bluuebunny/crossref_metadata_2025_split huggingface dataset:
User transparency: a fully sequential programming model for efficient data parallel image processing
Authors: Seinstra F. J. , Koelma D. 
Published: April 2004

AbstractAlthough many image processing applications are ideally suited for parallel implementation, most researchers in imaging do not benefit from high‐performance computing on a daily basis. Essentially, this is due to the fact that no parallelization tools exist that truly match the image processing researcher's frame of reference. As it is unrealistic to expect imaging researchers to become experts in parallel computing, tools must be provided to allow them to develop high‐performance applications in a highly familiar manner. In an attempt to provide such a tool, we have designed a software architecture that allows transparent (i.e. sequential) implementation of data parallel imaging applications for execution on homogeneous distributed memory MIMD‐style multicomputers. This paper presents an extensive overview of the design rationale behind the software architecture, and gives an assessment of the architecture's effectiveness in providing significant performance gains. In particular, we describe the implementation and automatic parallelization of three well‐known example applications that contain many fundamental imaging operations: (1) template matching; (2) multi‐baseline stereo vision; and (3) line detection. Based on experimental results we conclude that our software architecture constitutes a powerful and user‐friendly tool for obtaining high performance in many important image processing research areas. Copyright © 2004 John Wiley & Sons, Ltd.
Genetic screening for individuals at high risk for type 1 diabetes in the general population using HLA Class II alleles as disease markers. A comparison between three European populations with variable rates of disease incidence
Authors: Hermann R. , Bartsocas C. S. , Soltész Gy. , Vazeou A. , Paschou P. , Bozas E. , Malamitsi‐Puchner A. , Simell O. , Knip M. , Ilonen J. 
Published: April 2004

AbstractBackgroundTo develop screening strategies for identification of individuals at increased genetic risk for type 1 diabetes in three populations with variable disease incidence rates and distinct ethnic origin.MethodsA stepwise HLA DQB1‐DQA1‐DRB1‐based screening approach was evaluated. Patients with childhood‐onset type 1 diabetes were recruited from Finland (n = 1739), Hungary (n = 149), and Greece (n = 119). Consecutive newborns (2568 from Finland and 1047 from Greece) or healthy schoolchildren (n = 177 from Hungary) served as controls.ResultsThe DQB1*02/0302 genotype conferred the highest disease risk in all populations. The DQB1*02/y (y ≠ DQB1*0301,*0302,*0602,*0603, *0604) genotypes were more common and conferred a higher disease risk in the Greek population (OR 4.9) compared to the Finns (OR 1.2). DQB1*0302/x (x ≠ DQB1*02, *0301, *0602, *0603, *0604) genotypes were, in contrast, more prevalent among Finnish cases (32.7%) as compared to Hungarians (18.1%) or Greeks (13.5%). The protective DQB1*0602 or *0603 positive genotypes were most common in the Finns, while DQB1*0301 was more common in Hungarians and Greeks. In all groups, DQA1 and DRB1*04 typing considerably increased the sensitivity of the DQB1‐based screening. The different high‐risk genotype combinations present in about 10% of the background population had a diagnostic sensitivity of 60% in Finland and 80% in Hungary and Greece.ConclusionsHLA DR‐DQ‐based screening is a feasible tool for the identification of individuals at increased genetic risk for type 1 diabetes in populations with diverse genetic background. The risk markers should, however, be individually selected for the target population since the screening efficiency of various markers is highly dependent on the ethnic group studied. Copyright © 2004 John Wiley & Sons, Ltd.
Investigation of Multi‐Nickel‐Substituted Tungstophosphates and Their Stability and Electrocatalytic Properties in Aqueous Media
Authors: Jabbour Darine , Keita Bineta , Mbomekalle Israel‐Martyr , Nadjo Louis , Kortz Ulrich 
Published: April 2004

