bluuebunny/crossref_metadata_2025_split huggingface dataset:
The infamous upper tail
Authors: Janson Svante , Ruciński Andrzej 
Published: August 2002

AbstractLet Γ be a finite index set and k ≥ 1 a given integer. Let further 𝒮 ⊆ [Γ]≤k be an arbitrary family of k element subsets of Γ. Consider a (binomial) random subset Γp of Γ, where p = (pi : i ∈ Γ) and a random variable X counting the elements of 𝒮 that are contained in this random subset. In this paper we survey techniques of obtaining upper bounds on the upper tail probabilities ℙ(X ≥ λ + t) for t > 0. Seven techniques, ranging from Azuma's inequality to the purely combinatorial deletion method, are described, illustrated, and compared against each other for a couple of typical applications. As one application, we obtain essentially optimal bounds for the upper tails for the numbers of subgraphs isomorphic to K4 or C4 in a random graph G(n, p), for certain ranges of p. © 2002 Wiley Periodicals, Inc. Random Struct. Alg., 20:317–342 2002
Small worlds
Authors: Barbour A. D. , Reinert Gesine 
Published: August 2002

AbstractSmall world models are networks consisting of many local links and fewer long range ‘shortcuts’. In this paper, we consider some particular instances, and rigorously investigate the distribution of their inter‐point network distances. Our results are framed in terms of approximations, whose accuracy increases with the size of the network. We also give some insight into how the reduction in typical inter‐point distances occasioned by the presence of shortcuts is related to the dimension of the underlying space. © 2001 John Wiley & Sons, Inc. Random Struct. Alg., 19, 54–74, 2001
Student goal orientation in learning inquiry skills with modifiable software advisors
Authors: Shimoda Todd A. , White Barbara Y. , Frederiksen John R. 
Published: August 2002

AbstractA computer support environment (SCI‐WISE) for learning and doing science inquiry projects was designed. SCI‐WISE incorporates software advisors that give general advice about a skill such as hypothesizing. By giving general advice (rather than step‐by‐step procedures), the system is intended to help students conduct experiments that are more epistemologically authentic. Also, students using SCI‐WISE can select the type of advice the advisors give and when they give advice, as well as modify the advisors' knowledge bases. The system is based partly on a theoretical framework of levels of agency and goal orientation. This framework assumes that giving students higher levels of agency facilitates higher‐level goal orientations (such as mastery or knowledge building as opposed to task completion) that in turn produce higher levels of competence. A study of sixth grade science students was conducted. Students took a pretest questionnaire that measured their goal orientations for science projects and their inquiry skills. The students worked in pairs on an open‐ended inquiry project that requires complex reasoning about human memory. The students used one of two versions of SCI‐WISE—one that was modifiable and one that was not. After finishing the project, the students took a posttest questionnaire similar to the pretest, and evaluated the version of the system they used. The main results showed that (a) there was no correlation of goal orientation with grade point average, (b) knowledge‐oriented students using the modifiable version tended to rate SCI‐WISE more helpful than task‐oriented students, and (c) knowledge‐oriented pairs using the nonmodifiable version tended to have higher posttest inquiry skills scores than other pair types. © 2002 Wiley Periodicals, Inc.Sci Ed86:244–263, 2002; DOI 10.1002/sce.10003
Gaining legitimacy? Sustainable development in business school curricula
Authors: Springett Delyse , Kearins Kate 
Published: August 2002

