bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of Diallel Table for Experiments in Block Designs
Authors: Ceranka B. , Kielczewska H. 
Published: May 2007

AbstractIn this paper the analysis of genotypes obtained in diallel crossing system, including parents, one set of F1s and reciprocal F1's, is given. This analysis is presented for data obtained from the experiments laid out in block designs. The analysis of variance, estimator of reciprocal effects, estimators of general and specific combining abilities as well as statistics for testing of hypotheses concerning those parameters are given.
The Almost‐one Parameter Hypothesis Applied to Pharmacokinetics of Ethanol Infusion
Authors: Masuyama M. 
Published: May 2007

AbstractThey say that the pharmacokinetics of constant‐rate intravenous infusion of ethanol obeys the Henri‐Michaelis‐Menten (H‐M‐M) model. In analysing the original data from the viewpoint of the almost‐one parameter hypothesis (see box 1), we found that the whole process should be divided into four phases and the H‐M‐M model was valid only in the last phase.
Optimization of Taxonomic Keys by Means of Probabilistic Modelling
Authors: Sviridov A. V. , Leuschner D. 
Published: May 2007

AbstractAt present biological systematics, i. e. classification and identification of organisms, is also a subject of the employment of mathematical methods. The topic of this paper is identification. One of the most important methods of identification is that by means of keys. Therefore a short review on the types of keys and their valuation is represented. Moreover there are discussed the essential properties of keys: reliability and velocity of identification. Further in connection with these two quantities probabilistic models are treated. The last part of the article deals with the optimization of keys concerning theory and practice of the problem.
A Multivariate Analysis of Variance of Categorical Data
Authors: Onukogu Ike B. 
Published: May 2007

AbstractTwo methods of testing multivariate hypotheses in an IXJXK contingency table are presented. In one case, use is made of the trace of the matrix of sum of squares and sum of products while in the other, determinants of the matrices are used to construct test statistics. Asymptotic equivalence of the methods is shown.
The Two Period Binary Response Cross‐Over Trial
Authors: Nagelkerke N. J. D. , Hart A. A. M. , Oosting J. 
Published: May 2007

AbstractThe cross‐over design for clinical trials when responses are binary is discussed. Three tests which have been proposed for the analysis of this problem are compared by an assessment of their assumptions. A simple test to establish whether it is appropriate to include observations from the second period is presented.
Two Stage Sampling for Simultaneously Testing Main and Side Effects in Clinical Trials
Authors: Bauer P. 
Published: May 2007

AbstractIn clinical trials for the comparison of two treatments it seems reasonable to stop the study if either one treatment has worked out to be markedly superior in the main effect, or one to be severely inferior with respect to an adverse side effect. Two stage sampling plans are considered for simultaneously testing a main and side effect, assumed to follow a bivariate normal distribution with known variances, but unknown correlation. The test procedure keeps the global significance level under the null hypothesis of no differences in main and side effects. The critical values are chosen under the side condition, that the probability for ending at the first or second stage with a rejection of the elementary null hypothesis for the main effect is controlled, when a particular constellation of differences in mean holds; analogously the probability of ending with a rejection of the null hypotheses for the side effect, given certain treatment differences, is controlled too. Plans “optimal” with respect to sample size are given.
On the Accuracy of Numerical Solutions for Some Stereological Problems such as the Wicksell Corpuscle Problem
Authors: Gerlach W. , Ohser J. 
Published: May 2007

AbstractTwo stereological problems—the estimation of sphere diameter distributions and the estimation of sheet thickness distributions from linear or plane sections—are considered. Their numerical solution consists in the solution of linear equation systems. To compare the quality of various methods theoretically, not only by experiments, the condition numbers of the matrices of the corresponding equation systems are determined.
Analysis of Trends in Proportions with an Ordinally Scaled Determinant
Authors: Nurminen M. 
Published: May 2007

AbstractIn this paper the analysis of several proportions in a comparative study setting is discussed. The case of ordinal grouping variates is considered. F statistics are formulated to test for trend in the proportions over the scored values of the determinant variate. The null chi‐square or F (t square) functions are presented separately for the unstratified and stratified analysis, and in either situation the corresponding functions with angular transformed proportions are also expressed. Generalizations to deal with the parameters in the nonnull range are outlined. Throughout, the intimate relation between the presented statistics and standard methods is pointed out.
Interaction Pair‐potentials for a System of Ant's Nests
Authors: Takacs R. , Fiksel Th. 
Published: May 2007

