bluuebunny/crossref_metadata_2025_split huggingface dataset:
Proportional hazards model for interval‐censored failure times and time‐dependent covariates: application to hazard of HIV infection of injecting drug users in prison
Authors: Seaman S. R. , Bird S. M. 
Published: September 2002

AbstractInterval‐censored survival data are data in which the failure times are not known precisely, but are known to lie within an interval. Such data can be analysed using a proportional hazards model with piecewise‐exponential baseline hazard, a model which can be fitted by an EM algorithm easily programmed in standard statistical software. In this paper we extend the model to allow for time‐dependent covariates and left‐truncation, and demonstrate its use by assessing the effect of imprisonment on hazard of HIV infection in a cohort of injecting drug users from Edinburgh. No conclusive effect of incarceration on hazard of HIV infection was found, but there was a suggestion that imprisonment might have been a significant relative risk factor for infection in the later period, when risk behaviour among drug users in the community was reduced. Copyright © 2001 John Wiley & Sons, Ltd.
Covariate adjustment for non‐parametric tests for censored survival data
Authors: Li Zhengqing 
Published: September 2002

AbstractWe develop a method for covariate adjustment for a general class of non‐parametric tests for censored survival data which includes the widely used logrank and Wilcoxon tests. The covariate‐adjusted tests improve the power of the unadjusted counterparts and have advantages over the covariate‐adjusted Cox score test when there are outliers in the covariable space. We investigate the small sample properties of such test statistics through Monte Carlo simulations. Examples are given to illustrate the proposed procedures. Copyright © 2001 John Wiley & Sons, Ltd.
Bayesian cost‐effectiveness analysis from clinical trial data
Authors: O'Hagan Anthony , Stevens John W. , Montmartin Jacques 
Published: September 2002

AbstractA key tool for assessing the relative cost‐effectiveness of two treatments in health economics is the incremental C/E acceptability curve. We present Bayesian computations for this curve in the case where data on both costs and efficacy are available from a clinical trial. Analysis is given under various formulations of prior information. A case study is analysed in which reasonable prior information is shown to strengthen substantially the posterior inference, leading to a more conclusive assessment of cost‐effectiveness. Calculations can be performed using readily available Bayesian software. Copyright © 2001 John Wiley & Sons, Ltd.
Maximum likelihood estimation of a survival function with a change point for truncated and interval‐censored data
Authors: Lim Heejeong , Sun Jianguo , Matthews David E. 
Published: September 2002

AbstractThis paper considers estimation of a survival function when there exists a change point and the survival time of interest is defined as elapsed time between two related events. Furthermore, there exists censoring on observations on the occurrences of both events and truncation on observations on the occurrence of the second event and thus the survival time of interest. To obtain the maximum likelihood estimator of a survival function, an EM algorithm is developed when the survival function is completely unknown before the change point and known up to a vector of unknown parameters after the change point. The idea is a generalization of that discussed in Moeschberger and Klein. Simulations and an example are used to evaluate and illustrate the algorithm. Copyright © 2002 John Wiley & Sons, Ltd.
An approach for extracting code fragments that implement functionality from source programs
Authors: Tan Hee Beng Kuan , Kow Juan Tiang 
Published: September 2002

AbstractA data‐intensive program interacts with its environment through accepting and delivering information from and to its environment respectively. As such, the functionality in a program is achieved through its input/output statements. Based on this hypothesis, this paper proposes a novel approach for the extraction of code fragments for implementing functionality from program source code. This helps the software maintainer identify affected code fragments for making changes to program functionality. The code fragments extracted may also be suitable for reuse in other software projects. Copyright © 2001 John Wiley & Sons, Ltd.
Investigating the emotional roller‐coaster ride: a case study‐based assessment of the Future Search Conference design
Authors: Oels Angela 
Published: September 2002

