bluuebunny/crossref_metadata_2025 huggingface dataset:
Recyclization on Condensation of Alkylhydrazones of 2‐Phenacyl‐1H‐benzimidazole with Acylating Agents.
Authors: Dzvinchuk I. B.
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Triazene Formation via Reaction of Imidazol‐2‐ylidenes with Azides.
Authors: Khramov Dimitri M. , Bielawski Christopher W.
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Condensation of Pyrazol‐5‐ones Unsubstituted in the Position 1 with β‐Keto Esters. Synthesis of Pyrano[2,3‐c]pyrazol‐6‐ones.
Authors: Nam N. L. , Grandberg I. I.
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Reaction of Salicyl N‐Tosylimines with 2‐Cyclohexenone: A Facile Access to Tetrahydroxanthenones.
Authors: Shi Yong‐Ling , Shi Min
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
One‐Step Synthesis of Substituted 3,5‐Dinitropiperidines and 1,5‐Dinitro‐3,7‐diazabicyclo[3.3.1]nonanes from 1,3‐Dinitropropanes.
Authors: Yarmukhamedov N. N. , Baibulatova N. Z. , Dokichev V. A. , Khakimova T. V. , Spirikhin L. V. , Tomilov Yu. V. , Yunusov M. S.
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
2‐R‐7‐Hydroxy‐8‐methyl‐3‐(2‐quinolyl)chromones.
Authors: Shokol T. V. , Turov A. V. , Khilya V. P.
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
An Expeditious Approach to Quinolines via Friedlaender Synthesis Catalyzed by FeCl3 or Mg(ClO4)2.
Authors: Wu Jie , Zhang Liang , Diao Tian‐Ning
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Reactions of Methyl Trifluoropyruvate 2‐Pyridylimines with Trimethyl Phosphite.
Authors: Sokolov V. B. , Aksinenko A. Yu. , Martynov I. V.
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Synthesis of New 1H‐Pyridazine Derivatives peri‐Anellated with Acenaphthene and Acenaphthylene.
Authors: Mezheritskii V. V. , Minyaeva L. G. , Tyurin R. V.
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Silica Gel Promoted Synthesis of 3,4,5‐Triaryltetrahydro‐1,4‐thiazine Derivatives from β,β′‐Dichloro Sulfides and Aromatic Amines.
Authors: Mihara Masatoshi , Ito Takatoshi , Ishino Yoshio , Oderaotoshi Yoji , Minakata Satoshi , Komatsu Mitsuo
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
A New Approach to the Synthesis of Dibenzodiazacrown Compounds.
Authors: Gromov S. P. , Churakova M. V. , Dmitrieva S. N.
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Synthesis of 6,7‐Benzo‐3‐borabicyclo[3.3.1]nonane and Its 3‐Aza Analogue from 2‐Allylphenyl(diallyl)borane. Intramolecular Arylboration of the C=C Bond.
Authors: Kuznetsov N. Yu. , Starikova Z. A. , Averkiev B. B. , Bubnov Yu. N.
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Spiropyrans and Spirooxazines. Part 3. Synthesis of Photochromic 5′‐(4,5‐Diphenyl‐1,3‐oxazol‐2‐yl)‐spiro[indoline‐2,3′‐naphtho [2,3‐b]pyran].
Authors: Voloshin N. A. , Chernyshev A. V. , Metelitsa A. V. , Raskita I. M. , Voloshina E. N. , Minkin V. I.
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Two New Meroterpenoids, Penisimplicin A and B, Isolated from Penicillium simplicissimum.
Authors: Komai Shin‐ichirou , Hosoe Tomoo , Itabashi Takeshi , Nozawa Koohei , Okada Kaoru , de Campos Takaki Galba Maria , Yaguchi Takashi , Takizawa Kayoko , Fukushima Kazutaka , Kawai Ken‐ichi
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
NMR Structure Determination of (11E)‐Trinervita‐1(14),2,11‐triene, a New Diterpene from Sexual Glands of Termites.
Authors: Budesinsky Milos , Valterova Irena , Semon Etienne , Cancello Eliana , Bordereau Christian
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Synthesis of Nitrogen‐ and Oxygen‐Containing Macrocycles — Derivatives of Lithocholic Acid.
Authors: Averin Alexei D. , Ranyuk Elena R. , Lukashev Nikolai V. , Beletskaya Irina P.
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Synthesis of the Branched‐Chain Sugar Aceric Acid (I): A Unique Component of the Pectic Polysaccharide Rhamnogalacturonan‐II.