AbstractSeveral sandwich‐type polyoxometallates based on the trivacant [PW9O34]9− fragment with different Ni nuclearities were selected. Their stability and redox behaviour in aqueous media were evaluated by UV/Vis spectroscopy and cyclic voltammetry as a function of pH with the aim of finding the conditions under which these compounds could be suitable candidates for electrocatalytic processes. Two polyoxoanions — [Ni3Na(H2O)2(PW9O34)2]11− and (to a lesser extent) [Ni4Mn2P3W24O94]17− — were found to be stable over a wide pH domain, while [Ni4(H2O)2(PW9O34)2]10− requires the pH to be greater than 4 for its stability. The other derivatives are only suitable for solid‐state studies. The stable polyoxoanions were tested for their activity in the electrocatalytic reduction of nitrate. The results suggest unambiguously that an increase in the number of Ni centres within these sandwich‐type polyanions has a beneficial effect on the electrocatalytic process. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Sensitivity of a physically based method for terrain interpolation to initial conditions and its conditioning on stream location
Authors: Grimaldi Salvatore , Teles Vanessa , Bras Rafael L. 
Published: April 2004

AbstractProduction of digital elevation maps often requires interpolation of observations at particular locations. For hydrologic applications the resulting surface should have well deﬁned drainage directions, should reproduce the roughness of natural terrain and should ideally preserve distributions of elevations, slopes and curvatures. The work of J. Niemann et al. (Water Resources Research, 2003, vol. 39, pp. 1017–1032) proposes a physically based interpolation method that is an improvement over commonly used linear or fractal interpolators. The methodology does have difﬁculty dealing with very sparse initial elevation and boundary ﬂux information. This work suggests that using the commonly available horizontal location of main channels (‘blue lines’) improves the physical interpolation signiﬁcantly. The results are illustrated on two river basins. Copyright © 2004 John Wiley & Sons, Ltd.
Performance analysis of multifractal network traffic
Authors: Dinh Dang Trang , Molnár Sándor , Maricza István 
Published: April 2004

AbstractIn this paper we present some new results in the framework of multifractal performance analysis including both the characterization and modeling of multifractal network traffic, and also the multifractal queueing performance analysis. We first propose a new multifractal traffic model for network traffic based on the combination of a multiplicative cascade with an independent lognormal process. This traffic model is able to provide a very accurate fit to the multifractal characteristics of datatraffic including both the scaling function and the moment factor, but it is also simple enough from a practical point of view having only three parameters. In addition, the model features many important properties observed in datatraffic including long‐range dependence (LRD), multifractality and lognormality. We also present an approximation for the queue tail asymptotics in an infinite capacity single server queue serviced at a constant rate driven by a general multifractal input process. We show that in the special and important case of the monofractal fractional Brownian motion (fBm) input traffic our result gives the well‐known Weibullian tail. We prove that the class of Gaussian processes with scaling properties is in the class of monofractal processes and we derive the related characterization functions. Applying the approximation we provide a new practical method for queueing performance estimation of general multifractal traffic. Finally, we present a practical case study to show the practical application of our framework for measured data traffic and also to validate both our multifractal model and our queueing results. Copyright © 2004 AEI
A 2D implicit time‐marching algorithm for shallow water models based on the generalized wave continuity equation
Authors: Dresback Kendra M. , Kolar Randall L. , Dietrich J. Casey 
Published: April 2004

AbstractThis paper builds upon earlier work that developed and evaluated a 1D predictor–corrector time‐marching algorithm for wave equation models and extends it to 2D. Typically, the generalized wave continuity equation (GWCE) utilizes a three time‐level semi‐implicit scheme centred at k, and the momentum equation uses a two time‐level scheme centred at k+12. It has been shown that in highly non‐linear applications, the algorithm becomes unstable at even moderate Courant numbers. This work implements and analyses an implicit treatment of the non‐linear terms through the use of an iterative time‐marching algorithm in the two‐dimensional framework. Stability results show at least an eight‐fold increase in the maximum time step, depending on the domain. Studies also examined the sensitivity of the G parameter (a numerical weighting parameter in the GWCE) with results showing the greatest increase in stability occurs when 1⩽G/τmax⩽10, a range that coincides with the recommended range to minimize errors. Convergence studies indicate an increase in temporal accuracy from first order to second order, while overall error is less than the original algorithm, even at higher time steps. Finally, a parallel implementation of the new algorithm shows that it scales well. Copyright © 2004 John Wiley & Sons, Ltd.
Assessment of two‐equation turbulence modelling for high Reynolds number hydrofoil flows
Authors: Mulvany N. , Tu J. Y. , Chen L. , Anderson B. 
Published: April 2004