AbstractThe aim of this paper is to make recommendations for the procedural optimization of the Future Search Conference design on the basis of empirical evidence from two case study conferences in Germany and the United Kingdom. The paper presents the major criticisms that have been raised against the step‐by‐step conference design in the theoretical literature and contrasts these with the empirical findings of two stakeholder‐based evaluations. The author draws attention to a number of weaknesses in the conference opening, the common ground phase and the action planning phase of the Future Search Conference design and makes proposals for design changes. The paper suggests that a systematic and stakeholder‐oriented evaluation should be part of interventions like Future Search Conferences. The paper concludes with a reminder that the political context and local power relations are a key variable in determining success or failure of a Future Search conference. Copyright © 2002 John Wiley & Sons, Ltd.
Communications security on the internet
Authors: Aura Tuomas , Gollmann Dieter 
Published: September 2002

AbstractThe Internet is an open network where all traffic is subject to interception by malicious outsiders. TUOMAS AURA and DIETER GOLLMANN overview the current major threats and security solutions for communication over the Internet. They note that the lack of satisfactory authentication infrastructures and guaranteed quality of service remain the main impediments for secure communication. Continuous evolution of the protection mechanisms, developer skills, and user culture are necessary to stay on track with the progress in communication technology. Copyright © 2001 John Wiley & Sons, Ltd.
An overview of program slicing
Authors: Harman Mark , Hierons Robert 
Published: September 2002

AbstractMARK HARMANandROBERT HIERONSreview three semantic paradigms for slicing — static, dynamic and conditioned; and two syntactic paradigms — syntax‐preserving and amorphous. Slicing has been applied to many software development problems including testing, reuse, maintenance and evolution. This paper describes the main forms of program slice and some of the applications to which slicing has been put. Copyright © 2001 John Wiley & Sons, Ltd.
Plasmalemmal μ‐opioid receptor distribution mainly in nondopaminergic neurons in the rat ventral tegmental area
Authors: Garzón Miguel , Pickel Virginia M. 
Published: September 2002

AbstractOpiate‐evoked reward and motivated behaviors reflect, in part, the enhanced release of dopamine produced by activation of the μ‐opioid receptor (μOR) in the ventral tegmental area (VTA). We examined the functional sites for μOR activation and potential interactions with dopaminergic neurons within the rat VTA by using electron microscopy for the immunocytochemical localization of antipeptide antisera raised against μOR and tyrosine hydroxylase (TH), the synthesizing enzyme for catecholamines. The cellular and subcellular distribution of μOR was remarkably similar in the two major VTA subdivisions, the paranigral (VTApn) and parabrachial (VTApb) nuclei. In each region, somatodendritic profiles comprised over 50% of the labeled structures. μOR immunolabeling was often seen at extrasynaptic/perisynaptic sites on dendritic plasma membranes, and 10% of these dendrites contained TH. μOR‐immunoreactivity was also localized to plasma membranes of axon terminals and small unmyelinated axons, none of which contained TH. The μOR‐immunoreactive axon terminals formed either symmetric or asymmetric synapses that are typically associated with inhibitory and excitatory amino acid transmitters. Their targets included unlabeled (30%), μOR‐labeled (25%), and TH‐labeled (45%) dendrites. Our results suggest that μOR agonists in the VTA affect dopaminergic transmission mainly indirectly through changes in the postsynaptic responsivity and/or presynaptic release from neurons containing other neurotransmitters. They also indicate, however, that μOR agonists directly affect a small population of dopaminergic neurons expressing μOR on their dendrites in VTA and/or terminals in target regions. Synapse 41:311–328, 2001. © 2001 Wiley‐Liss, Inc.
Regional distribution and cellular localization of 5‐HT2C receptor mRNA in monkey brain: Comparison with [3H]mesulergine binding sites and choline acetyltransferase mRNA
Authors: López‐Giménez Juan F. , Mengod Guadalupe , Palacios José M. , Vilaró M. Teresa 
Published: September 2002

