1,607 research outputs found
Prevalence of incidental breast cancer and precursor lesions in autopsy studies: A systematic review and meta-analysis
Abstract Background Autopsy studies demonstrate the prevalence pool of incidental breast cancer in the population, but estimates are uncertain due to small numbers in any primary study. We aimed to conduct a systematic review of autopsy studies to estimate the prevalence of incidental breast cancer and precursors. Methods Relevant articles were identified through searching PubMed and Embase from inception up to April 2016, and backward and forward citations. We included autopsy studies of women with no history of breast pathology, which included systematic histological examination of at least one breast, and which allowed calculation of the prevalence of incidental breast cancer or precursor lesions. Data were pooled using logistic regression models with random intercepts (non-linear mixed models). Results We included 13 studies from 1948 to 2010, contributing 2363 autopsies with 99 cases of incidental cancer or precursor lesions. More thorough histological examination (≥20 histological sections) was a strong predictor of incidental in-situ cancer and atypical hyperplasia (OR = 126·8 and 21·3 respectively, p < 0·001), but not invasive cancer (OR = 1·1, p = 0·75). The estimated mean prevalence of incidental cancer or precursor lesion was 19·5% (0·85% invasive cancer + 8·9% in-situ cancer + 9·8% atypical hyperplasia). Conclusion Our systematic review in ten countries over six decades found that incidental detection of cancer in situ and breast cancer precursors is common in women not known to have breast disease during life. The large prevalence pool of undetected cancer in-situ and atypical hyperplasia in these autopsy studies suggests screening programs should be cautious about introducing more sensitive tests that may increase detection of these lesions
Traffic stops, race, and perceptions of fairness
Traffic stops are the most common reason for face-to-face encounters between police officers and citizens. Contact with police can affect citizens’ behaviour toward the police, particularly when citizens perceive unfair treatment by officers during these encounters. Yet, few studies have examined how experiencing a traffic stop affects citizens’ decisions to seek assistance from police or report non-crime emergencies. This study analysed data from the Police-Public Contact Survey (PPCS) to examine (a) the relationship between experiencing traffic stops and calling police for help and/or to report non-crime emergencies and (b) why perceptions of fairness and reasons for the traffic stop might affect these outcomes across different racial/ethnic categories. Results from multivariate logistic regression models show that citizens stopped for traffic violations are significantly less likely to seek help from the police and/or to report non-crime emergencies compared to those with other types of face-to-face police contacts. Additionally, those who perceived unfair treatment during traffic stops were less likely to report non-crime emergencies compared to those who felt the police treated them fairly. The effects of perception of fairness and the reason for a stop on reporting non-crime emergencies were significantly different among Hispanic citizens compared to White citizens. Policy implications of the results are discussed and recommendations for future research are provided
The detection and photometric redshift determination of distant galaxies using SIRTF's Infrared Array Camera
We investigate the ability of the Space Infrared Telescope Facility's
Infrared Array Camera to detect distant (z ~ 3)galaxies and measure their
photometric redshifts. Our analysis shows that changing the original long
wavelength filter specifications provides significant improvements in
performance in this and other areas.Comment: 28 pages incl 12 figures; to appear in June 1999 PASP. Fig.12
replaced with corrected versio
Feshbach-resonance-induced atomic filamentation and quantum pair correlation in atom-laser-beam propagation
We study the propagation of an atom laser beam through a spatial region with
a magnetic field tuned to a Feshbach resonance. Tuning the magnetic field below
the resonance produces an effective focusing Kerr medium that causes a
modulational instability of the atomic beam. Under appropriate circumstances,
this results in beam breakup and filamentation seeded by quasi-particle
fluctuations, and in the generation of correlated atomic pairs
Videomicroscopy as a tool for investigation of the microcirculation in the newborn
