bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Bayesian analysis of a proportion under non‐ignorable non‐response
Authors: Nandram Balgobin , Choi Jai Won 
Published: August 2002

AbstractThe National Health Interview Survey (NHIS) is one of the surveys used to assess one aspect of the health status of the U.S. population. One indicator of the nation's health is the total number of doctor visits made by the household members in the past year. We study the binary variable of at least one doctor visit versus no doctor visit by all household members to each of the 50 states and the District of Columbia. The proportion of households with at least one doctor visit is an indicator of the status of health of the U.S. population. There is a substantial number of non‐respondents among the sampled households. The main issue we address here is that the non‐response mechanism should not be ignored because respondents and non‐respondents differ. The purpose of this work is to estimate the proportion of households with at least one doctor visit, and to investigate what adjustment needs to be made for non‐ignorable non‐response. We consider a non‐ignorable non‐response model that expresses uncertainty about ignorability through the ratio of odds of a household doctor visit among respondents to the odds of doctor visit among all households, and this ratio varies from state to state. We use a hierarchical Bayesian selection model to accommodate this non‐response mechanism. Because of the weak identifiability of the parameters, it is necessary to ‘borrow strength’ across states as in small area estimation. We also perform a simulation study to compare the expansion model with an alternative expansion model, an ignorable model and a non‐ignorable model. Inference for the probability of a doctor visit is generally similar across the models. Our main result is that for some of the states the non‐response mechanism can be considered non‐ignorable, and that 95 per cent credible intervals of the probability for a household doctor visit and the probability that a household responds shed important light on the NHIS data. Copyright 2002 © John Wiley & Sons, Ltd.
Modification of the sample size and the schedule of interim analyses in survival trials based on data inspections
Authors: Schäfer Helmut , Müller Hans‐Helge 
Published: August 2002

AbstractA method is presented which allows us to adapt the sample size as well as the number and time points of interim analyses to the treatment difference observed at an interim look during the course of a clinical trial with censored survival time as the endpoint. The method allows the inclusion of data inspections during the course of the trial and redesign of the trial on the basis of the observed treatment difference without affecting the type I error risk. Formulae for recalculating the required number of events and the number of further patients to be randomized as a function of the observed hazard rates and the detectable hazard ratio are given. Copyright © 2001 John Wiley & Sons, Ltd.
Diffusion and prediction of Leishmaniasis in a large metropolitan area in Brazil with a Bayesian space–time model
Authors: Assunção Renato M. , Reis Ilka A. , Oliveira Claudia Di Lorenzo 
Published: August 2002

AbstractWe present results from an analysis of human visceral Leishmaniasis cases based on public health records of Belo Horizonte, Brazil, from 1994 to 1997. The main emphasis in this study is on the development of a spatial statistical model to map and project the rates of visceral Leishmaniasis in Belo Horizonte. The model allows for space–time interaction and it is based on a hierarchical Bayesian approach. We assume that the underlying rates evolve in time according to a polynomial trend specific to each small area in the region. The parameters of these polynomials receive a spatial distribution in the form of an autonormal distribution. While the raw rates are extremely noisy and inadequate to support decisions, the resulting smoothed rates estimates are considerably less affected by small area issues and provide very clear directions to implement public health actions. Copyright © 2001 John Wiley & Sons, Ltd.
Sex differences in cortisol excretion during anticipation of a psychological stressor: possible support for the tend–and–befriend hypothesis
Authors: Ennis Michael , Kelly Kimberly S. , Lambert Paul L. 
Published: August 2002