AbstractIn this paper two methods for the estimation of pair‐potentials of Gibbsian point processes are described. These are applied to a point pattern of ant's nests to obtain information on the degree of interaction of two different species. Furthermore an estimation method of mark‐point potentials is demonstrated and applied to the same example.
Some Extensions of Buser and Baroni‐Urbani's Clustering Method
Authors: Dragomirescu L. 
Published: May 2007

AbstractWe consider that the algorithm of numerical taxonomy focused upon the concept of “homogeneity”, proposed by Buser and Baroni‐Urbani (1982) for binary data, satisfies best from all the other algorithms known by us, the conditions of classification in biology formulated by Beckner in 1959. Therefore the paper proposes and studies homogeneities for binary and for ordered multi‐states data, which model explicitly Beckner's conditions. From all these, the homogeneity denoted by h* has the remarkable quality of generalizing the famous Jaccard's similarity coefficient. Moreover, using h* in this algorithm “naturally” improved by us, we can achieve the performance of a correct classification of the remarkable example proposed by Watanabe (1969).
Robustness of Selection Procedures
Authors: Domröse H. , Rasch D. 
Published: May 2007

AbstractIn the article Bechhofers Indifference‐zone formulation for selecting the t populations with the t highest means is considered in a set of non‐normal distributions.Selection rules based on the sample mean, the 10% and the 20% trimmed means, two estimators proposed by Tiku (1981) for valuating the smallest and highest accepted sample values higher, the sample median and a linear combination of quantile estimators, two adaptive procedures and a ranksum procedure are investigated in a large scale simulation experiment in respect of their robustness against deviations from an assumed distribution. Robustness is understood as a small percentage of the difference βA‐β between the actual probability of incorrect selection βA and the nominal β‐value. We obtained a relatively good robustness for the classical sample mean selection rule and useful derivations for the employment of other selection rules in an area of practical importance.
Phenotypic Stability of Mixtures – Relations Between the Stability Parameters of a Mixture and Its Components
Authors: Hühn M. 
Published: May 2007

AbstractFor each of the two stability parameters (‘regression coefficient’ and ‘sum of squared deviations from the regression’) of the common regression approach (= regression of the yield of population i in environment j on the environmental index of this evironment j which often has been estimated by the mean of all tested populations in this environment j) the phenotypic stability of a mixture and it's components have been analysed theoretically. It can be shown that in practical applications (for example: variety testing) the regression coefficient of a mixture often can be sufficiently approximated by the arithmetic mean of the regression coefficients of the components grown singly. This simple relation between a mixture and it's components don't hold for the second stability parameter ‘sum of squared deviations from the regression’. The exact relation has been deduced and useful and clear approximations are discussed. All the theoretical results are demonstrated and applied using the well‐known experimental barley data of Sandfaer (1970).
A Note on the Analysis of the Two‐Period Crossover Design When the Period‐Treatment Interaction is Significant
Authors: Grieve A. P. 
Published: May 2007

AbstractIn the analysis of a two‐period crossover study Grizzle (1965) suggests that, if a preliminary test for a period by treatment interaction (residual effect, carryover effect) is significant at the 10 % level, the direct effects of the treatments should be compared by performing a t‐test on the data from the first period only. In this note it is shown that under Grizzle's model the comparison of the direct treatment effects is equivalent to a Behrens‐Fisher problem. Depending on one's viewpoint–Bayesian, fiducial, or sampling theory–different solutions are possible. The solutions are illustrated using three well‐known data sets.
Discretizing a Normal Prior for Change Point Estimation in Switching Regressions
Authors: Piegorsch Walter W. 
Published: May 2007

AbstractBayes decision procedures are considered for change point estimation in the simple bilinear segmented model. A discretized normal prior density is employed as the prior distribution for the change point index. Posterior probability functions are developed for this index under a vague prior formulation on the regression parameters. The procedure is applied to an example involving mercury toxicity data.
One‐ and Two‐Sample Tests of Kendall's τ
Authors: Schemper M. 
Published: May 2007

AbstractSeveral methods of testing general one‐sample and two‐sample hypotheses of Kendall's τ are discussed. The performance of these procedures in typical situations likely to occur in practice was investigated by numerous Monte Carlo experiments. The common one‐sample test (H0: τ = 0) based on the permutational variance performs very similar to bootstrap or jackknife testing for true τ near zero. For true |τ| perhaps greater than 0.4 and moderate sample sizes bootstrap techniques are the methods of choice.
Analysis of Diallel Table for Experiments Carried Out in BIB Designs‐Mixed Model
Authors: Ceranka B. , Mejza S. 
Published: May 2007

