bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two — Sample Rank Tests in General Models
Authors: Brunner E. , Neumann N. 
Published: May 2007

AbstractIn the several sample case for independent observations suitable rank tests can be derived, if a location model is assumed. In more general models it is difficult to deduce such statistics. If only two samples are considered, rank tests can be developed without problems. For general two‐sample designs rank statistics and their associated variance estimators are derived.
Two Estimators of Mean Frequency in Products of Multinormal Probability Models
Authors: Onukogu Ike B. 
Published: May 2007

AbstractTwo estimators, one additive the other multiplicative, are considered for mean frequencies in a complete three‐way table. Using the mean square error criterion it is shown that preference for the additive estimator can be as high 7/8 in tables with row‐column independence and in homogeneous tables. Extension to other estimators are discussed.
Tables of Bonferroni‐limits for Simultaneous F‐Tests
Authors: Ludwig O. , Gottlieb R. , Lienert G. A. 
Published: May 2007

AbstractBonferroni adjusted F‐tables are given for α=0.10 and α = 0.001 with degrees of freedom following classical tables of Fisher and Yates. The tables may be used in simultaneous analysis of variances or in evaluating binomial tests by means of F‐tables in configural frequency testing.
Estimating Ratio of Proportions Using Auxiliary Information
Authors: Singh G. , Singh R. K. , Kaur P. 
Published: May 2007

AbstractThe problem of estimation of ratio of population proportions is considered and a difference‐type estimator is proposed using auxiliary information. The bias and mean squared error of the proposed estimator is found and compared to the usual estimator and also to WYNN'S (1976) type estimator. An example is included for illustration.
A Stochastic Epidemic Model with Seasonal Variations in Infection Rate
Authors: Prajneshu  , Gupta C. K. , Sharma Usha 
Published: May 2007

AbstractIn this paper we consider a modification of Bailey's stochastic model for the spread of an epidemic when there are seasonal variations in infection rate. The resulting nonlinear model is analyzed by employing the diffusion approximation technique. We have shown that for a large population the process, on suitable scaling and normalization, converges to a non‐stationary Ornstein‐Uhlenbeck process. Consequently the number of infectives has in the steady state a gaussian distribution.
Comparison of Resubstitution, Data Splitting, the Bootstrap, and the Jackknife as Methods for Estimating Validity Indices of New Marker Tests: A Monte Carlo Study
Authors: Abel U. , Berger J. 
Published: May 2007

AbstractEstimating the diagnostic efficiency of marker tests on the basis of the training set is an intricate problem of discriminant analysis for which no analytical solution exists. The paper outline the problem, describes various popular estimation procedures and presents the results of computer simulations comparing the estimators with respect to both bias and variance.
Pre‐post Treatment Evaluation by Symmetry Testing in Square Contingency Table
Authors: Havránek T. , Lienert G. A. 
Published: May 2007

AbstractStarting from an r × r contingency table derived from ordinal pre‐ and post treatment observations, the traditional Bowker symmetry test is suggested to be replaced by one of the following alternatives (1) a globals test of general improvement, (2) a set of simultaneous symmetry tests of differential improvement without assuming general improvement under H0 and (3) a set of simultaneous symmetry tests beyond assuming general improvement under H0. The tests are illustrated by a bivariate example of observing neuroticism and introversion binarily (+, ‐) before and after Rogerian psychotherapy in a sample of clients.
A Note on the Bonferroni's Inequalities
Authors: Mǎrgǎritescu E. 
Published: May 2007

AbstractIn this note we present improved Bonferroni type inequalities for the union of a set of nonexchangeable events. These new bounds are stronger than or equivalent with the bounds proposed by KOUNIAS (1968), HUNTER (1976), MARGOLIN & MAURER (1976), GALAMBOS (1977) and by Mǎrgǎkritescu (1983). In the particular case of the exchangeable events, the bounds given by SOBEL & UPPULURI (1972) can be derived. A generalization in terms of a partition of {1, 2, …, n} is also established.
A Note on Maximum Likelihood Ratio Test of No Outliers in Regression Models
Authors: Paul S. R. 
Published: May 2007

AbstractA derivation of the maximum likelihood ratio test for testing no outliers in regression models is given using the method of WETHERILL (1981, pp. 106–107) for estimating the regression parameters. This method is essentially similar to the one outlined in BARNETT and LEWIS (1978, p. 263), although by our detailed derivation it is easier to see that the maximum likelihood estimate of θ of model (3) under the hypothesis that the ith observation in an outlier is the same as that obtained from model (1) when the ith observation is removed.
Conditional Quadratic Discrimination in the Identification of Biological Markers for Disease Screening
Authors: Rawlings R. R. , Graubard B. I. , Teper S. , Ryback R. S. , Eckardt M. J. 
Published: May 2007