AbstractThe present experiment tested the hypothesis that differential neuroendocrine elicitation is prompted by subjects' cognitive expectations of an anticipated stressor. Subjects making a ‘threat appraisal’ of an academic examination were predicted to have increased hypothalamic–pituitary–adrenal (HPA) activation, while activation was expected to be unchanged in subjects making a ‘challenge appraisal.’ Self‐reported anxiety in relation to these variables was also examined. HPA activation was assessed by urinary cortisol at baseline (at least 1 week before the examination) and at pre‐test (immediately before the examination). Contrary to the hypothesis, there was an unexpected sex × time interaction that was particularly robust in subjects making a challenge appraisal. Males in the challenge appraisal group had a significant increase in cortisol excretion from baseline to pre‐test, with greater reported anxiety than the threat appraisal group. In contrast, females had a decrease in cortisol excretion that was significant for only the challenge appraisal group, although reported anxiety between the challenge and threat groups was not different. Results may support the recent proposition that the female stress response has evolved differently than that of males, or they may reflect sex differences in production of corticosteroid‐binding globulin. Copyright © 2001 John Wiley & Sons, Ltd.
The impact of market liberalization on vertical scope: the case of Argentina
Authors: Toulan Omar N. 
Published: August 2002

AbstractThis paper analyzes the impact of market liberalization on the vertical scope of firms. Using the case of Argentina, it is shown how the opening of the economy can improve contracting abilities and heighten competition, increasing the ability and incentive of firms to outsource. Survey findings support the main hypothesis as well as the specific importance of reforms relating to inflation, import costs, and heightened demand standards in increasing the use of outsourcing. A case study of the steel producer Siderar, highlights that while firms may reduce their presence in peripheral activities, they may also increase their presence in core areas so as to increase their value proposition. Copyright © 2002 John Wiley & Sons, Ltd.
Function‐point analysis using design specifications based on the Unified Modelling Language
Authors: Uemura Takuya , Kusumoto Shinji , Inoue Katsuro 
Published: August 2002

AbstractFunction‐point analysis was introduced to help measure the functionality of software systems. For more than a decade, function points have been widely used to measure the size of information systems, often as a part of estimating the effort required for software development and maintenance processes. Limiting the use of function point measurement have been concerns about variable judgements on the part of the personnel doing the measurement, yielding differences in function‐point measures for the same software product even in the same organization. Also, if an organization tries to introduce function‐point analysis, the process normally starts with measurements from the organization's own past software products—a time consuming task with start‐up costs. In this paper, we propose detailed function‐point analysis measurement rules using design specifications based on the Unified Modelling Language and describe a function‐point measurement tool, whose inputs are design specifications developed on Rational Rose®. Then in this paper, we report tool validation work on software involved in software evolution at an organization where we have applied the tool to actual design specifications and examined the differences between the function point values obtained by the tool and those of an experienced function point measurement specialist at the organization. Copyright © 2001 John Wiley & Sons, Ltd.
A decision framework for enterprise resource planning maintenance and upgrade: A client perspective
Authors: Ng Celeste See Pui 
Published: August 2002

AbstractOver the last decade, many large organizations have been shifting from developing their own information system (IS) to licensing and installing large software packages known as enterprise resource planning (ERP) systems. These organizations now face the challenge of maintaining these costly systems and many are about to make their first upgrade decisions. The study reported herein aims to address the following research questions from the ERP‐client perspective: (1) What are the fundamental factors driving ERP maintenance and upgrade decisions? (2) How do these factors differ from those for traditional custom, in‐house software? and (3) Do existing software and hardware replacement models suffice for ERP maintenance and upgrade decision modeling? A single case study method and empirical data analysis were conducted and are presented here. We observe that ERP maintenance and upgrade characteristics are indeed unique in three ways: (1) most organizations maintain and upgrade their ERP systems in order to realize increased business benefits from the systems; (2) a new version upgrade reduces the number of ERP‐client‐done enhancement modifications; and (3) a new version upgrade potentially reduces future legal change patch (LCP) maintenance distributed by the ERP vendor. It was also found that on average LCP maintenance is almost as costly as user enhancements. Based on these findings, we conclude that the existing in‐house software and hardware replacement models are insufficient for ERP situations. We propose a preliminary ERP decision model that overcomes the observed insufficiencies. Copyright © 2001 John Wiley & Sons, Ltd.
Coordinating distributed components on the web: an integrated development environment
Authors: Fuentes Lidia , Troya José María 
Published: August 2002

