797 research outputs found
The Association between Fatal Coronary Heart Disease and Ambient Particulate Air Pollution: Are Females at Greater Risk?
The purpose of this study was to assess the effect of long-term ambient particulate matter (PM) on risk of fatal coronary heart disease (CHD). A cohort of 3,239 nonsmoking, non-Hispanic white adults was followed for 22 years. Monthly concentrations of ambient air pollutants were obtained from monitoring stations [PM < 10 μm in aerodynamic diameter (PM(10)), ozone, sulfur dioxide, nitrogen dioxide] or airport visibility data [PM < 2.5 μm in aerodynamic diameter (PM(2.5))] and interpolated to ZIP code centroids of work and residence locations. All participants had completed a detailed lifestyle questionnaire at baseline (1976), and follow-up information on environmental tobacco smoke and other personal sources of air pollution were available from four subsequent questionnaires from 1977 through 2000. Persons with prevalent CHD, stroke, or diabetes at baseline (1976) were excluded, and analyses were controlled for a number of potential confounders, including lifestyle. In females, the relative risk (RR) for fatal CHD with each 10-μg/m(3) increase in PM(2.5) was 1.42 [95% confidence interval (CI), 1.06–1.90] in the single-pollutant model and 2.00 (95% CI, 1.51–2.64) in the two-pollutant model with O(3). Corresponding RRs for a 10-μg/m(3) increase in PM(10-2.5) and PM(10) were 1.62 and 1.45, respectively, in all females and 1.85 and 1.52 in postmenopausal females. No associations were found in males. A positive association with fatal CHD was found with all three PM fractions in females but not in males. The risk estimates were strengthened when adjusting for gaseous pollutants, especially O(3), and were highest for PM(2.5). These findings could have great implications for policy regulations
Chronic Obstructive Pulmonary Disease Mortality in Diesel-Exposed Railroad Workers
Diesel exhaust is a mixture of combustion gases and ultrafine particles coated with organic compounds. There is concern whether exposure can result in or worsen obstructive airway diseases, but there is only limited information to assess this risk. U.S. railroad workers have been exposed to diesel exhaust since diesel locomotives were introduced after World War II, and by 1959, 95% of the locomotives were diesel. We conducted a case–control study of railroad worker deaths between 1981 and 1982 using U.S. Railroad Retirement Board job records and next-of-kin smoking, residential, and vitamin use histories. There were 536 cases with chronic obstructive pulmonary disease (COPD) and 1,525 controls with causes of death not related to diesel exhaust or fine particle exposure. After adjustment for age, race, smoking, U.S. Census region of death, vitamin use, and total years off work, engineers and conductors with diesel-exhaust exposure from operating trains had an increased risk of COPD mortality. The odds of COPD mortality increased with years of work in these jobs, and those who had worked ≥ 16 years as an engineer or conductor after 1959 had an odds ratio of 1.61 (95% confidence interval, 1.12–2.30). These results suggest that diesel-exhaust exposure contributed to COPD mortality in these workers. Further study is needed to assess whether this risk is observed after exposure to exhaust from later-generation diesel engines with modern emission controls
Performance of a tool to identify different types of self-reported sexual risk among women attending a contraception and sexual health clinic: results of a cross-sectional survey
INTRODUCTION: A clinical prediction rule (CPR) using psychosocial questions was previously derived to target sexual healthcare in general practice by identifying women at risk of unintended pregnancy (UIP) and sexually transmitted infections (STIs). This psychosocial CPR may help target resources within contraception and sexual health (CASH) services. This study investigated how well it predicted recent self-reported risk of UIP and STI acquisition among women attending a CASH clinic.
METHODS: Female patients aged 16-44 years attending a CASH clinic in South-East England were offered a questionnaire on arrival. This comprised psychosocial questions, and others addressing three sexual risks: (1) two or more male sexual partners in the last year (2+P), (2) risk of STI acquisition through most recent partner and (3) risk of UIP in the last 6 months. A CPR score was calculated for each participant and cross-tabulated against self-report of each sexual risk to estimate CPR sensitivity and specificity.
RESULTS: The psychosocial questions predicting 2+P had sensitivity 83.2% (95% CI 79.3% to 86.5%) and specificity 56.1% (95% CI 51.3%-60.6%). Those predicting combined 2+P and/or risk of STI acquisition through most recent partner had a sensitivity of 89.1% (95% CI 85.7%-91.8%) and specificity of 43.7% (95% CI 39.0%-48.5%). Questions predicting risk of UIP in the last 6 months had a sensitivity of 82.5% (95% CI 78.6%-86.0%) and specificity of 48.3% (95% CI 43.4%-53.1%).
