202 research outputs found

    The VLA 1.4GHz Survey of the Extended Chandra Deep Field South: Second Data Release

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    Deep radio observations at 1.4GHz for the Extended Chandra Deep Field South were performed in June through September of 2007 and presented in a first data release (Miller et al. 2008). The survey was made using six separate pointings of the Very Large Array (VLA) with over 40 hours of observation per pointing. In the current paper, we improve on the data reduction to produce a second data release (DR2) mosaic image. This DR2 image covers an area of about a third of a square degree and reaches a best rms sensitivity of 6 uJy and has a typical sensitivity of 7.4 uJy per 2.8" by 1.6" beam. We also present a more comprehensive catalog, including sources down to peak flux densities of five or more times the local rms noise along with information on source sizes and relevant pointing data. We discuss in some detail the consideration of whether sources are resolved under the complication of a radio image created as a mosaic of separate pointings each suffering some degree of bandwidth smearing, and the accurate evaluation of the flux densities of such sources. Finally, the radio morphologies and optical/near-IR counterpart identifications (Bonzini et al. 2012) are used to identify 17 likely multiple-component sources and arrive at a catalog of 883 radio sources, which is roughly double the number of sources contained in the first data release.Comment: to appear in the Astrophysical Journal Supplement Series; 41 page

    Effects of inhalable particulate matter on blood coagulation.

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    BACKGROUND: Particulate matter (PM) exposure has been linked to increased risk of cardiovascular disease, possibly resulting from hypercoagulability and thrombosis. Lung and systemic inflammation resulting from PM inhalation may activate blood coagulation, but mechanisms for PM-related hypercoagulability are still largely unknown. OBJECTIVES: To identify coagulation mechanisms activated by PM in a population with well-characterized exposure. METHODS: We measured prothrombin time (PT), activated partial thromboplastin time, endogenous thrombin potentials (ETPs) with/without exogenous triggers and with/without soluble thrombomodulin, tissue-type plasminogen activator (t-PA) antigen, D-dimer and C-reactive protein (CRP) in 37 workers in a steel production plant with well-characterized exposure to PM with aerodynamic diameter of < 1 mum (PM(1)) and coarse PM (PM(10) - PM(1)). Blood samples were collected from each subject on the first (baseline) and last (postexposure) day of a 4-day work week. We analyzed differences between baseline and postexposure levels using a paired Student's t-test. We fitted multivariate mixed-regression models to estimate the associations of interquartile range PM(1) and coarse PM exposure with parameter levels. RESULTS: None of the parameters showed any significant changes from baseline in postexposure samples. However, exposure levels were associated with shorter PT (beta[PM(1)] = -0.33 s, P = 0.08; beta[PM(coarse)] = - 0.33 s, P = 0.01), and higher ETP without exogenous triggers and with thrombomodulin (beta[PM(1)] = + 99 nm min, P = 0.02; beta[PM(coarse)] = + 66 nm min, P = 0.05), t-PA (beta[PM(1)] = + 0.72 ng mL(-1), P = 0.01; beta[PM(coarse)] = + 0.88 ng mL(-1), P = 0.04), and CRP (beta[PM(1)] = + 0.59 mg L(-1), P = 0.03; beta[PM(coarse)] = + 0.48 mg L(-1), P = 0.01). CONCLUSIONS: PM exposure did not show any short-term effect within the week of the study. The association of PM exposure with PT, ETP and CRP provides some evidence of long-term effects on inflammation and coagulation

    Linking the X-ray and infrared properties of star-forming galaxies at z < 1.5

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    We present the most complete study to date of the X-ray emission from star formation in high-redshift (median z = 0.7; z −3 in both hard and soft X-ray bands. From the sources which are star formation dominated, only a small fraction are individually X-ray detected and for the bulk of the sample we calculate average X-ray luminosities through stacking. We find an average soft X-ray to infrared ratio of log ?L SX /L IR ? = −4.3 and an average hard X-ray to infrared ratio of log?L HX /L IR ?=−3.8.WereportthattheX-ray/IRcorrelationisapproximatelylinearthrough the entire range of L IR and z probed and, although broadly consistent with the local (z < 0.1) one, it does display some discrepancies. We suggest that these discrepancies are unlikely to be physical, i.e. due to an intrinsic change in the X-ray properties of star-forming galaxies with cosmic time, as there is no significant evidence for evolution of the L X /L IR ratio with redshift. Instead, they are possibly due to selection effects and remaining AGN contamination. We also examine whether dust obscuration in the galaxy plays a role in attenuating X-rays from star formation, by investigating changes in the L X /L IR ratio as a function of the average dust temperature. We conclude that X-rays do not suffer any measurable attenuation in the host galaxy

    Exploring the Prognostic Role of Ki67 Proliferative Index in Merkel Cell Carcinoma of the Skin: Clinico-Pathologic Analysis of 84 Cases and Review of the Literature.