AbstractExploring reasons why sustainable development remains largely at the margins of business school curricula and seeking to develop courses of action to embed its ethos more firmly in the institutions in which they work, the authors review international evidence and reflect on their experiences.A number of related factors appear to contribute to the marginalization of sustainable development in business school curricula. There is the tendency for the tertiary sector to follow the corporate world in market‐driven values and goals, with concomitant reluctance on the part of many business school academics to step outside mainstream orthodoxy. A degree of resistance to interdisciplinary and non‐traditional pedagogical approaches and evaluative methods required by sustainable development is also manifest within many business schools. Encouraging signs are seen, however, in a burgeoning academic literature and growing opportunities for collegial support internationally.Means by which business studies curricula can incorporate the concept of sustainable development are considered in conjunction with their implications for traditional conceptions of organizational theory, and for tertiary institutions more generally. A modus operandi for a national programme for environmental responsibility in New Zealand tertiary institutions is outlined as an example of a possible way forward. Copyright © 2001 John Wiley & Sons, Ltd. and ERP Environment
Institutional sustainability indicators: an analysis of the institutions in Agenda 21 and a draft set of indicators for monitoring their effectivity
Authors: Spangenberg Joachim H. 
Published: August 2002

AbstractObjectives of sustainable development are defined for the economic, social and environmental dimension, but for effective compliance as well as for sustainability characteristics such as justice or participation they must be complemented by core institutional objectives. The CSD's set of sustainability indicators was the first one to explicitly take into account the institutional dimension of sustainability, and other organizations such as the World Bank and the OECD have followed. Like most pioneers, the indicators suggested offer significant room for improvement.In order to measure the effectiveness of the relevant institutions, Agenda 21 has been analysed regarding its institutional content (organizations, mechanisms, orientations). From this basis, the purposes of the institutions have been determined in a stepwise approach and indicators developed that permit us to measure the progress achieved against the purposes of the respective institution.The methodology developed can be applied to other international agreements, providing the basis for an integrated reporting system. Copyright © 2002 John Wiley & Sons, Ltd. and ERP Environment.
Grain boundary segregation and fracture resistance of engineering steels
Authors: Misra R. D. K. 
Published: August 2002

AbstractThe developments in surface analytical techniques and experimental measurements have made it possible to understand grain boundary segregation processes and related fracture mechanisms. This article shows how experimental contributions have led to the concept of grain boundary segregation isotherms for a complete understanding of grain boundary segregation behavior, and its effect on material properties in terms of the kinetics of segregation, the interaction processes amongst trace and solute elements and the influence of solute elements, heat treatment practice and applied tensile stress on grain boundary segregation processes. The determining role of grain boundary chemistry in obtaining a marked improvement in toughness of engineering steels at the specified levels of strength is elucidated here. Copyright © 2001 John Wiley & Sons, Ltd.
High‐resolution analytical electron microscopy characterization of corrosion and cracking at buried interfaces
Authors: Bruemmer S. M. , Thomas L. E. 
Published: August 2002

AbstractRecent results are presented demonstrating the application of cross‐sectional analytical transmission electron microscopy (ATEM) to corrosion and cracking in high‐temperature water environments. Microstructural, chemical and crystallographic characterization of buried interfaces at near‐atomic resolutions is shown to reveal evidence for unexpected local environments, corrosion reactions and material transformations. Information obtained by a wide variety of high‐resolution imaging and analysis methods indicates the processes occurring during crack advance and provides insights into the mechanisms controlling environmental degradation. Examples of intergranular attack and cracking in type 316 austenitic stainless steel and Ni‐based alloy 600 are presented to illustrate the potential for this approach. The presence of deeply attacked grain boundaries off the main cracks, revealed by TEM, is believed to indicate a major role of active corrosion in the stress corrosion cracking (SCC) process. Corroded boundaries were filled with oxides to the leading edges of attack. Analyses of the oxide films and impurities in the narrow intergranular penetrations and crack tips with widths of 10 nm or less indicate influences of the grain boundary characteristics and water chemistry. Boundary and precipitate corrosion structures can be used to identify the local electrochemistry promoting degradation in complex service environments. Solution impurities such as lead are found in high concentrations at nanometer‐wide reaction zones in samples from secondary water environments, indicating water access at leading edges of the attack and the influence of these impurities on the corrosion processes. Results for specific samples are used to demonstrate the ability of cross‐sectional ATEM to reveal new details of buried corrosion structures that cannot be detected by other methods. Copyright © 2001 John Wiley & Sons, Ltd.
Simplified equations for correction parameters for elastic scattering effects in AES and XPS for Q, β and attenuation lengths
Authors: Seah M. P. , Gilmore I. S. 
Published: August 2002

