A Study of a Mini-drift GEM Tracking Detector

A GEM tracking detector with an extended drift region has been studied as part of an effort to develop new tracking detectors for future experiments at RHIC and for the Electron Ion Collider that is being planned for BNL or JLAB. The detector consists of a triple GEM stack with a small drift region that was operated in a mini TPC type configuration. Both the position and arrival time of the charge deposited in the drift region were measured on the readout plane which allowed the reconstruction of a short vector for the track traversing the chamber. The resulting position and angle information from the vector could then be used to improve the position resolution of the detector for larger angle tracks, which deteriorates rapidly with increasing angle for conventional GEM tracking detectors using only charge centroid information. Two types of readout planes were studied. One was a COMPASS style readout plane with 400 micron pitch XY strips and the other consisted of 2x10mm2 chevron pads. The detector was studied in test beams at Fermilab and CERN, along with additional measurements in the lab, in order to determine its position and angular resolution for incident track angles up to 45 degrees. Several algorithms were studied for reconstructing the vector using the position and timing information in order to optimize the position and angular resolution of the detector for the different readout planes. Applications for large angle tracking detectors at RHIC and EIC are also discussed.Comment: Submitted to the IEEE Transactions on Nuclear Scienc

Reconstrucción tridimensional de la musculatura F-actina de Dorvillea kastjani (Dorvilleidae: Polychaeta) por medio de marcado con phalloidina y cLSM

This paper is part of a series investigating the muscular architecture of various “Polychaeta”, aiming to ascertain the presence of circular muscles in the body wall, which have recently been thought to be lacking more often than hitherto known. The F-actin muscular subset of Dorvillea kastjani was labelled with phalloidin and the architecture three-dimensionally reconstructed by means of confocal laser scanning microscopy. Three pairs of longitudinal, two transverse and numerous radial muscles ensure shape and flexibility of the prostomium. Mobility of the sub-biramous parapodia and their chaetae is achieved by seven different muscle types. The body wall contains transverse and bracing muscles and in total five longitudinal muscle strands: two dorsolateral, two ventral and one ventromedial. Numerous transverse fibres extend from the dorsal side peripherally and ventrally and become concentrated into six or seven pairs of bundles per segment on the ventral side. They terminate before reaching the midline, leaving a gap of only a few micrometres between them. Within the intersegmental furrows these fibres form complete rings in a supralongitudinal postion. Thus, true circular fibres exist in D. kastjani but are weakly developed.Este trabajo forma parte de una serie de trabajos que investigan la arquitectura muscular de diferentes especies de Poliquetos con el objetivo de comprobar la presencia de musculatura circular en su cuerpo; recientemente se piensa que dicha musculatura podría estar ausente más a menudo de lo hasta ahora pensado. La musculatura F-actina de Dorvillea kastjani fue marcada con phalloidina y su arquitectura reconstruida tridimensionalmente por medio de microscopia de scanning laser confocal. Tres pares longitudinales, dos tranversales y numerosos músculos radiales aseguran la flexibilidad y la forma del prostómio. La mobilidad de los parápodos sub-biramios y sus quetas se obtiene gracias a siete diferentes tipos de músculos. La cavidad del cuerpo contiene musculos tranversales y diagonales y en total cinco ramas de músculos longitudinales: dos dorsolaterales, dos ventrales y una medioventral. Numerosas fibras transversales se extienden desde la zona dorsal periféricamente y centralmente y se concentran en seis o siete pares de paquetes por segmento en la cara ventral. Estos terminan antes de alcanzar la línea central dejando un vacio de unas micras entre ellos. Entre los surcos entre segmentos, las fibras forman anillos completos en una posición supralongitudinal. Además, verdaderas fibras circulares existen en Dorvillea kastjani pero están débilmente desarrolladas. &nbsp

Quenching and Tomography from RHIC to LHC

We compare fully perturbative and fully nonperturbative pictures of high-pT energy loss calculations to the first results from LHC. While over-suppressed compared to published ALICE data, parameter-free pQCD predictions based on the WHDG energy loss model constrained to RHIC data simultaneously describe well the preliminary CMS hadron suppression, ATLAS charged hadron v2, and ALICE D meson suppression; we also provide for future reference WHDG predictions for B meson RAA. However, energy loss calculations based on AdS/CFT also qualitatively describe well the RHIC pion and non-photonic electron suppression and LHC charged hadron suppression. We propose the double ratio of charm to bottom quark RAA will qualitatively distinguish between these two energy loss pictures.Comment: 4 pages, 3 figures. Proceedings for Quark Matter 201

A new fireworm (Amphinomidae) from the Cretaceous of Lebanon identified from three-dimensionally preserved myoanatomy

© 2015 Parry et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. The attached file is the published version of the article