374 research outputs found
Search Tracker: Human-derived object tracking in-the-wild through large-scale search and retrieval
Humans use context and scene knowledge to easily localize moving objects in
conditions of complex illumination changes, scene clutter and occlusions. In
this paper, we present a method to leverage human knowledge in the form of
annotated video libraries in a novel search and retrieval based setting to
track objects in unseen video sequences. For every video sequence, a document
that represents motion information is generated. Documents of the unseen video
are queried against the library at multiple scales to find videos with similar
motion characteristics. This provides us with coarse localization of objects in
the unseen video. We further adapt these retrieved object locations to the new
video using an efficient warping scheme. The proposed method is validated on
in-the-wild video surveillance datasets where we outperform state-of-the-art
appearance-based trackers. We also introduce a new challenging dataset with
complex object appearance changes.Comment: Under review with the IEEE Transactions on Circuits and Systems for
Video Technolog
The HERMES Dual-Radiator Ring Imaging Cerenkov Detector
The construction and use of a dual radiator Ring Imaging Cerenkov(RICH)
detector is described. This instrument was developed for the HERMES experiment
at DESY which emphasizes measurements of semi-inclusive deep-inelastic
scattering. It provides particle identification for pions, kaons, and protons
in the momentum range from 2 to 15 GeV, which is essential to these studies.
The instrument uses two radiators, C4F10, a heavy fluorocarbon gas, and a wall
of silica aerogel tiles. The use of aerogel in a RICH detector has only
recently become possible with the development of clear, large homogeneous and
hydrophobic aerogel. A lightweight mirror was constructed using a newly
perfected technique to make resin-coated carbon-fiber surfaces of optical
quality. The photon detector consists of 1934 photomultiplier tubes for each
detector half, held in a soft steel matrix to provide shielding against the
residual field of the main spectrometer magnet.Comment: 25 pages, 23 figure
HER2 testing in breast cancer: Opportunities and challenges
Human epidermal growth factor receptor 2 (HER2) is overexpressed in 15-25% of breast cancers, usually as a result of HER2 gene amplification. Positive HER2 status is considered to be an adverse prognostic factor. Recognition of the role of HER2 in breast cancer growth has led to the development of anti-HER2 directed therapy, with the humanized monoclonal antibody trastuzumab (Herceptin (R)) having been approved for the therapy of HER2-positive metastatic breast cancer. Clinical studies have further suggested that HER2 status can provide important information regarding success or failure of certain hormonal therapies or chemotherapies. As a result of these developments, there has been increasing demand to perform HER2 testing on current and archived breast cancer specimens. This article reviews the molecular background of HER2 function, activation and inhibition as well as current opinions concerning its role in chemosensitivity and interaction with estrogen receptor biology. The different tissue-based assays used to detect HER2 amplification and overexpression are discussed with respect to their advantages and disadvantages, when to test (at initial diagnosis or pre-treatment), where to test (locally or centralized) and the need for quality assurance to ensure accurate and valid testing results
The ATLAS3D project - XXVII : Cold gas and the colours and ages of early-type galaxies
Date of Acceptance: 16/12/2013We present a study of the cold gas contents of the ATLAS3D early-type galaxies, in the context of their optical colours, near-ultraviolet colours and Hβ absorption line strengths. Early-type (elliptical and lenticular) galaxies are not as gas poor as previously thought, and at least 40 per cent of local early-type galaxies are now known to contain molecular and/or atomic gas. This cold gas offers the opportunity to study recent galaxy evolution through the processes of cold gas acquisition, consumption (star formation) and removal. Molecular and atomic gas detection rates range from 10 to 34 per cent in red sequence early-type galaxies, depending on how the red sequence is defined, and from 50 to 70 per cent in blue early-type galaxies. Notably, massive red sequence early-type galaxies (stellar masses >5 × 1010 M⊙, derived from dynamical models) are found to have H I masses up to M(H I)/M* ∼ 0.06 and H2 masses up to M(H2)/M* ∼ 0.01. Some 20 per cent of all massive early-type galaxies may have retained atomic and/or molecular gas through their transition to the red sequence. However, kinematic and metallicity signatures of external gas accretion (either from satellite galaxies or the intergalactic medium) are also common, particularly at stellar masses ≤5 × 1010 M⊙, where such signatures are found in ∼50 per cent of H2-rich early-type galaxies. Our data are thus consistent with a scenario in which fast rotator early-type galaxies are quenched former spiral galaxies which have undergone some bulge growth processes, and in addition, some of them also experience cold gas accretion which can initiate a period of modest star formation activity. We discuss implications for the interpretation of colour–magnitude diagramsPeer reviewedFinal Accepted Versio
