2,082 research outputs found
Wavelength calibration for OSIRIS/GTC* tunable filters
OSIRIS (Optical System for Imaging and low Resolution Integrated
Spectroscopy) is the first light instrument of the Gran Telescopio Canarias
(GTC). It provides a flexible and competitive tunable filter (TF). Since it is
based on a Fabry-Perot interferometer working in collimated beam, the TF
transmission wavelength depends on the position of the target with respect to
the optical axis. This effect is non-negligible and must be accounted for in
the data reduction. Our paper establishes a wavelength calibration for OSIRIS
TF with the accuracy required for spectrophotometric measurements using the
full field of view (FOV) of the instrument. The variation of the transmission
wavelength across the FOV is well described by
, where is the central
wavelength, represents the physical distance from the optical axis, and
mm is the effective focal length of the camera lens. This
new empirical calibration yields an accuracy better than 1\,\AA\ across the
entire OSIRIS FOV (8\arcmin8\arcmin), provided that the position
of the optical axis is known within 45 m ( 1.5 binned pixels). We
suggest a calibration protocol to grant such precision over long periods, upon
re-alignment of OSIRIS optics, and in different wavelength ranges. This
calibration differs from the calibration in OSIRIS manual which, nonetheless,
provides an accuracy \AA\, for R\lesssim 2\arcmin.Comment: 22 pages, 7 figures, accepted for publication in PAS
Alectinib after failure to crizotinib in patients with ALK-positive non-small cell lung cancer : results from the Spanish early access program
Altres ajuts: Roche Farma, S.A.This retrospective observational study analyzed the clinical characteristics, treatment patterns and outcomes of 120 patients with advanced ALK-positive nonsmall-cell lung cancer (ALK+ NSCLC) according to data collected between November 2019 and October 2020 in 38 Spanish hospitals. Patients had progressed after 1-5 prior treatment lines (which included crizotinib in any prior line) and received subsequent therapy with alectinib in a local expanded access program. Median age was 58.7 years, 50% of patients were female, 64.1% had ECOG PS of 0-1, 85% presented stage IV, 95% had adenocarcinoma histology and 20.8% had brain metastases. After a median 9.6 months of alectinib treatment, objective response rate (ORR) was 54.5%, disease control rate (DCR) was 80%, median progression-free survival (PFS) was 9.4 months and median overall survival (OS) was 24.1 months. Patients with brain metastases achieved an intracranial DCR of 71.4%. Adverse events (AEs) were reported in 35.8% of patients (14.2% of AEs were grade â„3). Over 40% of patients received some treatment after alectinib, most frequently lorlatinib (65.2%) and brigatinib (32.6%). This study provides information on real-world treatment patterns and confirms the tolerability and prolonged PFS and OS observed with alectinib in clinical trials, in unselected pretreated patients with advanced ALK+ NSCLC
The intrinsic shape of galaxy bulges
The knowledge of the intrinsic three-dimensional (3D) structure of galaxy
components provides crucial information about the physical processes driving
their formation and evolution. In this paper I discuss the main developments
and results in the quest to better understand the 3D shape of galaxy bulges. I
start by establishing the basic geometrical description of the problem. Our
understanding of the intrinsic shape of elliptical galaxies and galaxy discs is
then presented in a historical context, in order to place the role that the 3D
structure of bulges play in the broader picture of galaxy evolution. Our
current view on the 3D shape of the Milky Way bulge and future prospects in the
field are also depicted.Comment: Invited Review to appear in "Galactic Bulges" Editors: Laurikainen
E., Peletier R., Gadotti D. Springer Publishing. 24 pages, 7 figure
Five-Year Outcomes With Pembrolizumab Versus Chemotherapy for Metastatic Non-Small-Cell Lung Cancer With PD-L1 Tumor Proportion Score â„ 50.
