Two-loop cusp anomaly in ABJM at strong coupling

We compute the null cusp anomalous dimension of ABJM theory at strong coupling up to two-loop order. This is done by evaluating corrections to the corresponding superstring partition function, weighted by the AdS 4 × ℂℙ3 action in AdS light-cone gauge. We compare our result, where we use an anomalous shift in the AdS 4 radius, with the cusp anomaly of N = 4 SYM, and extract the two-loop contribution to the non-trivial integrable coupling h(λ) of ABJM theory. It coincides with the strong coupling expansion of the exact expression for h(λ) recently conjectured by Gromov and Sizov. Our work provides thus a non-trivial perturbative check for the latter, as well as evidence for two-loop UV-finiteness and quantum integrability of the Type IIA AdS 4 × ℂℙ3 superstring in this gauge

Influence of Jpeg coding on image descriptors

We present in this paper an experimental study on robustness of main image descriptors regarding to the Jpeg coding noise . We particularly introduce some results concerning histograms and differential characteristics of a given image . This study is a preliminary work of our team in the context of content-based indexation of images and videos .Cet article propose une étude expérimentale de la robustesse des principaux descripteurs d'images par rapport aux distorsions introduites par le codage Jpeg. Tout particulièrement, nous présentons les résultats obtenus pour les histogrammes et les éléments différentiels d'une image. Cette étude est préliminaire à nos travaux sur l'indexation d'images et de vidéo1

Document segmentation by interest areas detection

This paper presents a new approach of document structuring by the description of a foveated vision system implied in extracting visual and eye-catching information of a document . The simulation system is based on psycho-perceptive rules for visual data capturing. It allows us to obtain a representation of segmented document by using simple low-level processing . The low-level process is based on a visual integrative memory which displays the unequal importance of information in the visual field . The resulting segmentation enhances the fact that the access of information is directly linked to the search of attractive areas . The technical approach of the segmentation (using a space-variant geometry and a multiresolution process) lays a sound basis for elaborating the kinetic of the ocular displacement on a document. It provides not only a document representation in blocks, but shows a unified view corresponding to the integration of time-variant representations of the same visual field . The resulting blocks (text, graphs, image) are determined and localized all the better, such that the number of fixation points increases and yields a more complete and detailed description of components .Cette étude présente une nouvelle approche de la structuration de documents imprimés basée sur l'exploitation de la dynamique du regard dans le repérage de l'information. Le système qui a été mis en place nous permet d'obtenir une représentation du document segmenté en faisant appel à des procédures d'extraction de primitives géométriques simples (traitements de bas niveau) relevant de la prise en compte de certains comportements caractéristiques chez l'homme dans l'extraction d'information. Il utilise une série de représentations de type multirésolution du document où la nature du sous-échantillonnage est une fonction de la position du regard. Cette approche est basée sur la recherche des zones de focalisation de l'attention permettant de conserver une description précise des éléments dans les zones de fixation, tout en résumant les régions présentant un « intérêt » moindre. La simulation du parcours de l'oeil sur le document que nous avons retenue traduit la segmentation que ferait un lecteur qui aborde le document sans a priori sur ce qu'il veut trouver. Pour cela, nous nous sommes inspirés d'une stratégie exploratoire particulière : le survol. Celle-ci s'appuie essentiellement sur l'aspect visuel du document, c'est-à-dire sur les caractéristiques visuelles de bas niveau de l'image. Elle permet en outre une perception équilibrée des données en privilégiant l'organisation globale du document. La technique mise en oeuvre s'appuie sur un partitionnement évolutif de l'espace, en zones centrées aux points de fixation successifs. C'est sur la base de ce partitionnement, que la description des différentes régions ciblées du document évolue et converge vers une représentation segmentée

The NIKA2 instrument, a dual-band kilopixel KID array for millimetric astronomy

NIKA2 (New IRAM KID Array 2) is a camera dedicated to millimeter wave astronomy based upon kilopixel arrays of Kinetic Inductance Detectors (KID). The pathfinder instrument, NIKA, has already shown state-of-the-art detector performance. NIKA2 builds upon this experience but goes one step further, increasing the total pixel count by a factor $\sim$10 while maintaining the same per pixel performance. For the next decade, this camera will be the resident photometric instrument of the Institut de Radio Astronomie Millimetrique (IRAM) 30m telescope in Sierra Nevada (Spain). In this paper we give an overview of the main components of NIKA2, and describe the achieved detector performance. The camera has been permanently installed at the IRAM 30m telescope in October 2015. It will be made accessible to the scientific community at the end of 2016, after a one-year commissioning period. When this happens, NIKA2 will become a fundamental tool for astronomers worldwide.Comment: Proceedings of the 16th Low Temperature Detectors workshop. To be published in the Journal of Low Temperature Physics. 8 pages, 4 figures, 1 tabl

