1,045 research outputs found
Carboxyhaemoglobin levels and their determinants in older British men
Background: Although there has been concern about the levels of carbon monoxide exposure, particularly among older people, little is known about COHb levels and their determinants in the general population. We examined these issues in a study of older British men.Methods: Cross-sectional study of 4252 men aged 60-79 years selected from one socially representative general practice in each of 24 British towns and who attended for examination between 1998 and 2000. Blood samples were measured for COHb and information on social, household and individual factors assessed by questionnaire. Analyses were based on 3603 men measured in or close to (< 10 miles) their place of residence.Results: The COHb distribution was positively skewed. Geometric mean COHb level was 0.46% and the median 0.50%; 9.2% of men had a COHb level of 2.5% or more and 0.1% of subjects had a level of 7.5% or more. Factors which were independently related to mean COHb level included season (highest in autumn and winter), region (highest in Northern England), gas cooking (slight increase) and central heating (slight decrease) and active smoking, the strongest determinant. Mean COHb levels were more than ten times greater in men smoking more than 20 cigarettes a day (3.29%) compared with non-smokers (0.32%); almost all subjects with COHb levels of 2.5% and above were smokers (93%). Pipe and cigar smoking was associated with more modest increases in COHb level. Passive cigarette smoking exposure had no independent association with COHb after adjustment for other factors. Active smoking accounted for 41% of variance in COHb level and all factors together for 47%.Conclusion: An appreciable proportion of men have COHb levels of 2.5% or more at which symptomatic effects may occur, though very high levels are uncommon. The results confirm that smoking (particularly cigarette smoking) is the dominant influence on COHb levels
Work-related psychological health among clergywomen in Australia
Drawing on the classic model of balanced affect, the Francis Burnout Inventory conceptualises good work-related psychological health among clergy in terms of negative affect being balanced by positive affect. This paper sets out to explore the relationship between work-related psychological health and psychological type (as assessed by the Francis Psychological-Type Scales) among a sample of 212 Australian clergywomen who completed the National Church Life Survey Form L in 2006. The data supported the internal consistency reliability of the Francis Burnout Inventory and Francis Psychological-Type Scales and found that work-related psychological health was positively related to extraversion and sensing
A stochastic model updating method for parameter variability quantification based on response surface models and Monte Carlo simulation
Stochastic model updating must be considered for quantifying uncertainties inherently existing in real-world engineering structures. By this means the statistical properties,instead of deterministic values, of structural parameters can be sought indicating the parameter variability. However, the implementation of stochastic model updating is much more complicated than that of deterministic methods particularly in the aspects of theoretical complexity and low computational efficiency. This study attempts to propose a simple and cost-efficient method by decomposing a stochastic updating process into a series of deterministic ones with the aid of response surface models and Monte Carlo simulation. The response surface models are used as surrogates for original FE models in the interest of programming simplification, fast response computation and easy inverse optimization. Monte Carlo simulation is adopted for generating samples from the assumed or measured probability distributions of responses. Each sample corresponds to an individual deterministic inverse process predicting the deterministic values of parameters. Then the parameter means and variances can be statistically estimated based on all the parameter predictions by running all the samples. Meanwhile, the analysis of variance approach is employed for the evaluation of parameter variability significance. The proposed method has been demonstrated firstly on a numerical beam and then a set of nominally identical steel plates tested in the laboratory. It is found that compared with the existing stochastic model updating methods, the proposed method presents similar accuracy while its primary merits consist in its simple implementation and cost efficiency in response computation and inverse optimization
Towards quality criteria for regional public health reporting: concept mapping with Dutch experts
Background: In the Netherlands, municipal health assessments are carried out by 28 Regional Health Services, serving 418 municipalities. In the absence of guidelines, regional public health reports were developed in two pilot regions on the basis of the model and experience of national health reporting. Though they were well received and positively evaluated, it was not clear which specific characteristics determined ‘good public health reporting’. Therefore, this study was set up to develop a theoretical framework for the quality of regional public health reporting in The Netherlands. Methods: Using concept mapping as a standardized tool for conceptualization, 35 relevant reporting experts formulated short statements in two different brainstorming sessions, describing specific quality criteria of regional public health reports. After the removal of duplicates, the list was supplemented with international criteria, and the statements were sent to each participant for rating and sorting. The results were processed statistically and represented graphically. The output was discussed and interpreted, leading to the final concept map. Results: The final concept map consisted of 97 criteria, grouped into 13 clusters, and plotted in two dimensions: a ‘product’ dimension, ranging from ‘production’ to ‘content’, and a ‘context’ dimension, ranging from ‘science’ to ‘policy’. The three most important clusters were: (i) ‘solution orientation’, (ii) ‘policy relevance’ and (iii) ‘policy impact’. Conclusion: This study provided a theoretical framework for the quality of regional public health reporting, indicating relevant domains and criteria. Further work should translate domains and criteria into operational indicators for evaluating regional public health reports
Nanotechnology in Head and Neck Cancer: The Race Is On
Rapid advances in the ability to produce nanoparticles of uniform size, shape, and composition have started a revolution in the sciences. Nano-sized structures herald innovative technology with a wide range of potential therapeutic and diagnostic applications. More than 1000 nanostructures have been reported, many with potential medical applications, such as metallic-, dielectric-, magnetic-, liposomal-, and carbon-based structures. Of these, noble metallic nanoparticles are generating significant interest because of their multifunctional capacity for novel methods of laboratory-based diagnostics, in vivo clinical diagnostic imaging, and therapeutic treatments. This review focuses on recent advances in the applications of nanotechnology in head and neck cancer, with special emphasis on the particularly promising plasmonic gold nanotechnology
Who are the low-risk patients that could benefit from watch-and-wait regarding the neck?
