bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Power of the Anderson‐Hauck Test and the Double T‐Test
Authors: Müller‐Cohrs J. 
Published: June 2010

AbstractWhen the object of an experiment is to demonstrate equivalence of two treatments then, under normal theory, there are two competing methods: The double t‐test and the test of Anderson and Hauck. Viewing the operating characteristic as a function of the noncentrality parameter the double t‐test has slightly more power, especially for few degrees of freedom, in the upper range of the curve (power ≥0.6). In contrast, the test of Anderson‐Hauck is considerably more powerful towards the lower end of the power curve.
Internal Covariance Structure of Some Coronary Heart Disease Risk Variables Investigated in Two Groups of Data
Authors: Bartkowiak Anna , Lukasik S. , Chwistecki K. , Mrukowicz M. , Morgenstern W. 
Published: June 2010

AbstractIn a former paper BARTKOWIAK (1987) has shown some aspects of simultaneous diagonalization of two covariance matrices in the context of a medical data set in which the considered variables were strongly dependent.In this paper we show a real example (considering some coronary disease risk factors) when the considered variables are nearly independent and for which the problem of equal covariance structure is relevant both from statistical and medical point of view.In Section 1 we present the medical problem and the motivation for performing this study.In Section 2 we recall the problem of seeking for common principal components coordinate system by a simultaneous diagonalization of two covariance matrices by use of one common rotation matrix.In Section 3 we show the effects of a simultaneous diagonalization applied to two groups of individuals (“Alive” and “CHD death”) It comes out with P = 0.68 that these groups can have a common principal component coordinate system.In Section 4 we gather more close at the correlations between the considered variables looking for some peculiarities occurring in the recorded data.
On a Problem of Increasing the Efficiency of Second‐order Rotatable Designs
Authors: Huda Shahariar 
Published: June 2010

AbstractThe problem considered is that of supplementing any given second‐order rotatable design DO with additional design points in order to gain maximal increase in efficiency when the experimenter is allowed to double the number of design points subject to the condition that the composite design, consisting of DO plus the additional points, should also be rotatable. Using generalized variance as a measure of efficiency some interesting results are derived.
On the Equivalence of the Johnson‐Neyman Technique and Fieller's Theorem
Authors: Schwenke James R. 
Published: June 2010

AbstractIt is shown that for the one‐way analysis of covariance model with one covariate, when the hypothesis of a common slope parameter has been rejected, the Johnson‐Neyman procedure results in a confidence interval equivalent to that obtained using Fieller's theorem. It is noted in Fieller's paper that the theory behind this technique was first introduced by Bliss, but not specifically applied to the analysis of covariance problem. Credit for this procedure should be shared by Bliss, Fieller, and Johnson and Neyman.
Estimation of Epidemiologic Interaction of Etiologic Factors in Biomedical Studies
Authors: Rao B. Raja 
Published: June 2010

AbstractIn the present paper, a multiple logistic model has been proposed to estimate the exposure‐specific incidence rates of several dichotomous etiologic factors from case‐control data. The relative probability of falling in a given exposure level with respect to the unexposed population for cases is expressed as a logistic function of the exposure levels (1 if exposed, 0 if not) of these factors. The odds ratio of the exposure category of cases relative to the controls comes out to be an exponential function of the exposure levels. It is shown how the maximum likelihood estimates of the logistic parameters can be obtained. The term ‘marginal effect’ of a factor is introduced. This is the effect of a factorAin the presence of one or more of other factors. The differenceSAbetween the marginal effect and the individual effect of a factorAis the increase in the effect ofAwhen it interacts with other factors. A simple relationship has been established between the Hogan et al. measure and the increasesSA,SB, … of two or more factors. Several numerical examples illustrate the results.
Robust Estimation of Relative Potency in Dilution Assays
Authors: Hill N. J. , Padmanabhan A. R. 
Published: June 2010

AbstractFor inference regarding relative potency in dilution assays with possible latent effects, a robust procedure is proposed. Monte Carlo studies show that this procedure compares favourably with known procedures. The theory is illustrated by an application to the tolerances of cats for tinctures of strophanthus.
Evaluation of the Noncentral t Distribution with S‐Systems
Authors: Voit E. O. , Rust P. F. 
Published: June 2010

