1,099 research outputs found
A Detailed Monte-Carlo Simulation for the Belle TOF System
We have developed a detailed Monte Carlo simulation program for the Belle TOF
system. Based on GEANT simulation, it takes account of all physics processes in
the TOF scintillation counters and readout electronics. The simulation
reproduces very well the performance of the Belle TOF system, including the
dE/dx response, the time walk effect, the time resolution, and the hit
efficiency due to beam background. In this report, we will describe the Belle
TOF simulation program in detail.Comment: To be submitted to NI
The church and paediatric HIV care in rural South Africa
Religion has substantial – positive and negative – influence on South Africa’s HIV context. This qualitative study explored possibilities for positive church engagement in paediatric HIV care in a rural district in Limpopo Province, South Africa.
Opinions, attitudes and experiences of various stakeholders including religious leaders, healthcare workers and people infected/affected with/by HIV were investigated through participant observation, semi-structured interviews and focus group discussions. During the research the original focus on paediatric HIV care shifted to HIV care in general in reaction to participant responses. Participants identified three main barriers to positive church engagement in HIV care:
(a) stigma and disclosure;
(b) sexual associations with HIV and
(c) religious beliefs and practices.
All participant groups appreciated the opportunity and relevance of strengthening church involvement in HIV care. Opportunities for positive church engagement in HIV care that participants identified included:
(a) comprehensive and holistic HIV care when churches and clinics collaborate;
(b) the wide social reach of churches and
(c) the safety and acceptance in churches.
Findings indicate that despite barriers great potential exists for increased positive church engagement in HIV care in rural South Africa. Recommendations include increased medical knowledge and dialogue on HIV/AIDS within church settings, and increased collaboration between churches and the medical sector
Gravitational waves from eccentric compact binaries: Reduction in signal-to-noise ratio due to nonoptimal signal processing
Inspiraling compact binaries have been identified as one of the most
promising sources of gravitational waves for interferometric detectors. Most of
these binaries are expected to have circularized by the time their
gravitational waves enter the instrument's frequency band. However, the
possibility that some of the binaries might still possess a significant
eccentricity is not excluded. We imagine a situation in which eccentric signals
are received by the detector but not explicitly searched for in the data
analysis, which uses exclusively circular waveforms as matched filters. We
ascertain the likelihood that these filters, though not optimal, will
nevertheless be successful at capturing the eccentric signals. We do this by
computing the loss in signal-to-noise ratio incurred when searching for
eccentric signals with those nonoptimal filters. We show that for a binary
system of a given total mass, this loss increases with increasing eccentricity.
We show also that for a given eccentricity, the loss decreases as the total
mass is increased.Comment: 14 pages, 4 figures, ReVTeX; minor changes made after referee's
comment
Actinobacillus pleuropneumoniae serovar 8 predominates in England and Wales
This work was supported by a Longer and Larger (LoLa) grant from the Biotechnology and Biological Sciences Research Council (BBSRC grant numbers BB/G020744/1, BB/G019177/1, BB/G019274/1 and BB/G018553/1) and Zoetis (formerly Pfizer Animal Health) awarded to the Bacterial Respiratory Diseases of Pigs-1 Technology (BRaDP1T) Consortium
Probing Sub-Micron Forces by Interferometry of Bose-Einstein Condensed Atoms
We propose a technique, using interferometry of Bose-Einstein condensed
alkali atoms, for the detection of sub-micron-range forces. It may extend
present searches at 1 micron by 6 to 9 orders of magnitude, deep into the
theoretically interesting regime of 1000 times gravity. We give several
examples of both four-dimensional particles (moduli), as well as
higher-dimensional particles -- vectors and scalars in a large bulk-- that
could mediate forces accessible by this technique.Comment: 32 pages, 5 figures, RevTeX4, expanded discussion of interactions,
references added, to appear in PR
Gravitational radiation from a particle in circular orbit around a black hole. V. Black-hole absorption and tail corrections
A particle of mass moves on a circular orbit of a nonrotating black
hole of mass . Under the restrictions and , where
is the orbital velocity, we consider the gravitational waves emitted by such a
binary system. We calculate , the rate at which the gravitational
waves remove energy from the system. The total energy loss is given by , where denotes that part of the
gravitational-wave energy which is carried off to infinity, while
denotes the part which is absorbed by the black hole. We show that the
black-hole absorption is a small effect: . We
also compare the wave generation formalism which derives from perturbation
theory to the post-Newtonian formalism of Blanchet and Damour. Among other
things we consider the corrections to the asymptotic gravitational-wave field
which are due to wave-propagation (tail) effects.Comment: ReVTeX, 17 page
Patient-reported outcomes with durvalumab, with or without tremelimumab, plus chemotherapy as first-line treatment for metastatic non-small-cell lung cancer (POSEIDON).