Authors: Jones Nigel A. , Nepogodiev Sergey A. , MacDonald Colin J. , Hughes David L. , Field Robert A.
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
One‐Pot Synthesis of TBMPS (Bis(tert‐butyl)‐1‐pyrenylmethyl‐silyl) Chloride as a Novel Fluorescent Silicon‐Based Protecting Group for Protection of 5′‐OH Nucleosides and Its Use as Purification Handle in Oligonucleotide Synthesis.
Authors: Tripathi Snehlata , Misra Krishna , Sanghvi Yogesh S.
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Structure of Levorin A3, a Minor Component of Levorin Complex.
Authors: Pawlak J. , Sowinski P. , Bieszczad T. , Borowski E.
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Synthesis and Cytotoxicities of 7‐Aza Rebeccamycin Analogues Bearing Various Substituents on the Sugar Moiety, on the Imide Nitrogen and on the Carbazole Framework.
Authors: Messaoudi Samir , Anizon Fabrice , Leonce Stephane , Pierre Alain , Pfeiffer Bruno , Prudhomme Michelle
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Cervimycin A—D: A Polyketide Glycoside Complex from a Cave Bacterium Can Defeat Vancomycin Resistance.
Authors: Herold Kerstin , Gollmick Friedrich A. , Groth Ingrid , Roth Martin , Menzel Klaus‐Dieter , Moellmann Ute , Graefe Udo , Hertweck Christian
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
45 Years of Nickel Hydride — History and Perspectives
Authors: Baranowski B. , Filipek S. M.
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Current Progress in the Magnetism of Rare‐Earth—Hydrogen Systems
Authors: Vajda P.
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Recent Developments in the Application of Radiotracer Methods in Corrosion Studies
Authors: Horanyi G. , Kalman E.
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Current Trends in the Improvement and Development of Catalyst Preparation Methods
Authors: Pakhomov N. A. , Buyanov R. A.
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Phosphines and Phosphonium Salts
Authors: Allen D. W.
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Advances in 1,3‐Dipolar Cycloaddition Reaction of Azides and Alkynes: A Prototype of “Click” Chemistry
Authors: Wang Qian , Chittaboina Srinivas , Barnhill Hannah N.
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Extending Mechanistic Routes in Heterazolium Catalysis — Promising Concepts for Versatile Synthetic Methods
Authors: Zeitler Kirsten
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
1,4‐Migration of Rhodium and Palladium in Catalytic Organometallic Reactions
Authors: Ma Shengming , Gu Zhenhua
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Synthesis of N‐Substituted 3‐Aminomethylidenetetramic Acids.
Authors: Pirc Samo , Bevk David , Jakse Renata , Recnik Simon , Golic Ljubo , Golobic Amalija , Meden Anton , Stanovnik Branko , Svete Jurij
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Synthesis of Zein Derivatives and Their Mechanical Properties
Authors: Biswas Atanu , Sessa David J. , Gordon Sherald H. , Lawton John W. , Willett J. L.
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Synthesis and Applications of Cryptands
Authors: Menon Shobhana K. , Hirpara Sanjay V. , Harikrishnan Uma
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Transition Metal Catalyzed [2 + 2 + 2] Cycloadditions with Ynamides
Authors: Zhang Yanshi , Hsung Richard P.
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Catalytic Processes Involving Dihydrogen Complexes and Other σ‐Bond Complexes
Authors: Kubas Gregory J.
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Tetraalkyl Ammonium Carbonates in Organic Synthesis
Authors: Rossi Leucio
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
Asymmetric Synthesis of (R)‐ and (S)‐α‐Methylcysteine
Authors: Singh Satendra
Published: January 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.
A field experiment to assess the interruption effect of pop-up promotions
Authors: Moe Wendy W.
Published: January 2006