AbstractDensities, cumulatives, and quantiles of the noncentral distributions are notoriously difficult to calculate. It is shown how the noncentral t distribution is represented in the canonical S‐system form, i.e., as a set of first‐order nonlinear differential equations in which the derivative of each variable equals a difference of two products of power‐law functions. By solving the S‐system numerically one rapidly obtains densities, cumulatives, quantiles, and moments of the central and noncentral t distributions, as well as power functions for the t‐test.
A Test for Bivariate Symmetry of Dependent Competing Risks
Authors: Deshpande J. V. 
Published: June 2010

AbstractIn the competing risks set up with two dependent competing risks letF(x, y)be the joint probability distribution of(X, Y), the notional times to failure under the two risks. Actual independent observations are (Ti,δi),i= 1, 2,…,nwhereTi= min (Xi, Yi) and δi=I (Xi≦ Yi). To testH0: F(x, y) = F(y, x) for allx, y, againstH1:S1(t) ≦S2(t) whereS1(t) =P(T≦t, δ = 1) andS2(t) =P(T≦t, δ = 0), it is proposed to use the Wilcoxon signed rank type statistic Jc= ∑δi(n+ 1 —Ri) whereRi= Rank (Ti) among (T1,T2, …,Tn). TheJctest is seen to be generally more efficient than the sign test except in case of alternatives under whichTand δ are independent, in which case the opposite is true.
Linearized Dentition Plot
Authors: Masuyama M. 
Published: June 2010

AbstractThe dentition is a fundamental process in life. Then the almost‐one parameter hypothesis suggests us that the individual difference would be represented by one parameter. In fact, the logarithmically transformed chronological ages Yαi at the eruption of deciduous teeth Dα are represented by a linear equation of its mean Yα.(4), where two coefficients ai, and bi are highly negatively correlated. It implies the existence of a quasi‐fixed point close to this line. See Fig. 1 and Fig. 2, where this point is denoted by a cross. This point is utilized to forecast the age at the subsequent eruption.
Comparing the Means of Two Independent Groups
Authors: Wilcox Rand R. 
Published: June 2010

AbstractRecently, CRESSIE and WHITFORD (1986) showed that Welch's test of H0 :μ1 = μ2 can be biased, under nonnormality, where μ1 and μ2 are the means of two independent treatment groups. They suggested, therefore, that a two‐sample analog of Johnson's test be used instead. One goal in this paper is to examine the extent to which a two‐sample analog of Johnson's test improves upon Welch's technique in terms of Type I errors and power when sample sizes are small or moderately large. Several alternative procedures are also considered including an additional modification of Johnson's procedure, a procedure suggested by DUNNETT (1982) that uses Tiku's modified maximum likelihood estimate with 10% trimming, two versions of Efron's bootstrap, and a test recently proposed by WILCOX (1989). The paper also describes situations where Welch's procedure is not robust in terms of Type I errors. This is important because based on results currently available, Welch's procedure is thought to be nonrobust in terms of power, but robust in terms of Type I errors.
Bias Adjustment with Polychotomous Logistic Regression in Matched Case‐Control Studies with Two Control Groups
Authors: Becher K.‐H. , Jöckel K.‐H. 
Published: June 2010

AbstractRelative risk estimation in case‐control studies is based on the premise that the control group represents the underlying population. Often more than one control group is collected in order to minimize the possibility of accepting a false result.In this paper it is assumed that a case is matched individually to two different controls and that one control group may lack representativeness with respect to some risk factors. It is discussed whether this group may be used for relative risk estimation and a polychotomous logistic regression model is suggested in which these differences between the control groups are taken into account. A practical method for model search is given.Data of two case‐control studies are used to demonstrate the method. In a simulation study its efficiency is investigated. Some computations illustrate the effect of ignoring a bias in one control group.
Estimation of Distances and Variances in Bookstein's Landmark Model
Authors: Stoyan D. 
Published: June 2010

AbstractPlanar random figures can be described by series of landmarks. Bookstein's model assumes that the landmarks result from independent individual fluctuations around fixed fictive landmark centres. The aim of this paper is to estimate the distances between the centers and the variances of fluctuations around them. Furthermore, two new shape variable estimators are suggested and compared with an estimator of Bookstein.
On the Estimation of the Nearest Neighbour Distribution, G(t), for Point Processes
Authors: Doguwa S. I. , Upton G. J. G. 
Published: June 2010

