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 Author:
 Qu, Pingping; Qu, Yinsheng
 Source:
 Biometrics 2000 v.56 no.4 pp. 12491255
 ISSN:
 0006341X
 Subject:
 algorithms; atrisk population; bioassays; biometry; confidence interval; insecticide resistance; insecticides; insects; models; pesticide application
 Abstract:
 ... After continued treatment with an insecticide, within the population of the susceptible insects, resistant strains will occur. It is important to know whether there are any resistant strains, what the proportions are, and what the median lethal doses are for the insecticide. Lwin and Martin (1989, Biometrics45, 721–732) propose a probit mixture model and use the EM algorithm to obtain the maximum ...
 DOI:
 10.1111/j.0006341X.2000.01249.x

http://dx.doi.org/10.1111/j.0006341X.2000.01249.x
 Author:
 Solow, Andrew R.
 Source:
 Biometrics 2000 v.56 no.4 pp. 12721273
 ISSN:
 0006341X
 Subject:
 biometry; ecology; models
 Abstract:
 ... A common problem in ecology is to determine whether the diversity of a. biological community has changed over time or in response to a disturbance. This involves testing the null hypothesis that diversity is constant against the alternative hypothesis that it has changed. As the power of this test may be low, Fritsch and Hsu (1999, Biometrics55, 1300â1305) proposed reversing the null and alterna ...
 DOI:
 10.1111/j.0006341X.2000.01272.x

http://dx.doi.org/10.1111/j.0006341X.2000.01272.x
 Author:
 Parker, Corette B.; Belong, Elizabeth R.
 Source:
 Biometrics 2000 v.56 no.4 pp. 9961001
 ISSN:
 0006341X
 Subject:
 biometry; covariance; diagnostic techniques; models; regression analysis; risk
 Abstract:
 ... Changes in maximum likelihood parameter estimates due to deletion of individual observations are useful statistics, both for regression diagnostics and for computing robust estimates of covariance. For many likelihoods, including those in the exponential family, these delete‐one statistics can be approximated analytically from a one‐step Newton‐Raphson iteration on the full maximum likelihood solu ...
 DOI:
 10.1111/j.0006341X.2000.0996.x

http://dx.doi.org/10.1111/j.0006341X.2000.0996.x
 Author:
 Strand, Matthew
 Source:
 Biometrics 2000 v.56 no.4 pp. 12221226
 ISSN:
 0006341X
 Subject:
 Escherichia coli O157; biometry; testosterone; variance
 Abstract:
 ... Treatment means in factorial experiments are lattice ordered when there is an increase in mean response as the level of any factor is increased while holding the other factors fixed. Such means occur naturally in many experiments. A nonparametric test for latticeâordered means involving a Kendallâtype statistic will be summarized for kâfactor factorial experiments. Specifically, the form of ...
 DOI:
 10.1111/j.0006341X.2000.01222.x

http://dx.doi.org/10.1111/j.0006341X.2000.01222.x
 Author:
 Hauptmann, Michael; Wellmann, Jürgen; Lubin, Jay H.; Rosenberg, Philip S.; Kreienbrock, Lothar
 Source:
 Biometrics 2000 v.56 no.4 pp. 11051108
 ISSN:
 0006341X
 Subject:
 casecontrol studies; cigarettes; exposure duration; human diseases; linear models; lung neoplasms; risk; smoking (habit); Germany
 Abstract:
 ... To examine the time‐dependent effects of exposure histories on disease, we estimate a weight function within a generalized linear model. The shape of the weight function, which is modeled as a cubic B‐spline, gives information about the impact of exposure increments at different times on disease risk. The method is evaluated in a simulation study and is applied to data on smoking histories and lun ...
 DOI:
 10.1111/j.0006341X.2000.01105.x

http://dx.doi.org/10.1111/j.0006341X.2000.01105.x
 Author:
 Proschan, Michael A.; Wittes, Janet
 Source:
 Biometrics 2000 v.56 no.4 pp. 11831187
 ISSN:
 0006341X
 Subject:
 biometry; people; variance
 Abstract:
 ... Sample size calculations for a continuous outcome require specification of the anticipated variance; inaccurate specification can result in an underpowered or overpowered study. For this reason, adaptive methods whereby sample size is recalculated using the variance of a subsample have become increasingly popular. The first proposal of this type (Stein, 1945, Annals of Mathematical Statistics16, 2 ...
 DOI:
 10.1111/j.0006341X.2000.01183.x

http://dx.doi.org/10.1111/j.0006341X.2000.01183.x
 Author:
 Venkatraman, E. S.
 Source:
 Biometrics 2000 v.56 no.4 pp. 11341138
 ISSN:
 0006341X
 Subject:
 data analysis; experimental design; simulation models
 Abstract:
 ... We developed a permutation test in our earlier paper (Venkatraman and Begg, 1996, Biometrika83, 835–848) to test the equality of receiver operating characteristic curves based on continuous paired data. Here we extend the underlying concepts to develop a permutation test for continuous unpaired data, and we study its properties through simulations. ...
 DOI:
 10.1111/j.0006341X.2000.01134.x

