First results on light readout from the 1-ton ArDM liquid argon detector for dark matter searches

ArDM-1t is the prototype for a next generation WIMP detector measuring both the scintillation light and the ionization charge from nuclear recoils in a 1-ton liquid argon target. The goal is to reach a minimum recoil energy of 30\,keVr to detect recoiling nuclei. In this paper we describe the experimental concept and present results on the light detection system, tested for the first time in ArDM on the surface at CERN. With a preliminary and incomplete set of PMTs, the light yield at zero electric field is found to be between 0.3-0.5 phe/keVee depending on the position within the detector volume, confirming our expectations based on smaller detector setups.Comment: 14 pages, 10 figures, v2 accepted for publication in JINS

Data-based analysis of speech and gesture: the Bielefeld Speech and Gesture Alignment corpus (SaGA) and its applications

Lücking A, Bergmann K, Hahn F, Kopp S, Rieser H. Data-based analysis of speech and gesture: the Bielefeld Speech and Gesture Alignment corpus (SaGA) and its applications. Journal on Multimodal User Interfaces. 2013;7(1-2):5-18.Communicating face-to-face, interlocutors frequently produce multimodal meaning packages consisting of speech and accompanying gestures. We discuss a systematically annotated speech and gesture corpus consisting of 25 route-and-landmark-description dialogues, the Bielefeld Speech and Gesture Alignment corpus (SaGA), collected in experimental face-to-face settings. We first describe the primary and secondary data of the corpus and its reliability assessment. Then we go into some of the projects carried out using SaGA demonstrating the wide range of its usability: on the empirical side, there is work on gesture typology, individual and contextual parameters influencing gesture production and gestures’ functions for dialogue structure. Speech-gesture interfaces have been established extending unification-based grammars. In addition, the development of a computational model of speech-gesture alignment and its implementation constitutes a research line we focus on

Condensation of zinc vapor in a supersonic carrier gas

A study of the condensation of a metal vapor in an inert carrier gas is made. Superheated zinc vapor is generated in a hot shot wind tunnel in a helium carrier gas and expanded in a converging-diverging nozzle. Static pressure measurements along the length of the nozzle are made to determine the location of the onset of condensation. A conical nominal Mach 5 (helium) nozzle is employed. The amount of supercooling before the onset of condensation is found to be approximately 430 K, measured along the isentrope over a range of initial zinc mass fractions of .35 to .70 for saturation partial pressures of zinc between 10 psia and 70 psia. The measurements are compared with results of an analysis based on the classical liquid drop model of nucleation. The computed results agree reasonably well with the measurements.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41794/1/10494_2004_Article_BF00382286.pd

VLPs and particle strategies for cancer vaccines

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A point mutation in Euglena gracilis chloroplast tRNA(Glu) uncouples protein and chlorophyll biosynthesis.

The universal precursor of tetrapyrrole pigments (e.g., chlorophylls and hemes) is 5-aminolevulinic acid (ALA), which in Euglena gracilis chloroplasts is derived via the two-step C5 pathway from glutamate charged to tRNA(Glu). The first enzyme in this pathway, Glu-tRNA reductase (GluTR) catalyzes the reduction of glutamyl-tRNA(Glu) (Glu-tRNA) to glutamate 1-semialdehyde (GSA) with the release of the uncharged tRNA(Glu). The second enzyme, GSA-2,1-aminomutase, converts GSA to ALA. tRNA(Glu) is a specific cofactor for the NADPH-dependent reduction by GluTR, an enzyme that recognizes the tRNA in a sequence-specific manner. This RNA is the normal tRNA(Glu), a dual-function molecule participating both in protein and in ALA and, hence, chlorophyll biosynthesis. A chlorophyll-deficient mutant of E. gracilis (Y9ZNalL) does not synthesize ALA from glutamate, although it contains GluTR and GSA-2,1-aminomutase activity. The tRNA(Glu) isolated from the mutant can still be acylated with glutamate in vitro and in vivo. Furthermore, it supports chloroplast protein synthesis; however, it is a poor substrate for GluTR. Sequence analysis of the tRNA and of its gene revealed a C56-->U mutation in the resulting gene product. C56 is therefore an important identity element for GluTR. Thus, a point mutation in the T loop of tRNA uncouples protein from chlorophyll biosynthesis