/~kblekas/greedy/GreedyEM.html

Contact: kblekas@cs.uoi.gr

* To whom correspondence should be addressed.
Gene expression data preprocessing
Authors: Herrero J. , Díaz-Uriarte R. , Dopazo J.
Published: March 2003

Summary: We present an interactive web tool for preprocessing microarray gene expression data. It analyses the data, suggests the most appropriate transformations and proceeds with them after user agreement. The normal preprocessing steps include scale transformations, management of missing values, replicate handling, flat pattern filtering and pattern standardization and they are required before performing any pattern analysis. The processed data set can be sent to other pattern analysis tools.

Availability: The web interface is accessible through http://bioinfo.cnio.es/cgi-bin/tools/dnarray/preprocess

Contact: jdopazo@cnio.es

* To whom correspondence should be addressed.
Cellerator: extending a computer algebra system to include
biochemical arrows for signal transduction simulations
Authors: Shapiro Bruce E. , Levchenko Andre , Meyerowitz Elliot M. , Wold Barbara J. , Mjolsness Eric D.
Published: March 2003

Summary: Cellerator describes single and multi-cellular signal transduction networks (STN) with a compact, optionally palette-driven, arrow-based notation to represent biochemical reactions and transcriptional activation. Multi-compartment systems are represented as graphs with STNs embedded in each node. Interactions include mass-action, enzymatic, allosteric and connectionist models. Reactions are translated into differential equations and can be solved numerically to generate predictive time courses or output as systems of equations that can be read by other programs. Cellerator simulations are fully extensible and portable to any operating system that supports Mathematica, and can be indefinitely nested within larger data structures to produce highly scaleable models.

Availability: Cellerator can be licensed free of charge to noncommercial academic, U.S. government, and nonprofit users. Details and sample notebooks are available at http://www-aig.jpl.nasa.gov/public/mls/cellerator.

Contact: bshapiro@jpl.nasa.gov

* To whom correspondence should be addressed.
MHCBN: a comprehensive database of MHC binding and non-binding
peptides
Authors: Bhasin Manoj , Singh Harpreet , Raghava G. P. S.
Published: March 2003

Summary: MHCBN is a comprehensive database of Major Histocompatibility Complex (MHC) binding and non-binding peptides compiled from published literature and existing databases. The latest version of the database has 19 777 entries including 17 129 MHC binders and 2648 MHC non-binders for more than 400 MHC molecules. The database has sequence and structure data of (a) source proteins of peptides and (b) MHC molecules. MHCBN has a number of web tools that include: (i) mapping of peptide on query sequence; (ii) search on any field; (iii) creation of data sets; and (iv) online data submission. The database also provides hypertext links to major databases like SWISS-PROT, PDB, IMGT/HLA-DB, GenBank and PUBMED.

Availability: MHCBN is available at http://www.imtech.res.in/raghava/mhcbn/. It’s SRS version is available from http://srs.ebi.ac.uk/

Contact: raghava@imtech.res.in

Supplementary information: http://www.imtech.res.in/raghava/mhcbn/supl/

* To whom correspondence should be addressed.
How Bayes tests of molecular phylogenies compare with
frequentist approaches
Authors: Aris-Brosou Stéphane
Published: March 2003

Motivation: The desire to compare molecular phylogenies has stimulated the design of numerous tests. Most of these tests are formulated in a frequentist framework, and it is not known how they compare with Bayes procedures. I propose here two new Bayes tests that either compare pairs of trees (Bayes hypothesis test, BHT), or test each tree against an average of the trees included in the analysis (Bayes significance test, BST).

Results: The algorithm, based on a standard Metropolis–Hastings sampler, integrates nuisance parameters out and estimates the probability of the data under each topology. These quantities are used to estimate Bayes factors for composite vs. composite hypotheses. Based on two data sets, the BHT and BST are shown to construct similar confidence sets to the bootstrap and the Shimodaira Hasegawa test, respectively. This suggests that the known difference among previous tests is mainly due to the null hypothesis considered.

Availability: http://statgen.ncsu.edu/stephane/

Contact: stephane@statgen.ncsu.edu

Supplementary Information: Supplemental material referenced in the text can be found at http://statgen.ncsu.edu/stephane/bayestests.htm

* Present address: Bioinformatics Research Center, North Carolina State University Raleigh, NC 27695-7566, USA
Acetylation regulates subcellular localization of the Wnt signaling nuclear effector POP-1
Authors: Gay Frédérique , Calvo Dominica , Lo Miao-Chia , Ceron Julian , Maduro Morris , Lin Rueyling , Shi Yang
Published: March 2003

