A Test of the Lauer--Postman Bulk Flow

We use Tully--Fisher distances for a sample of field late spiral galaxies to test the Lauer and Postman (1994; hereinafter LP) result suggestive of a bulk flow with respect to the Cosmic Microwave Background reference frame, of amplitude of +689 km/s in the direction l=343, b=+52. A total of 432 galaxies are used, subdivided between two cones, of 30deg semiaperture each and pointed respectively toward the apex and antapex of the LP motion. The peculiar velocities in the two data sets are inconsistent with a bulk flow of the amplitude claimed by LP. When combined in opposition, the peculiar velocity medians in shells of constant redshift width are never larger than half the amplitude of the LP bulk flow. Out to 5000 km/s the median bulk velocity in the LP apex--antapex cones is about 200 km/s or less, dropping to a value indistinguishable from zero beyond that distance. It can be excluded that field spiral galaxies within 8000 km/s partake of a bulk flow of the amplitude and direction reported by LP.Comment: 9 pages including figures embedded in text; uses AAS LaTex and psfi

The linked survival prospects of siblings : evidence for the Indian states

This paper reports an analysis of micro-data for India that shows a high correlation in infant mortality among siblings. In 13 of 15 states, we identify a causal effect of infant death on the risk of infant death of the subsequent sibling (a scarring effect), after controlling for mother-level heterogeneity. The scarring effects are large, the only other covariate with a similarly large effect being mother’s (secondary or higher) education. The two states in which evidence of scarring is weak are Punjab, the richest, and Kerala, the socially most progressive. The size of the scarring effect depends upon the sex of the previous child in three states, in a direction consistent with son-preference. Evidence of scarring implies that policies targeted at reducing infant mortality will have social multiplier effects by helping avoid the death of subsequent siblings. Comparison of other covariate effects across the states offers some interesting new insights

Survival and risk of adverse events in older patients receiving postoperative adjuvant chemotherapy for resected stages II-IIIA lung cancer: observational cohort study

Objective To compare the survival and risk of serious adverse events in older patients with stages II-IIIA non-small cell lung cancer treated with or without postoperative platinum based chemotherapy

Type II Quasars from the Sloan Digital Sky Survey: V. Imaging host galaxies with the Hubble Space Telescope

Type II quasars are luminous Active Galactic Nuclei whose centers are obscured by large amounts of gas and dust. In this paper we present 3-band HST images of nine type II quasars with redshifts 0.2 < z < 0.4 selected from the Sloan Digital Sky Survey based on their emission line properties. The intrinsic luminosities of these AGN are estimated to be -24 > M_B > -26, but optical obscuration allows their host galaxies to be studied unencumbered by bright nuclei. Each object has been imaged in three continuum filters (`UV', `blue' and `yellow') placed between the strong emission lines. The spectacular, high quality images reveal a wealth of details about the structure of the host galaxies and their environments. Six of the nine galaxies in the sample are ellipticals with de Vaucouleurs light profiles, one object has a well-defined disk component and the remaining two have marginal disks. Stellar populations of type II quasar hosts are more luminous (by a median of 0.3-0.7 mag, depending on the wavelength) and bluer (by about 0.4 mag) than are M* galaxies at the same redshift. When smooth fits to stellar light are subtracted from the images, we find both positive and negative residuals that become more prominent toward shorter wavelengths. We argue that the negative residuals are due to kpc-scale dust obscuration, while most positive residuals are due to the light from the nucleus scattered off interstellar material in the host galaxy. Scattered light makes a significant contribution to the broad band continuum emission and can be the dominant component of the extended emission in the UV in extreme cases.Comment: 51 pages, including 12 grey scale figures, 4 color figures, 5 tables. In press in AJ. Version with higher-resolution images available at http://www.astro.princeton.edu/~nadia/qso2.html. (Minor changes in response to the referee report

Cell clusters overlying focally disrupted mammary myoepithelial cell layers and adjacent cells within the same duct display different immunohistochemical and genetic features: implications for tumor progression and invasion