AbstractIn this paper the analysis of genotypes obtained in a diallel crossing system, including parents, one set of F1′s and reciprocal F1′s, is given. This analysis is presented for data obtained from the experiments carried out in a block design in which block effects are random. The analysis of variance, estimators of reciprocal effects, estimators of general and specific combining abilities are considered. Also statistics for testing hypotheses concerning some genetical parameters are given.
Robustness of Multiple Comparison Procedures: Treatment versus Control
Authors: Rudolph P. E. 
Published: May 2007

AbstractComputer simulation techniques were used to investigate the Type I and Type II error rates of one parametric (Dunnett) and two nonparametric multiple comparison procedures for comparing treatments with a control under nonnormality and variance homogeneity. It was found that Dunnett's procedure is quite robust with respect to violations of the normality assumption. Power comparisons show that for small sample sizes Dunnett's procedure is superior to the nonparametric procedures also in non‐normal cases, but for larger sample sizes the multiple analogue to Wilcoxon and Kruskal‐Wallis rank statistics are superior to Dunnett's procedure in all considered nonnormal cases. Further investigations under nonnormality and variance heterogeneity show robustness properties with respect to the risks of first kind and power comparisons yield similar results as in the equal variance case.
Spread of Drug Addiction in the Presence of Two Competing Drugs
Authors: Dayananda P. W. A. 
Published: May 2007

AbstractThis paper considers the spread of drug addiction when addiction is by taking one of two competing drugs available. Community is assumed to be closed and each individual is classified as belonging to one of three mutually exclusive groups: susceptibles, addicts and pushers. A deterministic model is presented in general form and, in a special case, the stochastic model is analysed. An illustration is also presented where the parameters take a specific set of numerical values.
Cycloaddition Reactions of 16‐Electron d4 Metallocene Complexes with C60: A Theoretical Study
Authors: Sheu Jeng‐Horng , Su Ming‐Der 
Published: May 2007

AbstractThe potential‐energy surfaces of the cycloaddition reaction Cp2M+C60→Cp2M(C60) (Cp=η5‐C5H5; M=Cr, Mo, and W) were studied at the B3LYP/LANL2DZ level of theory. Two competing reaction pathways were found, which can be classified as [6,5] attack (path A) and [6,6] attack (path B). Given the same reaction conditions, the [6,6]‐attack pathway for cycloaddition to C60 is more favorable than the [6,5]‐attack pathway, both kinetically and thermodynamically. A qualitative model, based on the theory of Pross and Shaik, was used to develop an explanation for the reaction barrier heights. Thus, our theoretical findings suggest that the singlet–triplet splitting ΔEst (=Etriplet−Esinglet) of the 16‐electron d4 Cp2M and C60 species are a guide to predicting their reactivity towards cycloaddition. Our model results demonstrate that the propensity for cycloaddition to C60 increases in the order Cp2Cr<Cp2Mo<Cp2W. We show that both electronic and geometric effects play a decisive role in determining the energy barriers and reaction enthalpies.
Leukemic involvement is a common feature in mantle cell lymphoma
Authors: Ferrer Ana , Salaverria Itziar , Bosch Francesc , Villamor Neus , Rozman María , Beà Silvia , Giné Eva , López‐Guillermo Armando , Campo Elías , Montserrat Emili 
Published: May 2007

AbstractBACKGROUND.The reported incidence of peripheral blood involvement in patients with mantle cell lymphoma (MCL) ranges from 13% to 77%. The aim of the study was to analyze the prevalence and the biologic and clinical significance of leukemic involvement in a series of patients with MCL.METHODS.Leukemic expression was assessed by conventional morphology and flow cytometry (FC) in 48 patients. In addition, comparative genomic hybridization (CGH) was performed in 27 patients.RESULTS.At diagnosis, 44 patients (92%) had evidence of leukemic expression by FC, including 8 patients (17%) without morphologically apparent leukemic involvement. Moreover, a lymphocyte count ≥5 × 109/L was observed in 25 cases (52%). The most frequent imbalances detected by CGH were gains of 3q, 7p, 8q, 9q, 12q, and 13q, and losses of 13q, 1p, 9p, 11q, 10p, 17p, 6q, 8p, and 9q. Using a cutoff of 5 × 109/L lymphocytes, cases with lymphocytosis more frequently presented with gains of 3q (P = .02), losses of 10p (P = .05), a low response rate (P = .04), and a short survival (P = .05).CONCLUSIONS.Leukemic expression at diagnosis detected by FC was found to be highly frequent in this series of patients with MCL. Although morphologically apparent leukemic expression was not associated with specific chromosomal alterations detected by CGH, a lymphocyte count ≥5 × 109/L was correlated with particular genetic abnormalities and a poor outcome. Cancer 2007. © 2007 American Cancer Society.
Xeya3 regulates survival and proliferation of neural progenitor cells within the anterior neural plate of Xenopus embryos
Authors: Kriebel Martin , Müller Frank , Hollemann Thomas 
Published: May 2007