AbstractA new method is proposed for estimatingG(t), the distribution function of the distance from an object to its nearest neighbour in a spatial point process. The new method makes more complete use of the information available and has a smaller mean squared error than that of the existing alternatives. The method appears equally effective with random, clustered and regular patterns.
Estimation of the Size Distribution of Spherical Grains in the Boolean Model
Authors: Molohanov Ilya S. 
Published: June 2010

AbstractA method of strong consistent estimation of the radius' distribution of spherical grains in the Boolean model inRd,d≦3, is proposed. It is based on the evaluation of the empirical capacity functional and application of the Glivenko‐Cantelli theorem for random closed sets.
Robust Discriminant Functions in Assisting Medical Diagnosis. Application to the Chronic Obturative Lung Disease Data
Authors: Krusińska Ewa , Liebhart Jerzy 
Published: June 2010

AbstractThe results of assisting medical diagnosis in bronchial asthma and chronic bronchitis via robust discriminant functions are presented in the paper. The robust discriminant functions are obtained by replacing classical estimates of mean vectors and covariance matrices by their robust equivalents. The new methods were compared with classical ones. These methods resulted in the improvement of automatic diagnosis especially when the “new” data set was classified on the basis of individuals collected earlier.
A Generalized Logistic Model for Quantal Response Bioassay
Authors: El‐Saidi M. A. , George E. O. 
Published: June 2010

AbstractIn bioassay, where different levels of the stimulus may represent different doses of a drug, the binary response is the death or survival of an individual receiving a specified dose. In such applications, it is common to model the probability of a positive response P at the stimulus level x by P = F(x′β), where F is a cumulative distribution function and β is a vector of unknown parameters which characterize the response function. The two most popular models used for modelling binary response bioassay involve the probit model [BLISS (1935), FINNEY (1978)], and the logistic model [BERKSON (1944), BROWN (1982)]. However, these models have some limitations. The use of the probit model involves the inverse of the standard normal distribution function, making it rather intractable. The logistic model has a simple form and a closed expression for the inverse distribution function, however, neither the logistic nor the probit can provide a good fit to response functions which are not symmetric or are symmetric but have a steeper or gentler incline in the central probability region. In this paper we introduce a more realistic model for the analysis of quantal response bioassay. The proposed model, which we refer to it as the generalized logistic model, is a family of response curves indexed by shape parameters m1 and m2. This family is rich enough to include the probit and logistic models as well as many others as special cases or limiting distributions.In particular, we consider the generalized logistic three parameter model where we assume that m1 = m, m is a positive real number, and m2 = 1. We apply this model to various sets of data, comparing the fit results to those obtained previously by other dose‐response curves such as the logistic and probit, and showing that the fit can be improved by using the generalized logistic.
Anticancer and chemosensitizing abilities of cycloviolacin O2 from Viola odorata and psyle cyclotides from Psychotria leptothyrsa
Authors: Gerlach Samantha L. , Rathinakumar Ramesh , Chakravarty Geetika , Göransson Ulf , Wimley William C. , Darwin Steven P. , Mondal Debasis 
Published: June 2010

AbstractCycloviolacin O2 (CyO2), a cyclotide from Viola odorata (Violaceae) has antitumor effects and causes cell death by membrane permeabilization. In the breast cancer line, MCF‐7 and its drug resistant subline MCF‐7/ADR, the cytotoxic effects of CyO2 (0.2–10 μM) were monitored in the presence and absence of doxorubicin (0.1–5 μM) using cell proliferation assays to establish its chemosensitizing abilities. SYTOX Green assays were performed to verify membrane permeabilization and showed cellular disruption correlates with cyclotide chemosensitization. Fluorescence microscopy studies demonstrated increased cellular internalization of doxorubicin in drug resistant cells when coexposed to CyO2. Interestingly, CyO2 did not produce significant membrane disruption in primary human brain endothelial cells, which suggested cyclotide specificity toward induced pore formation in highly proliferating tumor cells. Furthermore, three novel cyclotides (psyle A, C and E) from Psychotria leptothyrsa (Rubiaceae) were also monitored for cytotoxic activity. The cyclotides displayed potent cytotoxicity (IC50 = 0.64–>10 μM), and coexposure to cyclotides significantly enhanced doxorubicin induced toxicity (IC50 = 0.39–0.76 μM). This study documents several cyclotides with robust cytotoxicity that may be promising chemosensitizing agents against drug resistant breast cancer. © 2010 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 94: 617–625, 2010.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Optimized Fmoc solid‐phase synthesis of the cysteine‐rich peptide linaclotide
Authors: Góngora‐Benítez Miriam , Tulla‐Puche Judit , Paradís‐Bas Marta , Werbitzky Oleg , Giraud Matthieu , Albericio Fernando 
Published: June 2010