In the phase 3 POSEIDON study, first-line tremelimumab plus durvalumab and chemotherapy significantly improved overall survival and progression-free survival versus chemotherapy in metastatic non-small-cell lung cancer (NSCLC). We present patient-reported outcomes (PROs).
Treatment-naïve patients were randomized 1:1:1 to tremelimumab plus durvalumab and chemotherapy, durvalumab plus chemotherapy, or chemotherapy. PROs (prespecified secondary endpoints) were assessed using the European Organisation for Research and Treatment of Cancer 30-item core quality of life questionnaire version 3 (QLQ-C30) and its 13-item lung cancer module (QLQ-LC13). We analyzed time to deterioration (TTD) of symptoms, functioning, and global health status/quality of life (QoL) from randomization by log-rank test and improvement rates by logistic regression.
972/1013 (96 %) patients randomized completed baseline QLQ-C30 and QLQ-LC13 questionnaires, with scores comparable between treatment arms. Patients receiving tremelimumab plus durvalumab and chemotherapy versus chemotherapy had longer median TTD for all PRO items. Hazard ratios for TTD favored tremelimumab plus durvalumab and chemotherapy for all items except diarrhea; 95 % confidence intervals did not cross 1.0 for global health status/QoL, physical functioning, cognitive functioning, pain, nausea/vomiting, insomnia, constipation, hemoptysis, dyspnea, and pain in other parts. For durvalumab plus chemotherapy, median TTD was longer versus chemotherapy for all items except nausea/vomiting and diarrhea. Hazard ratios favored durvalumab plus chemotherapy for all items except appetite loss; 95 % confidence intervals did not cross 1.0 for global health status/QoL, physical functioning, role functioning, dyspnea, and pain in other parts. For both immunotherapy plus chemotherapy arms, improvement rates in all PRO items were numerically higher versus chemotherapy, with odds ratios > 1.
Tremelimumab plus durvalumab and chemotherapy delayed deterioration in symptoms, functioning, and global health status/QoL compared with chemotherapy. Together with significant improvements in survival, these results support tremelimumab plus durvalumab and chemotherapy as a first-line treatment option in metastatic NSCLC
Variability in lutetium-177 SPECT quantification between different state-of-the-art SPECT/CT systems
Background: Quantitative SPECT imaging in targeted radionuclide therapy with lutetium-177 holds great potential for individualized treatment based on dose assessment. The establishment of dose-effect relations requires a standardized method for SPECT quantification. The purpose of this multi-center study is to evaluate quantitative accuracy and inter-system variations of different SPECT/CT systems with corresponding commercially available quantitative reconstruction algorithms. This is an important step towards a vendor-independent standard for quantitative lutetium-177 SPECT. Methods: Four state-of-the-art SPECT/CT systems were included: Discovery™ NM/CT 670Pro (GE Healthcare), Symbia Intevo™, and two Symbia™ T16 (Siemens Healthineers). Quantitative accuracy and inter-system variations were evaluated by repeatedly scanning a cylindrical phantom with 6 spherical inserts (0.5 – 113 ml). A sphere-to-background activity concentration ratio of 10:1 was used. Acquisition settings were standardized: medium energy collimator, body contour trajectory, photon energy window of 208 keV (± 10%), adjacent 20% lower scatter window, 2 × 64 projections, 128 × 128 matrix size, and 40 s projection time. Reconstructions were performed using GE Evolution with Q.Metrix™, Siemens xSPECT Quant™, Siemens Broad Quantification™ or Siemens Flash3D™ algorithms using vendor recommended settings. In addition, projection data were reconstructed using Hermes SUV SPECT™ with standardized reconstruction settings to obtain a vendor-neutral quantitative reconstruction for all systems. Volumes of interest (VOI) for the spheres were obtained by applying a 50% threshold of the sphere maximum voxel value corrected for background activity. For each sphere, the mean and maximum recovery coefficient (RCmean and RCmax) of three repeated measurements was calculated, defined as the imaged activity concentration divided by the actual activity concentration. Inter-system variations were defined as the range of RC over all systems. Re
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