113 research outputs found
Toxaphene and Other Organochlorines in Arctic Ocean Fauna: Evidence for Atmospheric Delivery
Residues of the insecticide toxaphene (polychlorinated camphenes, PCCs) and other organochlorines (OCs) were determined in air, snow, seawater, zooplankton, and benthic amphipods collected from an ice island in the Canadian Arctic. The simultaneous determination of OCs in the atmospheric, hydrologic, and biologic compartments provided evidence of an atmospheric link to polar food chains. PCCs were identified and quantified using capillary gas chromatography - negative ion mass spectrometry. The order of OCs abundance in arctic air was: hexachlorocyclohexanes (HCHs) > hexachlorobenzene > PCCs > polychlorinated biphenyls (PCBs) > chlordanes > DDTs. In seawater, PCCs were exceeded only by the HCHs. Concentrations of PCBs and PCCs in two samples of benthic amphipods were the highest of the OCs detected.Key words: Arctic, Canada, pollution, organochlorines, air, water, biotaMots clés: Arctique, Canada, pollution, organochlorés, air, eau, biot
A Mechanism-Based Explanation of the Institutionalization of Semantic Technologies in the Financial Industry
Part 3: Creating Value through ApplicationsInternational audienceThis paper explains how the financial industry is solving its data, risk management, and associated vocabulary problems using semantic technologies. The paper is the first to examine this phenomenon and to identify the social and institutional mechanisms being applied to socially construct a standard common vocabulary using ontology-based models. This standardized ontology-based common vocabulary will underpin the design of next generation of semantically-enabled information systems (IS) for the financial industry. The mechanisms that are helping institutionalize this common vocabulary are identified using a longitudinal case study, whose embedded units of analysis focus on central agents of changeâthe Enterprise Data Management Council and the Object Management Group. All this has important implications for society, as it is intended that semantically-enabled IS will, for example, provide stakeholders, such as regulators, with better transparency over systemic risks to national and international financial systems, thereby mitigating or avoiding future financial crises
Participatory action research in two communities in Bolivia and the United States
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66665/2/10.1177_002087289203500214.pd
Sensitivity of the IceCube Detector to Astrophysical Sources of High Energy Muon Neutrinos
We present the results of a Monte-Carlo study of the sensitivity of the
planned IceCube detector to predicted fluxes of muon neutrinos at TeV to PeV
energies. A complete simulation of the detector and data analysis is used to
study the detector's capability to search for muon neutrinos from sources such
as active galaxies and gamma-ray bursts. We study the effective area and the
angular resolution of the detector as a function of muon energy and angle of
incidence. We present detailed calculations of the sensitivity of the detector
to both diffuse and pointlike neutrino emissions, including an assessment of
the sensitivity to neutrinos detected in coincidence with gamma-ray burst
observations. After three years of datataking, IceCube will have been able to
detect a point source flux of E^2*dN/dE = 7*10^-9 cm^-2s^-1GeV at a 5-sigma
significance, or, in the absence of a signal, place a 90% c.l. limit at a level
E^2*dN/dE = 2*10^-9 cm^-2s^-1GeV. A diffuse E-2 flux would be detectable at a
minimum strength of E^2*dN/dE = 1*10^-8 cm^-2s^-1sr^-1GeV. A gamma-ray burst
model following the formulation of Waxman and Bahcall would result in a 5-sigma
effect after the observation of 200 bursts in coincidence with satellite
observations of the gamma-rays.Comment: 33 pages, 13 figures, 6 table
On the selection of AGN neutrino source candidates for a source stacking analysis with neutrino telescopes
The sensitivity of a search for sources of TeV neutrinos can be improved by
grouping potential sources together into generic classes in a procedure that is
known as source stacking. In this paper, we define catalogs of Active Galactic
Nuclei (AGN) and use them to perform a source stacking analysis. The grouping
of AGN into classes is done in two steps: first, AGN classes are defined, then,
sources to be stacked are selected assuming that a potential neutrino flux is
linearly correlated with the photon luminosity in a certain energy band (radio,
IR, optical, keV, GeV, TeV). Lacking any secure detailed knowledge on neutrino
production in AGN, this correlation is motivated by hadronic AGN models, as
briefly reviewed in this paper.
The source stacking search for neutrinos from generic AGN classes is
illustrated using the data collected by the AMANDA-II high energy neutrino
detector during the year 2000. No significant excess for any of the suggested
groups was found.Comment: 43 pages, 12 figures, accepted by Astroparticle Physic
Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study
A41 Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study
In: Addiction Science & Clinical Practice 2017, 12(Suppl 1): A4
Highly-parallelized simulation of a pixelated LArTPC on a GPU
The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype
Piping by queens of Apis cerana Fabricius 1793 and Apis koschevnikovi v Buttel-Reepen 1906
Piping queens of Apis cerana and A koschevnikovi were recorded in Sabah, Malaysia. The tooting calls of the 2 species were similar and consisted of a single continuous call lasting 2-5 s. In contrast, A mellifera queens give a 1-2 s tone followed by several shorter tones. Quacking by an A koschevnikovi queen in a queen cell was very similar to the quacking reported for A mellifera except the tempo was more rapid (4.39 quacks/s vs 3.0 quacks/s)
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