Lymphoid enhancer factor/T-cell factor (LEF/TCF) are transcription factors that mediate the Wnt signaling pathway, and have crucial roles during embryonic development in various organisms. Here we report that acetylation enhances nuclear retention of POP-1, theCaenorhabditis elegansLEF/TCF homolog, through increasing nuclear import and blocking nuclear export. We identify three lysines that are acetylated in vivo, and demonstrate their essential requirement for proper nuclear localization and biological activity of POP-1 duringC. elegansembryogenesis. The conservation of these lysines among other LEF/TCF family members suggests that acetylation may be an important, evolutionarily conserved mechanism regulating subcellular distribution of LEF/TCF factors.
Pdgfr-αmediates testis cord organization and fetal Leydig cell development in the XY gonad
Authors: Brennan Jennifer , Tilmann Christopher , Capel Blanche
Published: March 2003

During testis development, the rapid morphological changes initiated bySryrequire the coordinate integration of many signaling pathways. Based on the established role of the platelet-derived growth factor (PDGF) family of ligands and receptors in migration, proliferation, and differentiation of cells in various organ systems, we have investigated the role of PDGF in testis organogenesis. Analysis of expression patterns and characterization of the gonad phenotype inPdgfr-α−/−embryos identified PDGFR-α as a critical mediator of signaling in the early testis at multiple steps of testis development.Pdgfr-α−/−XY gonads displayed disruptions in the organization of the vasculature and in the partitioning of interstitial and testis cord compartments. Closer examination revealed severe reductions in characteristic XY proliferation, mesonephric cell migration, and fetal Leydig cell differentiation. This work identifies PDGF signaling through the α receptor as an important event downstream ofSryin testis organogenesis and Leydig cell differentiation.
Asynchronous replication timing of imprinted loci is independent of DNA methylation, but consistent with differential subnuclear localization
Authors: Gribnau Joost , Hochedlinger Konrad , Hata Ken , Li En , Jaenisch Rudolf
Published: March 2003

Genomic imprinting in mammals marks the two parental alleles resulting in differential gene expression. Imprinted loci are characterized by distinct epigenetic modifications such as differential DNA methylation and asynchronous replication timing. To determine the role of DNA methylation in replication timing of imprinted loci, we analyzed replication timing inDnmt1- andDnmt3L-deficient embryonic stem (ES) cells, which lack differential DNA methylation and imprinted gene expression. Asynchronous replication is maintained in these ES cells, indicating that asynchronous replication is parent-specific without the requirement for differential DNA methylation. Imprinting centers are required for regional control of imprinted gene expression. Analysis of replication fork movement and three-dimensional RNA and DNA fluoroscent in situ hybridization (FISH) analysis of theIgf2-H19locus in various cell types indicate that theIgf2-H19imprinting center differentially regulates replication timing of nearby replicons and subnuclear localization. Based on these observations, we suggest a model in whichciselements containing nonmethylation imprints are responsible for the movement of parental imprinted loci to distinct nuclear compartments with different replication characteristics resulting in asynchronous replication timing.
The yeast eIF3 subunits TIF32/a, NIP1/c, and eIF5 make critical connections with the 40S ribosome in vivo
Authors: Valášek Leoš , Mathew Amy A. , Shin Byung-Sik , Nielsen Klaus H. , Szamecz Béla , Hinnebusch Alan G.
Published: March 2003

Initiation factor 3 (eIF3) forms a multifactor complex (MFC) with eIF1, eIF2, and eIF5 that stimulates Met-tRNAiMetbinding to 40S ribosomes and promotes scanning or AUG recognition. We have previously characterized MFC subcomplexes produced in vivo from affinity-tagged eIF3 subunits lacking discrete binding domains for other MFC components. Here we asked whether these subcomplexes can bind to 40S ribosomes in vivo. We found that the N- and C-terminal domains of NIP1/eIF3c, the N- and C-terminal domains of TIF32/eIF3a, and eIF5 have critical functions in 40S binding, with eIF5 and the TIF32-CTD performing redundant functions. The TIF32-CTD interacted in vitro with helices 16–18 of domain I in 18S rRNA, and the TIF32-NTD and NIP1 interacted with 40S protein RPS0A. These results suggest that eIF3 binds to the solvent side of the 40S subunit in a way that provides access to the interface side for the two eIF3 segments (NIP1-NTD and TIF32-CTD) that interact with eIF1, eIF5, and the eIF2/GTP/Met-tRNAiMetternary complex.
Tpit determines alternate fates during pituitary cell differentiation
Authors: Pulichino Anne-Marie , Vallette-Kasic Sophie , Tsai Judy Peih-Ying , Couture Catherine , Gauthier Yves , Drouin Jacques
Published: March 2003