AbstractThe distribution of serotonin 5‐HT2C receptor mRNA in monkey brain was studied by in situ hybridization and compared with the distribution of [3H]mesulergine binding sites as visualized by receptor autoradiography. 5‐HT2C receptor transcripts showed a widespread and heterogeneous distribution. The strongest hybridization signal was detected in choroid plexus. In neocortex, 5‐HT2C mRNA was detected in layer V of all cortical regions examined except in the calcarine sulcus, which was devoid of signal. Several structures within the striatum and basal forebrain were strongly labeled: nucleus accumbens, ventral aspects of anterior caudate and putamen, septal nuclei, diagonal band, ventral striatum, and extended amygdala. Several thalamic, midbrain, and brainstem nuclei also contained 5‐HT2C mRNA. Comparison of the distributions of 5‐HT2C mRNA and specific [3H]mesulergine binding sites showed a good agreement in the majority of brain regions, suggesting a predominant somatodendritic localization of 5‐HT2C receptors. A possible localization to axon terminals of 5‐HT2C receptors is suggested by the disagreement observed in some regions such as septal nuclei and horizontal limb of the diagonal band (presence of mRNA with apparent absence of binding sites) and interpeduncular nucleus (presence of binding sites with apparent absence of mRNA). Comparison of 5‐HT2C receptor and choline acetyltransferase mRNA distributions indicate that some regions where cholinergic cells are located are also enriched in cells containing 5‐HT2C mRNA. Although the present methodology does not allow strict colocalization of both mRNA species to the same cells, the codistribution observed in several regions provides a possible anatomical substrate for the described modulation of acetylcholine release by 5‐HT2C receptors. Synapse 42:12–26, 2001. © 2001 Wiley‐Liss, Inc.
Blockade of NMDA receptors by MK‐801 reverses the changes in striatal glutamate immunolabeling in 6‐OHDA‐lesioned rats
Authors: Robinson Siobhan , Krentz Lisa , Moore Cynthia , Meshul Charles K. 
Published: September 2002

AbstractA lesion of the dopamine (DA)‐containing nigrostriatal pathway with 6‐hydroxydopamine (6‐OHDA) results in an increase in the density of nerve terminal glutamate immunolabeling and in the mean percentage of asymmetrical synapses containing a discontinuous postsynaptic density [Meshul et al. (1999) Neuroscience 88:1–16]. Similar alterations in striatal glutamate synapses have been reported following blockade of striatal DA D‐2 receptors with subchronic haloperidol treatment [Meshul et al. (1994) Brain Res 648:181–195]. The haloperidol‐induced change in glutamate synapses was blocked by coadministration of the N‐methyl‐D‐aspartate (NMDA) noncompetitive receptor antagonist MK‐801. In order to determine if blockade of NMDA receptors could alter the density of nerve terminal glutamate immunolabeling following a 6‐OHDA lesion of the nigrostriatal pathway, MK‐801 was administered to lesioned animals for 14 days. In addition, the number of apomorphine‐induced contralateral rotations was determined prior to and following the administration of MK‐801. MK‐801 administration reversed the increase in the density of nerve terminal glutamate immunolabeling due to a 6‐OHDA lesion. There was a small but significant decrease in the number of apomorphine‐induced contralateral rotations following administration of MK‐801 compared to the number of rotations prior to treatment with the NMDA antagonist. These results demonstrate that blockade of postsynaptic NMDA receptors affects the density of presynaptic glutamate immunolabeling and that this change in nerve terminal glutamate density is associated with a decreased behavioral response to direct DA receptor stimulation. Whether the effect of MK‐801 is directly on the striatum or acts through other excitatory pathways of the basal ganglia remains unclear. Synapse 42:54–61, 2001. Published 2001 Wiley‐Liss, Inc.
The establishing of performance level thresholds for steel moment‐resisting frame using an energy approach
Authors: Choi Byong J. , Shen Jay H. 
Published: September 2002

AbstractIn this study, an energy design approach is proposed within the framework of the performance‐based seismic design of steel frames. Accumulated plastic rotation is selected as a parameter to establish the performance level thresholds. The test results of steel connections are investigated to quantify the performance level thresholds. The hysteretic energy input is acquired from a previous statistical study of twelve six‐storey steel moment‐resisting frames. The seismic performance of three‐storey steel moment resisting frames using the energy approach is examined. The research concluded that the structure designed by the energy method performed better than the steel frame designed by the equivalent lateral force (ELF) of UBC‐97 in view of accumulated plastic rotation. Performance levels such as functional, life safety and collapse are discussed based on the ductility level and the performance characteristics. Copyright © 2001 John Wiley & Sons, Ltd.
Ethical dilemmas of relationship building in china
Authors: Stanley Snell Robin , Tseng Choo‐sin 
Published: September 2002

