240 research outputs found
Ethnic Differences in Bladder Cancer Survival
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
Improved Algorithms for Approximate String Matching (Extended Abstract)
The problem of approximate string matching is important in many different
areas such as computational biology, text processing and pattern recognition. A
great effort has been made to design efficient algorithms addressing several
variants of the problem, including comparison of two strings, approximate
pattern identification in a string or calculation of the longest common
subsequence that two strings share.
We designed an output sensitive algorithm solving the edit distance problem
between two strings of lengths n and m respectively in time
O((s-|n-m|)min(m,n,s)+m+n) and linear space, where s is the edit distance
between the two strings. This worst-case time bound sets the quadratic factor
of the algorithm independent of the longest string length and improves existing
theoretical bounds for this problem. The implementation of our algorithm excels
also in practice, especially in cases where the two strings compared differ
significantly in length. Source code of our algorithm is available at
http://www.cs.miami.edu/\~dimitris/edit_distanceComment: 10 page
Long-Term Survival Rates after Resection for Locally Advanced Kidney Cancer: Memorial Sloan Kettering Cancer Center 1989 to 2012 Experience
Purpose: We analyzed the 23-year Memorial Sloan Kettering Cancer Center experience with surgical resection, and concurrent adrenalectomy and lymphadenectomy for locally advanced nonmetastatic renal cell carcinoma. Materials and Methods: We retrospectively reviewed the records of 802 patients who underwent nephrectomy with or without concurrent adrenalectomy or lymphadenectomy for locally advanced renal cell carcinoma, defined as stage T3 or greater and M0. Patients who received adjuvant treatment within 3 months of surgery or had fewer than 3 months of followup or bilateral renal masses at presentation were excluded from analysis. Five and 10-year progression-free and overall survival was estimated by the Kaplan-Meier method. Differences between groups were analyzed by the log rank test. Results: A total of 596 (74%) and 206 patients (26%) underwent radical and partial nephrectomy, respectively. Renal cell carcinoma progressed in 189 patients and 104 died of the disease. Median followup in patients without progression was 4.6 years. Symptoms at presentation, ASA (R) classification, tumor stage, histological subtype, grade and lymph node status were significantly associated with progression-free and overall survival. On multivariate analysis adrenalectomy use decreased with time but lymphadenectomy use increased (OR 0.82 vs 1.16 per year). Larger tumors were associated with a higher likelihood of concurrent adrenalectomy and lymphadenectomy. Conclusions: In our series of patients with locally advanced nonmetastatic renal cell carcinoma survival was favorable in those in good health who were asymptomatic at presentation with T3 tumors and negative lymph nodes. Further, there has been a trend toward more selective use of adrenalectomy and increased use of lymphadenectomy
In-flight performance and calibration of the Infrared Array Camera (IRAC) for the Spitzer Space Telescope
The Infrared Array Camera (IRAC) is one of three focal plane instruments on board the Spitzer Space Telescope. IRAC is a four-channel camera that obtains simultaneous broad-band images at 3.6, 4.5, 5.8, and 8.0 μm in two nearly adjacent fields of view. We summarize here the in-flight scientific, technical, and operational performance of IRAC
The Anatomy of Star Formation in NGC 300
The Spitzer Space Telescope was used to study the mid-infrared to
far-infrared properties of NGC 300, and to compare dust emission to Halpha to
elucidate the heating of the ISM and the star formation cycle at scales < 100
pc. The new data allow us to discern clear differences in the spatial
distribution of 8 micron dust emission with respect to 24 micron dust and to
HII regions traced by the Halpha light. The 8 micron emission highlights the
rims of HII regions, and the 24 micron emission is more strongly peaked in star
forming regions than at 8 microns. We confirm the existence and approximate
amplitude of interstellar dust emission at 4.5 microns, detected statistically
in Infrared Space Observatory (ISO) data, and conclude it arises in star
forming regions. When averaging over regions larger than ~ 1 kpc, the ratio of
Halpha to Aromatic Feature emission in NGC 300 is consistent with the values
observed in disks of spiral galaxies. The mid-to-far-infrared spectral energy
distribution of dust emission is generally consistent with pre-Spitzer models.Comment: to appear in the ApJS Spitzer special issue (September 2004
The Infrared Array Camera (IRAC) for the Spitzer Space Telescope
The Infrared Array Camera (IRAC) is one of three focal plane instruments in
the Spitzer Space Telescope. IRAC is a four-channel camera that obtains
simultaneous broad-band images at 3.6, 4.5, 5.8, and 8.0 microns. Two nearly
adjacent 5.2x5.2 arcmin fields of view in the focal plane are viewed by the
four channels in pairs (3.6 and 5.8 microns; 4.5 and 8 microns). All four
detector arrays in the camera are 256x256 pixels in size, with the two shorter
wavelength channels using InSb and the two longer wavelength channels using
Si:As IBC detectors. IRAC is a powerful survey instrument because of its high
sensitivity, large field of view, and four-color imaging. This paper summarizes
the in-flight scientific, technical, and operational performance of IRAC.Comment: 7 pages, 3 figures. Accepted for publication in the ApJS. A higher
resolution version is at http://cfa-www.harvard.edu/irac/publication
The galactic first-look survey with the Spitzer space telescope
The galactic first look survey (GFLS) of the Spitzer space telescope was executed during 1–11 December 2003 as one of the first science observations during nominal operations. The aim of the FLS is to provide a characteristic “first-look” at the mid-and far-infrared sky at sensitivities that allow the detection of point sources ≈100 times fainter than those in previous systematic large-area surveys. The whole program took 35.5 h to complete and consisted of the following elements:
•Galactic longitudinal strips of size 15′ × 1° with IRAC and MIPS at l = 105.6° and 254.4° and various galactic latitudes.