AbstractComponent‐based software has become an important alternative for building applications, especially distributed ones, so it is essential to define new software development processes based on components. Within this trend, we propose a complete framework‐based method which guides application developers in exactly determining application requirements. It also guides how to build them using the compositional framework MultiTEL from the collaborative and multimedia applications domain. Although many multimedia frameworks are available, none of them offer a design methodology for understanding and adapting the framework classes or components to each derived application. By applying an architecture description language (ADL) we are able to document the framework and help designers in: constructing; reusing, and connecting components; extending the framework architecture; and adding components to meet user requirements. Tools for the automatic generation of code from the ADL specifications are also described. Copyright © 2001 John Wiley & Sons, Ltd.
A hybrid software process simulation model
Authors: Donzelli Paolo , Iazeolla Giuseppe 
Published: August 2002

AbstractThis paper deals with simulation modeling of software processes and proposes the combination of three traditional modeling methods (analytical, continuous and discrete‐event) into a unique hybrid two‐level modeling approach. At the higher abstraction level, the process is modeled by a discrete‐event queuing network, which represents the component activities (i.e. service stations), their interactions, and the exchanged artifacts. The implementation details of the introduced activities are given at the lower abstraction level, where the analytical and continuous methods are used. The proposed approach is applied to a waterfall‐based software process to study the effects of requirements instability on various process quality attributes, as effort, delivery time, productivity, rework percentage and product quality. Simulation results show that the use of the model can provide both qualitative and quantitative suggestions on how to change the software process to improve its quality or to achieve specific organizational goals. The model is primarily designed to represent the behavior of hypothetical projects, to allow researchers to view the implications of their assumptions. However, with small improvements, it can be extended to become a tool for analyzing and predicting the behavior of actual projects. Copyright © 2001 John Wiley & Sons, Ltd.
Observation of the breast cancer patient with a tumor‐positive sentinel node: Implications of the ACOSOG Z0011 trial
Authors: Grube Baiba J. , Giuliano Armando E. 
Published: August 2002

AbstractAxillary lymph node status has been the most important prognostic factor for breast cancer throughout the past century. During the past decade, intraoperative lymphatic mapping with sentinel lymph node dissection (SLND) has been investigated as an alternative staging modality. This technique may be as accurate as ALND, and certainly is less invasive. Adjuvant treatment recommendations, which historically were made on the basis of lymph node status alone, now take into account primary tumor features, molecular markers, and patient characteristics. This evolution of current treatment patterns is driven in part by the diminishing size of tumors, the simultaneous decrease in the presence of axillary metastases, and a better understanding of tumor‐specific risk factors. How do these trends affect the interpretation of a tumor‐positive sentinel node (SN)? Can an axilla with a positive SN be observed? Should it be observed? This review examines the implications of a positive SN in the context of smaller tumor size, decreased nodal disease, and increased reliance on alternative prognostic factors for treatment decisions. The historical data comparing ALND to no ALND in clinically node‐negative patients is reviewed and discussed in the context of observation for a positive SN. These are the issues underlying the ACOSOG Z0010 and Z0011 trials. Semin. Surg. Oncol. 20:230–237, 2001. © 2001 Wiley‐Liss, Inc.
Adjuvant therapy for resectable rectal adenocarcinoma
Authors: Hu Kenneth S. , Harrison Louis B. 
Published: August 2002

AbstractThe mainstay of treatment for rectal cancer over the past 100 years has been surgical resection. However, for the majority of rectal cancers treated conventionally by resection alone, locoregional recurrence is the major mode of failure. Over the past several decades, significant progress has been made in developing effective adjuvant regimens. In the United States, postoperative chemoradiation is standard treatment for T3 or node‐positive patients. However, preoperative radiation with or without chemotherapy decreases local recurrence, increases sphincter preservation, and may improve survival. The purpose of this article is to review the role of adjuvant therapy in resectable rectal cancers and to update the status of ongoing randomized trials. Semin. Surg. Oncol. 19:336–349, 2000. © 2000 Wiley‐Liss, Inc.
Efficiency of a simple approach to damper allocation in MDOF structures
Authors: Lopez Garcia D. , Soong T. T. 
Published: August 2002