AbstractWe analyze and discuss some ethical dilemmas of doing business on the Chinese Mainland, referring to detailed accounts of the gift‐giving and contract‐getting experiences of two overseas Chinese managers in dealings with Mainland Chinese managers in the sporting and leisure industries. We compare these cases with accounts of transactions in worldwide ship repair, and with a newspaper report of a sport‐related case in Hong Kong. Using a version of Kohlberg's moral‐stages model, and identifying key differences between guanxi and rational‐legal ethics, we explain how guanxi can become entangled with corruption in China. We link our explanations to the absence of rational‐legal moral governance, and to the sociological phenomena of anomie and relative deprivation. We conclude with suggestions about the conduct of China business. � 2001 John Wiley & Sons, Inc.
Not just another financial derivatives book!
Authors: Lhabitant Fran�ois‐serge 
Published: September 2002

AbstractRubinstein M.: (1999) Derivatives: A PowerPlus Pic‐ture Book, In the Money, 381 pages plus CD‐ROM, distributed only through the Internet (http://www.in‐the‐money.com) Rubinstein M.: (2001) Rubinstein on Derivatives, Lon‐don: Risk Books, 471 pages, ISBN 1‐899332‐53‐7
An experimental approach to the determination of the surface ionization φ(0) in electron probe microanalysis
Authors: Bastin G. F. , Dijkstra J. M. , Heijligers H. J. M. 
Published: September 2002

AbstractA compilation of experimentally determined surface ionization values for Al Kα and Pd Lα radiation on a wide variety of substrates, ranging from beryllium to bismuth, and measured between 4 and 30 kV, is presented. The values were extracted from our previously reported thin‐film measurements on aluminum and palladium films by electron probe microanalysis. The φ(0) values were determined by establishing the ratios of the intensities emitted from the supported and unsupported films for six film thicknesses and extrapolating towards a film thickness approaching zero. Some 180 φ(0) data each for Al Kα and Pd Lα x‐radiation were collected in this way. The purpose of this work was to provide systematic data on which the numerous existing expressions for φ(0) could be tested. In the final assessment procedure, in which we also included 108 data from the literature, we compared the performances of the various expressions from the literature for φ(0) and a newly developed expression of our own. Our final conclusion is that there is little to be chosen between the three to four of the highest ranking expressions. Copyright © 2001 John Wiley & Sons, Ltd.
Analysis of pine needles by XRF scanning techniques
Authors: Viksna A. , Selin Lindgren E. , Standzenieks P. 
Published: September 2002

AbstractConcentrations of both essential and toxic elements in pine needles are known to be influenced by environmental factors, either directly from air pollutants or indirectly from acidification. In most previous work, mean concentrations for bulk samples of pine needles have been reported. In this investigation, elemental distributions along the length of pine needles without any visible morphological damage were studied for a number of important elements. The needles were sampled from locations with essentially sandy soils of different pH in different parts of Latvia. The variation of element concentrations along the needle length proved to be very large for some elements, e.g. Zn and Mn, whereas it was almost constant for others, e.g. Cu and Fe. For some elements, large differences between needles of different age class were observed, and also variations with soil pH and light conditions. Healthy needles of the same age class, growing under similar environmental conditions, have identical elemental concentration profiles. Scanning energy‐dispersive x‐ray fluorescence Spectrometry was used and the results were validated by independent analysis with graphite furnace atomic absorption spectrometry. Copyright © 2001 John Wiley & Sons, Ltd.
Synchrotron radiation‐induced TXRF of reactor steel samples
Authors: Pepponi G. , Wobrauschek P. , Streli C. , Zöger N. , Hegedüs F. 
Published: September 2002