http://dx.doi.org/10.1111/j.0006341X.2000.01134.x
 Author:
 Bellio, R.; Jensen, J. E.; Seiden, P.
 Source:
 Biometrics 2000 v.56 no.4 pp. 12041212
 ISSN:
 0006341X
 Subject:
 bioassays; biometry; detection limit; dose response; herbicides; models; prediction; statistical analysis
 Abstract:
 ... Dose–response models are intensively used in herbicide bioassays. Despite recent advancements the development of new herbicides, statistical analyses are commonly based on asymptotic approximations are sometimes poor. This paper presents the use of recent results in higher order asymptotics for likelihood‐based inference in nonlinear regression. The methods presented provide accurate approximation ...
 DOI:
 10.1111/j.0006341X.2000.01204.x

http://dx.doi.org/10.1111/j.0006341X.2000.01204.x
 Author:
 Wu, Rongling; Li, Bailian
 Source:
 Biometrics 2000 v.56 no.4 pp. 10981104
 ISSN:
 0006341X
 Subject:
 biometry; gene frequency; genes; genetic techniques and protocols; genetic variation; heterosis; interspecific variation; models; natural selection; outcrossing; quantitative trait loci
 Abstract:
 ... A genetic model based on a twoâlevel intraâ and interspecific mating design is proposed to estimate the genetic architecture of species differences and heterosis for outcrossing species. The underlying genetic analyses make use of classical quantitative genetic theories and recent results from molecular genetic studies. Gene effects across different quantitative trait loci (QTL) can be approxi ...
 DOI:
 10.1111/j.0006341X.2000.01098.x

http://dx.doi.org/10.1111/j.0006341X.2000.01098.x
 Author:
 Kozumi, Hideo
 Source:
 Biometrics 2000 v.56 no.4 pp. 10021006
 ISSN:
 0006341X
 Subject:
 Bayesian theory; Markov chain; Monte Carlo method; biometry; models
 Abstract:
 ... This paper considers the discrete survival data from a Bayesian point of view. A sequence of the baseline hazard functions, which plays an important role in the discrete hazard function, is modeled with a hidden Markov chain. It is explained how the resultant model is implemented via Markov chain Monte Carlo methods. The model is illustrated by an application of real data. ...
 DOI:
 10.1111/j.0006341X.2000.01002.x

http://dx.doi.org/10.1111/j.0006341X.2000.01002.x
 Author:
 McKeague, Ian W.; Tighiouart, Mourad
 Source:
 Biometrics 2000 v.56 no.4 pp. 10071015
 ISSN:
 0006341X
 Subject:
 algorithms; biometry; nasopharynx; stochastic processes
 Abstract:
 ... This article introduces a new Bayesian approach to the analysis of rightâcensored survival data. The hazard rate of interest is modeled as a product of conditionally independent stochastic processes corresponding to (1) a baseline hazard function and (2) a regression function representing the temporal influence of the covariates. These processes jump at times that form a timeâhomogeneous Poiss ...
 DOI:
 10.1111/j.0006341X.2000.01007.x

http://dx.doi.org/10.1111/j.0006341X.2000.01007.x
 Author:
 Paik, Myunghee; Sacco, Ralph; Lin, I.âFeng
 Source:
 Biometrics 2000 v.56 no.4 pp. 11451156
 ISSN:
 0006341X
 Subject:
 biometry; computer software; functional status; regression analysis; stroke; variance
 Abstract:
 ... One of the objectives in the Northern Manhattan Stroke Study is to investigate the impact of stroke subtype on the functional status 2 years after the first ischemic stroke. A challenge in this analysis is that the functional status at 2 years after stroke is not completely observed. In this paper, we propose a method to handle nonignorably missing binary functional status when the baseline value ...
 DOI:
 10.1111/j.0006341X.2000.01145.x

http://dx.doi.org/10.1111/j.0006341X.2000.01145.x
 Author:
 Concordet, Didier; Nunez, Olivier G.
 Source:
 Biometrics 2000 v.56 no.4 pp. 10401046
 ISSN:
 0006341X
 Subject:
 antibiotics; biometry; milk; models; prediction; statistics
 Abstract:
 ... We propose calibration methods for nonlinear mixed effects models. Using an estimator whose asymptotic properties are known, four different statistics are used to perform the calibration. Simulations are carried out to compare the performance of these statistics. Finally, the milk discard time prediction of an antibiotic, which has motivated this study, is performed on real data. ...
 DOI:
 10.1111/j.0006341X.2000.01040.x