AbstractConditional multivariate normal density functions are used to construct conditional quadratic discriminant functions that adjust for covariate differences between disease groups. An expected actual error rate for the conditional discriminant function is defined. The purpose of this paper is to use the conditional quadratic discriminant function and its misolassification error rate in order to help determine if a set of discriminators is a good biological marker for disease screening. The conditional quadratic discriminant analysis is illustrated using data from two alcoholism classification problems. It is shown how the discriminant functions can identify a set of variables that can be used as biological markers.
A Stochastic Model for Estimating Adolescent Sterility Among Married Women
Authors: Agrafiotis G. K. 
Published: May 2007

AbstractIn this paper a stochastic model is presented for the time to the first conception of a cohort of married women. By identifying three states “adolescent sterility”, “ovulation” and “conceived”, into which the women can be placed, the model incorporates individual differences for the women in the “adolescent sterility” state which allow for the individual characteristics to affect the conversion of these women into the “ovulation” state. Using straightforward probabilistic arguments it is shown that the model provides a close fit to recently published data, compares favorably with previously published models on the same subject and it is useful for planning purposes in predicting future developments.
Asymptotic Expansions and Estimation of the Expected Error Rate for Equal‐Mean Discrimination with Uniform Covariance Structure
Authors: Marco Virgil R. , Young Dean M. , Turner Danny W. 
Published: May 2007

AbstractThe asymptotic error rate of the equal‐mean, uniform‐covariance‐matrix classification rule is approximated by a first order asymptotic expansion. The approximation is compared for accuracy with a Monte Carlo simulation. Finally, an estimator of the error rate and an estimator of the variance of the error rate estimator are derived and applied to a classical example.
On the Asymptotic Relative Efficiency of the Mantel‐Haenszel Test
Authors: Haber M. 
Published: May 2007

AbstractThe Mantel‐Haenszel test is optimal when the odds ratio is constant. This paper investigates the effects of departures from the assumption of a constant odds ratio on the behavior of the Mantel‐Haenzel test. A simple approximation is proposed for the non‐null distribution of the test statistic. Based on this approximation, the asymptotic relative efficiency of the Mantel‐Haenszel test, compared to the overall χ2test for no partial association, is calculated. For the case of 2 strata, it is shown that the Mantel‐Haenszel test is efficient as long as the logarithms of the odds ratios are of the same sign and their absolute values exceed 1.
The Linear Discriminant Function: Sampling from the Truncated Normal Distribution
Authors: Kocherlakota S. , Balakrishnan N. , Kocherlakota K. 
Published: May 2007

AbstractA study is made of the behaviour of the linear discriminant function in the classification of an observation when sampling from a truncated normal distribution. It is shown that the truncation proves ‘beneficial’ in that it reduces the error rates.
Note on Systematic Sampling
Authors: Bennett B. M. 
Published: May 2007

AbstractIn the use of systematic sampling in surveys it is known that the effect of negative correlations (=ϱwst) between deviations from stratum means of pairs of items in the same systematic sample is such that the resulting variance V(ȳst) can be zero for systematic sample means ȳst (e.g., Cochran, 1977, ch. 8). For such populations systematic sampling is then superior both to stratified sampling (one unit per stratum) and to simple random sampling.Cochran (loc. cit.) does not identify special types of finite populations for which ϱwst = −1/(n ‐1) and hence V(ȳst) =0. It is the purpose of this paper to present one type of population for which this condition is satisfied.
Inverse Sampling in Case Control Studies Involving a Rare Exposure
Authors: Kikuchi David A. 
Published: May 2007

AbstractIn case‐control studies where the outcome is not uncommon but the exposure is rare, inverse sampling may be used to reduce the total number of subjects required to find a fixed number of exposed cases and controls. The sampling distribution is negative binomial rather than binomial. Logistic regression for adjustment of covariates may be implemented on the computer program GLIM by the appropriate use of macros. An example is given.
Nonparametric Identification of Multivariate Improvement Effects Using Configural Analysis of Complementary Increments (CACI) from Pre‐post Treatment Designs
Authors: Lienert G. A. , Von Eye A. 
Published: May 2007