The T-box transcription factor Tpit was identified as a cell-specific factor for expression of the pituitary proopiomelanocortin (POMC) gene. Expression of this factor is exclusively restricted to the pituitary POMC-expressing lineages, the corticotrophs and melanotrophs. We have now determined the role of this factor in pituitary cell differentiation. Tpit is a positive regulator for late POMC cell differentiation and POMC expression, but it is not essential for lineage commitment. The pituitary intermediate lobe normally contains only Tpit-expressing melanotrophs. Inactivation of theTpitgene results in almost complete loss of POMC-expressing cells in this tissue, which now has a large number of gonadotrophs and a few clusters of Pit-1-independent thyrotrophs. The role of Tpit as a negative regulator of gonadotroph differentiation was confirmed in transgenic gain-of-function experiments. One mechanism to account for the negative role of Tpit in differentiation may be trans-repression between Tpit and the gonadotroph-restricted factor SF1. These data suggest that antagonism between Tpit and SF1 may play a role in establishment of POMC and gonadotroph lineages and that these lineages may arise from common precursors.
A model of repression: CTD analogs and PIE-1 inhibit transcriptional elongation by P-TEFb
Authors: Zhang Fan , Barboric Matjaz , Blackwell T. Keith , Peterlin B. Matija
Published: March 2003

The positive transcription elongation factor b (P-TEFb) contains cyclin T1 (CycT1) and cyclin-dependent kinase 9 (Cdk9). For activating the expression of eukaryotic genes, the histidine-rich sequence in CycT1 binds the heptapeptide repeats in the C-terminal domain (CTD) of RNA polymerase II (RNAPII), whereupon Cdk9 phosphorylates the CTD. We found that alanine-substituted heptapeptide repeats that cannot be phosphorylated also bind CycT1. When placed near transcription units, these CTD analogs block effects of P-TEFb. Remarkably, the transcriptional repressor PIE-1 fromCaenorhabditis elegansbehaves analogously. It binds CycT1 via an alanine-containing heptapeptide repeat and inhibits transcriptional elongation. Thus, our findings reveal a new mechanism by which repressors inhibit eukaryotic transcription.
A procedure towards the automatic solution of crystal structures by means of topological analysis of Fourier maps
Authors: Menéndez-Velázquez Amador , García-Granda Santiago
Published: March 2003

The last step of a crystal structure determination that requires human intervention is the interpretation of Fourier maps, displayed as peaks in a favourable projection. Crystallographers infer bonding by empirically assigning bonds between peaksviapurely geometrical criteria. In this paper, a network connecting peaks and passes of the density function is suggested in order to avoid human intervention and bonding inference. A completely automatic algorithm for the full analysis of critical points and recognition of the molecular graph in Fourier maps has been developed and implemented into the packageDIRDIF. This procedure has been applied successfully to a wide variety of crystal structures. In most cases, the complete structure is recovered and the connectivity matrix is constructed without any user intervention.
Multiple-data-set Rietveld analysis using isotopes in powder neutron diffraction. 2. Positional and anisotropic thermal displacement parameter determinations in CuO (tenorite) at 2 K and 300 K
Authors: Henry Paul F. , Nowell Harriott , Weller Mark T. , Wilson Chick C.
Published: March 2003

The technique of isotope-substitution neutron diffraction (ISND) and combined-data-set Rietveld analysis from powder neutron data of crystalline materials is presented and compared with single-data-set powder refinement methods. The rationale behind improvements in the precision and accuracy of the refined model as a result of reduction in parameter correlation in the least-squares technique is described. The improvements are demonstrated practically through a study of isotopically copper-substituted tenorite, CuO, at 2 and 300 K. Typically, the estimated errors on structural parameters from the combined analysis technique are 30% lower than separate single-data-set analyses. Comparison of the precision and accuracy of the structural models obtained from this investigation with previous single-crystal X-ray studies are also presented.
X-ray interferometer using wavefront division
Authors: Yamazaki Hiroshi , Ishikawa Tetsuya
Published: March 2003

The properties of an X-ray Laue-case wavefront-dividing interferometer have been analysed using time-dependent dynamical diffraction theory. The visibility and the fringe spacing of the interference pattern depend both on the coherence function of the isochronous wavefields on the entrance surface of the interferometer and the spreads of the wavefields into Borrmann fans in the Laue plates. Interference patterns for partially coherent incident X-rays were observed experimentally. The changes of the visibility and of the fringe spacing with respect to the coherence length of the incident X-rays agreed well with the results of the calculations from the dynamical theory.
Solution of organic crystal structures from powder diffraction by combining simulated annealing and direct methods
Authors: Altomare Angela , Caliandro Rocco , Giacovazzo Carmelo , Moliterni Anna Grazia Giuseppina , Rizzi Rosanna
Published: March 2003

Theab initiocrystal structure solution from powder diffraction data can be attemptedviadirect methods. If heavy atoms are present, they are usually correctly located; then some crystal chemical information can be exploited to complete the partial structure model. Organic structures are more resistant to direct methods; as an alternative, their molecular geometry is used as prior information for Monte Carlo methods. In this paper, a new procedure is described which combines the information contained in the electron density map provided by direct methods with a Monte Carlo method which uses simulated annealing as a minimization algorithm. A figure of merit has been designed based on the agreement between the experimental and calculated profiles, and on the positions of the peaks in the electron density map. The procedure is completely automatic and has been included inEXPO; its performance has been validated and tested for a set of known molecular structures.
Bulk-solvent correction for fast translation search in molecular replacement: service programs forAMoReandCNS
Authors: Fokine Andrei , Capitani Guido , Grütter Markus G. , Urzhumtsev Alexandre
Published: March 2003