Determination of dichlobenil and its major metabolite (BAM) in onions by PTV–GC–MS using PARAFAC2 and experimental design methodology
The optimization of a GC–MS analytical procedure which includes derivatization, Quick Easy Cheap Effective Rugged and Safe (QuEChERS) and programmed temperature vaporization (PTV) using design of experiments is performed to determine 2,6-dichlorobenzonitrile (dichlobenil) and 2,6-dichlorobenzamide (BAM) in onions, using 3,5-dichlorobenzonitrile and 2,4-dichlorobenzamide as internal standards. The use of a central composite design and two D-optimal designs, together with the desirability function, makes it possible to significantly reduce the economic, time and environmental cost of the study. The usefulness of PARAFAC2 for solving problems as the interference of unexpected derivatization artifacts unavoidably linked to some derivatization agents, or the presence of coeluents from the complex matrix, which share m/z ratios with the target compounds, is shown. The limits of decision (CCα) of the optimized procedure, 5.00 μg kg− 1 for dichlobenil and 1.55 μg kg− 1 for BAM (α = 0.05), are below the maximum residue limit (MRL) established by the EU for dichlobenil (20 μg kg− 1) in this commodity.Ministerio de Economía y Competitividad (CTQ2011-26022) and Junta
de Castilla y León (BU108A11-2
Joint modelling of confounding factors and prominent genetic regulators provides increased accuracy in genetical genomics studies.
Expression quantitative trait loci (eQTL) studies are an integral tool to investigate the genetic component of gene expression variation. A major challenge in the analysis of such studies are hidden confounding factors, such as unobserved covariates or unknown subtle environmental perturbations. These factors can induce a pronounced artifactual correlation structure in the expression profiles, which may create spurious false associations or mask real genetic association signals. Here, we report PANAMA (Probabilistic ANAlysis of genoMic dAta), a novel probabilistic model to account for confounding factors within an eQTL analysis. In contrast to previous methods, PANAMA learns hidden factors jointly with the effect of prominent genetic regulators. As a result, this new model can more accurately distinguish true genetic association signals from confounding variation. We applied our model and compared it to existing methods on different datasets and biological systems. PANAMA consistently performs better than alternative methods, and finds in particular substantially more trans regulators. Importantly, our approach not only identifies a greater number of associations, but also yields hits that are biologically more plausible and can be better reproduced between independent studies. A software implementation of PANAMA is freely available online at http://ml.sheffield.ac.uk/qtl/
Influence of slag composition on the stability of steel in alkali-activated cementitious materials
Among the minor elements found in metallurgical slags, sulfur and manganese can potentially influence the corrosion process of steel embedded in alkali-activated slag cements, as both are redox-sensitive. Particularly, it is possible that these could significantly influence the corrosion process of the steel. Two types of alkali-activated slag mortars were prepared in this study: 100% blast furnace slag and a modified slag blend (90% blast furnace slag? 10% silicomanganese slag), both activated with sodium silicate. These mortars were designed with the aim of determining the influence of varying the redox potential on the stability of steel passivation under exposure to alkaline and alkaline chloride-rich solutions. Both types of mortars presented highly negative corrosion potentials and high current density values in the presence of chloride. The steel bars extracted from mortar samples after exposure do not show evident pits or corrosion product layers, indicating that the presence of sulfides reduces the redox potential of the pore solution of slag mortars, but enables the steel to remain in an apparently passive state. The presence of a high amount of MnO in the slag does not significantly affect the corrosion process of steel under the conditions tested. Mass transport through the mortar to the metal is impeded with increasing exposure time; this is associated with refinement of the pore network as the slag continued to react while the samples were immersed
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