Image Classification for Age-related Macular Degeneration Screening Using Hierarchical Image Decompositions and Graph Mining

Age-related Macular Degeneration (AMD) is the most common cause of adult blindness in the developed world. This paper describes a new image mining technique to perform automated detection of AMD from color fundus photographs. The technique comprises a novel hierarchical image decomposition mechanism founded on a circular and angular partitioning. The resulting decomposition is then stored in a tree structure to which a weighted frequent sub-tree mining algorithm is applied. The identified sub-graphs are then incorporated into a feature vector representation (one vector per image) to which classification techniques can be applied. The results show that the proposed approach performs both efficiently and accurately

International nosocomial infection control consortium (INICC) report, data summary of 36 countries, for 2004-2009

The results of a surveillance study conducted by the International Nosocomial Infection Control Consortium (INICC) from January 2004 through December 2009 in 422 intensive care units (ICUs) of 36 countries in Latin America, Asia, Africa, and Europe are reported. During the 6-year study period, using Centers for Disease Control and Prevention (CDC) National Healthcare Safety Network (NHSN; formerly the National Nosocomial Infection Surveillance system [NNIS]) definitions for device-associated health care-associated infections, we gathered prospective data from 313,008 patients hospitalized in the consortium's ICUs for an aggregate of 2,194,897 ICU bed-days. Despite the fact that the use of devices in the developing countries' ICUs was remarkably similar to that reported in US ICUs in the CDC's NHSN, rates of device-associated nosocomial infection were significantly higher in the ICUs of the INICC hospitals; the pooled rate of central line-associated bloodstream infection in the INICC ICUs of 6.8 per 1,000 central line-days was more than 3-fold higher than the 2.0 per 1,000 central line-days reported in comparable US ICUs. The overall rate of ventilator-associated pneumonia also was far higher (15.8 vs 3.3 per 1,000 ventilator-days), as was the rate of catheter-associated urinary tract infection (6.3 vs. 3.3 per 1,000 catheter-days). Notably, the frequencies of resistance of Pseudomonas aeruginosa isolates to imipenem (47.2% vs 23.0%), Klebsiella pneumoniae isolates to ceftazidime (76.3% vs 27.1%), Escherichia coli isolates to ceftazidime (66.7% vs 8.1%), Staphylococcus aureus isolates to methicillin (84.4% vs 56.8%), were also higher in the consortium's ICUs, and the crude unadjusted excess mortalities of device-related infections ranged from 7.3% (for catheter-associated urinary tract infection) to 15.2% (for ventilator-associated pneumonia). Copyright © 2012 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved

Multi-scale AM-FM for lesion phenotyping

Age-related macular degeneration (AMD) is the most common cause of visual loss in the United States and is a growing public health problem. The presence and severity of AMD in current epidemiological studies is detected by the grading of color stereoscopic fundus photographs. The purpose of this study was to show that a mathematical technique, amplitude-modulation frequency modulation (AM-FM) can be used to generate multi-scale features for classifying pathological structures, such as drusen, on a retinal image. AM-FM features were calculated for N=120 40times40 regions from 5 retinal images presenting with age-related macular degeneration. The results show that with this technique, drusen can be differenced from normal retinal structures by more than three standard deviations using the AM-FM histograms. In addition, by using different color spaces highly accurate classification of structures of the retina is achieved. These results are the first step in the development of an automated AMD grading system

Measurement of the photon beam asymmetry in γ - p→K+ ς0 at Eγ=8.5 GeV

We report measurements of the photon beam asymmetry ς for the reaction γ - p→K+ς0(1193) using the GlueX spectrometer in Hall D at Jefferson Lab. Data were collected by using a linearly polarized photon beam in the energy range of 8.2-8.8 GeV incident on a liquid hydrogen target. The beam asymmetry ς was measured as a function of the Mandelstam variable t, and a single value of ς was extracted for events produced in the u channel. These are the first exclusive measurements of the photon beam asymmetry ς for the reaction in this energy range. For the t channel, the measured beam asymmetry is close to unity over the t range studied, -t=(0.1-1.4)(GeV/c)2, with an average value of ς=1.00±0.05. This agrees with theoretical models that describe the reaction via the natural-parity exchange of the K∗(892) Regge trajectory. A value of ς=0.41±0.09 is obtained for the u channel integrated up to -u=2.0 (GeV/c)2. © 2020 American Physical Society