AbstractIn this work we develop simple equations, suitable for the analyst, based on the Monte Carlo calculations of Jablonski, for the corrections arising from elastic scattering. These concern modification of the angular anisotropy in XPS and the absolute intensities in both Auger electron spectroscopy (AES) and x‐ray photoelectron spectroscopy (XPS) as a function of the atomic number Z. We also derive more accurate equations for these parameters and the ratio of the attenuation length, L, to the inelastic mean free path (IMFP) based on a knowledge of ω, where ω is the ratio of the IMFP to the sum of the transport mean free path (TrMFP) and the IMFP.The first equations give the corrections to the anisotropy, βeff(α)/β, and the total emission, Q(α), from Jablonski's work in terms of a total of four equations and a total of 19 coefficients to replace Jablonski's two equations with a total of 2376 coefficients. The present equations describe the dependencies of βeff(α)/β and Q(α) on the angle of electron emission α, the electron energy E and the atomic number of the matrix in the ranges 0° < α < 70°, 300 < E < 1500 eV and 6 < Z < 83. The standard deviation of the scatter with regard to Jablonski's calculations are 4.6% for βeff(α)/β and 1.35% for Q(α), giving an overall uncertainty for quantification, relative to the Monte Carlo calculations, of better than 2%. The equations allow values of βeff(α) to be calculated for revised values of β and for elements other than the 27 studied by Jablonski. They also allow Q(α) to be calculated for other elements and for energies appropriate to Auger electrons within the above ranges.More complex equations, derived from a slight modification to the transport equations, allow βeff(0)/β, Q(0) and the ratio L/IMFP to be derived from a knowledge of ω. These equations exhibit a standard deviation of scatter of 2.8%, 0.3% and 1.1%, respectively, compared with the Monte Carlo calculations of Jablonski and of Cumpson and Seah, leading to uncertainties in quantification of the order of 1%. These equations are more complex for the analyst to use than the simple equations as a function of Z, but have superior accuracies and accuracies that are probably limited by the precision of the Monte Carlo calculations. © Crown Copyright 2001. Reproduced by permission of the Controller of HMSO. Published by John Wiley & Sons, Ltd.
Yield enhancement effect of low‐energy O2+ ion bombardment in Ga focused ion beam SIMS
Authors: Kikuma Jun , Imai Hideaki 
Published: August 2002

AbstractThe effect of low‐energy oxygen ion irradiation during Ga focused ion beam (FIB) SIMS analyses has been investigated. The positive secondary ion yield in Ga FIB‐SIMS analysis was increased dramatically due to the bombardment of O2+ ions. The degree of yield enhancement increased with increased oxygen doses until it became constant above 1.5 × 1016 atoms cm−2, indicating saturation of the oxygen concentration at the analysis depth. Secondary ion images of a line‐and‐space pattern of boron in the silicon matrix have been obtained with 3 keV and 0.7 keV O2+ ions. It was revealed that the enhancement effect of irradiation with 0.7 keV O2+ ions is of the same degree as that with the 3 keV O2+ ions. From the perspective of sensitivity, however, a lower energy beam is more effective because the sputtering of the sample surface by the O2+ irradiation is reduced, resulting in a greater volume for analysis by the Ga+ beam. A secondary ion image of 0.6 at.% boron from the 0.5 µm line width with an analysis depth of 6 nm has been obtained readily by irradiation of the 0.7 keV O2+ beam. Copyright © 2001 John Wiley & Sons, Ltd.
A refined method for the meta‐analysis of controlled clinical trials with binary outcome
Authors: Hartung Joachim , Knapp Guido 
Published: August 2002