•10′ × 10′ IRAC maps at l = 97.5° and b = 0°, ±4°, and +16°.
•Coverage of L1228 with 2° scan maps.
Even at these large distances from the galactic center, confusion sets a limit to the detection of point sources in the galactic plane for IRAC channel 1 (3.6 μm) at 100 μJy ≈ 16.1^m. As positive galactic latitudes were mainly sampled at l = 97.5° and 105.6° and negative latitudes at 254.4° galactic longitude, the observations are well suited to derive information on the warp of the galactic disk. In order to reproduce the source counts from the GFLS we had to assume an amplitude of the warp within 20% of that derived from 2MASS. The whole survey is included in the Spitzer science archive which opened in April 2004
Near and Mid-IR Photometry of the Pleiades, and a New List of Substellar Candidate Members
We make use of new near and mid-IR photometry of the Pleiades cluster in
order to help identify proposed cluster members. We also use the new photometry
with previously published photometry to define the single-star main sequence
locus at the age of the Pleiades in a variety of color-magnitude planes.
The new near and mid-IR photometry extend effectively two magnitudes deeper
than the 2MASS All-Sky Point Source catalog, and hence allow us to select a new
set of candidate very low mass and sub-stellar mass members of the Pleiades in
the central square degree of the cluster. We identify 42 new candidate members
fainter than Ks =14 (corresponding to 0.1 Mo). These candidate members should
eventually allow a better estimate of the cluster mass function to be made down
to of order 0.04 solar masses.
We also use new IRAC data, in particular the images obtained at 8 um, in
order to comment briefly on interstellar dust in and near the Pleiades. We
confirm, as expected, that -- with one exception -- a sample of low mass stars
recently identified as having 24 um excesses due to debris disks do not have
significant excesses at IRAC wavelengths. However, evidence is also presented
that several of the Pleiades high mass stars are found to be impacting with
local condensations of the molecular cloud that is passing through the Pleiades
at the current epoch.Comment: Accepted to ApJS; data tables and embedded-figure version available
at http://spider.ipac.caltech.edu/staff/stauffer/pleiades07
Direct imaging of the young spectroscopic binary HD 160934
We report on the direct detection of a close companion to HD 160934, a young
active star, SB1 spectroscopic binary, and suggested member of the AB Doradus
moving group. High angular resolution at the Calar Alto 2.2m telescope was
achieved by means of the Lucky Imaging technique, allowing direct imaging close
to the diffraction limit in the SDSS z' band. Our results are combined with
pre-discovery HST archive data, own UBVRI broadband photometry, published JHK
magnitudes, and available radial velocity measurements to constrain the
physical properties of the HD 160934 close binary. We suggest that the direct
detection may be identical to the spectroscopically discovered companion.Comment: 5 pages, 1 figure, submitted to A&
Short and long term retention in antiretroviral care in health facilities in rural Malawi and Zimbabwe.
Despite the successful scale-up of ART services over the past years, long term retention in ART care remains a major challenge, especially in high HIV prevalence and resource-limited settings. This study analysed the short (<12 months) and long (>12 months) term retention on ART in two ART programmes in Malawi (Thyolo district) and Zimbabwe (Buhera district)
- …