A new software package,BULK, was developed to allow fast and easy use of low-resolution data for the translation problem in molecular replacement. When the search model is relatively complete but not precise, or when its orientation is imprecisely determined, low-resolution data contribute very favourably to the solution of the translation-search problem.BULKcomprises a specially developed program and a set of procedures complementary to the programAMoRe, as well as an input file for theCNSsuite.
A sensitive method to detect strain in silicon crystals using X-ray dynamical diffraction
Authors: Saka Takashi
Published: March 2003

A very sensitive method to detect long-range strain in otherwise perfect crystalline materials is presented. In this method, a specimen is set vertically in a diffraction apparatus under the symmetrical Laue condition, in which the scattering vector is horizontal. The specimen is then rotated along the scattering vector, with the Bragg condition being kept satisfied. Experiments were carried out using Si crystals of 714 µm thickness with X-rays of 0.4 Å wavelength. The Si crystals were strained by scratching the surface with a glass-cutter. A characteristic behaviour of the integrated intensities was observed. When the specimens were rotated in the opposite direction, the integrated intensities were different and sharply enhanced integrated intensities of the higher order reflections were observed when the specimens were rotated from their initial vertical positions. The observed results can be explained using the dynamical theory of X-ray diffraction for distorted crystals, with the assumption that the specimens were bent along an axis lying on the specimen surface. This method of rotating the crystal along the scattering vector is a very sensitive method to detect minute strains induced by device fabrication processes. The detection limit for the presented specimen is estimated to be equivalent to a uniform bending with a radius of curvature of 7000 m.
Local structure at a ferrofluid surface: chain-like aggregates revealed by non-specular X-ray reflection
Authors: Takahashi I. , Tanaka N. , Doi S.
Published: March 2003

The surface structure of a ferrofluid was investigated by means of non-specular X-ray reflection. Strong intensity that is impossible to explain by surface fluctuations due to capillary waves was observed. It can be related to lateral correlation within aggregates of super-paramagnetic fine particles in the vicinity of the specimen surface. The fractal dimension of these surface-induced aggregates and the surface-tension coefficient of the ferrofluid were simultaneously determined. The fractal dimension was found to be around 1.1, indicating a chain-like character of the aggregates that have few branches. Strong and anisotropic interaction among the particles, as well as irreversible aggregation kinetics must be the origin of such a high-density and low-fractal-dimension system of dipolar 10 nm sized particles. The temperature variation of the fractal dimension indicated that the fractal aggregates stabilize themselves by losing their branches at increasing temperatures.
Automated profile analysis for single-crystal diffraction data
Authors: Angel R. J.
Published: March 2003

An integration method for step-scanned single-crystal intensity data based upon fitting of the individual diffraction profiles by a pseudo-Voigt function is presented. Algorithms for both the recovery of weak intensities from data sets and the rejection of aberrant peak profiles are discussed. The ideas presented in this paper have been implemented in a software package for Microsoft Windows,WinIntegrStp, which is available at http://www.crystal.vt.edu/.
Mixed valences in nanometric ferrites investigated by resonant powder diffraction
Authors: Lorimier J. , Bernard F. , Niepce J.-C. , Guigue-Millot N. , Isnard O. , Bérar J.-F.
Published: March 2003

The dependence of the absorption-edge position on ion valence in resonant scattering can be used to analyse the ionic composition of complex oxides. As the diffraction spectra are more sensitive to f^{\,\prime} than to f^{\,\prime\prime}, the shift in f^{\,\prime} associated with the valence can be used to refine the cation distribution. Below the absorption edge the shape of f^{\,\prime} is quite insensitive to other site parameters. High-angle data are important to reach significant variation of the diffraction lines. The feasibility of this method for powder materials was tested using a nanometric powder of magnetite, Fe3O4. More complex ferrites were then investigated and the results compared with neutron diffraction experiments.
Easy editing of Protein Data Bank formatted files withEMACS
Authors: Bond Charles S.
Published: March 2003

A protein crystallographer typically spends a large proportion of time manipulating Protein Data Bank (PDB) formatted coordinate files. Of the many situations where such coordinate data must be altered for a particular purpose, a combination of a simple text editor and a number of programs is required.pdb-modeforEMACSprovides a set of commonly used commands that allow many of these repetitive or trivial computational tasks to be performed within the environment of theEMACSeditor, without recourse to writing temporary files and running external programs.
A procedure for setting up high-throughput nanolitre crystallization experiments. I. Protocol design and validation
Authors: Walter T. S. , Diprose J. , Brown J. , Pickford M. , Owens R. J. , Stuart D. I. , Harlos K.
Published: March 2003