AbstractThe transcriptional coactivater and tyrosine phosphatase eyes absent (eya) is vital for eye development in Drosophila. We identified a vertebrate member of the Eya family, Xeya3, which is expressed in the anterior neural plate, including the eye field. Overexpression of wild‐type Xeya3 or of a phosphatase‐negative version of Xeya3 creates massive enlargements of brain and retinal tissues, mainly caused by overproliferation of neural precursor cells. On the other hand, suppression of Xeya3 function induces local apoptosis within the sensorial layer of the anterior neuroectoderm. Thus, Xeya3 is key factor for the formation and size control of brain and eyes in vertebrates. Developmental Dynamics 236:1526–1534, 2007. © 2007 Wiley‐Liss, Inc.
Structure Determination of Photoproducts of Anthracenes with (Arylmethoxymethyl) Sidechains
Authors: Dobis Silvia , Schollmeyer Dieter , Gao Chunmei , Cao Derong , Meier Herbert 
Published: May 2007

AbstractIrradiation of 9‐(arylmethoxymethyl)anthracenes 3 leads either to a cyclomer and cyclodimer mixture (3a → 4a,5a), to selectively formed dimers (3b → 5b), or a selectively formed cyclomer (3c → 4c). The [4π+4π]cyclodimerization is under the conditions used a regioselective head‐to‐tail process. In the crystals of the dimers 5a,b, the sidechains are attached in an antiperiplanar position related to the CC bonds generated in the dimerization. In solutions, however, the structures consist of three rotamers the equilibration of which was studied by temperature‐dependent NMR spectra. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
MEKC combined with SPE and sample stacking for multiple analysis of pesticides in water samples at the ng/L level
Authors: Ravelo‐Pérez Lidia M. , Hernández‐Borges Javier , Cifuentes Alejandro , Rodríguez‐Delgado Miguel Á. 
Published: May 2007

AbstractIn this work, a new multiresidue analytical method based on MEKC with UV detection combined with SPE as off‐line preconcentration strategy, and reversed‐electrode polarity stacking mode (REPSM) as on‐line stacking procedure, has been developed for the monitoring of 12 pesticides (carbendazim, pirimicarb, metalaxyl, pyrimethanil, procymidone, nuarimol, azoxystrobin, tebufenozide, fenarimol, benalaxyl, penconazole, and tetradifon) that are currently being used in the Canary Islands (Spain). The optimized MEKC buffer, consisting of 100 mM sodium tetraborate and 30 mM SDS at pH 8.5 with 6% v/v 1‐propanol, provided baseline resolution of the 12 pesticides in less than 20 min. The developed method was applied to the analysis of mineral, stagnant, and tap water samples. The proposed SPE‐REPSM‐MEKC‐UV method showed high extraction efficiencies with detection limits (LODs) at the low ng/L level providing LOD values down to 64 ng/L for these real samples.
The Xichong flora of Yunnan, China: diversity in late Mid Devonian plant assemblages
Authors: Yi Wang , Berry C. M. , Shougang Hao , Honghe Xu , Qiang Fu 
Published: May 2007

