Université libre de Bruxelles

About: Université libre de Bruxelles is a education organization based out in Brussels, Belgium. It is known for research contribution in the topics: Population & Breast cancer. The organization has 24974 authors who have published 56969 publications receiving 2084303 citations. The organization is also known as: ULB.

The IceCube data acquisition system: Signal capture, digitization, and timestamping

Abstract: IceCube is a km-scale neutrino observatory under construction at the South Pole with sensors both in the deep ice (InIce) and on the surface (IceTop). The sensors, called Digital Optical Modules (DOMs). detect, digitize and timestamp the signals from optical Cherenkov-radiation photons. The DOM Main Board (MB) data acquisition subsystem is connected to the central DAQ in the IceCube Laboratory (ICL) by a single twisted copper wire-pair and transmits packetized data on demand. Time calibration is maintained throughout the array by regular transmission to the DOMs of precisely timed analog signals, synchronized to a central GPS-disciplined clock. The design goals and consequent features, functional capabilities, and initial performance of the DOM MB, and the operation of a combined array of DOMs as a system, are described here. Experience with the first InIce strings and the IceTop stations indicates that the system design and performance goals have been achieved. (c) 2009 Elsevier B.V. All rights reserved.

Structural Features of Protein−Nucleic Acid Recognition Sites†

Abstract: We analyzed the atomic models of 75 X-ray structures of protein−nucleic acid complexes with the aim of uncovering common properties. The interface area measured the extent of contact between the protein and nucleic acid. It was found to vary between 1120 and 5800 A2. Despite this wide variation, the interfaces in complexes of transcription factors with double-stranded DNA could be broken up into recognition modules where 12 ± 3 nucleotides on the DNA side contact 24 ± 6 amino acids on the protein side, with interface areas in the range 1600 ± 400 A2. For enzymes acting on DNA, the recognition module is on average 600 A2 larger, due to the requirement of making an active site. As judged by its chemical and amino acid composition, the average protein surface in contact with the DNA is more polar than the solvent accessible surface or the typical protein−protein interface. The protein side is rich in positively charged groups from lysine and arginine side chains; on the DNA side the negative charges from pho...

Opening the Black Box: Structural Factor Models with Large Cross-Sections

Abstract: This paper shows how large-dimensional dynamic factor models are suitable for structural analysis. We argue that all identification schemes employed in structural vector autoregression (SVAR) analysis can be easily adapted in dynamic factor models. Moreover, the problem of fundamentalness, which is intractable in SVARs, can be solved, provided that the impulse-response functions are sufficiently heterogeneous. We provide consistent estimators for the impulse-response functions and for (n, T) rates of convergence. An exercise with U.S. macroeconomic data shows that our solution of the fundamentalness problem may have important empirical consequences. © 2009 Copyright Cambridge University Press 2009.