A protocol for setting up nanolitre sitting-drop vapour-diffusion experiments is reported. The procedure uses standard crystallization screening kits and 96-well crystallization plates. Reservoir solutions are transferred from 96-deep-well blocks to crystallization plates in a single step with a Robbins-Hydra pipettor. Nanolitre droplets of protein as well as reservoir solution are dispensed by a Cartesian pipetting instrument. Experiments have been carried out to characterize the performance of this instrument. Adaptations to the Cartesian, which include an anti-evaporation cover plate, are described and tested. The protocol was designed for a high-throughput facility, but can be used in any standard crystallography laboratory.
Reconstruction of grain boundaries in polycrystals by filtered back-projection of diffraction spots
Authors: Poulsen Henning Friis , Schmidt Soeren
Published: March 2003

A reconstruction method is presented for the generation of three-dimensional maps of the grain boundaries within powders or polycrystals. The grains are assumed to have a mosaic spread below 1°. They are mapped non-destructively by diffraction with hard X-rays, using a uniform mm2-sized beam. First the diffraction spots are sorted with respect to grain of origin by the indexing programGRAINDEX. Next, for each grain the reconstruction is performed by a variant of the filtered back-projection algorithm. The reconstruction method is verified by a simulation over ten grains. Using 64 reflections for each grain, sub-pixel accuracy is obtained. The potential of the method is outlined.
Resolution, truncation and smearing of the one-dimensional spin echo small-angle scattering instrument
Authors: Yuan Peng , Zhao Jinkui
Published: March 2003

The resolution of the spin echo small-angle neutron scattering (SESANS) instrument is limited by the precession Larmor fields and by the wavelength of the neutrons. It can reach to about a micrometer with thermal neutrons and to a few tens of micrometers with cold neutrons. Since a SESANS instrument will have a limited coverage in scattering angles or in neutron momentum transfers, there will be truncation errors in the measured correlation functions. These truncation errors increase with smaller scattering particles and they limit the smallest particle that can be effectively studied by the instrument. The off-plane scatterings in one-dimensional SESANS as well as the inhomogeneity of the precession fields cause smearing effects in the correlation functions. Desmearing procedures developed for the traditional small-angle scattering instruments can be used to restore the true parameters of the scattering particle.
Consumer evaluations of “really new” services: the TrafficPulse system
Authors: Krieger Abba , Green Paul , Lodish Leonard , D’Arcangelo Jim , Rothey Chris , Thirty Paul
Published: March 2003

Conjoint analysis is a class of techniques for analyzing consumers’ preferences and trade‐offs regarding their selection of products and services. Typically, conjoint analysis has been applied to established markets such as frequently purchased packaged goods, consumer durables, communication services, and business‐to‐business products. Recently, marketing researchers have extended conjoint methodology to cope with the measurement of buyer trade‐offs associated with “really new” products and services, for which there is little or no prior buyer knowledge or experience. The researcher’s task is twofold: to educate the potential buyer regarding the pros and cons of the new product/service while, at the same time, obtaining the respondent’s evaluation of the new product/service itself. This article describes the application of conjoint techniques to a new service, TrafficPulse, that enables subscribers to obtain continuous 24/7 updates on traffic conditions, travel times, and alternative routes, should congestion occur. In particular, describes how traditional conjoint analysis can be embellished to obtain relevant information about consumer evaluations of new goods and services prior to their actual use by prospective consumers. In short, the prospective consumer can be “educated” about the new product/service before obtaining evaluation of its potential worth. The paper also shows how conjoint analysis can be modified to accommodate restrictions on various attribute levels, how the use of BASES‐like norms can be incorporated, and how optimization algorithms can be used at either the single product or multiple product (i.e. product line) level.
The impact of the relational plan on adoption of electronic banking
Authors: Rexha Nexhmi , Kingshott Russel Philip John , Shang Shang Aw Audrey
Published: March 2003

Marketing managers in financial institutions should be aware that customers are likely to embody electronic banking provided that such technology contributes to existing relationships. Based on a survey of bank corporate clients in Singapore, the impact of satisfaction, trust and the use of electronic banking on commitment towards current banks was investigated. It was found that trust was the key factor influencing the adoption of electronic banking. Perceived customer satisfaction with the bank only impacted indirectly on the adoption of electronic banking. The cumulative effects of customer satisfaction were found to have a positive impact on trust directed towards the bank, and this greatly impacted on the propensity to use electronic banking. Customer satisfaction, trust, and the use of electronic banking were found to have a positive impact on the corporate clients’ commitment towards their bank.
Market orientation and performance in service firms: role of innovation
Authors: Agarwal Sanjeev , Krishna Erramilli M. , Dev Chekitan S.
Published: March 2003

