Relaxing the Gaussian assumption in Shrinkage and SURE in high dimension

Shrinkage estimation is a fundamental tool of modern statistics, pioneered by Charles Stein upon the discovery of his famous paradox. Despite a large subsequent literature, the efficiency of shrinkage, and the associated procedure known as Stein's Unbiased Risk Estimate, or SURE, has mainly been analysed in the Gaussian setting. Importing tools developed for use in the probabilistic area now known as Stein's method, the present work investigates the domain of validity of shrinkage and SURE away from the Gaussian. We show that shrinkage is efficient away from the Gaussian under very mild conditions on the distribution of the noise. SURE is also proved to be adaptive under similar assumptions, and in particular in a way that retains the classical asymptotics of Pinsker's theorem. Notably, shrinkage and SURE are shown to be efficient under mild distributional assumptions

Les inscriptions du temps sur les cadrans solaires

La sociologie temporaliste ne s’est guère intéressée à l’épigraphie du cadran solaire. Nous tentons de réparer cette lacune en montrant que les devises constituent de précieuses archives pour la recherche sur les temporalités. Après une brève présentation du cadran solaire, de son évolution historique et de son utilité sociale, nous abordons la question des devises en comparant les usages gnomoniques aux règles de l’emblématique. L’étude empirique porte sur un volumineux recueil, constitué au début du XXe siècle, par un collectionneur français (Boursier, 1936). L’analyse de ce corpus par la méthode Alceste débouche sur une catégorisation des données en deux, puis quatre classes de signification, qui témoignent toutes d’une « sensibilité au temps ». Celle-ci s’exprime à travers un jeu de postures, renvoyant face à face un énonciateur qui ordonne le temps et un allocutaire qui le subit, non sans déploration. Cette mise en scène de l’information, où les rôles majeurs sont tenus par la divinité et le sujet humain, nous amène à conclure sur le théocentrisme des devises anciennes, et, conséquemment, sur les traces du religieux dans la représentation du temps.Temporal sociology has not taken much interest in the epigraphy of sundials. We are attempting to redress this lack by showing that mottoes constitute precious archives for research into temporalities. Following a short presentation of sundials, their historic evolution and their social utility, we approach the question of mottoes by comparing gnomonic usage to emblematic rules. The empiric study is based on a voluminous collection, made up at the start of the 20th century, by a French collector (Boursier, 1936). The analysis of this corpus by the Alceste method leads to a categorisation of the data into at first two and then four classes of significance, which all bear witness to a ‘sensitivity to time’. This is expressed through a game of postures, bringing face to face an enunciator who orders time and a speaker who suffers this, not without deploring it. This staging of information, where the major roles are taken by divinity and a human subject, lead us to conclude on the theocentricity of the ancient mottoes, and consequently, on the traces of religion found in the representation of time

Serum vitamin D levels of patients with oral squamous cell carcinoma (OSCC) and expression of vitamin D receptor in oral precancerous lesions and OSCC

Background: Resistance to programmed cell death (apoptosis) is a crucial factor for the carcinogenesis of oral squamous cell carcinoma (OSCC). Vitamin D (calcitriol) may overcome apoptosis resistance in tumor cells of OSCC. Vitamin D receptor (VDR) expression in oral precancerous lesions of OSCC has not been analyzed and serum vitamin D level seems to be a predictor of cancer development. Material and Methods: Expression of VDR was analyzed in normal oral mucosa (n=5), oral precursor lesions (simple hyperplasia, n=11; squamous intraepithelial neoplasia, SIN I-III, n=35), and OSCC specimen (n=42) by immunohistochemistry (IHC). Moreover, serum vitamin D levels were measured by 25(OH)D3 (calcidiol) in patients with OSCC (n=42) and correlated with IHC results. Results: Expression of VDR was significantly increased in precancerous and OSCC compared with normal tissue. Compared with SIN I-III lesions VDR expression significantly decreased in OSCC. Severe vitamin D deficiency was detected in our OSCC patient cohort but there was no significant correlation analyzed between serum vitamin D levels and corresponding immunohistochemically detected VDR expression in OSCC. Conclusions: Our survey provides the first evidence of VDR expression in precancerous lesions of OSCC. Apoptosis induction of VDR+ cells in oral precancerous lesions and OSCC by natural vitamin D or synthetic vitamin D compounds could be useful for chemoprevention. Moreover, systemically and/or locally applied, these compounds may act as sensitizers for apoptosis mediated by radio-, and chemotherapy treatment in OSCC

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

Computational strategies to combat COVID-19: useful tools to accelerate SARS-CoV-2 and coronavirus research

SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) is a novel virus of the family Coronaviridae. The virus causes the infectious disease COVID-19. The biology of coronaviruses has been studied for many years. However, bioinformatics tools designed explicitly for SARS-CoV-2 have only recently been developed as a rapid reaction to the need for fast detection, understanding and treatment of COVID-19. To control the ongoing COVID-19 pandemic, it is of utmost importance to get insight into the evolution and pathogenesis of the virus. In this review, we cover bioinformatics workflows and tools for the routine detection of SARS-CoV-2 infection, the reliable analysis of sequencing data, the tracking of the COVID-19 pandemic and evaluation of containment measures, the study of coronavirus evolution, the discovery of potential drug targets and development of therapeutic strategies. For each tool, we briefly describe its use case and how it advances research specifically for SARS-CoV-2. All tools are free to use and available online, either through web applications or public code repositories.Peer Reviewe

Processus catégorique et co-construction des sujets et des mondes à travers l'analyse statitique de différents corpus

International audienc

Quelques interrogations à propos de l' "objet" d'une analyse de discours de type statistique et de la réponse "Alceste"

REINERT Max - What can be the meaning of a statistical discourse analysis ? In this article, the creator of Alceste tries to show in what way his method is in the line of Jean-Paul Benzécri's Harris-type approach and in what way it departs from it. He first describes the propositional model that led Benzécri to envisage tables of a "Subjets x Predicates" sort. He then attempts to extend the notion of logical propositions, which reflect a state of things, to a more pragmatic unit of discourse (with a marked reference to the work of Charles Sanders Peirce). Finally, he presents the hypotheses which are at the basis of his own method of splitting up a corpus into "context units" ("unités de contexte").Dans cet article, le créateur d'Alceste essaie de montrer en quoi sa méthode se situe en continuité avec ce qu'il appelle l'approche Harissienne de Jean-Paul Benzécri et en quoi elle s'en démarque. Il évoque d'abord le modèle propositionnel qui a conduit Benzécri à s'intéresser à des tableaux de données du type "sujets x prédicats". Il tente ensuite d'élargir la notion de proposition logique, reflet d'un état de chose, à une unité de discours plus pragmatique (avec une référence marquée aux travaux de Charles Sanders Peirce) pour enfin présenter ses propres hypothèses à la base de sa méthode de découpage du corpus en "unités de contexte".Max Reinert. Quelques interrogations à propos de l' "objet" d'une analyse de discours de type statistique et de la réponse "Alceste". In: Langage et société, n°90, 1999. pp. 57-70