CONCLUSIONS: The CPR demonstrated good sensitivity but low specificity, so may be suited to triaging or stratifying which interventions to offer CASH patients and by which mode (eg, online vs face-to-face). Further investigation of causal links between psychosocial factors and sexual risk is warranted to support development of psychosocial interventions for this patient group
Messy entanglements: research assemblages in heart transplantation discourses and practices
The paper engages with a variety of data around a supposedly single biomedical event, that of heart transplantation. In conventional discourse, organ transplantation constitutes an unproblematised form of spare part surgery in which failing biological components are replaced by more efficient and enduring ones, but once that simple picture is complicated by employing a radically interdisciplinary approach, any biomedical certainty is profoundly disrupted. Our aim, as a cross-sectorial partnership, has been to explore the complexities of heart transplantation by explicitly entangling research from the arts, biosciences and humanities without privileging any one discourse. It has been no easy enterprise yet it has been highly productive of new insights. We draw on our own ongoing funded research with both heart donor families and recipients to explore our different perceptions of what constitutes data and to demonstrate how the dynamic entangling of multiple data produces a constitutive assemblage of elements in which no one can claim priority. Our claim is that the use of such research assemblages and the collaborations that we bring to our project breaks through disciplinary silos to enable a fuller comprehension of the significance and experience of heart transplantation in both theory and practice
A Method to Estimate the Chronic Health Impact of Air Pollutants in U.S. Residences
Background: Indoor air pollutants (IAPs) cause multiple health impacts. Prioritizing mitigation options that differentially affect individual pollutants and comparing IAPs with other environmental health hazards require a common metric of harm
The X-ray lightcurve of Sgr A* over the past 150 years inferred from Fe-Ka line reverberation in Galactic Centre molecular clouds
We examine the temporal and spectral properties of nine Fe-Ka bright
molecular clouds within about 30 pc of Sgr A*, in order to understand and
constrain the primary energising source of the Fe fluorescence. Significant
Fe-Ka variability was detected, with a spatial and temporal pattern consistent
with that reported in previous studies. The main breakthrough that sets our
paper apart from earlier contributions on this topic is the direct measurement
of the column density and the Fe abundance of the MCs in our sample. We used
the EW measurements to infer the average Fe abundance within the clouds to be
1.60.1 times solar. The cloud column densities derived from the spectral
analysis were typically of the order of 10 cm, which is
significantly higher than previous estimates. This in turn has a significant
impact on the inferred geometry and time delays within the cloud system. Past
X-ray activity of Sgr A* is the most likely source of ionisation within the
molecular clouds in the innermost 30 pc of the Galaxy. In this scenario, the
X-ray luminosity required to excite these reflection nebulae is of the order of
10 erg s, significantly lower than that estimated for the
Sgr B2 molecular cloud. Moreover, the inferred Sgr A* lightcurve over the past
150 years shows a long-term downwards trend punctuated by occasional
counter-trend brightening episodes of at least 5 years duration. Finally, we
found that contributions to the Fe fluorescence by X-ray transient binaries and
cosmic-ray bombardment are very likely, and suggest possible ways to study this
latter phenomenon in the near future.Comment: 23 pages, 14 figures, accepted for publication in Astronomy &
Astrophysic
PenQuest Volume 4, Number 1
Table of Contents for this Volume:
Poetry by Brad Ross
Untitled by Bruce Abbey
it\u27s back by Leslie M. Brown
De-thinging the Thingumbob by Michael R. McMahon
Untitled by Mark Davis
Fractures by Peggy De Broux
Until I Knew by Lori Loper
Untitled by Mark Davis
The Local Art of Darkness by Michael R. McMahon
Home by Peggy de Broux
Untitled by Bruce Abbey
Hooked by Robert M. Hart
Parable of the Balloon (Demonstrated by the Poet to his Dog) by Michael R. McMahon
Flight by Brad Ross
The Stucco Room by Peggy de Broux
Growing Up In America by E. R. Sukovich
I Hear Them Scratching by Brad Ross
It\u27s In The Bag by Susan Torode
Untitled by Mark Davis
Lawrence at Seventeen Coming Home by Brad Ross
Untitled by Brad Ross
Jere\u27s Antiques by Susan Torode
Untitled by Bruce Abbey
Simpson\u27s, for lunch, of course by Joni E. Dooley
Untitled by Mark Davis
Moments For an autobiography by Jocelyn W. Griffo
Untitled by Bruce Abbe
Evaluation of the Algorithms and Parameterizations for Ground Thawing and Freezing Simulation in Permafrost Regions
Ground thawing and freezing depths (GTFDs) strongly influence the hydrology and energy balances of permafrost regions. Current methods to simulate GTFD differ in algorithm type, soil parameterization, representation of latent heat, and unfrozen water content. In this study, five algorithms (one semiempirical, two analytical, and two numerical), three soil thermal conductivity parameterizations, and three unfrozen water parameterizations were evaluated against detailed field measurements at four field sites in Canada’s discontinuous permafrost region. Key findings include: (1) de Vries’ parameterization is recommended to determine the thermal conductivity in permafrost soils; (2) the three unfrozen water parameterization methods exhibited little difference in terms of GTFD simulations, yet the segmented linear function is the simplest to be implemented; (3) the semiempirical algorithm reasonably simulates thawing at permafrost sites and freezing at seasonal frost sites with site-specific calibration. However, large interannual and intersite variations in calibration coefficients limit its applicability for dynamic analysis; (4) when driven by surface forcing, analytical algorithms performed marginally better than the semiempirical algorithm. The inclusion of bottom forcing improved analytical algorithm performance, yet their results were still poor compared with those achieved by numerical algorithms; (5) when supplied with the optimal inputs, soil parameterizations, and model configurations, the numerical algorithm with latent heat treated as an apparent heat capacity achieved the best GTFD simulations among all algorithms at all sites. Replacing the observed bottom temperature with a zero heat flux boundary condition did not significantly reduce simulation accuracy, while assuming a saturated profile caused large errors at several sites
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