First Characterization of the Ultra-Shielded Chamber in the Low-noise Underground Laboratory (LSBB) of Rustrel Pays d'Apt

In compliance with international agreements on nuclear weapons limitation, the French ground-based nuclear arsenal has been decommissioned in its totality. One of its former underground missile control centers, located in Rustrel, 60 km east of Avignon (Provence) has been converted into the ``Laboratoire Souterrain \`a Bas Bruit de Rustrel-Pays d'Apt'' (LSBB). The deepest experimental hall (500 m of calcite rock overburden) includes a 100 m$^{2}$ area of sturdy flooring suspended by and resting on shock absorbers, entirely enclosed in a 28 m-long, 8 m-diameter, 1 cm-thick steel Faraday cage. This results in an unparalleled combination of shielding against cosmic rays, acoustic, seismic and electromagnetic noise, which can be exploited for rare event searches using ultra low-temperature and superconducting detectors. The first characterization measurements in this unique civilian site are reported. For more info see http://home.cern.ch/collar/RUSTREL/rustrel.htmlComment: Homepage and quoted hyperlinks have been updated: see http://home.cern.ch/collar/RUSTREL/rustrel.htm

First Results from the HDMS experiment in the Final Setup

The Heidelberg Dark Matter Search (HDMS) is an experiment designed for the search for WIMP dark matter. It is using a special configuration of Ge detectors, to efficiently reduce the background in the low-energy region below 100 keV. After one year of running the HDMS detector prototype in the Gran Sasso Underground Laboratory, the inner crystal of the detector has been replaced with a HPGe crystal of enriched $^{73}$Ge. The final setup started data taking in Gran Sasso in August 2000. The performance and the first results of the measurement with the final setup are discussed.Comment: 8 pages, revtex, 7 figures, Home Page of Heidelberg Non-Accelerator Particle Physics Group: http://www.mpi-hd.mpg.de/non_acc

On the relation between Differential Privacy and Quantitative Information Flow

Differential privacy is a notion that has emerged in the community of statistical databases, as a response to the problem of protecting the privacy of the database's participants when performing statistical queries. The idea is that a randomized query satisfies differential privacy if the likelihood of obtaining a certain answer for a database $x$ is not too different from the likelihood of obtaining the same answer on adjacent databases, i.e. databases which differ from $x$ for only one individual. Information flow is an area of Security concerned with the problem of controlling the leakage of confidential information in programs and protocols. Nowadays, one of the most established approaches to quantify and to reason about leakage is based on the R\'enyi min entropy version of information theory. In this paper, we analyze critically the notion of differential privacy in light of the conceptual framework provided by the R\'enyi min information theory. We show that there is a close relation between differential privacy and leakage, due to the graph symmetries induced by the adjacency relation. Furthermore, we consider the utility of the randomized answer, which measures its expected degree of accuracy. We focus on certain kinds of utility functions called "binary", which have a close correspondence with the R\'enyi min mutual information. Again, it turns out that there can be a tight correspondence between differential privacy and utility, depending on the symmetries induced by the adjacency relation and by the query. Depending on these symmetries we can also build an optimal-utility randomization mechanism while preserving the required level of differential privacy. Our main contribution is a study of the kind of structures that can be induced by the adjacency relation and the query, and how to use them to derive bounds on the leakage and achieve the optimal utility

Neutralizing monoclonal antibodies define two different functional sites in human interleukin-4

Human interleukin-4 (IL-4) is a small four-helix-bundle protein which is essential for organizing defense reactions against macroparasites, in particular helminths. Human IL-4 also appears to exert a pathophysiological role during various IgE-mediated allergic diseases. Seven different monoclonal antibodies neutralizing the activity of human IL-4 were studied in order to identify functionally important epitopes. A collection of 41 purified IL-4 variants was used to analyse how defined amino acid replacements affect binding affinity for each individual mAb. Specific amino acid positions could be assigned to four different epitopes. mAbs recognizing epitopes on helix A and/or C interfered with IL-4 receptor binding and thus inhibited IL-4 function. However, other mAbs also inhibiting IL-4 function recognized an epitope on helix D of IL-4 and did not inhibit IL-4 binding to the receptor protein. One mAb, recognizing N-terminal and C-terminal residues, partially competed for binding to the receptor. The results of these mAb epitope analyses confirm and extend previous data on the functional consequences of the amino acid replacements which showed that amino acid residues in helices A and C of IL-4 provide a binding site for the cloned IL-4 receptor and that a signalling site in helix D interacts with a further receptor protein