Purpose We report the first 5-year follow-up of any first-line phase III immunotherapy trial for non-small-cell lung cancer (NSCLC). KEYNOTE-024 (ClinicalTrials.gov identifier: NCT02142738) is an open-label, randomized controlled trial of pembrolizumab compared with platinum-based chemotherapy in patients with previously untreated NSCLC with a programmed death ligand-1 (PD-L1) tumor proportion score of at least 50% and no sensitizing EGFR or ALK alterations. Previous analyses showed pembrolizumab significantly improved progression-free survival and overall survival (OS).Methods Eligible patients were randomly assigned (1:1) to pembrolizumab (200 mg once every 3 weeks for up to 35 cycles) or platinum-based chemotherapy. Patients in the chemotherapy group with progressive disease could cross over to pembrolizumab. The primary end point was progression-free survival; OS was a secondary end point.Results Three hundred five patients were randomly assigned: 154 to pembrolizumab and 151 to chemotherapy. Median (range) time from randomization to data cutoff (June 1, 2020) was 59.9 (55.1-68.4) months. Among patients initially assigned to chemotherapy, 99 received subsequent anti-PD-1 or PD-L1 therapy, representing a 66.0% effective crossover rate. Median OS was 26.3 months (95% CI, 18.3-40.4) for pembrolizumab and 13.4 months (9.4-18.3) for chemotherapy (hazard ratio, 0.62; 95% CI, 0.48-0.81). Kaplan-Meier estimates of the 5-year OS rate were 31.9% for the pembrolizumab group and 16.3% for the chemotherapy group. Thirty-nine patients received 35 cycles (ie, approximately 2 years) of pembrolizumab, 82.1% of whom were still alive at data cutoff (approximately 5 years). Toxicity did not increase with longer treatment exposure.Conclusion Pembrolizumab provides a durable, clinically meaningful long-term OS benefit versus chemotherapy as first-line therapy for metastatic NSCLC with PD-L1 tumor proportion score of at least 50%
Operations of and Future Plans for the Pierre Auger Observatory
Technical reports on operations and features of the Pierre Auger Observatory,
including ongoing and planned enhancements and the status of the future
northern hemisphere portion of the Observatory. Contributions to the 31st
International Cosmic Ray Conference, Lodz, Poland, July 2009.Comment: Contributions to the 31st ICRC, Lodz, Poland, July 200
Measurement of the Depth of Maximum of Extensive Air Showers above 10^18 eV
We describe the measurement of the depth of maximum, Xmax, of the
longitudinal development of air showers induced by cosmic rays. Almost four
thousand events above 10^18 eV observed by the fluorescence detector of the
Pierre Auger Observatory in coincidence with at least one surface detector
station are selected for the analysis. The average shower maximum was found to
evolve with energy at a rate of (106 +35/-21) g/cm^2/decade below 10^(18.24 +/-
0.05) eV and (24 +/- 3) g/cm^2/decade above this energy. The measured
shower-to-shower fluctuations decrease from about 55 to 26 g/cm^2. The
interpretation of these results in terms of the cosmic ray mass composition is
briefly discussed.Comment: Accepted for publication by PR
The Pierre Auger Observatory III: Other Astrophysical Observations
Astrophysical observations of ultra-high-energy cosmic rays with the Pierre
Auger ObservatoryComment: Contributions to the 32nd International Cosmic Ray Conference,
Beijing, China, August 201
Atmospheric effects on extensive air showers observed with the Surface Detector of the Pierre Auger Observatory
Atmospheric parameters, such as pressure (P), temperature (T) and density,
affect the development of extensive air showers initiated by energetic cosmic
rays. We have studied the impact of atmospheric variations on extensive air
showers by means of the surface detector of the Pierre Auger Observatory. The
rate of events shows a ~10% seasonal modulation and ~2% diurnal one. We find
that the observed behaviour is explained by a model including the effects
associated with the variations of pressure and density. The former affects the
longitudinal development of air showers while the latter influences the Moliere
radius and hence the lateral distribution of the shower particles. The model is
validated with full simulations of extensive air showers using atmospheric
profiles measured at the site of the Pierre Auger Observatory.Comment: 24 pages, 9 figures, accepted for publication in Astroparticle
Physic
The exposure of the hybrid detector of the Pierre Auger Observatory
The Pierre Auger Observatory is a detector for ultra-high energy cosmic rays.
It consists of a surface array to measure secondary particles at ground level
and a fluorescence detector to measure the development of air showers in the
atmosphere above the array. The "hybrid" detection mode combines the
information from the two subsystems. We describe the determination of the
hybrid exposure for events observed by the fluorescence telescopes in
coincidence with at least one water-Cherenkov detector of the surface array. A
detailed knowledge of the time dependence of the detection operations is
crucial for an accurate evaluation of the exposure. We discuss the relevance of
monitoring data collected during operations, such as the status of the
fluorescence detector, background light and atmospheric conditions, that are
used in both simulation and reconstruction.Comment: Paper accepted by Astroparticle Physic
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