There is wide acceptance of the precept that market orientation is associated with superior firm performance. However, empirical support for the proposition in prior literature is weak. This study examines the relationship between market orientation and performance with data from 201 international hotels and finds that market orientation is positively associated with both judgmental measures of performance – service quality, customer satisfaction, and employee satisfaction, and objective measures of performance – occupancy rate, gross operating profit, and market share. Specifically, the study finds that the immediate impact of market orientation is to spur innovation, which, in turn, enhances judgmental performance, which, in turn, enhances objective performance.
Why are capital market actors ambivalent to information about certain indicators on intellectual capital?
Authors: Johanson UIf
Published: March 2003

An increasing body of literature is documenting a high pay‐off from human capital investment. However, different studies of the interest from capital market actors to take information about intangibles into account reveal contradictory findings. The interest with respect to intellectual capital indicators is ambivalent. Why? In the present article five reasons for this ambivalent interest are discussed; capital market actors may first, not understand the importance of intangibles (the knowledge problem); second, not trust the indicators with respect to validity and reliability (the uncertainty problem); third, exaggerate the risk of losing the intangible resource (the ownership problem); fourth, not feel secure about the management’s capability of taking action upon data (the management problem). However, the most important deterrent to account for is maybe the fifth, the mentality of capital market actors as a group.
The relevance of intellectual capital disclosure: a paradox?
Authors: Nikolaj Bukh Per
Published: March 2003

Many firms have started disclosing information on intellectual capital. Financial analysts, however, ask for more disclosure related to strategy and often find intellectual capital statement less relevant. Drawing on results from a study of disclosure of information on intellectual capital in Danish initial public offering (IPO) prospectuses, this commentary argues that the perceived irrelevance of intellectual capital is somewhat paradoxical since intellectual capital reports and recent prospectuses share remarkable similarities with respect to the intellectual capital indicators disclosed. Further, the commentary argues that, for intellectual capital disclosure to be perceived as relevant from a capital market perspective, the information should be disclosed as an integral part of a framework illuminating the value creation processes of the firm. The emerging practice with respect to intellectual capital offers such a framework for disclosing the business model of the knowledge‐based company.
Factors explaining the inefficient valuation of intangibles
Authors: García‐Ayuso Manuel
Published: March 2003

The inefficient valuation of the intangible determinants of the financial position of business companies may result in significant damages for both firms and their stakeholders. Based on the empirical literature in accounting and finance, this paper suggests possible reasons for the inefficient valuation of intangibles, provides explanations for the existence of biases in analysts’ earnings forecasts and proposes alternative ways for the improvement of the resource allocation mechanisms in the capital markets.
Cash to accrual and cash to accrual
Authors: Scott Julie E.M. , McKinnon Jill L. , Harrison Graeme L.
Published: March 2003

This study traces the development of financial reporting in two publicly funded hospitals in New South Wales over the period 1857 to post‐1975, with particular focus on the use of cash and accrual accounting. The historical analysis draws on process and contextual change and stakeholder theory, and uses both primary and secondary data, to describe patterns of change (and non‐change) in the hospitals’ financial reporting and to identify the social and political influences associated with such reporting. The study provides historical context for recent developments in public sector reporting and accountability in Australia, particularly the (re)introduction of accrual accounting, and provides insights into the nature of accounting change both in public sector organizations and generally.
Metadata, controlled vocabulary and directories: electronic document management and standards for records management
Authors: Tough Alistair , Moss Michael
Published: March 2003

The authors argue that the development and use of elaborate embedded directory structures or file plans, derived from functional analysis, should be a key component in the future development of the discipline of records management. Directory structures thus conceptualised are explicitly intellectual constructs and their construction will require considerable effort, particularly if they are to be portable. Their greatest advantage is that they provide a coherent schema from which to derive folder/file names that can be embedded in metadata. One of the major challenges is to design systems that derive metadata from the directory structure or file plan and attach them automatically to documents at the point of creation, thereby minimising the need for human intervention and opportunities for human error.
Obstacles to utilization of information held by archival institutions: a review of literature
Authors: Kemoni Henry N. , Wamukoya Justus , Kiplang’at Joseph
Published: March 2003

The paper reviews literature on the obstacles that hinder the use of information held in archival institutions. First, it highlights the importance of records and archives as sources of information. Second, the paper examines the problems which hinder archival access, mainly focusing on those that are of a professional and technical nature. Third, it presents the components of a good archival programme to enhance the use of archival information. A summary of the key findings is given and the paper concludes by noting that archival institutions need to take certain measures in order to enhance the exploitation of information in their custody.
Generation Y female consumer decision‐making styles
Authors: Bakewell Cathy , Mitchell Vincent‐Wayne
Published: March 2003