AbstractA simple approach to the design of optimal damper configurations has recently been suggested. This practical method is designated simplified sequential search algorithm (SSSA). Although some comparisons showed that the efficiency of the SSSA is similar to that of more sophisticated methods, a more comprehensive investigation is needed in order to gain more insight into its effectiveness. In this study, the SSSA is applied to several regular building models with different natural periods, numbers of storeys, levels of added damping, and different ground motions. Only one type of passive energy dissipation device is considered: linear viscous dampers. It is concluded that, in the case of regular buildings, the SSSA will generally lead to efficient damper configurations, particularly for low‐to‐medium‐rise buildings and for a number of dampers equal to or greater than 1.5–2 times the number of storeys. The resulting damper configurations are found to be sensitive to ground motion characteristics, especially for low levels of supplemental damping. Copyright © 2002 John Wiley & Sons, Ltd.
Software model checking: extracting verification models from source code†
Authors: Holzmann Gerard J. , H. Smith Margaret 
Published: August 2002

AbstractTo formally verify a large software application, the standard method is to invest a considerable amount of time and expertise into the manual construction of an abstract model, which is then analysed for its properties by either a mechanized or a human prover. There are two problems with this approach. The first problem is that this verification method can be no more reliable than the humans that perform the manual steps. If the average rate of error for human work is a function of the problem size, this holds not only for the construction of the original application, but also for the construction of the model. The standard verification trajectory therefore tends to become less reliable for larger applications. The second problem is one of timing and relevance. Software applications built by teams of programmers can change rapidly, often daily. Manually constructing an accurate abstraction of any one version of the application, though, can take weeks, which may jeopardize the validity of the results. In this paper a different verification method that avoids these problems is discussed. This method, which may be the precursor of a new class of testing techniques, was originally developed to allow for a thorough testing of parts of the software of a new commercial telephone switch. Here it is argued, though, that the method also has broad applicability to distributed software systems design in general.
Excitatory and inhibitory responses of dopamine neurons in the ventral tegmental area to nicotine
Authors: Erhardt Sophie , Schwieler Lilly , Engberg Göran 
Published: August 2002

AbstractIn the present electrophysiological study the mechanisms by which nicotine activates dopamine neurons in the ventral tegmental area in anesthetized Sprague‐Dawley rats were analyzed. Intravenous administration of nicotine caused a dose‐dependent increase in firing rate and percentage of spikes fired in bursts of ventral tegmental area dopamine neurons. However, this activation was preceded by an instantaneous but short‐lasting inhibition of the firing rate. The excitation of dopamine neurons by nicotine (1.5–400 μg/kg i.v.) was antagonized and even reversed into an inhibitory response by elevated levels (four‐fold) of the endogenous glutamate receptor antagonist kynurenic acid, as induced by a potent inhibitor of kynurenine 3‐hydroxylase (PNU 156561A, 40 mg/kg, i.v., 5–9 h). The antagonistic action induced by PNU 156561A pretreatment was prevented by administration of D‐cycloserine (128 mg/kg, i.v., 5 min). Administration of the GABAB‐receptor antagonist CGP 35348 (200 mg/kg, i.v., 3 min) facilitated the nicotine‐induced increase in burst firing activity of dopamine neurons and antagonized the short‐lasting decrease in firing rate by nicotine. The results of the present study show that nicotine produces both inhibition and excitation of ventral tegmental area dopamine neurons, actions that appear to be related to the release of GABA and glutamate, respectively. Whereas the excitatory action of nicotine may be associated with motivational processes underlying learning and cognitive behavior, the inhibitory action of the drug may play a more prominent role in the situation of a profound dysregulation of the mesocorticolimbic dopamine system and may help to explain the high prevalence of tobacco‐smoking in schizophrenics. Synapse 43:227–237, 2002. © 2002 Wiley‐Liss, Inc.
Temporal profiling of methamphetamine‐induced changes in gene expression in the mouse brain: Evidence from cDNA array
Authors: Cadet Jean Lud , Jayanthi Subramaniam , Mccoy Michael T. , Vawter Marquis , Ladenheim Bruce 
Published: August 2002