This article highlights a large-scale field experiment conducted at an informational Web site where the timing of pop-up promotions being offered was varied. The experiment examines the Web user's reaction to the promotion in terms of (a) a direct response to the promotion (i.e., clickthrough) and (b) any indirect response in terms of the user's Web-site-exit behavior. Factors such as delay in offering the pop-up promotion and the page on which the pop-up appears are identified as variables that can be manipulated to enhance the individual's response. The context, or the page on which the pop-up promotion is offered, also is examined. Overall, this article suggests that characteristics of pop-up promotions, beyond just the message of the promotion, can be utilized to improve the consumer response.
Group chromatic number of planar graphs of girth at least 4
Authors: Lai Hong‐Jian , Li Xiangwen
Published: January 2006

Jeager et al. introduced a concept of group connectivity as a generalization of nowhere zero flows and its dual concept group coloring, and conjectured that every 5‐edge connected graph is Z3‐connected. For planar graphs, this is equivalent to that every planar graph with girth at least 5 must have group chromatic number at most 3. In this article, we show that if G is a plane graph with girth at least 4 such that all 4 cycles are independent, every 4‐cycle is a facial cycle and the distance between every pair of a 4‐cycle and a 5‐cycle is at least 1, then the group chromatic number of G is at most 3. As a special case, we show that the conjecture above holds for planar graphs. We also prove that if G is a connected K3,3‐minor free graph with girth at least 5, then the group chromatic number is at most 3. © 2006 Wiley Periodicals, Inc. J Graph Theory 52: 51–72, 2006
Orthorhombic α‐Ca(HCOO)2 and monoclinic LiH2C6H4SO3 · H2O crystals – new materials for Raman lasers with large frequency shifts
Authors: Kaminskii A. A. , Haussühl E. , Haussühl S. , Eichler H. J. , Rhee H.
Published: January 2006

We report on the first observation of χ(3)‐nonlinear lasing effects – efficient high‐order stimulated Raman scattering (SRS) in LiH2C6H4SO3 · H2O and α‐Ca(HCOO)2 single crys‐ tals. We classify these materials as promising SRS‐media for Raman laser converters with many large frequency shifts. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Second-Order Factors
Authors: Thurstone L. L.
Published: January 2006

Second-order factors are defined and illustrated in terms of a literal notation, a physical example, a diagrammatic representation, a geometrical example, and the matrix equations relating the first-order and second-order domains. Both kinds of factors are discussed as parameters which may be not only descriptive of the individual objects in a statistical population but also descriptive of the restrictive conditions under which the objects were generated or selected. Second-order factors may be of significance in reconciling the several theories of intelligence. This paper is concerned with test configurations that show simple structure. If such a structure is not revealed, then the second-order domain is indeterminate.
A General Approach to Confirmatory Maximum Likelihood Factor Analysis
Authors: Jöreskog K. G.
Published: January 2006

We describe a general procedure by which any number of parameters of the factor analytic model can be held fixed at any values and the remaining free parameters estimated by the maximum likelihood method. The generality of the approach makes it possible to deal with all kinds of solutions: orthogonal, oblique and various mixtures of these. By choosing the fixed parameters appropriately, factors can be defined to have desired properties and make subsequent rotation unnecessary. The goodness of fit of the maximum likelihood solution under the hypothesis represented by the fixed parameters is tested by a large sample x2 test based on the likelihood ratio technique. A by-product of the procedure is an estimate of the variance-covariance matrix of the estimated parameters. From this, approximate confidence intervals for the parameters can be obtained. Several examples illustrating the usefulness of the procedure are given.
Numerical Methods for Polynomial Models in Nonlinear Factor Analysis
Authors: McDonald Roderick P.
Published: January 2006

The basic concepts of nonlinear factor analysis are introduced and some extensions of the general theory are developed. An elementary account of the class of multiple-factor polynomial models is presented, using more elementary algebraic methods than have been employed in earlier accounts of this theory. Working formulas are developed for the multiple-factor polynomial model without product terms.

Some empirical results are presented.
Simultaneous Linear Prediction
Authors: Fortier Jean J.
Published: January 2006

Given a set of items (predictors) suppose one wishes to predict another set of items (predictands) in asimultaneous way. Such a situation may occur when the predictands are different measurable aspects of the same phenomenon. Alternatively one might wish to predict the success of an event (say a successfully performed task) which has many correlated or uncorrelated failure modes (say a set of possible mental or physical disabilities each of them by itself precluding the achievement of the said task.) In such a case a unidimensional prediction is of value only if prediction is simultaneous for all possible failure modes. A linear summarization of the predictors is suggested, which is unique and has “maximum” predictability value for all predictands simultaneously. Other summarizations or scores are found that give “maximum” explanation of residual measures on the predictands and that are uncorrelated. The set of those simultaneous linear predictions is compared to the set of the individual multiple regression predictions as used, for instance, in the same context by Horst [4] for each predictand given the original predictors. We suggest that this technique can be applied in particular to the summarization of a subset of items when the whole set of items constitutes the set of predictands.
A Model for Serial Verbal Learning
Authors: Kuno Ulara
Published: January 2006

