Multiple points of the Brownian sheet in critical dimensions

It is well known that an $N$-parameter $d$-dimensional Brownian sheet has no $k$-multiple points when $(k-1)d>2kN$, and does have such points when $(k-1)d<2kN$. We complete the study of the existence of $k$-multiple points by showing that in the critical cases where $(k-1)d=2kN$, there are a.s. no $k$-multiple points.Comment: Published at http://dx.doi.org/10.1214/14-AOP912 in the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org

Concert recording 2018-03-06

[Track 1]. Songs of longing and desire, op. 156. I. Gift [Track 2]. II. Having Left [Track 3]. III. America / Bradley A. Bombardier text by Jonathan Dallas -- [Track 4]. Die Lebendigen und die Todten. I. Die Todten [Track 5]. II. Die Lebendigen / Robert K. Mueller -- [Track 6]. String quartet, no. 4. I. Flowing [Track 7]. II. Moderato [Track 8]. III. Scherzo-adagietto [Track 9]. IV. Cortege / Bombardier -- [Track 10]. Flowers of heaven. I. The home village [Track 11]. II. Wildflowers of the mountain [Track 12]. III. Return to heaven / Mueller -- [Track 13]. Into the lion\u27s den / Bombardier -- [Track 14]. A still small voice. I. Wind [Track 15]. II. Quake [Track 16]. III. Fire / Mueller

Lawrence K. Williams

[Excerpt] In 1952, Professor Williams graduated cum laude from Tufts University. He received his Masters Degree in 1954 from the University Illinois. In 1960, he earned a PhD in psychology from the University of Michigan. Professor Williams served in the U.S. Army from 1954-56, and worked as a research psychologist. In 1961 he came to Cornell University as an assistant professor, and became a full professor in 1969. When he retired in 1999, his colleagues awarded him an emeritus professorship. During his long career, Professor Williams served for a period as chairman of the Department of Organizational Behavior and for 25 years was the director of graduate studies for the school of Industrial and Labor Relations. He served on the committees of over 250 graduate students and was chairman for more than 70 students. He was also one of the founders and directors of GOALS, a foundation to support under represented minority graduate students in Human Resources and Industrial Relations. Professor Williams was also a Fulbright scholar in Peru during 1967-72

Polarization Elements-A Group Theoretical Study

The Classification of Polarization elements, the polarization affecting optical devices which have a Jones matrix representation, according to the types of eigenvectors they possess, is given a new visit through the Group-theoretical connection of polarization elements. The diattenuators and retarders are recognized as the elements corresponding to boosts and rotations respectively. The structure of homogeneous elements other than diattenuators and retarders are identified by giving the quaternion corresponding to these elements. The set of degenerate polarization elements is identified with the so called `null' elements of the Lorentz Group. Singular polarization elements are examined in their more illustrative Mueller matrix representation and finally the eigenstructure of a special class of singular Mueller matrices is studied.Comment: 7 pages, 2 tables, submitted to `Optics Communications

Reversibility of Arctic Sea Ice Retreat - A Multi-Scale Modeling Approach

Arctic summer sea ice has been retreating rapidly over past decade. Climate model projections show further retreat under typical forcing scenarios. The mode of the retreat is a matter of debate. Low-order models show reversible and irreversible retreat depending on the shape of the albedo parametrization. Climate models do not show irreversible sea ice losses, but generally underestimate the current trend of retreat

Adaptive kNN using Expected Accuracy for Classification of Geo-Spatial Data

The k-Nearest Neighbor (kNN) classification approach is conceptually simple - yet widely applied since it often performs well in practical applications. However, using a global constant k does not always provide an optimal solution, e.g., for datasets with an irregular density distribution of data points. This paper proposes an adaptive kNN classifier where k is chosen dynamically for each instance (point) to be classified, such that the expected accuracy of classification is maximized. We define the expected accuracy as the accuracy of a set of structurally similar observations. An arbitrary similarity function can be used to find these observations. We introduce and evaluate different similarity functions. For the evaluation, we use five different classification tasks based on geo-spatial data. Each classification task consists of (tens of) thousands of items. We demonstrate, that the presented expected accuracy measures can be a good estimator for kNN performance, and the proposed adaptive kNN classifier outperforms common kNN and previously introduced adaptive kNN algorithms. Also, we show that the range of considered k can be significantly reduced to speed up the algorithm without negative influence on classification accuracy

Évaluation de l’activité antibactérienne des extraits de feuilles de Solanum torvum Swartz (Solanaceae) sur la croissance in vitro de 3 souches d’entérobactéries

Objectif: Établir des bases scientifiques de l’action antibactérienne de Solanum torvum Swartz (Solanaceae), une plante médicinale utilisée en médecine traditionnelle contre les infections bactériennes.Méthodologie et Résultats: Les extraits issus de cette plante ont été testés sur la croissance in vitro des souches de E. coli, de K. pneumoniae et de Salmonella sp en milieu liquide et solide de Mueller-Hinton. Les résultats ont révélé que ces extraits ont une activité antibactérienne dose-dépendante sur ces souches bactériennes utilisées. Cependant, l’extrait acétonique 100% a un meilleur potentiel antibactérien sur la souche de E. coli (CMI = 6,25 mg/mL et CMB = 1,563 mg/mL) que sur c el l e d e Salmonella sp (CMI = 3,125 mg/mL et CMB = 6,25 mg/mL) et de K. pneumoniae (CMI = 6,25 mg/mL et CMB = 12,5 mg/mL).Conclusion et application des résultats: Cet extrait peut être utilisé pour la mise au point de phytomédicaments contre les gastroentérites à E. coli et à Salmonella sp.Mots clés: Antibactérienne, extraits, Solanum torvum, in vitro, gastroentéritesEnglish AbstractObjective: Establish scientific bases of the antibacterial action of Solanum torvum Swartz (Solanaceae), a medicinal plant used in traditional medicine against the bacterial infections.Methodology and Results: The extracts resulting from this plant were tested on in vitro growth of the stocks of E. coli, K. pneumoniae and Salmonella sp in Mueller-Hinton broth and Mueller-Hinton naehrboden agar. The results have revealed that these extracts have dose-dependent action against bacteria targeted. However, the 100% acetonic extract has a better antibacterial potential on the stock of E. coli (MIC = 6.25 mg/mL and MBC = 1.563 mg/mL) than on Salmonella sp (MIC = 3.125 mg/mL and MBC = 6.25 mg/mL) and of K. pneumoniae (MIC = 6.25 mg/mL and MBC = 12.5 mg/mL).Conclusion and application of the results: This extract can be used to formulate a drug against the gastroenteritis with E. coli and Salmonella sp.Keywords: Antibacterial, extracts, Solanum torvum, in vitro, gastroenteriti

Mueller matrix differential decomposition for direction reversal: application to samples measured in reflection and backscattering

Mueller matrix differential decomposition is a novel method for analyzing the polarimetric properties of optical samples. It is performed through an eigenanalysis of the Mueller matrix and the subsequent decomposition of the corresponding differential Mueller matrix into the complete set of 16 differential matrices which characterize depolarizing anisotropic media. The method has been proposed so far only for measurements in transmission configuration. In this work the method is extended to the backward direction. The modifications of the differential matrices according to the reference system are discussed. The method is successfully applied to Mueller matrices measured in reflection and backscattering