201 research outputs found
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Performance of the CDF Silicon VerteX detector
The current status of the online and offline performance of the CDF Silicon VerteX detector is presented. So far, at low radiation dose, the device delivers good quality data. After the latest alignment using collision data, a spatial resolution of 13 pm is achieved in the transverse plane, demonstrating that CDF has a powerful tool to detect b decay vertices
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The method of Laplace Transform MultiQuadrics (LTMQ) for the solution of the groundwater flow equation
This paper presents a new numerical method, the Laplace Transform MultiQuadrics (LTMQ) method, developed for the solution of the diffusion-type parabolic Partial Differential Equation (PDE) of fluid flow through porous media. LTMQ combines a MultiQuadrics (MQ) approximation scheme with a Laplace transform formulation. The use of MQ in the spatial approximations allows the accurate description of problems in complex porous media with a very limited number of nodes. The Laplace transform formulation eliminates the need for time discretization, thus allowing an unlimited time step size without any loss of accuracy. LTMQ is tested against results from three test problems of groundwater flow obtained from a standard Finite Difference (FD) model, as well as from analytical solutions. An excellent agreement between the LTMQ and the analytical and FD solutions is observed, while significant reductions in computer execution times may be achieved
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Automatic lighting controls demonstration: Long-term results
An advanced electronically ballasted lighting control system was installed in a portion of an office building to measure the energy and demand savings. The lighting control system used an integrated lighting control scenario that included daylight following, lumen depreciation correction, and scheduling. The system reduced lighting energy on weekdays by 62% and 51% in the north and south daylit zones, respectively, compared to a reference zone that did not have controls. During the summer, over 75% energy savings were achieved on weekdays in the north daylit zone. Even in the south interior zone, which benefitted lime from daylight, correction strategies and adjustment of the aisleway lights to a low level resulted in energy use of only half that of the reference zone. Although, in general, the savings varied over the year due to changing daylight conditions, the energy reduction achieved with controls could be fit using a simple analytical model. Significant savings also occurred during core operating hours when it is more expensive to supply and use energy. Compared to the usage in the reference zone, energy reductions of 49%, 44%, and 62% were measured in the south daylight, south interior, and north daylight zones, respectively, during core operating hours throughout the year. Lighting energy usage on weekends decreased dramatically in the zones with controls, with the usage in the north daylit zone only 10% that of the reference zone. A simple survey developed to assess occupant response to the lighting control system showed that the occupants were satisfied with the light levels provided
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Surface structures and surface-atom vibrations determined using photoelectron diffraction
Surface structures of {radical}3 {times} {radical}3 R30{degrees} Cl/Ni(111) and c(2 {times} 2)Cl/Cu(001) were determined using low- temperature angle-resolved photoemission extended fine structure (ARPEFS), which yields both more accurate surface and near-surface structural information for deeper substrate layers. A study of surface-atom vibrations for {radical}3 {times} {radical}3 R30{degrees} Cl/Ni(111) and c(2 {times} 2)Cl/Cu(001) was made using temperature-dependent ARPEFS. A model for predicting the adsorbate vibrational anisotropy from surface structures was proposed and also successfully applied to several adsorbate systems. This model offered a simple and straightforward physical picture for understanding different types of vibrational anisotropy
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Detection of fragments arising from >10 GeV electron-nucleus collisions
Much is understood about the interaction of both high energy electrons with nucleons and lower energy electrons with nucleons and nuclei. Although a number of experiments involving high energy inelastic scattering of electrons from quarks bound in nuclei have been performed, many interpretations of the data are still discussed. A project called PEGASYS was conceived at PEP to further investigate this physics. Unfortunately, the termination of PEP operations curtailed this experiment and much of the physics remains unexplored. In this paper we present some details of one proposed part of this project (tagged nuclear structure functions) and some considerations made in designing a detector suitable for observing very low momentum nuclear fragements around a cold-cluster gas target
Improved prognostic classification of breast cancer defined by antagonistic activation patterns of immune response pathway modules.