A model for analyzing the learning process with a special emphasis on serial-position effect is proposed. This model consists of two analyses, one being an analysis of the learning process of each item in a list by a stochastic method, and the other being an analysis of serial-position effect in terms of pro- and retroactive inhibitions, and of forgetting. The model is experimentally verified, and moreover, it is found that the model permits prediction of the results of many experiments with lists of various lengths and varying difficulty.
On Testing Hypotheses Regarding a Class of Covariance Structures
Authors: Srivastava J. N.
Published: January 2006

Let x be a p-component random variable having a multivariate normal distribution with covariance matrix Σ. In this paper, we consider the problem of testing hypotheses of the form H0:Σ = b1Σ1 + … + bmΣm, where bi's are unknown scalars, and Σi's are a set of known and simultaneously diagonalizable matrices. This problem has both psychometric and statistical interest, and its basic theory is developed here. Besides, the problem of obtaining likelihood-ratio statistic for testing H0 is studied, and the statistic obtained in a special case.
The Information Theoretic Entropy Function as a Total Expected Participation Index for Communication Network Experiments
Authors: Mackenzie Kenneth D.
Published: January 2006

This paper shows how the concept of an incidence matrix of communications can be used to define the entropy of a finite scheme. The properties of the entropy function are examined and the function is found to be best interpreted as a total expected participation index. Data is presented showing the relationship between structural centrality and the new total expected participation index. In general, as the network becomes more centralized the smaller the value of the participation index and as the network becomes more structurally decentralized the greater the participation index.
The True Distributions of the Range of Rank Totals in the Two-Way Classification
Authors: Dunn-Rankin Peter , Wilcoxon Frank
Published: January 2006

This paper presents the results from an investigation of the true probability distributions of the range of rank totals. A procedure for generating an approximation to the true distributions is also given. A comparison of the results of this approximation with an extensive criterion of generated true and sample distributions, and with other approximations is indicated. Accurate estimates of the critical ranges necessary to reach significance at three commonly used alpha levels, where the number of judges and items is less than or equal to sixteen, are presented in tabular form.
Some Remarks on Failure to Meet Assumptions in Discriminant Analyses
Authors: Melton Richard S.
Published: January 2006

The linear discriminant function and the generalized distance function, two special cases of discriminant technique, require multivariate normality and homogeneous variance-covariance matrices, and hence utilize only mean differences among groups. The more general methods can also utilize differences in variances and/or covariances. Tables are given showing the discriminatory value of differences in means, variances, and intercorrelations, taken singly. Equations which utilize all such differences are given for the normal multivariate distribution.
A Note on “Pattern Variants on a Square Field”
Authors: Moon John W.
Published: January 2006

It is shown how results of Prokhovnik on the number of pattern variants that may be formed by k markers on a square network of m2 positions may be derived more simply by means of a combinatorial theorem of Pólya's, which may also be used to solve systematically many other problems of this type.
Testable Conditions for Triads of Paired Comparison Choices
Authors: Morrison H. William
Published: January 2006

Forty-two choice models, each representing stimuli by one-dimensional probability distributions, are obtained by relaxing the assumptions of Thurstone's Case V Law of Comparative Judgment. The models which imply or fail to imply each of nine testable probabilistic conditions are determined. Stochastic transitivity is vulnerable in most of these models. The results suggest discarding weak stochastic transitivity, and in its place using the conjunction of weak stochastic transitivity and the triangular condition. However, unless it is possible to predict which stimuli will produce violations of the conditions, none of the conditions can be rejected on the basis of too frequent intransitive triads of choices.
Estimation of the Correlation Coefficient in Contingency Tables with Possibly Nonmetrical Characters
Authors: Lancaster H. O. , Hamdan M. A.
Published: January 2006

A method of estimating the product moment correlation from the polychoric series is developed. This method is shown to be a generalization of the method which uses the tetrachoric series to obtain the tetrachoric correlation. Although this new method involves more computational labor, it is shown to be superior to older methods for data grouped into a small number of classes.
Some Rao-Guttman Relationships
Authors: Harris Chester W.
Published: January 2006

An examination of the determinantal equation associated with Rao's canonical factors suggests that Guttman's best lower bound for the number of common factors corresponds to the number of positive canonical correlations when squared multiple correlations are used as the initial estimates of communality. When these initial communality estimates are used, solving Rao's determinantal equation (at the first stage) permits expressing several matrices as functions of factors that differ only in the scale of their columns; these matrices include the correlation matrix with units in the diagonal, the correlation matrix with squared multiple correlations as communality estimates, Guttman's image covariance matrix, and Guttman's anti-image covariance matrix. Further, the factor scores associated with these factors can be shown to be either identical or simply related by a scale change. Implications for practice are discussed, and a computing scheme which would lead to an exhaustive analysis of the data with several optional outputs is outlined.
A Note on Mathematical Models for Learning
Authors: Simon Herbert A.
Published: January 2006