AbstractFor the meta‐analysis of controlled clinical trials with binary outcome a test statistic for testing an overall treatment effect is proposed, which is based on a refined estimator for the variance of the treatment effect estimator usually used in the random‐effects model of meta‐analysis. In simulation studies it is shown that the proposed test keeps the prescribed significance level much better than the commonly used tests in the fixed‐effects and random‐effects model, respectively. Moreover, when using the test it is not necessary to choose between fixed effects and random effects approaches in advance. The proposed method applies in the same way to the analysis of a controlled multi‐centre study with binary outcome, including a possible interaction between drugs and centres. Copyright © 2001 John Wiley & Sons, Ltd.
Recruitment strategies in a cluster randomized trial – cost implications
Authors: Flynn Terry N. , Whitley Elise , Peters Tim J. 
Published: August 2002

AbstractThe presence of a non‐zero intracluster correlation coefficient in cluster randomized trial data has well‐known statistical implications for trial design, in particular, inflating the required sample size for given specifications. However, problems in recruitment are common in such trials and there may be different costs of recruitment resulting from different recruitment strategies. Examples of how such differences arise are taken from cluster randomized trials and more intuitive methods of describing clustering are summarized which, in conjunction with such cost issues, may provide a framework that enables triallists to consider explicitly the trade‐off between power and cost that is often inherent in such trials. Copyright © 2002 John Wiley & Sons, Ltd.
Exploring sources of heterogeneity in systematic reviews of diagnostic tests
Authors: Lijmer Jeroen G. , Bossuyt Patrick M. M. , Heisterkamp Siem H. 
Published: August 2002

AbstractIt is indispensable for any meta‐analysis that potential sources of heterogeneity are examined, before one considers pooling the results of primary studies into summary estimates with enhanced precision. In reviews of studies on the diagnostic accuracy of tests, variability beyond chance can be attributed to between‐study differences in the selected cutpoint for positivity, in patient selection and clinical setting, in the type of test used, in the type of reference standard, or any combination of these factors. In addition, heterogeneity in study results can also be caused by flaws in study design. This paper critically examines some of the potential reasons for heterogeneity and the methods to explore them. Empirical support for the existence of different sources of variation is reviewed. Incorporation of sources of variability explicitly into systematic reviews on diagnostic accuracy is demonstrated with data from a recent review. Application of regression techniques in meta‐analysis of diagnostic tests can provide relevant additional information. Results of such analyses will help understand problems with the transferability of diagnostic tests and to point out flaws in primary studies. As such, they can guide the design of future studies. Copyright © 2002 John Wiley & Sons, Ltd.
Applying sample survey methods to clinical trials data
Authors: LaVange L. M. , Koch G. G. , Schwartz T. A. 
Published: August 2002

AbstractThis paper outlines the utility of statistical methods for sample surveys in analysing clinical trials data. Sample survey statisticians face a variety of complex data analysis issues deriving from the use of multi‐stage probability sampling from finite populations. One such issue is that of clustering of observations at the various stages of sampling. Survey data analysis approaches developed to accommodate clustering in the sample design have more general application to clinical studies in which repeated measures structures are encountered. Situations where these methods are of interest include multi‐visit studies where responses are observed at two or more time points for each patient, multi‐period cross‐over studies, and epidemiological studies for repeated occurrences of adverse events or illnesses. We describe statistical procedures for fitting multiple regression models to sample survey data that are more effective for repeated measures studies with complicated data structures than the more traditional approaches of multivariate repeated measures analysis. In this setting, one can specify a primary sampling unit within which repeated measures have intraclass correlation. This intraclass correlation is taken into account by sample survey regression methods through robust estimates of the standard errors of the regression coefficients. Regression estimates are obtained from model fitting estimation equations which ignore the correlation structure of the data (that is, computing procedures which assume that all observational units are independent or are from simple random samples). The analytic approach is straightforward to apply with logistic models for dichotomous data, proportional odds models for ordinal data, and linear models for continuously scaled data, and results are interpretable in terms of population average parameters. Through the features summarized here, the sample survey regression methods have many similarities to the broader family of methods based on generalized estimating equations (GEE). Sample survey methods for the analysis of time‐to‐event data have more recently been developed and implemented in the context of finite probability sampling. Given the importance of survival endpoints in late phase studies for drug development, these methods have clear utility in the area of clinical trials data analysis. A brief overview of methods for sample survey data analysis is first provided, followed by motivation for applying these methods to clinical trials data. Examples drawn from three clinical studies are provided to illustrate survey methods for logistic regression, proportional odds regression and proportional hazards regression. Potential problems with the proposed methods and ways of addressing them are discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Order‐restricted dose‐related trend tests
Authors: Mancuso Jessica Y. , Ahn Hongshik , Chen James J. 
Published: August 2002