AbstractLinaclotide, a small 14‐mer peptide highly rich in cysteines, is currently in phase III clinical trials for the treatment of gastrointestinal disorders. The challenge in the assembly of linaclotide consists of achieving the correct and clean folding of its three disulfide bridges. For this purpose, a number of regioselective, semiregioselective, and random strategies have been studied. In addition to selecting distinct protecting groups for the thiol function, their position in the sequence, the influence of the neighboring protecting groups, as well as the order in which the disulfides fold were studied. Here we describe an optimized solid‐phase synthesis of linaclotide that should allow the production of this peptide in multigram amounts. © 2010 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 96: 69–80, 2011.
When emotionality trumps reason: A study of individual processing style and juror bias
Authors: Gunnell Justin J. , Ceci Stephen J 
Published: June 2010

Abstract“Cognitive Experiential Self Theory” (CEST) postulates that information‐processing proceeds through two pathways, a rational one and an experiential one. The former is characterized by an emphasis on analysis, fact, and logical argument, whereas the latter is characterized by emotional and personal experience. We examined whether individuals influenced by the experiential system (E‐processors) are more susceptible to extralegal biases (e.g. defendant attractiveness) than those influenced by the rational system (R‐processors). Participants reviewed a criminal trial transcript and defendant profile and determined verdict, sentencing, and extralegal susceptibility. Although E‐processors and R‐processors convicted attractive defendants at similar rates, E‐processors were more likely to convict less attractive defendants. Whereas R‐processors did not sentence attractive and less attractive defendants differently, E‐processors gave more lenient sentences to attractive defendants and harsher sentences to less attractive defendants. E‐processors were also more likely to report that extralegal factors would change their verdicts. Further, the degree to which emotionality trumped rationality within an individual, as measured by a novel scoring method, linearly correlated with harsher sentences and extralegal influence. In sum, the results support an “unattractive harshness” effect during guilt determination, an attraction leniency effect during sentencing and increased susceptibility to extralegal factors within E‐processors. Copyright © 2010 John Wiley & Sons, Ltd.
A Novel Indirect Wollastonite Carbonation Route for CO2 Sequestration
Authors: Zhang J. , Zhang R. , Geerlings H. , Bi J. 
Published: June 2010

AbstractA new CO2 sequestration approach through indirect wollastonite carbonation is proposed to mitigate anthropogenic CO2 emissions from fossil fuel combustion. The wollastonite carbonation process includes three steps: (1) dissolution of wollastonite in hydrochloric acid to leach Ca2+ from mineral matrix; (2) reaction of the resulting CaCl2 solution with CO2 in triisooctylamine (TIOA) at low temperature, producing CaCO3 and an amino acid complex; (3) regeneration of the extractant and acid by backextraction through a temperature swing process and recycling to the dissolution and carbonation steps. It was found that the wollastonite dissolution rate was accelerated by hydrochloric acid and a maximum Ca2+ dissolution extent of 95 % was obtained.
Particle‐by‐Particle Reconstruction of Ultrafiltration Cakes in 3D from Binarized TEM Images
Authors: Bourgeois F. , Courteille F. 
Published: June 2010