Measurement of beam asymmetry for π- Δ++ photoproduction on the proton at Eγ=8.5 GeV

We report a measurement of the π- photoproduction beam asymmetry for the reaction γp→π-Δ++ using data from the GlueX experiment in the photon beam energy range 8.2-8.8 GeV. The asymmetry ς is measured as a function of four-momentum transfer t to the Δ++ and compared to phenomenological models. We find that ς varies as a function of t: negative at smaller values and positive at higher values of |t|. The reaction can be described theoretically by t-channel particle exchange requiring pseudoscalar, vector, and tensor intermediaries. In particular, this reaction requires charge exchange, allowing us to probe pion exchange and the significance of higher-order corrections to one-pion exchange at low momentum transfer. Constraining production mechanisms of conventional mesons may aid in the search for and study of unconventional mesons. This is the first measurement of the process at this energy. © 2021 American Physical Society

Beam asymmetry ς for the photoproduction of η and η′ mesons at Eγ=8.8 GeV

We report on the measurement of the beam asymmetry ς for the reactions γ - p→pη and γ - p→pη′ from the GlueX experiment using an 8.2-8.8-GeV linearly polarized tagged photon beam incident on a liquid hydrogen target in Hall D at Jefferson Laboratory. These measurements are made as a function of momentum transfer -t with significantly higher statistical precision than our earlier η measurements and are the first measurements of η′ in this energy range. We compare the results to theoretical predictions based on t-channel quasiparticle exchange. We also compare the ratio of ςη to ςη′ to these models as this ratio is predicted to be sensitive to the amount of ss exchange in the production. We find that photoproduction of both η and η′ is dominated by natural parity exchange with little dependence on -t. © 2019 American Physical Society

First Measurement of Near-Threshold J /ψ Exclusive Photoproduction off the Proton

We report on the measurement of the γp→J/ψp cross section from Eγ=11.8 GeV down to the threshold at 8.2 GeV using a tagged photon beam with the GlueX experiment. We find that the total cross section falls toward the threshold less steeply than expected from two-gluon exchange models. The differential cross section dσ/dt has an exponential slope of 1.67±0.39 GeV-2 at 10.7 GeV average energy. The LHCb pentaquark candidates Pc+ can be produced in the s channel of this reaction. We see no evidence for them and set model-dependent upper limits on their branching fractions B(Pc+→J/ψp) and cross sections σ(γp→Pc+)×B(Pc+→J/ψp). © 2019 American Physical Society

Search for photoproduction of axionlike particles at GlueX

We present a search for axionlike particles, a, produced in photon-proton collisions at a center-of-mass energy of approximately 4 GeV, focusing on the scenario where the a-gluon coupling is dominant. The search uses a→γγ and a→π+π-π0 decays, and a data sample corresponding to an integrated luminosity of 168 pb-1 collected with the GlueX detector. The search for a→γγ decays is performed in the mass range of 180<ma<480 MeV, while the search for a→π+π-π0 decays explores the 600<ma<720 MeV region. No evidence for a signal is found, and 90% confidence-level exclusion limits are placed on the a-gluon coupling strength. These constraints are the most stringent to date over much of the mass ranges considered. © 2022 authors. Published by the American Physical Society

The GlueX beamline and detector

The GlueX experiment at Jefferson Lab has been designed to study photoproduction reactions with a 9-GeV linearly polarized photon beam. The energy and arrival time of beam photons are tagged using a scintillator hodoscope and a scintillating fiber array. The photon flux is determined using a pair spectrometer, while the linear polarization of the photon beam is determined using a polarimeter based on triplet photoproduction. Charged-particle tracks from interactions in the central target are analyzed in a solenoidal field using a central straw-tube drift chamber and six packages of planar chambers with cathode strips and drift wires. Electromagnetic showers are reconstructed in a cylindrical scintillating fiber calorimeter inside the magnet and a lead-glass array downstream. Charged particle identification is achieved by measuring energy loss in the wire chambers and using the flight time of particles between the target and detectors outside the magnet. The signals from all detectors are recorded with flash ADCs and/or pipeline TDCs into memories allowing trigger decisions with a latency of 3.3 . The detector operates routinely at trigger rates of 40 kHz and data rates of 600 megabytes per second. We describe the photon beam, the GlueX detector components, electronics, data-acquisition and monitoring systems, and the performance of the experiment during the first three years of operation