It is shown that a rational learning curve developed by Estes for paired associate learning is a special case of a more general function. The latter is the product of two functions and assumes that the discovery and fixation aspects of learning are independent. The indications are that the form of one of the functions has not been tested sharply by Estes in the paired associate learning setting.
Stimulus Programming in Psychophysics
Authors: Smith J. E. Keith
Published: January 2006

The appearance of a statistical paper in a symposium honoring the founding of psychophysies was surely to have been expected. These two disciplines had their modern beginnings in about the same period of time and the well-known founders of each made at least some contributions in the other. Karl Pearson’s research on the personal equation is still a good example of painstaking psychophysical experimentation. Indeed much of his statistical reputation rests on techniques he developed to analyze this data. Fifty years ago Urban published, in a psychological journal, the final form of the Müller-Urban weights. Twenty years later biologists rediscovered Urban’s weights and now use them routinely. Spearman, too, contributed to both fields.
Rotation to Achieve Factorial Invariance
Authors: Meredith William
Published: January 2006

Under certain conditions it is reasonable to assume that the same factor pattern matrix will describe the regression of observed on factor scores in different populations. However, ordinary factoring procedures will not reveal in general the existence of such a factor pattern matrix. Two procedures for rotating any number of factor pattern matrices based on different populations to conform to a single “best fitting” factor pattern matrix are developed in this paper. It is assumed that the same number of factors have been determined for each population. Both procedures will yield oblique results in the various populations. The procedures are illustrated with data taken from the 1939 Holzinger-Swineford monograph. Four groups of individuals are utilized.
A Probability Model for Errors of Classification. I. General Considerations
Authors: Sutcliffe J. P.
Published: January 2006

This paper seeks to meet the need for a general treatment of the problem of error in classification. Within an m-attribute classificatory system, an object's typical subclass is that subclass to which it is most often allocated under repeated experimentally independent applications of the classificatory criteria. In these terms, an error of classification is an atypical subclass allocation. This leads to definition of probabilities O of occasional subclass membership, probabilities T of typical subclass membership, and probabilities E of error or, more generally, occasional subclass membership conditional upon typical subclass membership. In the relationship f: (O, T, E) the relative incidence of independent O, T, and E values is such that generally one can specify O values given T and E, but one cannot generally specify T and E values given O. Under the restrictions of homogeneity of E values for all members of a given typical subclass, mutual stochastic independence of errors of classification, and suitable conditions of replication, one can find particular systems O = f (T, E) which are solvable for T and E given O. A minimum of three replications of occasional classification is necessary for a solution of systems for marginal attributes, and a minimum of two replications is needed with any cross-classification. Although for such systems one can always specify T and E values given O values, the solution is unique for dichotomous systems only.
Statistical Methods for a Theory of Cue Learning
Authors: Restle Frank
Published: January 2006

A theory of cue learning, which gives rise to a system of recurrent events in Feller's sense, is analyzed mathematically. The distribution of total errors and sampling distribution of mean errors are derived, and the learning curve is investigated. Maximum likelihood estimates of parameters and sampling variances of those estimates are derived. Likelihood ratio tests of the usual null hypotheses and approximate tests of goodness of fit of substantive hypotheses are developed. The distinguishing characteristic of these tests is that they are concerned with meaningful parameters of the learning process.
Subjective Geographic Distance: A Multidimensional Comparison
Authors: Lundberg Ulf , Ekman Gösta
Published: January 2006

The interdistances between thirteen places situated in different parts of the world were estimated by 60 subjects. The estimates were analysed by Kruskal's multidimensional technique and, after a cosine transformation, by factor analysis. It was found that both methods yielded the same three-dimensional solution. Also a two-dimensional configuration could describe the data, and it was shown that this configuration contained representations of unidimensional ratings obtained in other studies.
Some Models for Individual-Group Comparisons and Group Behavior
Authors: Fienberg Stephen E. , Larntz F. Kinley
Published: January 2006

In problem solving situations, it has been suggested the superiority of groups over individuals is due simply to the fact that groups consist of several individuals. In this paper, the Lorge and Solomon [1955] approach to such situations is reexamined using the method of maximum likelihood. Extensions to trichotomous response situations are also presented, and the resulting models are applied to data gathered by Staub [1970]. The partitioning of the likelihood ratio goodness-of-fit statistic is then discussed in order that the effects of additional variables on the response variate can be assessed. Finally, the small sample behavior of the likelihood ratio statistic is examined.
A Paired Compositions Model for Round-Robin Experiments
Authors: Gleason John R. , Halperin Silas
Published: January 2006