AbstractThis paper introduces configural analysis of complementary increments (CACI), a method for detecting multivariate shifes in location. CACI is based on the concept of multivariate point symmetry of dichotomous increments of outcome variables from pre‐to‐post treatment. Two‐sample CACI allows the evaluation of multivariate treatment effects even if there is a confound with spontaneous remission. The example given was taken from research on drugs. Clinical application and generalizations are also discussed.
On Testing Equality of Means of Correlated Variates with Incomplete Data
Authors: Bhoj D. S. 
Published: May 2007

AbstractA statistic is proposed for testing the hypothesis of equality of the means of a bivariate normal distribution with unknown common variance and correlation coefficient when observations are missing on one of the variates. Expressions for the second and fourth central moments of the statistic are obtained. These moments are used to approximate the distribution of the statistic by a Student's t distribution under the null hypothesis. The powers of the test are computed and compared with those of the conventional paired t and the other known statistics.
Nonparametric Comparison of Longitudinal Response Patterns from Unpaired Samples Using Configural Frequency Analysis
Authors: Lienert G. A. , Von Eye A. 
Published: May 2007

AbstractNonparametric methods of Configural Frequency Analysis (CFA) for the comparison of longitudinal response patterns are discussed. In particular, methods of transforming response patterns into profiles that can be analyzed using CFA are presented. When two independent samples are given, two sample CFA can be applied to perform local testing. An example is given from research on obesity. Two sample CFA of response pattern is compared to methods of global testing.
On Setting Limits on Bodily Fluids for Classifying Individuals as Pathological
Authors: Chou Youn‐Min , Owen D. B. 
Published: May 2007

AbstractThe problem solved in this paper is that of determining the minimum sample size for setting the ‘normal’ range for bodily fluids. The proportions of too low and too high values which are considered ‘abnormal’ are chosen based upon medical considerations. The criterion used to determine the minimum sample size is that the proportions of the too low and too high values will be not exceeded by more than a prescribed amount with a given probability. The resulting limits are β‐expectation tolerance limits with the added condition just noted, and are labeled β‐expectation inner tolerance limits.
Competing Risk Analysis of Censored Survival Data
Authors: Spivey Lonita B. , Gross Alan J. 
Published: May 2007

AbstractA competing risk model is developed to accommodate both planned Type I censoring and random withdrawals. MLE's, their properties, confidence regions for parameters and mean lifetimes are obtained for a model regarding random censoring as a competing risk and compared to those obtained for the model in which withdrawals are regarded as random censoring. Estimated net and crude probabilities are calculated and compared for the two models. The model is developed for two competing risks, one following a Weibull distribution and the other a Rayleigh distribution, and random withdrawals following a Weibull distribution.
On the Use of Factor Scores for Prediction
Authors: Schönemann P. H. , Haagen K. 
Published: May 2007

AbstractThere are two types of indeterminacy problems in factor analysis: the indeterminacy of the parameters, which is also known as the problem of identification, and the indeterminacy of the factor scores. The second problem, which will be treated here, is of great importance to the social sciences, given that the factor analysis model was historically developed with the theory of measuring intelligence, where the main interest was to determine one person's intelligence numerically. As a consequence of the indeterminacy of factor scores we will show, by means of a numerical example, that any criterion, including the dates of easter sunday, can be perfectly predicted by the intelligence factors.
A Note on the Characterization of the Normal Distribution
Authors: Ahsanullah M. 
Published: May 2007

AbstractSuppose X1, X2,…, Xn are independent and identically distributed random variables with absolutely continuous distribution function F. It is known that if F is standard normal distribution then (i)∑X2i is a chi‐square with n degrees of freedom and (ii)nX¯2 is a chi‐square with 1 degrees of freedom where X¯=1/n ∑Xi. Here the above two properties are utilized to characterize the normal distribution.
On the Assessment of the Performance of Multiple Test Procedures
Authors: Bauer P. 
Published: May 2007

AbstractBased on the concept of the multiple level of significance two criteria for assessing the performance of multiple tests are proposed: The simultaneous power is defined as the probability of rejecting all false null hypotheses. The probability of a correct decision is defined as the probability of correctly rejecting all false null hypotheses and accepting all true ones. Both criteria are discussed for nonstagewise and stagewise procedures in case of independent test statistics. For the example of 5 independently and normally distributed test statistics the values of the two criteria are calcutated under reasonably simple alternatives.
A Characterization of the Bivariate Exponential Distribution
Authors: Nair N. U. , Nair V. K. R. 
Published: May 2007