Muon-induced background in the EDELWEISS dark matter search

A dedicated analysis of the muon-induced background in the EDELWEISS dark matter search has been performed on a data set acquired in 2009 and 2010. The total muon flux underground in the Laboratoire Souterrain de Modane (LSM) was measured to be $\Phi_{\mu}=(5.4\pm 0.2 ^{+0.5}_{-0.9})$\,muons/m$^2$/d. The modular design of the muon-veto system allows the reconstruction of the muon trajectory and hence the determination of the angular dependent muon flux in LSM. The results are in good agreement with both MC simulations and earlier measurements. Synchronization of the muon-veto system with the phonon and ionization signals of the Ge detector array allowed identification of muon-induced events. Rates for all muon-induced events $\Gamma^{\mu}=(0.172 \pm 0.012)\, \rm{evts}/(\rm{kg \cdot d})$ and of WIMP-like events $\Gamma^{\mu-n} = 0.008^{+0.005}_{-0.004}\, \rm{evts}/(\rm{kg \cdot d})$ were extracted. After vetoing, the remaining rate of accepted muon-induced neutrons in the EDELWEISS-II dark matter search was determined to be $\Gamma^{\mu-n}_{\rm irred} < 6\cdot 10^{-4} \, \rm{evts}/(\rm{kg \cdot d})$ at 90%\,C.L. Based on these results, the muon-induced background expectation for an anticipated exposure of 3000\,\kgd\ for EDELWEISS-3 is $N^{\mu-n}_{3000 kg\cdot d} < 0.6$ events.Comment: 21 pages, 16 figures, Accepted for publication in Astropart. Phy

Consultancy-Based Projects

This chapter will:; ; ; Show how consultancy work can inform business discourse teaching;; ; ; Discuss how needs analysis and communication audits can be used to generate recommendations for teaching and training;; ; ; Profile a number of consultancy-based business discourse projects and show how they have informed training and course development;; ; ; Provide a case study, together with a set of tasks appropriate for the business discourse classroom, and a set of further readings

A siRNA-Based Screen for Genes Involved in Chromosome End Protection

Telomeres are nucleoprotein complexes which protect the ends of linear chromosomes from detection as DNA damage and provide a sequence buffer against replication-associated shortening. In mammals, telomeres consist of repetitive DNA sequence (TTAGGG) and associated proteins. The telomeric core complex is called shelterin and is comprised of the proteins TRF1, TRF2, POT1, TIN2, TPP1 and RAP1. Excessive telomere shortening or de-protection of telomeres through the loss of shelterin subunits allows the detection of telomeres as DNA damage, which can be visualized as DNA damage protein foci at chromosome ends called TIF (Telomere Dysfunction-Induced Foci). We sought to exploit the TIF phenotype as marker for telomere dysfunction to identify novel genes involved in telomere protection by siRNA-mediated knock-down of a set of 386 candidates. Here we report the establishment, specificity and feasibility of such a screen and the results of the genes tested. Only one of the candidate genes showed a unique TIF phenotype comparable to the suppression of the main shelterin components TRF2 or TRF1 and that gene was identified as a TRF1-like pseudogene. We also identified a weak TIF phenotype for SKIIP (SNW1), a splicing factor and transcriptional co-activator. However, the knock-down of SKIIP also induced a general, not telomere-specific DNA damage response, which complicates conclusions about a telomeric role. In summary, this report is a technical demonstration of the feasibility of a cell-based screen for telomere deprotection with the potential of scaling it to a high-throughput approach

Variations in the mineral content of bottled 'carbonated or sparkling' water across Europe : a comparison of 126 brands across 10 countries

Kidney stone disease is a common disease with high recurrence rates. Sufficient intake of water is the cornerstone in primary prevention of stone disease. However, the mineral composition of water can affect urinary minerals and influence stone formation. The aim of this study is to assess the variation in the mineral composition of bottled sparkling or carbonated drinking water across Europe. The two largest supermarket chains in each participating country were visited to obtain data on mineral composition regarding bicarbonate, calcium, magnesium, potassium, sodium and sulphates of sparkling or carbonated waters by reading the ingredient labels on the bottles supplied by the manufacturers. Alternatively, the web-shops of these supermarkets were consulted. In total, 126 sparkling water brands across ten European countries were analysed regarding mineral composition. The median concentrations per mineral varied greatly. The greatest variation in median mineral content was found for sodium and sulphates with levels ranging from 3.1 mg/l to 63.0 mg/l and 6.0 mg/l to 263.0 mg/l respectively. A wide distribution of calcium content was found in Switzerland, with calcium levels reaching up to 581.6 mg/l. This study confirms that the mineral composition of sparkling or carbonated water varies greatly across Europe. Patients with kidney stone disease should be aware that the mineral content of water may influence stone formation and be mindful of the great variation that exists between different water brands. Mineral water can be a source of potential promotors or inhibitors of stone formation and patients and urologists need to be mindful of this