Investigation of the effects of a series of treatment conditions upon some social behaviors may require observation of a set of subjects which have been mutually paired, in round-robin fashion. Data arising from such experiments are difficult to analyze, partly because they do not fit neatly into standard designs. A paired compositions scaling model due to Bechtel is adapted to provide a linear model for such round-robin experiments. Both fixed and mixed versions of the model are considered and some results of a Monte Carlo study of the mixed model are reported. The model is applied to illustrative data from the field of physiological psychology.
Comparing Regressions when Measurement Error Variances are known
Authors: Stroud T. W. F.
Published: January 2006

In a multiple (or multivariate) regression model where the predictors are subject to errors of measurement with a known variance-covariance structure, two-sample hypotheses are formulated for (i) equality of regressions on true scores and (ii) equality of residual variances (or covariance matrices) after regression on true scores. The hypotheses are tested using a large-sample procedure based on maximum likelihood estimators. Formulas for the test statistic are presented; these may be avoided in practice by using a general purpose computer program. The procedure has been applied to a comparison of learning in high schools using achievement test data.
Normal Ogive Model on the Continuous Response Level in the Multidimensional Latent Space
Authors: Samejima Fumiko
Published: January 2006

The homogeneous case of the continuous response model is expanded to the multi-dimensional latent space, and the normal ogive model is presented. The operating density characteristic of the continuous item response and the vector of basic functions are developed. It is found out that there is a vector of sufficient statistics for estimating the subject's vector of latent traits, given the item parameter vectors. The relationship between the model and the linear factor analysis is observed. The matrix of item response information functions is introduced. Some additional observations are also made.
Linear Programming Techniques for Multidimensional Analysis of Preferences
Authors: Srinivasan V. , Shocker Allan D.
Published: January 2006

This paper offers a new methodology for analyzing individual differences in preference judgments with regard to a set of stimuli prespecified in a multidimensional attribute space. The individual is modelled as possessing an “ideal point” denoting his most preferred stimulus location in this space and a set of weights which reveal the relative saliences of the attributes. He prefers those stimuli which are “closer” to his ideal point (in terms of a weighted Euclidean distance measure). A linear programming model is proposed for “external analysis” i.e., estimation of the coordinates of his ideal point and the weights (involved in the Euclidean distance measure) by analyzing his paired comparison preference judgments on a set of stimuli, prespecified by their coordinate locations in the multidimensional space. A measure of “poorness of fit” is developed and the linear programming model minimizes this measure over all possible solutions. The approach is fully nonmetric, extremely flexible, and uses paired comparison judgments directly. The weights can either be constrained nonnegative or left unconstrained. Generalizations of the model to consider ordinal or interval preference data and to allow an orthogonal transformation of the attribute space are discussed. The methodology is extended to perform “internal analysis,”i.e., to determine the stimuli locations in addition to weights and ideal points by analyzing the preference judgments of all subjects simultaneously. Computational results show that the methodology for external analysis is “unbiased”—i.e., on an average it recovers the “true” ideal point and weights. These studies also indicate that the technique performs satisfactorily even when about 20 percent of the paired comparison judgments are incorrectly specified.
The Estimation of Variance-Covariance and Correlation Matrices from Incomplete Data
Authors: Timm Neil H.
Published: January 2006

Employing simulated data, several methods for estimating correlation and variance-covariance matrices are studied for observations missing at random from data matrices. The effect of sample size, number of variables, percent of missing data and average intercorrelations of variables are examined for several proposed methods.
Multidimensional Analysis of Complex Structure: Mixtures of Class and Quantitative Variation
Authors: Degerman Richard
Published: January 2006

For certain kinds of structure consisting of quantitative dimensions superimposed on a discrete class structure, spatial representations can be viewed as being composed of two subspaces, the first of which reveals the discrete classes as isolated clusters and the second of which contains variation along the quantitative attributes. A numerical method is presented for rotating a multi-dimensional configuration or factor solution so that the first few axes span the space of classes and the remaining axes span the space of quantitative variation. The use of this method is then illustrated in the analysis of some experimental data.
A General Approach to Procrustes Pattern Rotation
Authors: Gruvaeus Gunnar T.
Published: January 2006

A method is introduced for oblique rotation to a pattern target matrix specified in advance. The target matrix may have all or only some of its elements specified. Values are estimated by means of a general procedure for minimization with equality constraints. Results are shown using data from Harman and Browne.
Recovery of Structure in Incomplete Data by Alscal
Authors: MacCallum Robert C.
Published: January 2006