AbstractThis paper presents an evaluation of the capability of turbulence models available in the commercial CFD code FLUENT 6.0 for their application to hydrofoil turbulent boundary layer separation flow at high Reynolds numbers. Four widely applied two‐equation RANS turbulence models were assessed through comparison with experimental data at Reynolds numbers of 8.284×106 and 1.657×107. They were the standard k–εmodel, the realizable k–εmodel, the standard k–ωmodel and the shear‐stress‐transport (SST) k–ωmodel. It has found that the realizable k–εturbulence model used with enhanced wall functions and near‐wall modelling techniques, consistently provides superior performance in predicting the flow characteristics around the hydrofoil. Copyright © 2004 John Wiley & Sons, Ltd.
A non‐linear dynamical system approach to finite amplitude Taylor‐Vortex flow of shear‐thinning fluids
Authors: Li Zhenyu , Khayat Roger E. 
Published: April 2004

AbstractThe effect of shear thinning on the stability of the Taylor–Couette flow is explored for a Carreau–Bird fluid in the narrow‐gap limit. The Galerkin projection method is used to derive a low‐order dynamical system from the conservation of mass and momentum equations. In comparison with the Newtonian system, the present equations include additional non‐linear coupling in the velocity components through the viscosity. It is found that the critical Taylor number, corresponding to the loss of stability of the circular Couette flow, becomes lower as the shear‐thinning effect increases. That is, shear thinning tends to precipitate the onset of Taylor vortex flow, which coincides with the onset of a supercritical bifurcation. Comparison with existing measurements of the effect of shear thinning on the critical Taylor and wave numbers show good agreement. The Taylor vortex cellular structure loses its stability in turn, as the Taylor number reaches a critical value. At this point, an inverse Hopf bifurcation emerges. In contrast to Newtonian flow, the bifurcation diagrams exhibit a turning point that sharpens with shear‐thinning effect. Copyright © 2004 John Wiley & Sons, Ltd.
Effect of γ‐irradiation on the biophysical and morphological properties of corn
Authors: Al‐Salhi Mohammed , Ghannam Magdi M. , Al‐Ayed Mohammed S. , El‐Kameesy Samir U. , Roshdy Shahira 
Published: April 2004

AbstractThe effects of γ‐irradiation on the biophysical and morphological properties of corn plants were investigated. The irradiation doses were 0, 1, 1.5, 2.5, 5, and 10 krad. Corn grains exposed to 1.5 and 2.5 krad showed highly significant changes in all growth parameters. Fluorescence and light absorption spectra of chlorophyll attributed to different doses treatments of corn grains clearly confirmed the superiority of 1.5 krad irradiation dose in stimulating corn plants. Furthermore, the frequency dependence of the relative permittivity and the electric conductivity of the treated samples have been performed and discussed. The obtained results give another support via the biophysical properties for the 1.5 krad irradiation dose to be the most favorable one to improve the plant growth characteristics.
Spontaneous ectopic recombination in cell‐type‐specific Cre mice removes loxP‐flanked marker cassettes in vivo
Authors: Eckardt Dominik , Theis Martin , Döring Britta , Speidel Dina , Willecke Klaus , Ott Thomas 
Published: April 2004