AbstractSynchrotron radiation‐induced total reflection x‐ray fluorescence (TXRF) analysis was used for the trace element analysis of steels exploited in the construction of core components of existing fission plants and future fusion power plants. Detection of traces of niobium in reactor pressure vessel steel allows a retrospective determination of the fast neutron flux. For the construction of future fusion reactors, low activation steels are being investigated. Traces of Nb, Pd, Ag, Eu, Gd, Tb, Dy, Ho, Er, Os and Bi cause a higher activity of the material than the steel itself. Synchrotron radiation allows the excitation of the heavier element K shells, avoiding the strong overlaps of their L lines. Moreover, the linear polarization of synchrotron radiation combined with side‐looking detection manages to reduce the scattering due to the matrix contained in the analysed samples. Experiments were carried out at Hasylab Beamline L (bending magnet). The experimental set‐up includes a double reflector collimator, a multilayer and a vacuum chamber. Chemical preparation of the sample included dissolution and separation by means of anion‐exchange chromatography. Minimum detectable concentrations of 37 ng g−1 for Nb and 400 ng g−1 for Tb in the steel were achieved. Copyright © 2001 John Wiley & Sons, Ltd.
Determination of dopants in ZnO‐based ceramic varistors by x‐ray fluorescence and inductively coupled plasma spectrometry
Authors: Caballero A. C. , Valle F. J. , Martín Rubí J. A. 
Published: September 2002

AbstractA method is proposed for the x‐ray fluorescence (XRF) analysis of dopant concentrations in ZnO ceramic materials. The accuracy of the results is good for all the dopants analyzed except Bi2O3. The thermal behavior of this component was followed by thermogravimetry, showing that in an anhydrous Li2B4O7 medium, partial Bi2O3 volatilization occurs at the temperatures needed for glass bead formation (1100–1200 °C). For comparison, inductively coupled plasma atomic emission spectrometry (ICP‐AES) analysis of the materials was carried out following a wet procedure for sample solution preparation. The results were in agreement with those obtained by XRF except for Bi2O3. However, if Bi2O3 volatilization is avoided, the analysis is accurate. Copyright © 2001 John Wiley & Sons, Ltd.
Efficient calculation method for glancing angle x‐ray techniques
Authors: Pérez Roberto Daniel , Sánchez Hector Jorge , Rubio Marcelo 
Published: September 2002

AbstractGeneral depth profiling involves all kind of concentration profiles. The most complex samples present a wide variation of elemental composition with depth. In those cases, calculations of x‐ray propagation at grazing angles are done by representing the sample as a stratified structure in order to obtain an analytical solution of the problem. The density of each layer is an average of the real density inside the layer, and a large number of surface layers may be necessary for a correct representation of the sample. This involves a large number of mathematical operations and therefore an efficient calculation method of x‐ray propagation at glancing angles is required. In this paper, a mathematical algorithm for the calculation of x‐ray propagation at grazing angles is presented. It applies a new formalism introduced recently in the field. This formalism uses a matrix approach to take advantage of well‐known mathematical results, such as Hessenberg's matrix properties. The model allows one to reduce the number of mathematical operations for glancing angle x‐ray techniques. The method was used to study surface oxidation of copper and roughness of a glass surface by the grazing exit XRF technique. Data analysis in these samples shows the advantage of the present mathematical algorithm since both samples present a continuous depth profile. Copyright © 2002 John Wiley & Sons, Ltd.
L‐shell Coster–Kronig yields for Pb
Authors: Kumar Ajay , Puri Sanjiv , Mehta D. , Arora B. K. , Singh Nirmal 
Published: September 2002

AbstractThe f13 Coster–Kronig yield for Pb was determined as 0.60±0.03 using measured intensities of the Lα x‐rays emitted following selective ionization in the L3 sub‐shell by the Rb K x‐rays (B < Einc. < B) and of those emitted following ionization in the Li (i = 1, 2, 3) sub‐shells by 59.54 keV γ‐rays (B < Einc. < BK), BK and B being the K shell and Li sub‐shell ionization thresholds of Pb, respectively. The measurements were performed using a 241Am annular source in direct excitation mode and in secondary excitation mode along with an RbNO3 secondary exciter as photon sources and an Si(Li) detector. Measurements of the f12 and f23 Coster–Kronig yields using similar experimental set‐ups are also discussed. It is concluded that the f12 and f23 Coster–Kronig yields for 12 elements with 59 ≤ Z ≤ 90 measured by Oz et al. using a similar experimental set‐up are not reliable. Copyright © 2002 John Wiley & Sons, Ltd.