AbstractMethods of isotonic regression are proposed to increase the power of common trend tests in situations where a monotonicity constraint is imposed upon the dose‐response function. Isotonic versions of Cochran–Armitage type trend tests for binary response data are developed, and the bootstrap method is used in finding the empirical distributions of the test statistics and their critical values. The isotonic likelihood ratio test with a survival adjustment is also proposed. This survival adjustment can be applied to the likelihood ratio test for either the order‐restricted or unrestricted parameter cases. To achieve the isotonic modifications, an amalgamation algorithm is applied when the observed dose‐response is non‐monotonic. A Monte Carlo simulation study comparing these trend tests shows the advantages of the isotonic modifications and survival adjustment. By applying the proposed methods to data from a toxicology and carcinogenesis study conducted as part of the National Toxicology Program, the effect of CI Pigment Red 23 is investigated. Copyright © 2001 John Wiley & Sons, Ltd.
Meta‐analysis of continuous outcome data from individual patients
Authors: Higgins Julian P. T. , Whitehead Anne , Turner Rebecca M. , Omar Rumana Z. , Thompson Simon G. 
Published: August 2002

AbstractMeta‐analyses using individual patient data are becoming increasingly common and have several advantages over meta‐analyses of summary statistics. We explore the use of multilevel or hierarchical models for the meta‐analysis of continuous individual patient outcome data from clinical trials. A general framework is developed which encompasses traditional meta‐analysis, as well as meta‐regression and the inclusion of patient‐level covariates for investigation of heterogeneity. Unexplained variation in treatment differences between trials is considered as random. We focus on models with fixed trial effects, although an extension to a random effect for trial is described. The methods are illustrated on an example in Alzheimer's disease in a classical framework using SAS PROC MIXED and MLwiN, and in a Bayesian framework using BUGS. Relative merits of the three software packages for such meta‐analyses are discussed, as are the assessment of model assumptions and extensions to incorporate more than two treatments. Copyright © 2001 John Wiley & Sons, Ltd.
Effects of psychosocial stress or food restriction on body mass and blood cellular immunity in laboratory rats
Authors: Stefanski Volker 
Published: August 2002

AbstractImmunological changes were studied in socially stressed loser rats and in rats restricted of food or water. Seven days of chronic social confrontation resulted in a significant loss of body mass as well as in marked alterations of blood cellular immunity in loser rats. Loser males showed increased numbers of granulocytes, reduced numbers of CD4 T cells, CD8 T cells, and B cells, as well as a lowered proliferative response of lymphocytes to concanavalin A. To test the possibility of whether the immunological change in loser males is a direct effect of altered nutritional state, non‐confronted males were restricted of food (−90 per cent) for 7 days to mimic the weight loss of loser males. While losers and food restricted males lost a similar 15 per cent of their initial body mass, their immunological outcome largely differed: food or water restriction had little immunological impact, except on granulocytes (reduced numbers). Obviously, social stress alters granulocyte numbers in a different direction than under food or water restriction. Together the data indicate that modulation of blood cellular immunity in loser males is unlikely to be caused by altered nutritional state during socially stressful confrontations. Copyright © 2001 John Wiley & Sons, Ltd.