Since environmental factors have influenced Generation Y shoppers (those born after 1977) to make them different from older groups, this study examines the decision making of Adult Female Generation Y consumers using Sproles and Kendall’s (1986) Consumer Styles Inventory (CSI). The study uses the CSI as a basis for segmenting Generation Y consumers in to five meaningful and distinct decision‐making groups, namely: “recreational quality seekers”, “recreational discount seekers”, “trend setting loyals”, “shopping and fashion uninterested” and “confused time/money conserving”. Implications for retailers and marketing practitioners targeting Generation Y consumers are discussed.
The wave transmission coefficients and coupling loss factors of point connected structures
Authors: Langley R. S. , Shorter P. J.
Published: March 2003

This analysis is concerned with the calculation of the elastic wave transmission coefficients and coupling loss factors between an arbitrary number of structural components that are coupled at a point. A general approach to the problem is presented and it is demonstrated that the resulting coupling loss factors satisfy reciprocity. A key aspect of the method is the consideration of cylindrical waves in two-dimensional components, and this builds upon recent results regarding the energetics of diffuse wavefields when expressed in cylindrical coordinates. Specific details of the method are given for beam and thin plate components, and a number of examples are presented.
Time-frequency model for echo-delay resolution in wideband biosonar
Authors: Neretti Nicola , Sanderson Mark I. , Intrator Nathan , Simmons James A.
Published: March 2003

A time/frequency model of the bat’s auditory system was developed to examine the basis for the fine (∼2 μs) echo-delay resolution of big brown bats (Eptesicus fuscus), and its performance at resolving closely spaced FM sonar echoes in the bat’s 20–100-kHz band at different signal-to-noise ratios was computed. The model uses parallel bandpass filters spaced over this band to generate envelopes that individually can have much lower bandwidth than the bat’s ultrasonic sonar sounds and still achieve fine delay resolution. Because fine delay separations are inside the integration time of the model’s filters (∼250–300 μs), resolving them means using interference patterns along the frequency dimension (spectral peaks and notches). The low bandwidth content of the filter outputs is suitable for relay of information to higher auditory areas that have intrinsically poor temporal response properties. If implemented in fully parallel analog-digital hardware, the model is computationally extremely efficient and would improve resolution in military and industrial sonar receivers.
Scattering of the fundamental shear horizontal mode from steps and notches in plates
Authors: Demma A. , Cawley P. , Lowe M.
Published: March 2003

The scattering of the SH0 mode from discontinuities in the geometry of a plate has been studied. Both finite element and modal decomposition methods have been used to study the reflection and transmission characteristics from a thickness step in a plate, obtaining very good agreement. The significance of nonpropagating modes in the scattering from steps in plates has been specifically investigated. A method to approximate the reflection from rectangular notches by superimposing the reflection from a step down (start of the notch) and a step up (end of the notch) has been proposed. It is demonstrated that it is possible to use this method to obtain the reflection from a notch of any depth and at any frequency. The effect of frequency on the reflection from notches has been examined. The limits of this method in approximating cracklike defects have also been studied.
Recovery from prior stimulation: Masking of speech by interrupted noise for younger and older adults with normal hearing
Authors: Dubno Judy R. , Horwitz Amy R. , Ahlstrom Jayne B.
Published: March 2003

In a previous study [Dubno et al., J. Acoust. Soc. Am. 111, 2897–2907 (2002)], older subjects benefitted less than younger subjects from momentary improvements in signal-to-noise ratio when listening to speech in interrupted maskers. It has been hypothesized that the benefit derived from interrupted maskers may be related to recovery from forward masking, i.e., the recovery of a response to a suprathreshold signal from prior stimulation by a masker. The effect of interrupted maskers on speech recognition may be well suited to test hypotheses regarding recovery from prior stimulation, given that both involve the perception of signals following a masker. Here, younger and older adults with normal but not identical audiograms listened to nonsense syllables at moderate and high levels in a speech-shaped noise that was modulated by a 2-, 10-, 25-, or 50-Hz square wave. An additional low-level noise was always present that was shaped to produce equivalent masked thresholds for all subjects. To assess recovery from forward masking, forward-masked thresholds were measured at 0.5 and 4.0 kHz as a function of the delay between the speech-shaped masker and the signal. Speech recognition in interrupted noise was poorer for older than younger subjects. Small but consistent age-related differences were observed in the decrease in score with interrupted noise relative to the score without interrupted noise. Forward-masked thresholds of older subjects were higher than those of younger subjects, but there were no age-related differences in the amount of forward masking or in simultaneous masking. Negative correlations were observed between speech-recognition scores in interrupted noise and forward-masked thresholds. That is, the benefit derived from momentary improvements in speech audibility in an interrupted noise decreased as forward-masked thresholds increased. Stronger correlations with forward masking were observed for the higher frequency signal, for higher noise interruption rates, and when the signal-to-noise ratio was poor. Comparisons of speech-recognition scores at moderate and high levels for younger and older subjects were not consistent with the hypothesis of an age-related difference in the contribution of low-spontaneous-rate fibers to speech recognition in interrupted noise.
Modal analysis of a violin octet
Authors: Bissinger George
Published: March 2003