AbstractOver the past 10 years, significant progress has been made in our understanding of late Mid Devonian floras of Yunnan Province, China. Based on new collections and a restudy of existing specimens, most of the old taxa have been emended, and some new taxa described. The late Mid Devonian Xichong flora of Yunnan is dominated by lycopsids, including prelycopsids, homosporous and herbaceous protolepidodendrids. The ‘fern’‐like and cladoxylopsid plants are important and are mainly endemic. A few small plants have also been reported. The Xichong flora is divided into two ecological levels: small tree and ground cover levels. The palaeoclimate of late Mid Devonian Yunnan belonged to the tropical zone. There are noticeable differences between the fossil plants of Yunnan and those of the late Mid Devonian in Laurussia and Venezuela. The Xichong flora is a special, endemic flora in a palaeogeographically isolated tropical area, controlled by local palaeoclimate. The sequence of floras developed in pre‐Carboniferous time in South China includes the Posongchong (Pragian), the Xichong (late Givetian) and the Wutung (late Famennian) floras. These floras are treated as pre‐Cathaysian floras. Further work is required to establish how much influence these pre‐Cathaysian floras had in the Carboniferous‐Permian development of the Cathaysian Flora. Copyright © 2007 John Wiley & Sons, Ltd.
Nitroimidazoles, part 4: Synthesis and anti‐HIV activity of new 5‐alkylsulfanyl and 5‐(4′‐arylsulfonyl)piperazinyl‐4‐nitroimidazole derivatives
Authors: Al‐Soud Yaseen A. , Al‐Masoudi Najim A. , De Clercq Erik , Paneccoque Christoph 
Published: May 2007

AbstractThe development of new HIV nonnucleoside reverse transcriptase inhibitors (NNRTIs) offers the possibility of generating structures of increased potency. On this basis, a series of 5‐alkylsulfanyl and 5‐(4′‐arylsulfonyl)piperazine derivatives of 1‐phenyl‐2‐alkyl‐4‐nitroimidazoles 5–21 was synthesized with the aim to develop new NNRTIs. The new synthesized compounds were assayed against HIV‐1 and HIV‐2 in MT‐4 cells. Compounds 9 and 13, with an alkylsulfanyl group at C‐5 of the 4‐nitroimidazole backbone, showed inhibition of HIV‐1 with EC50 4.04 μg/mL and 2.37 μg/mL, and therapeutic indexes (SI) of 17 and 13, respectively. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:333–340, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20301
A simple and convenient procedure for the synthesis of naphthoquinone fused cyclic α‐aminophosphoryl chloride
Authors: Wang Bin , Miao Zhiwei , Chen Ruyu 
Published: May 2007

AbstractThe synthesis of a novel quinone fused phosphorus heterocycle, 2‐chloro‐3,3‐disubstituents‐3,4‐dihydro‐2H‐naphtho[2,3‐e][1,4,2]oxazaphosphinane‐5,10‐dione 2‐oxide (3a–g), was described for the first time. These compounds, which have a readily leaving group Cl, can serve as intermediates of many quinone fused phosphorus heterocycles. The structures of 3a–g were characterized by using common spectroscopic methods. According to the X‐ray structure of 3a, these compounds may be used as DNA‐intercalators. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:359–362, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20306
Reactions with 3,6‐diaminothieno[2,3‐b]‐pyridines: Synthesis and characterization of several new fused pyridine heterocycles
Authors: Gad‐Elkareem Mohamed A. M. , Elneairy Mohamed A. A. , Taha Adel M. 
Published: May 2007

Abstract6‐Aminopyridine‐2(1H)thiones 1 reacting with α‐halo‐compounds 2a–c afforded the alkylthiopyridine derivatives 3a–c which in turn cyclized to the corresponding thieno[2,3‐b]pyridine derivatives 4a–c. Several thieno[2,3‐b]pyridine derivatives 7, 16, 19, pyrido[3′,2′:4,5]thieno[3,2‐d]pyrimidine derivatives 6a,b, 11a–c, 21 and pyrido[3′,2′:4,5]thieno[3,2‐c]pyridazine derivatives 13, 17 were prepared starting from compounds 4a–c. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:405–413, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20313
Synthesis of 4‐(5‐aryl‐1,3,4‐oxadiazol‐2‐yl)phenyl‐hydrazine derivatives from 3‐(4‐hydrazinocarbonyl‐phenyl)sydnones
Authors: Chang Hung‐Te , Chiang Kuo‐Chen , Wong Fung Fuh , Huang Chun‐Sheng , Liao Yang‐Ming , Kuo Wen‐Fa , Won Shaw‐Bing , Yeh Mou‐Yung 
Published: May 2007

AbstractThe synthesis of potential fluorescent active 4‐(5‐aryl‐1,3,4‐oxadiazol‐2‐yl)phenylhydrazine derivatives was accomplished in three steps. The key step was the dehydration cyclization of 1,2‐diacylhydrazines to form the 1,3,4‐oxadiazole ring by use of acetic anhydride/perchloric acid mixture as the dehydrating agent. The sydnone moiety served as the masked hydrazines, which could be demasked by HCl for further application. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:438–442, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20318