The Role of Language in Ethnic Identity Measurement: A Multitrait-Multimethod Approach to Construct Validation

The authors focused on the role of language use in measuring ethnic identity. They demonstrated the construct validity of a 3-dimensional measure and examined potential biases introduced by alternative methods such as constant sum scale. Their findings support the distinction between the 3 subdimensions of language use (English use in family, in media consumption, and while shopping). The authors found evidence of discriminant validity. By using 3 approaches to construct validity, they found that the support for discriminant validity strengthens the discriminant and convergent properties of the instrument. Findings concerning method effects were less obvious. If the traditional multitrait-multimethod approach indicates no method effects, more stringent approaches (e.g., analysis of variance and correlated uniqueness approach) indicate the presence of limited method effects. The authors provide implications regarding measurement of ethnic identity

Galectin-4 and sulfatides in apical membrane trafficking in enterocyte-like cells

We have previously reported that 1-benzyl-2-acetamido-2-deoxy-α-d-galactopyranoside (GalNAcα-O-bn), an inhibitor of glycosylation, perturbed apical biosynthetic trafficking in polarized HT-29 cells suggesting an involvement of a lectin-based mechanism. Here, we have identified galectin-4 as one of the major components of detergent-resistant membranes (DRMs) isolated from HT-29 5M12 cells. Galectin-4 was also found in post-Golgi carrier vesicles. The functional role of galectin-4 in polarized trafficking in HT-29 5M12 cells was studied by using a retrovirus-mediated RNA interference. In galectin-4–depleted HT-29 5M12 cells apical membrane markers accumulated intracellularly. In contrast, basolateral membrane markers were not affected. Moreover, galectin-4 depletion altered the DRM association characteristics of apical proteins. Sulfatides with long chain-hydroxylated fatty acids, which were also enriched in DRMs, were identified as high-affinity ligands for galectin-4. Together, our data propose that interaction between galectin-4 and sulfatides plays a functional role in the clustering of lipid rafts for apical delivery

Estimation for the distribution function of one- and two-dimensional censored variables or sojourn times of Markov renewal processes

International audienceSelf-consistency equations are established for the distribution functions of right- and left-censored one- and two-dimensional variables and sojourn times of a Markov renewal process. They have a unique solution that equals the product-limit estimator if a hazard function may be defined. Under right-censoring, the results presented here provide new formulations of known estimators. If the left- and right-censoring times are dependent, no estimators were available and simple algorithms are defined. All the estimators are Vn-consistent and converge weakly to centered Gaussian processe

Estimations AND Tests IN Change-Point Models Introduction

International audienc

Estimation and tests in finite mixture models of nonparametric densities

The aim is to study the asymptotic behavior of estimators and tests for the components of identifiable finite mixture models of nonparametric densities with a known number of components. Conditions for identifiability of the mixture components and convergence of identifiable parameters are given. The consistency and weak convergence of the identifiable parameters and test statistics are presented for several models

Change-points in the mean

International audienceThis chapter studies models with change-point in the mean of a real variable at an unknown threshold or at an unknown sampling index. We first consider the empirical estimators and the least squares estimator of the change-point then the maximum like-lihood with a known or unknown density, their convergence rates are established. Tests for the hypothesis of a constant mean are de fined by the same methods. The weak convergence of the estimators and the test statistics under the hypothesis and alternatives are proved