BACKGROUND: Elucidating the activation pattern of molecular pathways across a given tumour type is a key challenge necessary for understanding the heterogeneity in clinical response and for developing novel more effective therapies. Gene expression signatures of molecular pathway activation derived from perturbation experiments in model systems as well as structural models of molecular interactions ("model signatures") constitute an important resource for estimating corresponding activation levels in tumours. However, relatively few strategies for estimating pathway activity from such model signatures exist and only few studies have used activation patterns of pathways to refine molecular classifications of cancer. METHODS: Here we propose a novel network-based method for estimating pathway activation in tumours from model signatures. We find that although the pathway networks inferred from cancer expression data are highly consistent with the prior information contained in the model signatures, that they also exhibit a highly modular structure and that estimation of pathway activity is dependent on this modular structure. We apply our methodology to a panel of 438 estrogen receptor negative (ER-) and 785 estrogen receptor positive (ER+) breast cancers to infer activation patterns of important cancer related molecular pathways. RESULTS: We show that in ER negative basal and HER2+ breast cancer, gene expression modules reflecting T-cell helper-1 (Th1) and T-cell helper-2 (Th2) mediated immune responses play antagonistic roles as major risk factors for distant metastasis. Using Boolean interaction Cox-regression models to identify non-linear pathway combinations associated with clinical outcome, we show that simultaneous high activation of Th1 and low activation of a TGF-beta pathway module defines a subtype of particularly good prognosis and that this classification provides a better prognostic model than those based on the individual pathways. In ER+ breast cancer, we find that simultaneous high MYC and RAS activity confers significantly worse prognosis than either high MYC or high RAS activity alone. We further validate these novel prognostic classifications in independent sets of 173 ER- and 567 ER+ breast cancers. CONCLUSION: We have proposed a novel method for pathway activity estimation in tumours and have shown that pathway modules antagonize or synergize to delineate novel prognostic subtypes. Specifically, our results suggest that simultaneous modulation of T-helper differentiation and TGF-beta pathways may improve clinical outcome of hormone insensitive breast cancers over treatments that target only one of these pathways.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
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An interface configuration experiment on USML-1
Experiments were carried out for exotic'' rotationally symmetric containers aboard the first NASA United States Microgravity Laboratory Space Shuttle flight (USML-1). The containers have the property that they admit an entire continuum of distinct equilibrium rotationally-symmetric capillary free-surfaces for a given liquid volume and contact angle. It was found, after the containers were filled in orbit, that an initial equilibrium interface from the symmetric continuum reoriented, when perturbed, to a stable interface that was not rotationally symmetric, as predicted by the mathematical theory
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SDC solenoidal detector notes: Jets in the forward region
We examine jet shapes in the forward region, {eta}(jet) > 4, of 40 TeV proton-proton collisions and compare them with 90{degree} jets. In the laboratory, forward jets are Lorentz contracted into thin disks.'' For example, a jet which at {theta}{sub cm}(jet) = 90{degree} would have its particles located within a cone'' with angular widths {Delta}{theta}{sub cm} = {Delta}{phi} = 28{degree} (i.e., 0.5 radians), if boosted'' to {eta}(jet) = 4 ({theta}{sub cm} = 2{degree}) becomes a disk'' with an angular width of {Delta}{theta}{sub cm} = 1{degree} Jet shapes are roughly invariant when plotted versus pseudorapidity, {eta}, and azimuthal angle, {phi}. In addition, we examine how well the electromagnetic component (i.e., photons and electrons) of a jet tracks'' the true position of the jet
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Boiling and condensation processes in the Cerro Prieto beta reservoir under exploitation
The deep Cerro Prieto (Baja California, Mexico) beta reservoir is offset vertically by the southwest-northeast trending, normal H fault. Under exploitation pressures in the upthrown block have decreased strongly resulting in boiling and high-enthalpy production fluids. Significant differences in fluid chemical and isotopic compositions are observed in the two parts of the reservoir and particularly in an anomalous zone associated with the H fault. These differences result from intense boiling and adiabatic steam condensation, as well as from leakage of overlying cooler water along the fault
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Pion interferometry and resonances in pp and AA collisions
We study the sensitivity of pion interferometry in {bar p}p and {bar p}p collisions at ISR energies to the resonance abundance. We show that those data are not compatible with the full resonance fractions predicted by the Lund model. The preliminary S+S and O+Au data at 200 GeV are, however, not incompatible with the Lund predictions, although their sensitivity to resonances is significantly weaker than in the pp/{bar p}p case
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