Experimental modal analysis of a complete Hutchins–Schelleng violin octet, combined with cavity mode analysis and room-averaged acoustic analysis, gives a highly detailed characterization of the dynamics for this historic group of instruments. All the “signature” modes in the open string pitch region—cavity modes A0 (“main air”) and A1 (lowest longitudinal), C-bout “rhomboid,” the first corpus bending modes B1− and B1+ (comprising the “main wood”)—were observed across the octet. A0 was always the lowest dominant radiator, below all corpus modes. A1 contributed significant acoustic output only for larger instruments, but was the dominant contributor for the large bass in the “main wood” region. Acoustic results indicate either B1− or B1+ can be the major radiator. Damping results indicate that B1 modes overall radiate approximately 28% of their vibrational energy. “Doublet” B1 modes from substructure couplings were observed for three instruments. “A0-B0” coupling was not significant for the largest instruments. The original flat-plate-based scaling of the “main wood” resonance was generally successful across the octet, although that for the “main air” was not.
Diversity in noise-induced temporary hearing loss in otophysine fishes
Authors: Amoser Sonja , Ladich Friedrich
Published: March 2003

The effects of intense white noise (158 dB re 1 μPa for 12 and 24 h) on the hearing abilities of two otophysine fish species—the nonvocal goldfish Carassius auratus and the vocalizing catfish Pimelodus pictus—were investigated in relation to noise exposure duration. Hearing sensitivity was determined utilizing the auditory brainstem response (ABR) recording technique. Measurements in the frequency range between 0.2 and 4.0 kHz were conducted prior and directly after noise exposure as well as after 3, 7, and 14 days of recovery. Both species showed a significant loss of sensitivity (up to 26 dB in C. auratus and 32 dB in P. pictus) immediately after noise exposure, with the greatest hearing loss in the range of their most sensitive frequencies. Hearing loss differed between both species, and was more pronounced in the catfish. Exposure duration had no influence on hearing loss. Hearing thresholds of C. auratus recovered within three days, whereas those of P. pictus only returned to their initial values within 14 days after exposure in all but one frequency. The results indicate that hearing specialists are affected differently by noise exposure and that acoustic communication might be restricted in noisy habitats.
On the dynamic stiffness of preloaded vibration isolators in the audible frequency range: Modeling and experiments
Authors: Kari Leif
Published: March 2003

The nonlinear, preload-dependent dynamic stiffness of a cylindrical vibration isolator is examined via measurements and modeling within an audible frequency range covering 50 to 1000 Hz at various preloads. The stiffness is found to depend strongly on frequency—resulting in peaks and troughs, and on preload—particularly above 500 Hz. The problems of simultaneously modeling the rubber prestrain dependence and its audible short-term response are removed by adopting a nearly incompressible material model, being elastic in dilatation while displaying viscoelasticity in deviation. The latter exhibits a time strain separable relaxation tensor with a single function embodying its time dependence. This function is based on a continuous fractional order derivative model, the main advantage being the minimum number of parameters required to successfully model the rubber properties over a broad structure-borne sound frequency domain, while embodying a continuous distribution of relaxation time. The weak formulations corresponding to the stiffness problem are solved by an updated Lagrangian nonlinear finite-element procedure. The model and measurement results agree strikingly well with static and dynamic measurements throughout the whole frequency domain for the examined preloads.
Segmental intelligibility of four currently used text-to-speech synthesis methods
Authors: Venkatagiri Horabail S.
Published: March 2003

The study investigated the segmental intelligibility of four currently available text-to-speech (TTS) products under 0-dB and 5-dB signal-to-noise ratios. The products were IBM ViaVoice™ version 5.1, which uses formant coding, Festival version 1.4.2, a diphone-based LPC TTS product, AT&T Next-Gen™, a half-phone-based TTS product that uses harmonic-plus-noise method for synthesis, and FlexVoice™2, a hybrid TTS product that combines concatenative and formant coding techniques. Overall, concatenative techniques were more intelligible than formant or hybrid techniques, with formant coding slightly better at modeling vowels and concatenative techniques marginally better at synthesizing consonants. No TTS product was better at resisting noise interference than others, although all were more intelligible at 5 dB than at 0-dB SNR. The better TTS products in this study were, on the average, 22% less intelligible and had about 3 times more phoneme errors than human voice under comparable listening conditions. The hybrid TTS technology of FlexVoice had the lowest intelligibility and highest error rates. There were discernible patterns of errors for stops, fricatives, and nasals. Unrestricted TTS output—e-mail messages, news reports, and so on—under high noise conditions prevalent in automobiles, airports, etc. will likely challenge the listeners.