A Monte Carlo study was carried out in order to investigate the ability of ALSCAL to recover true structure inherent in simulated proximity measures when portions of the data are missing. All sets of simulated proximity measures were based on 30 stimuli and three dimensions, and selection of missing elements was done randomly. Properties of the simulated data varied according to (a) the number of individuals, (b) the level of random error, (c) the proportion of missing data, and (d) whether the same entries or different entries were deleted for each individual. Results showed that very accurate recovery of true distances, stimulus coordinates, and weight vectors could be achieved with as much as 60% missing data as long as sample size was sufficiently large and the level of random error was low.
Improving the Efficiency and Effectiveness of Interactively Selected MDS Data Designs
Authors: Green Rex S. , Bentler Peter M.
Published: January 2006

Two revisions of interactive MDS data selection procedures are presented. One revision improves the estimates of the MDS parameters by adding an analysis of the volume of the spatial coordinates of stimuli. Frames of stimuli augmented by an analysis of volume should more nearly surround the swarm of stimulus points. The second revision, based on randomly ordering the list of stimuli, permits more efficient data designs to be selected by reducing the number of judgments collected but never analyzed.
Admissible Values of γ in Direct Oblimin Rotation
Authors: Jennrich Robert I.
Published: January 2006

It is shown that for nonpositive values of the parameter γ in the oblimin criterion, the criterion achieves a minimum on the manifold of all possible oblique rotations of any given full rank initial loading matrix A. For every positive value of γ, on the other hand, it is shown that there exists a full rank initial loading matrix A for which the oblimin criterion does not achieve a minimum over the manifold of all oblique rotations of A. These results help explain the sometimes divergent behavior that results from using direct oblimin algorithms with γ set to a positive value.
Relative Costs and Statistical Power in the Extreme Groups Approach
Authors: Abrahams Norman M. , Alf Edward F.
Published: January 2006

The relationship between variables in applied and experimental research is often investigated by the use of extreme (i.e., upper and lower) groups. Recent analytical work has provided an extreme groups procedure that is more powerful than the standard correlational approach for all values of the correlation and extreme group size. The present article provides procedures to optimize power by determining the relative number of subjects to use in each of two stages of data collection given a fixed testing budget.
Determination of the GABA analogue succinic semialdehyde in urine and cerebrospinal fluid by dinitrophenylhydrazine derivatization and liquid chromatography–tandem mass spectrometry: Application to SSADH deficiency
Authors: Struys E. A. , Jansen E. E. W. , Gibson K. M. , Jakobs C.
Published: January 2006

Succinic semialdehyde (SSA) accumulates in the inborn error of meta‐ bolism succinic semialdehyde dehydrogenase deficiency owing to impaired enzymatic conversion to succinic acid. We developed a stable‐isotope dilution liquid chromato‐ graphy–tandem mass spectrometry method for the determination of SSA in urine and cerebrospinal fluid samples. Stable‐isotope‐labelled [13C4]SSA, serving as internal standard, was prepared by reaction of ninhydrin with L‐[13C5]glutamic acid. SSA in body fluids was converted to its dinitrophenylhydrazine (DNPH) derivative, without sample purification prior to the derivatization procedure. The DNPH derivative of SSA was injected onto a C18 analytical column and chromatography was performed by isocratic elution. Detection was accomplished by tandem mass spectrometry operating in the negative multiple‐reaction monitoring mode. The limit of detection was 10 nmol/L and the calibration curves over the range 0–500 pmol of SSA showed good linearity (r2 > 0.99). The intra‐day coefficient of variation (n = 10) for urine was 2.7% and inter‐day coefficient of variation (n = 5) for urine was 8.5%. The average recoveries performed on two levels by enriching urine and cerebrospinal fluid samples ranged between 85 and 115%, with coefficients of variation < 8%. The method enabled the first determination of normal values for SSA in urine and pathological values of SSA in urine and cerebrospinal fluid samples derived from patients with succinic semialdehyde dehydrogenase deficiency.
Cumulative incidence rates of the mucopolysaccharidoses in Germany
Authors: Baehner F. , Schmiedeskamp C. , Krummenauer F. , Miebach E. , Bajbouj M. , Whybra C. , Kohlschütter A. , Kampmann C. , Beck M.
Published: January 2006