AbstractTransmission electron microscopy (TEM) imaging is one of the few techniques available for direct observation of the microstructure of ultrafiltration cakes. TEM images yield local microstructural information in the form of two‐dimensional grayscale images of slices a few particle diameters in thickness. This work presents an innovative particle‐by‐particle reconstruction scheme for simulating ultrafiltration cake microstructure in three dimensions from TEM images. The scheme uses binarized TEM images, thereby permitting use of lesser‐quality images. It is able to account for short‐ and long‐range order within ultrafiltration cake structure by matching the morphology of simulated and measured microstructures at a number of resolutions and scales identifiable within the observed microstructure. In the end, simulated microstructures are intended for improving our understanding of the relationships between cake morphology, ultrafiltration performance, and operating conditions.
Identifying the Bond Responsible for the Fluorescence Modulation in an Amyloid Fibril Sensor
Authors: Srivastava Anvita , Singh Prabhat K. , Kumbhakar Manoj , Mukherjee Tulsi , Chattopadyay Subrata , Pal Haridas , Nath Sukhendu 
Published: June 2010

AbstractAn ultrafast intramolecular bond twisting process is known to be the responsible mechanism for the sensing activity of the extensively used amyloid fibril sensor thioflavin T (ThT). However, it is not yet known which one of the two possible single bonds in ThT is actually involved in the twisting process. To resolve this fundamental issue, two derivatives of ThT have been designed and synthesized and subsequently their photophysical properties have been studied in different solvents. It is understood from the present study that the rotation around the central CC single bond, and not that around the CN single bond, is primarily responsible for the sensor activity of ThT. Detailed viscosity‐dependent fluorescence studies revealed that the ThT derivative with restricted CN bond rotation acts as a better sensor than the derivative with free CN bond rotation. The better sensory activity is directly correlated with a shorter excited‐state lifetime. Results obtained from the photophysical studies of the ThT derivatives have also been supported by the results obtained from quantum chemical calculations.
Magnetic Coupling in Enantiomerically Pure Trinuclear Helicate‐Type Complexes Formed by Hierarchical Self‐Assembly
Authors: Albrecht Markus , Fiege Marcel , Kögerler Paul , Speldrich Manfred , Fröhlich Roland , Engeser Marianne 
Published: June 2010

AbstractBased on chiral, enantiomerically pure 7‐[(S)‐phenylethylurea]‐8‐hydroxyquinoline (1‐H), trinuclear helicate‐type complexes 2–5 are formed with divalent transition‐metal cations. X‐ray structural analyses reveal the connection of two monomeric complex units [M(1)3]− (M=Zn, Mn, Co, Ni) by a central metal ion to form a “dimer”. Due to the enantiopurity of the ligand, the complexes are obtained as pure enantiomers, resulting in pronounced circular dichroism (CD) spectra. Single‐ion effects and intra‐ and intermolecular coupling are observed with dominating ferromagnetic coupling in the case of the cobalt(II) and nickel(II) and dominating antiferromagnetic coupling in the case of the manganese(II) complex.
Cavity‐Shaped Ligands: Calix[4]arene‐Based Monophosphanes for Fast Suzuki–Miyaura Cross‐Coupling
Authors: Monnereau Laure , Sémeril David , Matt Dominique , Toupet Loïc 
Published: June 2010

AbstractFive conical calix[4]arenes that have a PPh2 group as the sole functional group anchored at their upper rim were assessed in palladium‐catalysed cross‐coupling reactions of phenylboronic acid with aryl halides (dioxane, 100 °C, NaH). With arylbromides, remarkably high activities were obtained with the catalytic systems remaining stable for several days. The performance of the ligands is comparable to a Buchwald‐type triarylphosphane, namely, (2′‐methyl[1,1′‐biphenyl]‐2‐yl)diphenylphosphane, which in contrast to the calixarenyl phosphanes tested may display chelating behaviour in solution. With the fastest ligand, 5‐diphenylphosphanyl‐25,26,27,28‐tetra(p‐methoxy)benzyloxy‐calix[4]arene (8), the reaction turnover frequency for the arylation of 4‐bromotoluene was 321 000 versus 214 000 mol(ArBr).mol(Pd)−1. h−1 for the reference ligand. The calixarene ligands were also efficient in Suzuki cross‐coupling reactions with aryl chlorides. Thus, by using 1 mol % of [Pd(OAc)2] associated with one of the phosphanes, full conversion of the deactivated arenes 4‐chloroanisole and 4‐chlorotoluene was observed after 16 h. The high performance of the calixarenyl–phosphanes in Suzuki–Miyaura coupling of aryl bromides possibly relies on their ability to stabilise a monoligand [Pd0L(ArBr)] species through supramolecular binding of the Pd‐bound arene inside the calixarene cavity.