AbstractMethamphetamine (METH) is a neurodegenerative drug of abuse. Its toxicity is characterized by destruction of monoaminergic terminals and by apoptosis in cortical and striatal cell bodies. Multiple factors appear to control METH neurotoxicity, including free radicals and transcription factors. Here, using cDNA arrays, we show the temporal profile of gene expression patterns in the cortex of mice treated with this drug. We obtained two patterns of changes from 588 genes surveyed. First, an early pattern is characterized by upregulation of transcription factors, including members of the jun family. Second, a delayed pattern includes genes related to cell death and to DNA repair. A number of trophic factors were also activated at the later timepoint. These observations suggest that METH can activate a multigene machinery that participates in the production of its toxic effects. The resulting degenerative effects of the drug are thus the result of a balance between protoxic and antiapoptotic mechanisms triggered by its administration to these animals. These observations are of clinical relevance because of the recent identification of degenerative changes in the brains of METH abusers. Synapse 41:40–48, 2001. © 2001 Wiley‐Liss, Inc.
Acute neuroleptic stimulates DOPA decarboxylase in porcine brain in vivo
Authors: Danielsen Erik H. , Smith Donald , Hermansen Flemming , Gjedde Albert , Cumming Paul 
Published: August 2002

AbstractThe activity of DOPA decarboxylase measured in homogenates from rat striatum, or calculated from the rate of tracer decarboxylation measured ex vivo, is stimulated following acute treatment with antagonists of dopamine D2‐like receptors. We used compartmental kinetics to test the hypothesis that utilization of the DOPA decarboxylase substrate [18F]fluorodopa is potentiated in living striatum following acute treatment with a typical neuroleptic. The kinetics of the tracer uptake were determined in eight anesthetized female pigs (40 kg) and in three animals receiving an infusion of haloperidol (75 μg kg−1 h−1) for 1 h prior to tracer administration and throughout the 2‐h positron emission recording. The relative activity of DOPA decarboxylase in striatum was increased threefold by the treatment. This potentiation of DOPA decarboxylation after pharmacological blockade of dopamine D2‐like receptors may be used to optimize the utilization of exogenous DOPA in the treatment of Parkinson's disease. Synapse 41:172–175, 2001. © 2001 Wiley‐Liss, Inc.
Defective hippocampal mossy fiber long‐term potentiation in endothelial nitric oxide synthase knockout mice
Authors: Doreulee Nanuli , Brown Ritchie E. , Yanovsky Yevgeni , Gödecke Axel , Schrader Jürgen , Haas Helmut L. 
Published: August 2002

AbstractMossy fiber long‐term potentiation (mfLTP) was compared in hippocampal slices prepared from wild‐type mice and mice lacking functional endothelial nitric oxide synthase (eNOS‐/‐ mice) using field potential recording. In the presence of D‐2‐amino‐5‐phosphonovaleric acid (AP5, 50 μM), the mfLTP induced by tetanic stimulation (100 Hz, 1 sec) was significantly reduced in knockouts (n = 8) in comparison with wild‐type (n = 8). Similarly, potentiation induced by forskolin (30 μM) or 8‐bromo‐cyclic adenosine monophosphate (8‐Br‐cAMP, 100 μM) was less pronounced in knockouts. However, in wild‐types the mfLTP‐induced in the presence of the nonselective pharmacological inhibitor of NOS (N‐nitro‐L‐Arginine, 100 μM, n = 6) was not significantly different from control (n = 8). Thus, eNOS is not directly involved in mfLTP, but lack of eNOS during development leads to a deficit downstream of adenylyl cyclase. Synapse 41:191–194, 2001. © 2001 Wiley‐Liss, Inc.