AbstractIn this article a characterisation of the Gumbel's Bivariate Exponential Distribution is established on the basis of the properties of the conditional expectation of the component variables. The characterising property is proposed as the definition of lack of memory in the bivariate case.
Singlet–Singlet Annihilation Leading to a Charge‐Transfer Intermediate in Chromophore‐End‐Capped Pentaphenylenes
Authors: Fron Eduard , Schweitzer Gerd , Jacob Josemon , Van Vooren Antoine , Beljonne David , Müllen Klaus , Hofkens Johan , Van der Auweraer Mark , De Schryver Frans C. 
Published: May 2007

AbstractThe excited‐state properties of two peryleneimide chromophore end‐capped pentaphenylene compounds were investigated in detail using femtosecond transient absorption and single‐photon timing experiments. Singlet–singlet annihilation was found to promote one chromophore into a higher excited state and results in the formation of an ultra‐short‐living intermediate charge‐transfer (CT) state in the Sn–S1deactivation pathway. In low‐polarity solvents, this CT state is found to be energetically higher than the first excited state and thus cannot be populated via one‐photon excitation. The observed CT state decays with a time constant of about 1 ps to form the lowest singlet excited state. These results demonstrate the potential use of the singlet–singlet annihilation as a novel tool in studying reactions occurring in states that are energetically above the S1.
Defect‐tolerant nanoelectronic pattern classifiers
Authors: Lee Jung Hoon , Likharev Konstantin K. 
Published: May 2007

AbstractMixed‐signal neuromorphic networks (‘CrossNets’), based on hybrid CMOS/nanodevice circuits, may provide unprecedented performance for important pattern classification tasks. The synaptic weights necessary for such tasks may be imported from an external ‘precursor’ network with either continuous or discrete synaptic weights (in the former case, with the quantization—‘clipping’—due to the binary character of the elementary synaptic nanodevices—latching switches.) Alternatively, the weights may be adjusted ‘in situ’ (inside the CrossNet) using a pseudo‐stochastic method, or set‐up using a mixed‐mode method partly employing external circuitry. Our calculations have shown that CrossNet pattern classifiers, using any of these synaptic weight adjustment methods, may be remarkably resilient. For example, in a CrossNet with synapses in the form of two small square arrays with 4 × 4 nanodevices each, the resulting weight discreteness may have a virtually negligible effect on the classification fidelity, while the fraction of defective devices which affects the performance substantially ranges from ∼20% to as high as 90% (!), depending on the training method. Copyright © 2007 John Wiley & Sons, Ltd.
Transcription factors Mesp2 and Paraxis have critical roles in axial musculoskeletal formation
Authors: Takahashi Yu , Takagi Atsuya , Hiraoka Shuichi , Koseki Haruhiko , Kanno Jun , Rawls Alan , Saga Yumiko 
Published: May 2007

AbstractMesp2 and Paraxis are basic helix–loop–helix (bHLH) ‐type transcription factors coexpressed in the presomitic mesoderm (PSM) and are required for normal somite formation. Here, we show that Mesp2/Paraxis double‐null mice exhibit a distinct phenotype unexpected from either Mesp2 or Paraxis single‐null mice. In the posterior region of the body, most of the skeletal components of both the vertebral body and neural arches are severely reduced and only a rudimental lamina and ribs remain, indicating a strong genetic interaction in the sclerotomal cell lineage. However, yeast two‐hybrid analyses revealed no direct interaction between Mesp2 and Paraxis. The Mesp2/Paraxis double‐null embryo has caudalized somites, revealed by expanded Uncx4.1 expression pattern observed in the Mesp2‐null embryo, but the expression level of Uncx4.1 was significantly decreased in mature somites, indicative of hypoplasia of lateral sclerotome derivatives. By focusing on vertebral column formation, we found that expressions of Pax1, Nkx3.1, and Bapx1 are regulated by Paraxis and that Pax9 expression was severely affected in the Mesp2/Paraxis double‐null embryo. Furthermore, the expression of Pax3, a crucial factor for hypaxial muscle differentiation, is regulated by both Mesp2 and Paraxis in the anteriormost PSM and nascent somite region. The present data strongly suggest that patterning events by bHLH‐type transcription factors have deep impacts on regional chondrogenic and myogenic differentiation of somitic cells, mainly by means of control of Pax genes. Developmental Dynamics 236:1484–1494, 2007. © 2007 Wiley‐Liss, Inc.
Synthesis and Glycosidase Inhibitory Activities of Pyrrolidines and Piperidines with N‐(Polyhydroxyalkyl) Side Chains
Authors: Boutefnouchet Sabrina , Moldvai István , Gács‐Baitz Eszter , Bello Claudia , Vogel Pierre 
Published: April 2007