AbstractConditional gene targeting using the Cre/loxP technology generally includes integration of a selection marker cassette flanked by loxP recognition sites (floxed) in the target gene locus. Subsequent marker removal avoids possible impairment of gene expression or mosaicism due to partial and total deletions after Cre‐mediated recombination in vivo. The use of deleter Cre mice for in vivo marker removal in floxed connexin43 mice revealed considerable mosaicism, but no selective marker removal. In addition, we noted that several Cre transgenic lines displayed spontaneous ectopic activity, reminiscent of deleter Cre mice, and required the confirmation of cell type‐specific deletion in every individual mouse. When we used myosin heavy chain promoter Cre (αMyHC‐Cre) mice for cardiomyocyte specific deletion, we observed, in addition to cardiomyocyte‐restricted or complete excision, selective marker removal in a subgroup of mice as well. Thus, selective marker removal can be achieved as a byproduct of cell‐type restricted deletion. genesis 38:159–165, 2004. © 2004 Wiley‐Liss, Inc.
Xenopus embryonic poly(A) binding protein 2 (ePABP2) defines a new family of cytoplasmic poly(A) binding proteins expressed during the early stages of vertebrate development
Authors: Good Peter J. , Abler Lisa , Herring Dina , Sheets Michael D. 
Published: April 2004

AbstractWe describe a new RNA binding protein from Xenopus we have named ePABP2 (embryonic poly(A) binding protein type II). Based on amino acid similarity, ePABP2 is closely related to the ubiquitously expressed nuclear PABP2 protein that directs the elongation of mRNA poly(A) tails during pre‐mRNA processing. However, in contrast to known PABP2 proteins, Xenopus ePABP2 is a cytoplasmic protein that is predominantly expressed during the early stages of Xenopus development and in adult ovarian tissue. Biochemical experiments indicate ePABP2 binds poly(A) with specificity and that this binding requires the RRM domain. Mouse and human ePABP2 proteins were also identified and mouse ePABP2 expression is also confined to the earliest stages of mouse development and adult ovarian tissue. We propose that Xenopus ePABP2 is the founding member of a new class of poly(A) binding proteins expressed in vertebrate embryos. Possible roles for this protein in regulating mRNA function in early vertebrate development are discussed. genesis 38:166–175, 2004. © 2004 Wiley‐Liss, Inc.
Senseless is required for pupal retinal development in Drosophila
Authors: Frankfort Benjamin J. , Pepple Kathryn L. , Mamlouk Mark , Rose Matthew F. , Mardon Graeme 
Published: April 2004

AbstractSummary: Drosophila sensory organs are specified by a family of proneural genes which induce the expression of several common targets. One such target is senseless, which encodes a zinc finger transcription factor. We analyzed the function of senseless during pupal retinal development and found that senseless is required for recruitment of both cone and pigment cells, the pupal‐derived ommatidial support cells. We also found that Senseless is expressed in neural precursors shortly after the larval–pupal transition and is both necessary and sufficient for interommatidial bristle development. Furthermore, senseless is the primary target of achaete and scute during interommatidial bristle development. We also identified several differences between the development of interommatidial bristles and other macrochaete. In particular, EGFR signaling is not required for interommatidial bristle development, nor is positive feedback regulation of proneural genes by senseless. A model for interommatidial bristle specification is presented. genesis 38:182–194, 2004. © 2004 Wiley‐Liss, Inc.
Transition nuclear proteins are required for normal chromatin condensation and functional sperm development
Authors: Zhao Ming , Shirley Cynthia R. , Hayashi Shotaro , Marcon Ludovic , Mohapatra Bhagyalaxmi , Suganuma Ryota , Behringer Richard R. , Boissonneault Guylain , Yanagimachi Ryuzo , Meistrich Marvin L. 
Published: April 2004