The perinatal period remains a time of significant risk of death or disability. Increasing evidence suggests that this depends on microcirculatory behavior. Sidestream dark-field orthogonal polarized light videomicroscopy (OPS) has emerged as a useful assessment of adult microcirculation but the values derived are not delineated for the newborn. We aimed to define these parameters in well term newborn infants. Demographic details were collected prospectively on 42 healthy term neonates (n = 20 females, n = 22 males). OPS videomicroscopy (Microscan) was used to view ear conch skin microcirculation at 6, 24, and 72 h of age. Stored video was analyzed by a masked observer using proprietary software. There were no significant differences between the sexes for any structural parameters at any time point. There was a significant increase over time in small vessel perfusion in female infants only (P = 0.009). A number of 6- and 72-h measurements were significantly correlated, but differed from the 24-h values. These observations confirm the utility of the ear conch for neonatal microvascular videomicroscopy. They provide a baseline for studies into the use of OPS videomicroscopy in infants. The changes observed are comparable with previous studies of term infants using these and other microvascular techniques. It is recommended that studies for examining the mature neonatal microvascular structure be delayed until 72 h of life, but studies of the physiology of cardiovascular transition should include the 24-h time point after delivery
The InfraRed Imaging Spectrograph (IRIS) for TMT: photometric precision and ghost analysis
The InfraRed Imaging Spectrograph (IRIS) is a first-light instrument for the
Thirty Meter Telescope (TMT) that will be used to sample the corrected adaptive
optics field by NFIRAOS with a near-infrared (0.8 - 2.4 m) imaging camera
and Integral Field Spectrograph (IFS). In order to understand the science case
specifications of the IRIS instrument, we use the IRIS data simulator to
characterize photometric precision and accuracy of the IRIS imager. We present
the results of investigation into the effects of potential ghosting in the IRIS
optical design. Each source in the IRIS imager field of view results in ghost
images on the detector from IRIS's wedge filters, entrance window, and
Atmospheric Dispersion Corrector (ADC) prism. We incorporated each of these
ghosts into the IRIS simulator by simulating an appropriate magnitude point
source at a specified pixel distance, and for the case of the extended ghosts
redistributing flux evenly over the area specified by IRIS's optical design. We
simulate the ghosting impact on the photometric capabilities, and found that
ghosts generally contribute negligible effects on the flux counts for point
sources except for extreme cases where ghosts coalign with a star of
m2 fainter than the ghost source. Lastly, we explore the photometric
precision and accuracy for single sources and crowded field photometry on the
IRIS imager.Comment: SPIE 2018, 14 pages, 14 figures, 4 tables, Proceedings of SPIE
10702-373, Ground-based and Airborne Instrumentation for Astronomy VII,
10702A7 (16 July 2018
The Infrared Imaging Spectrograph (IRIS) for TMT: Data Reduction System
IRIS (InfraRed Imaging Spectrograph) is the diffraction-limited first light
instrument for the Thirty Meter Telescope (TMT) that consists of a
near-infrared (0.84 to 2.4 m) imager and integral field spectrograph
(IFS). The IFS makes use of a lenslet array and slicer for spatial sampling,
which will be able to operate in 100's of different modes, including a
combination of four plate scales from 4 milliarcseconds (mas) to 50 mas with a
large range of filters and gratings. The imager will have a field of view of
3434 arcsec with a plate scale of 4 mas with many selectable
filters. We present the preliminary design of the data reduction system (DRS)
for IRIS that need to address all of these observing modes. Reduction of IRIS
data will have unique challenges since it will provide real-time reduction and
analysis of the imaging and spectroscopic data during observational sequences,
as well as advanced post-processing algorithms. The DRS will support three
basic modes of operation of IRIS; reducing data from the imager, the lenslet
IFS, and slicer IFS. The DRS will be written in Python, making use of
open-source astronomical packages available. In addition to real-time data
reduction, the DRS will utilize real-time visualization tools, providing
astronomers with up-to-date evaluation of the target acquisition and data
quality. The quicklook suite will include visualization tools for 1D, 2D, and
3D raw and reduced images. We discuss the overall requirements of the DRS and
visualization tools, as well as necessary calibration data to achieve optimal
data quality in order to exploit science cases across all cosmic distance
scales.Comment: 13 pages, 2 figures, 6 tables, Proceeding 9913-165 of the SPIE
Astronomical Telescopes + Instrumentation 201
- …