40 research outputs found

    Ethnic Differences in Bladder Cancer Survival

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    ObjectiveTo examine trends in bladder cancer survival among whites, blacks, Hispanics, and Asian/Pacific Islanders in the United States over a 30-year period. Racial disparities in bladder cancer outcomes have been documented with poorer survival observed among blacks. Bladder cancer outcomes in other ethnic minority groups are less well described.MethodsFrom the Surveillance, Epidemiology and End Results cancer registry data, we identified patients diagnosed with transitional cell carcinoma of the bladder between 1975 and 2005. This cohort included 163,973 white, 7731 black, 7364 Hispanic, and 5934 Asian/Pacific Islander patients. We assessed the relationship between ethnicity and patient characteristics. Disease-specific 5-year survival was estimated for each ethnic group and for subgroups of stage and grade.ResultsBlacks presented with higher-stage disease than whites, Hispanics, and Asian/Pacific Islanders, although a trend toward earlier-stage presentation was observed in all groups over time. Five-year disease-specific survival was consistently worse for blacks than for other ethnic groups, even when stratified by stage and grade. Five-year disease-specific survival was 82.8% in whites compared with 70.2% in blacks, 80.7% in Hispanics, and 81.9% in Asian/Pacific Islanders. There was a persistent disease-specific survival disadvantage in black patients over time that was not seen in the other ethnic groups.ConclusionEthnic disparities in bladder cancer survival persist between whites and blacks, whereas survival in other ethnic minority groups appears similar to that of whites. Further study of access to care, quality of care, and treatment decision making among black patients is needed to better understand these disparities

    Photometry using the Infrared Array Camera on the Spitzer Space Telescope

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    We present several corrections for point source photometry to be applied to data from the Infrared Array Camera (IRAC) on the Spitzer Space Telescope. These corrections are necessary because of characteristics of the IRAC arrays and optics and the way the instrument is calibrated in-flight. When these corrections are applied, it is possible to achieve a ~2% relative photometric accuracy for sources of adequate signal to noise in an IRAC image.Comment: 16 pages, 13 figures. Accepted for publication in the Publications of the Astronomical Society of the Pacifi

    A Spitzer IRAC Measure of the Zodiacal Light

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    The dominant non-instrumental background source for space–based infrared observatories is the zodiacal light (ZL). We present Spitzer Infrared Array Camera (IRAC) measurements of the ZL at 3.6, 4.5, 5.8, and 8.0 ÎŒm, taken as part of the instrument calibrations. We measure the changing surface brightness levels in approximately weekly IRAC observations near the north ecliptic pole over the period of roughly 8.5 years. This long time baseline is crucial for measuring the annual sinusoidal variation in the signal levels due to the tilt of the dust disk with respect to the ecliptic, which is the true signal of the ZL. This is compared to both Cosmic Background Explorer Diffuse Infrared Background Experiment data and a ZL model based thereon. Our data show a few percent discrepancy from the Kelsall et al.(1998) model including a potential warping of the interplanetary dust disk and a previously detected overdensity in the dust cloud directly behind the Earth in its orbit. Accurate knowledge of the ZL is important for both extragalactic and Galactic astronomy including measurements of the cosmic infrared background, absolute measures of extended sources, and comparison to extrasolar interplanetary dust models. IRAC data can be used to further inform and test future ZL models

    Comparison of laboratory and in-flight performance of infared array camera (IRAC) detector arrays on Spitzer Space Telescope

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    The Infrared Array Camera (IRAC) on Spitzer Space Telescope includes four Raytheon Vision Systems focal plane arrays, two with InSb detectors, and two with Si:As detectors. A brief comparison of pre- flight laboratory results vs. in-flight performance is given, including quantum efficiency and noise, as well as a discussion of irregular effects, such as residual image performance, "first frame effect", "banding", "column pull-down" and multiplexer bleed. Anomalies not encountered in pre-flight testing, as well as post-flight laboratory tests on these anomalies at the University of Rochester and at NASA Ames using sister parts to the flight arrays, are emphasized

    Protostars in the Elephant Trunk Nebula

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    The optically-dark globule IC 1396A is revealed using Spitzer images at 3.6, 4.5, 5.8, 8, and 24 microns to be infrared-bright and to contain a set of previously unknown protostars. The mid-infrared colors of the 24 microns detected sources indicate several very young (Class I or 0) protostars and a dozen Class II stars. Three of the new sources (IC 1396A: gamma, delta, and epsilon) emit over 90% of their bolometric luminosities at wavelengths greater than 3 microns, and they are located within ~0.02 pc of the ionization front at the edge of the globule. Many of the sources have spectra that are still rising at 24 microns. The two previously-known young stars LkHa 349 a and c are both detected, with component c harboring a massive disk and component a being bare. Of order 5% of the mass of material in the globule is presently in the form of protostars in the 10^5 to 10^6 yr age range. This high star formation rate was likely triggered by radiation from a nearby O star.Comment: Spitzer first ApJS special issue (in press

    A planet within the debris disk around the pre-main-sequence star AU Microscopii

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    AU Microscopii (AU Mic) is the second closest pre main sequence star, at a distance of 9.79 parsecs and with an age of 22 million years. AU Mic possesses a relatively rare and spatially resolved3 edge-on debris disk extending from about 35 to 210 astronomical units from the star, and with clumps exhibiting non-Keplerian motion. Detection of newly formed planets around such a star is challenged by the presence of spots, plage, flares and other manifestations of magnetic activity on the star. Here we report observations of a planet transiting AU Mic. The transiting planet, AU Mic b, has an orbital period of 8.46 days, an orbital distance of 0.07 astronomical units, a radius of 0.4 Jupiter radii, and a mass of less than 0.18 Jupiter masses at 3 sigma confidence. Our observations of a planet co-existing with a debris disk offer the opportunity to test the predictions of current models of planet formation and evolution.Comment: Nature, published June 24th [author spelling name fix
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