http://dx.doi.org/10.1111/j.0006341X.2000.01040.x
 Author:
 Seber, George A. F.; Huakau, John T.; Simmons, David
 Source:
 Biometrics 2000 v.56 no.4 pp. 12271232
 ISSN:
 0006341X
 Subject:
 animals; biometry; data collection; epidemiology; physicians; population size; surveys
 Abstract:
 ... In recent years, captureârecapture methods for closed populations have been extensively applied to epidemiology. For example, suppose we have several incomplete lists of diabetics and we wish to estimate the total number of diabetics by estimating the number missing from all the lists. A major problem is that the information about individuals on the lists may have been given incorrectly or the i ...
 DOI:
 10.1111/j.0006341X.2000.01227.x

http://dx.doi.org/10.1111/j.0006341X.2000.01227.x
 Author:
 Zhou, XiaoâHua; Tu, Wanzhu
 Source:
 Biometrics 2000 v.56 no.4 pp. 11181125
 ISSN:
 0006341X
 Subject:
 biometry; confidence interval; elderly; models; variance
 Abstract:
 ... In this paper, we consider the problem of interval estimation for the mean of diagnostic test charges. Diagnostic test charge data may contain zero values, and the nonzero values can often be modeled by a logânormal distribution. Under such a model, we propose three different interval estimation procedures: a percentileât bootstrap interval based on sufficient statistics and two likelihoodâb ...
 DOI:
 10.1111/j.0006341X.2000.01118.x

http://dx.doi.org/10.1111/j.0006341X.2000.01118.x
 Author:
 Yonezawa, Katsuei; Ishii, Takuro; Yano, Kentaro
 Source:
 Biometrics 2000 v.56 no.4 pp. 12131217
 ISSN:
 0006341X
 Subject:
 biometry; cost effectiveness; equations; prediction; probability; resource allocation
 Abstract:
 ... Equations to give exact predictions for the multistep yield selection in a finite population of plant varieties were defined. Not only the optimum resource allocation within a selection trial but also the optimum resource investment for a trial as a whole can be obtained based on the costâefficiency index defined in this article. ...
 DOI:
 10.1111/j.0006341X.2000.01213.x

http://dx.doi.org/10.1111/j.0006341X.2000.01213.x
 Author:
 Dunson, David B.; Dinse, Gregg E.
 Source:
 Biometrics 2000 v.56 no.4 pp. 10681075
 ISSN:
 0006341X
 Subject:
 animals; bioassays; biometry; breast neoplasms; carcinogenicity; carcinogens; chemoprevention; models
 Abstract:
 ... In some types of cancer chemoprevention experiments and shortâterm carcinogenicity bioassays, the data consist of the number of observed tumors per animal and the times at which these tumors were first detected. In such studies, there is interest in distinguishing between treatment effects on the number of tumors induced by a known carcinogen and treatment effects on the tumor growth rate. Since ...
 DOI:
 10.1111/j.0006341X.2000.01068.x

http://dx.doi.org/10.1111/j.0006341X.2000.01068.x
 Author:
 King, Madeleine; Dobson, Annette
 Source:
 Biometrics 2000 v.56 no.4 pp. 11971203
 ISSN:
 0006341X
 Subject:
 biometry; breast neoplasms; confidence interval; measuring devices; quality of life; surgery
 Abstract:
 ... The responsiveness of a measuring instrument is its ability to detect change over time. A commonly used index of responsiveness is the effect size for paired differences. This paper generalizes the effect size for paired differences to more than two repeated observations per subject. The sampling distribution of the generalized responsiveness statistic, Rt, is simulated for a range of plausible pa ...
 DOI:
 10.1111/j.0006341X.2000.01197.x

http://dx.doi.org/10.1111/j.0006341X.2000.01197.x
 Author:
 Ripatti, Samuli; Palmgren, Juni
 Source:
 Biometrics 2000 v.56 no.4 pp. 10161022
 ISSN:
 0006341X
 Subject:
 biometry; equations; models; probability; prostheses
 Abstract:
 ... There exists a growing literature on the estimation of gamma distributed multiplicative shared frailty models. There is, however, often a need to model more complicated frailty structures, but attempts to extend gamma frailties run into complications. Motivated by hip replacement data with a more complicated dependence structure, we propose a model based on multiplicative frailties with a multivar ...
 DOI:
 10.1111/j.0006341X.2000.01016.x

http://dx.doi.org/10.1111/j.0006341X.2000.01016.x
 Author:
 Cook, Richard J.; Ng, Edmund T. M.; Meade, Maureen O.
 Source:
 Biometrics 2000 v.56 no.4 pp. 11091117
 ISSN:
 0006341X
 Subject:
 Markov chain; biometry; diagnostic techniques; linear models; patients
 Abstract:
 ... We describe a method for making inferences about the joint operating characteristics of multiple diagnostic tests applied longitudinally and in the absence of a definitive reference test. Log‐linear models are adopted for the classification distributions conditional on the latent state, where inclusion of appropriate interaction terms accommodates conditional dependencies among the tests. A margin ...
 DOI:
 10.1111/j.0006341X.2000.01109.x

http://dx.doi.org/10.1111/j.0006341X.2000.01109.x