AbstractAmidification of L‐proline (3) with (+)‐(R,R)‐6 and (–)‐(S,S)‐tartaric anhydride diacetate (7) gave N‐substituted L‐proline derivatives 8a,b, respectively. Acids 8a,b were transformed into diesters 9a,b with MeOH/HCl. Similar reactions with methyl (2S,4R)‐4 and (2R,4S)‐4‐acetoxypipecolate (5) led to bicyclic lactams 14a,b and 15a. Compounds 8a,b were converted into N‐(trihydroxybutyl)pyrrolidine derivatives 8c,d, 10a,b and 11a,b. Methyl (2S,4R)‐20a and (2R,4S)‐4‐acetoxy‐N‐[(2S,3S)‐1,2,3‐trihydroxybutyl]pipecolate (20b) were obtained by displacement of (–)‐(2S,2S)‐2‐O‐benzyl‐3,4‐O‐isopropylidene‐1‐deoxy‐1‐iodothreitol (19) by 4 and 5. Compounds 20a,b were converted into (2S,4R,2′S,2′S)‐21a and(2R,4S,2′S,3′S)‐4‐hydroxy‐2‐hydromethyl‐N‐(2‐benzyloxy‐3,4‐isopropylidenedioxy)piperidine (21b) and finally into unprotected pentols 22a,b. Nonprotected (2S,2′S,3′S)‐11a and (2S,2′R,3′R)‐N‐(1,2,3‐trihydroxybutyl)prolinol (11b), as well as 22a,b, did not inhibit any of the 13 glycosidases assayed. However, a triacetoxy derivative, (2S,3S)‐2,3‐diacetoxy‐4‐[(2R,4S)‐4‐acetoxy‐2‐(methoxycarbonyl)piperidin‐1‐yl]‐4‐oxobutanoic acid (13b) is an inhibitor (IC50 = 157 μM) of α‐L‐fucosidase from bovine kidney.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
On the selective local stabilization of the mixed Q1–P0 element
Authors: Qin Jinshui , Zhang Shangyou 
Published: May 2007

AbstractIn this paper we study the stability and performance of the quadrilateral finite element 𝒬1–𝒫0 (bili‐ near/constant) for the Stokes equations. We set up a framework to show the stability of the element for a wide range of meshes with macroelement patches. We apply the new theory to show the stability of 𝒬1–𝒫0 elements on some previously studied meshes and on some newly suggested meshes. Nevertheless such earlier and newly suggested meshes are not effective in practice, compared to the traditional unstable meshes for the 𝒬1–𝒫0 element. The new theory leads naturally to a general idea in treating instability of square 𝒬1–𝒫0 elements by the local stabilization on macroelement patches of larger, but fixed sizes. The good performance of the traditional 𝒬1–𝒫0 square elements with filtering can be kept
in some cases after the local stabilization. Some numerical tests are provided to support the theory and to show the performance of stabilized 𝒬1–𝒫0 elements. Copyright © 2007 John Wiley & Sons, Ltd.
Des Kaisers neue Kolonien
Authors: Schmidt Wilhelm R. 
Published: April 2007

AbstractDas Koloniale Bildarchiv in Frankfurt bietet einzigartige Bildzeugnisse zur deutschen Kolonialgeschichte. Die Sammlung war lange Zeit vergessen. Nach ihrer aufwändigen Erschließung und Digitalisierung stehen die Fotodokumente heute Forschern im In‐ und Ausland via Internet zur Verfügung
A new convenient way to synthesize 1‐hydroxyphosphonates from heterocyclic aldehydes and ketones under microwave irradiation
Authors: Feng Dexin , Chen Ruyu , Huang You , Song Haibin 
Published: May 2007

AbstractA simple and efficient method has been developed for the synthesis of 1‐hydroxyphosphonates from heterocyclic aldehydes and ketones under solvent‐free conditions using microwave irradiation. Various phosphites have been used to find the influence of steric exclusion on the reaction. The products are readily obtained in satisfactory yields, on the solid support of MgO. The reactions are also induced by oil‐heat, and we find that the condition of microwave is better than oil‐heat with respect to reaction times and product yields. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:347–353, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20304