In order to estimate the cumulative incidence rates of the mucopolysaccharidoses (MPS) in Germany, a retrospective epidemiological survey covering the period between 1980 and 1995 was implemented. Multiple ascertainment sources were used to identify affected patients. A prevalence of approximately 0.69 cases per 100 000 births was obtained for MPS I (Hurler phenotype). Within the study period, 4 patients with Hurler/Scheie phenotype and 7 cases with Scheie disease were detected. The cumulative incidence for MPS II (Hunter syndrome) was estimated as 0.64 cases per 100 000 births (1.3 cases per 100 000 male live births); that for MPS III (Sanfilippo syndrome types A, B and C) as 1.57 cases in 100 000 births; that for MPS IV A (Morquio syndrome) as 0.38 cases in 100 000; and that for MPS VI (Maroteaux–Lamy syndrome) as 0.23 cases per 100 000 births. Two cases of MPS IVB (β‐galactosidase deficiency) have been identified, but no patients with MPS VII or MPS IX. A relatively high number of patients with MPS IIIB, MPS IVA and MPS VI were of Turkish origin. The crude rate for all types of mucopolysaccharidoses is approximately 3.53 cases in 100 000 live births. The cumulative incidence pattern of MPS in Germany was compared with the corresponding rates among other industrial nations obtained from recent literature: the crude cumulative rates for all types of mucopolysaccharidoses (3.4–4.5 in 100 000 live births) were similar among all published populations; however, different frequencies of the various forms of MPS were observed.
A novel assay for the prenatal diagnosis of Sjögren–Larsson syndrome
Authors: van den Brink D. M. , van Miert J. M. , Wanders R. J. A.
Published: January 2006

Sjögren–Larsson syndrome (SLS) is a metabolic disorder characterized by ichthyosis, mental retardation and spastic diplegia or tetraplegia. The biochemical defect has been identified as a deficiency of fatty aldehyde dehydrogenase (FALDH), which is part of an enzyme complex that converts fatty alcohols into fatty acids. Making use of the finding that FALDH is also involved in the degradation of phytol, we set up an enzymatic assay for the prenatal diagnosis of SLS in cultured chorionic villus fibroblasts (CVF) based on a deficiency in the conversion of phytol to phytenic acid. FALDH activity was assessed by incubating fibroblast homogenates with phytol in the presence of NAD+, followed by hexane extraction of the samples and quantification of phytenic acid production by gas chromatography–mass spectrometry (GC‐MS). FALDH activity could be detected in cultured CVF cells derived from control fetuses and the activity was found to be markedly deficient in cultured CVF cells derived from an affected SLS fetus. The new assay described in this paper has advantages over previous assays and we conclude that it may well contribute to the prenatal detection of SLS.
Congenital disorder of glycosylation (CDG) Ig: Report on a patient and review of the literature
Authors: Rocco M. Di , Hennet T. , Grubenmann C. E. , Pagliardini S. , Allegri A. E. M. , Frank C. G. , Aebi M. , Vignola S. , Jaeken J.
Published: January 2006

We report a new patient with CDG Ig and review the five other known patients. From the data on this small number of patients, it seems that the association of psychomotor retardation, male hypogenitalism and decreased serum IgG in a patient with a type 1 pattern of serum sialotransferrins might be a clue to the diagnosis of CDG Ig.
Retinitis pigmentosa in mevalonate kinase deficiency
Authors: Balgobind B. , Wittebol‐Post D. , Frenkel J.
Published: January 2006

Retinitis pigmentosa can occur as a complication of mevalonate kinase deficiency. This may be due to the unique isoprenoid metabolism in the retina. Early detection requires awareness on the part of the treating physician.
Modelling of sensory and instrumental texture parameters in processed cheese by near infrared reflectance spectroscopy
Authors: Blazquez Carmen , Downey Gerard , O'Callaghan Donal , Howard Vincent , Delahunty Conor , Sheehan Elizabeth , Everard Colm , O'Donnell Colm P
Published: January 2006

This study investigated the application of near infrared (NIR) reflectance spectroscopy to the measurement of texture (sensory and instrumental) in experimental processed cheese samples. Spectra (750 to 2498 nm) of cheeses were recorded after 2 and 4 weeks storage at 4 °C. Trained assessors evaluated 9 sensory properties, a texture profile analyser (TPA) was used to record 5 instrumental parameters and cheese ‘meltability’ was measured by computer vision. Predictive models for sensory and instrumental texture parameters were developed using partial least squares regression on raw or pre-treated spectral data. Sensory attributes and instrumental texture measurements were modelled with sufficient accuracy to recommend the use of NIR reflectance spectroscopy for routine quality assessment of processed cheese.