INTRODUCTION: Our previous studies detected focal disruptions in myoepithelial cell layers of several ducts with carcinoma in situ. The cell cluster overlying each of the myoepithelial disruptions showed a marked reduction in or a total loss of immunoreactivity for the estrogen receptor (ER). This is in contrast to the adjacent cells within the same duct, which were strongly immunoreactive for the ER. The current study attempts to confirm and expand previous observations on a larger scale. METHODS: Paraffin sections from 220 patients with ER-positive intraductal breast tumors were double immunostained with the same protocol previously used. Cross-sections of ducts lined by ≥ 40 epithelial cells were examined for myoepithelial cell layer disruptions and for ER expression. In five selected cases, ER-negative cells overlying the disrupted myoepithelial cell layer and adjacent ER-positive cells within the same duct were separately microdissected and assessed for loss of heterozygosity and microsatellite instability. RESULTS: Of the 220 cases with 5698 duct cross-sections examined, 94 showed disrupted myoepithelial cell layers with 405 focal disruptions. Of the 94 cases, 79 (84%) contained only ER-negative cell clusters, nine (9.6%) contained both ER-negative and ER-positive cell clusters, and six (6.4%) contained only ER-positive cell clusters overlying disrupted myoepithelial cell layers. Of the 405 disruptions, 350 (86.4%) were overlain by ER-negative cell clusters and 55 (13.6%) were overlain by ER-positive cell clusters (P < 0.01). Microdissected ER-negative and ER-positive cells within the same duct from all five selected cases displayed a different frequency or pattern of loss of heterozygosity and/or microsatellite instability at 10 of the 15 DNA markers. CONCLUSIONS: Cells overlying focally disrupted myoepithelial layers and their adjacent counterparts within the same duct displayed different immunohistochemical and molecular features. These features potentially represent an early sign of the formation of a biologically more aggressive cell clone and the myoepithelial cell layer breakdown possibly associated with tumor progression or invasion

Two Rare Magnetic Cataclysmic Variables with Extreme Cyclotron Features Identified in the Sloan Digital Sky Survey

Two newly identified magnetic cataclysmic variables discovered in the Sloan Digital Sky Survey (SDSS), SDSSJ155331.12+551614.5 and SDSSJ132411.57+032050.5, have spectra showing highly prominent, narrow, strongly polarized cyclotron humps with amplitudes that vary on orbital periods of 4.39 and 2.6 hrs, respectively. In the former, the spacing of the humps indicates the 3rd and 4th harmonics in a magnetic field of ~60 MG. The narrowness of the cyclotron features and the lack of strong emission lines imply very low temperature plasmas and very low accretion rates, so that the accreting area is heated by particle collisions rather than accretion shocks. The detection of rare systems like these exemplifies the ability of the SDSS to find the lowest accretion rate close binaries.Comment: Accepted for publication in the Astrophysical Journal, vol. 583, February 1, 2003; slight revisions and additions in response to referee's comments; 17 pages, 6 figures, AASTeX v4.

Reinventing grounded theory: some questions about theory, ground and discovery

Grounded theory’s popularity persists after three decades of broad-ranging critique. In this article three problematic notions are discussed—‘theory,’ ‘ground’ and ‘discovery’—which linger in the continuing use and development of grounded theory procedures. It is argued that far from providing the epistemic security promised by grounded theory, these notions—embodied in continuing reinventions of grounded theory—constrain and distort qualitative inquiry, and that what is contrived is not in fact theory in any meaningful sense, that ‘ground’ is a misnomer when talking about interpretation and that what ultimately materializes following grounded theory procedures is less like discovery and more akin to invention. The procedures admittedly provide signposts for qualitative inquirers, but educational researchers should be wary, for the significance of interpretation, narrative and reflection can be undermined in the procedures of grounded theory

High-Redshift SDSS Quasars with Weak Emission Lines

We identify a sample of 74 high-redshift quasars (z>3) with weak emission lines from the Fifth Data Release of the Sloan Digital Sky Survey and present infrared, optical, and radio observations of a subsample of four objects at z>4. These weak emission-line quasars (WLQs) constitute a prominent tail of the Lya+NV equivalent width distribution, and we compare them to quasars with more typical emission-line properties and to low-redshift active galactic nuclei with weak/absent emission lines, namely BL Lac objects. We find that WLQs exhibit hot (T~1000 K) thermal dust emission and have rest-frame 0.1-5 micron spectral energy distributions that are quite similar to those of normal quasars. The variability, polarization, and radio properties of WLQs are also different from those of BL Lacs, making continuum boosting by a relativistic jet an unlikely physical interpretation. The most probable scenario for WLQs involves broad-line region properties that are physically distinct from those of normal quasars.Comment: Updated to match version published in ApJ. 20 pages, 12 figure