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    The exact prediction of outcome of patients with Merkel cell carcinoma (MCC) of the skin is difficult to determine, although several attempts have been made to identify clinico-pathologic prognostic factors. The Ki67 proliferative index is a well-known marker routinely used to define the prognosis of patients with neuroendocrine neoplasms. However, its prognostic value has been poorly investigated in MCC, and available published results are often contradictory mainly because restricted to small series in the absence of standardized methods for Ki67 evaluation. For this reason, we explored the potential prognostic role of Ki67 proliferative index in a large series of MCCs using the WHO standardized method of counting positive cells in at least 500 tumor cells in hot spot areas on camera-captured printed images. In addition, since MCC may be considered as the cutaneous counterpart of digestive neuroendocrine carcinomas (NECs), we decided to stratify MCCs using the available and efficient Ki67 threshold of 55%, which was found prognostic in digestive NECs. This choice was also supported by the Youden index analysis. In addition, we analyzed the prognostic value of other clinico-pathologic parameters using both univariate and multivariate analysis. Ki67 index appeared significantly associated with prognosis at univariate analysis together with stage IV, lack of MCPyV, and p63 expression, but not at the multivariate analysis, where survival resulted independently influenced by p63 expression and tumor stage, only

    Effects of particulate matter on genomic DNA methylation content and iNOS promoter methylation

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    Background: Altered patterns of gene expression mediate the effects of particulate matter (PM) on human health, but mechanisms through which PM modifies gene expression are largely undetermined. Objectives: We aimed at identifying short- and long-term effects of PM exposure on DNA methylation, a major genomic mechanism of gene expression control, in workers in an electric furnace steel plant with well-characterized exposure to PM with aerodynamic diameters < 10 μm (PM10). Methods: We measured global genomic DNA methylation content estimated in Alu and long interspersed nuclear element-1 (LINE-1) repeated elements, and promoter DNA methylation of iNOS (inducible nitric oxide synthase), a gene suppressed by DNA methylation and induced by PM exposure in blood leukocytes. Quantitative DNA methylation analysis was performed through bisulfite PCR pyrosequencing on blood DNA obtained from 63 workers on the first day of a work week (baseline, after 2 days off work) and after 3 days of work (postexposure). Individual PM10 exposure was between 73.4 and 1,220 μg/m3. Results: Global methylation content estimated in Alu and LINE-1 repeated elements did not show changes in postexposure measures compared with baseline. PM10 exposure levels were negatively associated with methylation in both Alu [β = –0.19 %5-methylcytosine (%5mC); p = 0.04] and LINE-1 [β = –0.34 %5mC; p = 0.04], likely reflecting long-term PM10 effects. iNOS promoter DNA methylation was significantly lower in postexposure blood samples compared with baseline (difference = –0.61 %5mC; p = 0.02). Conclusions: We observed changes in global and gene specific methylation that should be further characterized in future investigations on the effects of PM

    Association between leukocyte telomere shortening and exposure to traffic pollution: a cross-sectional study on traffic officers and indoor office workers

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    BACKGROUND: Telomere shortening in blood leukocytes has been associated with increased morbidity and death from cardiovascular disease and cancer, but determinants of shortened telomeres, a molecular feature of biological aging, are still largely unidentified. Traffic pollution has been linked with both cardiovascular and cancer risks, particularly in older subjects. Whether exposure to traffic pollution is associated with telomere shortening has never been evaluated. METHODS: We measured leukocyte telomere length (LTL) by real-time PCR in blood DNA from 77 traffic officers exposed to high levels of traffic pollutants and 57 office workers (referents). Airborne benzene and toluene, as tracers for traffic exposure, were measured using personal passive samplers and gas-chromatography/flame-ionization detector analysis. We used covariate-adjusted multivariable models to test the effects of the exposure on LTL and obtain adjusted LTL means and 95\% Confidence Intervals (CIs). RESULTS: Adjusted mean LTL was 1.10 (95\%CI 1.04-1.16) in traffic officers and 1.27 in referents (95\%CI 1.20-1.35) [p < 0.001]. LTL decreased in association with age in both traffic officers (p = 0.01) and referents (p = 0.001), but traffic officers had shorter LTL within each age category. Among traffic officers, adjusted mean relative LTL was shorter in individuals working in high (n = 45, LTL = 1.02, 95\%CI 0.96-1.09) compared to low traffic intensity (n = 32, LTL = 1.22, 95\%CI 1.13-1.31) [p < 0.001]. In the entire study population, LTL decreased with increasing levels of personal exposure to benzene (p = 0.004) and toluene (p = 0.008). CONCLUSION: Our results indicate that leukocyte telomere length is shortened in subjects exposed to traffic pollution, suggesting evidence of early biological aging and disease risk
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