AbstractSummary: The histone‐to‐protamine transition is important in the formation of spermatozoa. In mammals this involves two steps: replacement of histones by transition nuclear proteins (TPs) and replacement of TPs by protamines. To determine the functions of the TPs and their importance for sperm development, we generated mice lacking both TPs, since mice lacking only TP1 or TP2 were fertile. Our results indicated that TP1 and TP2 had partially complemented each other. In mice lacking both TPs, nuclear shaping, transcriptional repression, histone displacement, and protamine deposition proceeded relatively normally, but chromatin condensation was irregular in all spermatids, many late spermatids showed DNA breaks, and protamine 2 was not posttranslationally processed. Nevertheless, genomic integrity was maintained in mature spermatids, since efficient fertilization and production of offspring were achieved by intracytoplasmic sperm injection. However, many mature spermatids were retained in the testis, epididymal spermatozoa were drastically reduced in number and were highly abnormal, and the mice were sterile. Most epididymal spermatozoa were incapable of fertilization even using intracytoplasmic sperm injection. Thus, in mammals TPs are required for normal chromatin condensation, for reducing the number of DNA breaks, and for preventing the formation of secondary defects in spermatozoa, eventual loss of genomic integrity, and sterility. genesis 38:200–213, 2004. © 2004 Wiley‐Liss, Inc.
Consolidation of CS and US representations in associative fear conditioning
Authors: Frankland Paul W. , Josselyn Sheena A. , Anagnostaras Stephan G. , Kogan Jeffrey H. , Takahashi Eiki , Silva Alcino J. 
Published: April 2004

AbstractMuch attention has been paid to the associative processes that are necessary to fuse together representations of the various components of an episodic memory. In the present study, we focus on the processes involved in the formation of lasting representations of the individual components that make up a fear‐conditioning episode. In one‐trial contextual fear conditioning experiments, weak conditioning to context occurs if the shock is delivered immediately following placement of the animal in a novel conditioning apparatus, a phenomenon known as the immediate shock deficit. We show that the immediate shock deficit in mice may be alleviated by pre‐exposure to either the context or shock. In using this approach to temporally dissect a contextual fear‐conditioning task into its constituent representational and associative processes, we are able to examine directly the processes that are important for formation of lasting representations of the context conditioned stimulus (CS) or unconditioned stimulus (US). Our data indicate that the formation of a lasting representation of the context or shock engages protein synthesis‐dependent processes. Furthermore, genetic disruption of cAMP‐responsive element binding protein (CREB), a transcription factor that regulates the synthesis of new proteins required for long‐term memory, disrupts the formation of lasting context memories. We go on to show that the stress hormone epinephrine modulates the consolidation of a context memory, and reverses consolidation deficits in the CREB‐deficient mice. Finally we show that disrupting either NMDA or calcium/calmodulin‐dependent kinase II (CaMKII) function impairs consolidation of context memories. Together, these data suggest that this approach is particularly suited for the characterization of molecular and cellular processes underlying the formation of stimulus representations. © 2004 Wiley‐Liss, Inc.
Overexpression of calbindin D28k in dentate gyrus granule cells alters mossy fiber presynaptic function and impairs hippocampal‐dependent memory
Authors: Dumas T.C. , Powers E.C. , Tarapore P.E. , Sapolsky R.M. 
Published: April 2004

AbstractCalcium is a key signaling ion for induction of synaptic plasticity processes that are believed to influence cognition. Mechanisms regulating activity‐induced increases in neuronal calcium and related synaptic modifications are not fully understood. Moreover, involvement of specific synapses in discrete aspects of spatial learning remains to be elucidated. We used herpes simplex amplicons to overexpress calbindin D28k (CaBP) selectively in dentate gyrus (DG) granule cells. We then examined the effects on hippocampal network activity by recording evoked synaptic responses in vivo and in vitro and analyzing hippocampal‐dependent behavior. Relative to Lac‐Z‐ and sham‐infected controls, CaBP overexpression increased mossy fiber (MF‐CA3) excitatory postsynaptic potentials and reduced paired‐pulse facilitation (PPF), suggesting an increase in presynaptic strength. Additionally, CaBP overexpression reduced long‐term potentiation (LTP), caused a frequency‐dependent inhibition of post‐tetanic potentiation (PTP), and impaired spatial navigation. Thus, increasing CaBP levels selectively in the DG disrupts MF‐CA3 presynaptic function and impairs spatial cognition. The results demonstrate the power of gene delivery in the study of the neural substrates of learning and memory and suggest that mossy fiber synaptic plasticity is critical for long‐term spatial memory. © 2004 Wiley‐Liss, Inc.