Managing deliberate self-harm in young people: An evaluation of a training program developed for school welfare staff using a longitudinal research design
BACKGROUND: Although deliberate self-harm is prevalent among young people, many who engage in deliberate self-harm receive sub-optimal care. Although schools are a well placed setting to support young people who engage in self-harm there are no specific training packages designed to assist school welfare staff to support these young people.The current study aimed to design, deliver and evaluate a training course specifically for school staff. METHODS: The study employed a longitudinal design. Two hundred and thirteen people participated in the training and evaluation. A questionnaire was administered at baseline, immediately after the training and at 6-month follow-up in order to determine if the training led to improvements in confidence when working with young people who self-harm, perceived skill, knowledge of, and attitudes towards people who self harm. RESULTS: Prior to the course, the majority of participants demonstrated relatively high levels of confidence, perceived skill and knowledge of self-harm and endorsed relatively positive attitudes towards people who engage in self-harm. Despite this, significant improvements were observed in terms of increased confidence, increased perceptions of skill along with increased knowledge of deliberate self-harm. These improvements were sustained over the follow-up period. CONCLUSION: The results demonstrated that the provision of specifically designed training can help school welfare staff to feel better equipped to support young people who are engaging in deliberate self-harm
Oscillations of neutrinos and mesons in quantum field theory
This report deals with the quantum field theory of particle oscillations in
vacuum. We first review the various controversies regarding quantum-mechanical
derivations of the oscillation formula, as well as the different
field-theoretical approaches proposed to settle them. We then clear up the
contradictions between the existing field-theoretical treatments by a thorough
study of the external wave packet model. In particular, we show that the latter
includes stationary models as a subcase. In addition, we explicitly compute
decoherence terms, which destroy interferences, in order to prove that the
coherence length can be increased without bound by more accurate energy
measurements. We show that decoherence originates not only in the width and in
the separation of wave packets, but also in their spreading through space-time.
In this review, we neither assume the relativistic limit nor the stability of
oscillating particles, so that the oscillation formula derived with
field-theoretical methods can be applied not only to neutrinos but also to
neutral K and B mesons. Finally, we discuss oscillations of correlated
particles in the same framework.Comment: v2, 124 pages, 10 figures (7 more); updated review of the literature;
complete derivation of the oscillation probability at short and large
distance; more details on the influence of the spreading of the amplitude on
decoherence; submitted to Physics Report
Measurement of the Proton Spin Structure Function g1p with a Pure Hydrogen Target
A measurement of the proton spin structure function g1p(x,Q^2) in
deep-inelastic scattering is presented. The data were taken with the 27.6 GeV
longitudinally polarised positron beam at HERA incident on a longitudinally
polarised pure hydrogen gas target internal to the storage ring. The kinematic
range is 0.021<x<0.85 and 0.8 GeV^2<Q^2<20 GeV^2. The integral
Int_{0.021}^{0.85} g1p(x)dx evaluated at Q0^2 of 2.5 GeV^2 is
0.122+/-0.003(stat.)+/-0.010(syst.).Comment: 7 pages, 3 figures, 1 table, RevTeX late
Measurement of the Neutron Radius of 208Pb Through Parity-Violation in Electron Scattering
We report the first measurement of the parity-violating asymmetry A_PV in the
elastic scattering of polarized electrons from 208Pb. A_PV is sensitive to the
radius of the neutron distribution (Rn). The result A_PV = 0.656 \pm 0.060
(stat) \pm 0.014 (syst) ppm corresponds to a difference between the radii of
the neutron and proton distributions Rn - Rp = 0.33 +0.16 -0.18 fm and provides
the first electroweak observation of the neutron skin which is expected in a
heavy, neutron-rich nucleus.Comment: 6 pages, 1 figur
Double-Spin Asymmetry in the Cross Section for Exclusive rho^0 Production in Lepton-Proton Scattering
Evidence for a positive longitudinal double-spin asymmetry = 0.24
+-0.11 (stat) +-0.02 (syst) in the cross section for exclusive diffractive
rho^0(770) vector meson production in polarised lepton-proton scattering was
observed by the HERMES experiment. The longitudinally polarised 27.56 GeV HERA
positron beam was scattered off a longitudinally polarised pure hydrogen gas
target. The average invariant mass of the photon-proton system has a value of
= 4.9 GeV, while the average negative squared four-momentum of the virtual
photon is = 1.7 GeV^2. The ratio of the present result to the
corresponding spin asymmetry in inclusive deep-inelastic scattering is in
agreement with an early theoretical prediction based on the generalised vector
meson dominance model.Comment: 10 pages, 4 embedded figures, LaTe
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