Large scale Gd-beta-diketonate based organic liquid scintillator production for antineutrino detection

Over the course of several decades, organic liquid scintillators have formed the basis for successful neutrino detectors. Gadolinium-loaded liquid scintillators provide efficient background suppression for electron antineutrino detection at nuclear reactor plants. In the Double Chooz reactor antineutrino experiment, a newly developed beta-diketonate gadolinium-loaded scintillator is utilized for the first time. Its large scale production and characterization are described. A new, light yield matched metal-free companion scintillator is presented. Both organic liquids comprise the target and "Gamma Catcher" of the Double Chooz detectors.Comment: 16 pages, 4 figures, 5 table

Large scale Gd-beta-diketonate based organic liquid scintillator production for antineutrino detection

Over the course of several decades, organic liquid scintillators have formed the basis for successful neutrino detectors. Gadolinium-loaded liquid scintillators provide efficient background suppression for electron antineutrino detection at nuclear reactor plants. In the Double Chooz reactor antineutrino experiment, a newly developed beta-diketonate gadolinium-loaded scintillator is utilized for the first time. Its large scale production and characterization are described. A new, light yield matched metal-free companion scintillator is presented. Both organic liquids comprise the target and "Gamma Catcher" of the Double Chooz detectors.Comment: 16 pages, 4 figures, 5 table

Large scale Gd-beta-diketonate based organic liquid scintillator production for antineutrino detection

Over the course of several decades, organic liquid scintillators have formed the basis for successful neutrino detectors. Gadolinium-loaded liquid scintillators provide efficient background suppression for electron antineutrino detection at nuclear reactor plants. In the Double Chooz reactor antineutrino experiment, a newly developed beta-diketonate gadolinium-loaded scintillator is utilized for the first time. Its large scale production and characterization are described. A new, light yield matched metal-free companion scintillator is presented. Both organic liquids comprise the target and "Gamma Catcher" of the Double Chooz detectors.Comment: 16 pages, 4 figures, 5 table

Physiological Phenomenology of Neurally-Mediated Syncope with Management Implications

BACKGROUND: Due to lack of efficacy in recent trials, current guidelines for the treatment of neurally-mediated (vasovagal) syncope do not promote cardiac pacemaker implantation. However, the finding of asystole during head-up tilt -induced (pre)syncope may lead to excessive cardioinhibitory syncope diagnosis and treatment with cardiac pacemakers as blood pressure is often discontinuously measured. Furthermore, physicians may be more inclined to implant cardiac pacemakers in older patients. We hypothesized that true cardioinhibitory syncope in which the decrease in heart rate precedes the fall in blood pressure is a very rare finding which might explain the lack of efficacy of pacemakers in neurally-mediated syncope. METHODS: We studied 173 consecutive patients referred for unexplained syncope (114 women, 59 men, 42 ± 1 years, 17 ± 2 syncopal episodes). All had experienced (pre)syncope during head-up tilt testing followed by additional lower body negative suction. We classified hemodynamic responses according to the modified Vasovagal Syncope International Study (VASIS) classification as mixed response (VASIS I), cardioinhibitory without (VASIS IIa) or with asystole (VASIS IIb), and vasodepressor (VASIS III). Then, we defined the exact temporal relationship between hypotension and bradycardia to identify patients with true cardioinhibitory syncope. RESULTS: Of the (pre)syncopal events during tilt testing, 63% were classified as VASIS I, 6% as VASIS IIb, 2% as VASIS IIa, and 29% as VASIS III. Cardioinhibitory responses (VASIS class II) progressively decreased from the youngest to the oldest age quartile. With more detailed temporal analysis, blood pressure reduction preceded the heart-rate decrease in all but six individuals (97%) overall and in 10 out of 11 patients with asystole (VASIS IIb). CONCLUSIONS: Hypotension precedes bradycardia onset during head-up tilt-induced (pre)syncope in the vast majority of patients, even in those classified as cardioinhibitory syncope according to the modified VASIS classification. Furthermore, cardioinhibitory syncope becomes less frequent with increasing age