Search

The translation process with versions of the instruments for use with pregnant women from Puerto Rico is discussed. The procedure of back translation was chosen as the most reliable method for translation of instruments.

Background Data routinely captured in clinical registries may be leveraged to enhance efficiency of prospective research. The quality of registry data for this purpose has not been studied, however. We evaluated the completeness and accuracy of perioperative data within congenital heart centers’ local surgical registries. Methods Within 12 Pediatric Heart Network (PHN) sites, we evaluated 31 perioperative variables (and their subcategories, totaling 113 unique fields) collected via sites’ local clinical registries for submission to The Society of Thoracic Surgeons Database, compared with chart review by PHN research coordinators. Both used standard STS definitions. Data were collected on 10 subjects for 2 to 5 procedures/site and adjudicated by the study team. Completeness and accuracy (agreement of registry data with medical record review by PHN coordinator, adjudicated by the study team) were evaluated. Results A total of 56,500 data elements were collected on 500 subjects. With regard to data completeness, 3.1% of data elements were missing from the registry, 0.6% from coordinator-collected data, and 0.4% from both. Overall, registry data accuracy was 98%. In total, 94.7% of data elements were both complete/non-missing and accurate within the registry, although there was variation across data fields and sites. Mean total time for coordinator chart review per site was 49.1 hours versus 7.0 hours for registry query. Conclusions This study suggests that existing surgical registry data constitute a complete, accurate, and efficient information source for prospective research. Variability across data fields and sites also suggest areas for improvement in some areas of data quality. [ABSTRACT FROM AUTHOR]

Current signal systems for managing road traffic in many urban areas around the world lack a coordinated approach to detecting the spatial and temporal evolution of congestion across control regions within city networks. This severely inhibits these systems’ ability to detect reliably, on a strategic level, the onset of congestion and implement effective preventative action. As traffic is a time-dependent and non-linear system, Chaos Theory is a prime candidate for application to Urban Traffic Control (UTC) to improve congestion and pollution management. Previous applications have been restricted to relatively uncomplicated motorway and inter-urban networks, arguably where the associated problems of congestion and vehicle emissions are less severe, due to a general unavailability of high-resolution temporal and spatial data that preserve the variability in short-term traffic patterns required for Chaos Theory to work to its full potential. This paper argues that this restriction can now be overcome due to the emergence of new sources of high-resolution data and large data storage capabilities. Consequently, this opens up the real possibility for a new generation of UTC systems that are better able to detect the dynamic states of traffic and therefore more effectively prevent the onset of traffic congestion in urban areas worldwide. [ABSTRACT FROM AUTHOR]

Heavy Goods Vehicles, HGV, and Light Goods Vehicles, LGV, are a significant contributor to air pollution problems in urban areas. This paper quantifies the contribution to the environment of the deliveries to a single, large city employer addressing a research gap in the literature. Analysis of data from comprehensive surveys carried out over two years demonstrated that freight delivery traffic generated by an urban establishment with multiple properties in a compact urban setting, is characterised by a high proportion of LGV consistent with recent national and international trends. Also, despite freight traffic is only 10% of local traffic, more than 50% serves the single establishment, suggesting a different approach to policy making driven by the employer should be explored. The modelling results showed, relatively, the largest contribution to total emissions comes from HGVs in the AM peak, 13.8%, 43.7%, 9.2% for CO2, NOx and PM respectively. LGV contribute less, with 5.5%, 3.8%, 6% for CO2, NOx and PM respectively but more responsible for local congestion due to their numbers. This research is the first known study of its type and with the unique combination of measurement and traffic microsimulation allowed consideration of more effective traffic management strategies as well as providing evidence to support a consolidation centre for deliveries outside the city with fewer electric or low emissions last mile vehicles reducing substantially the environmental impact. The research outputs are relevant to many other similar cases in UK and Europe. The paper contributes to the ongoing development of research and policy looking to achieve sustainable urban logistics through receiver and purchasing led initiatives. [ABSTRACT FROM AUTHOR]

Background The timely publication of findings in peer-reviewed journals is a primary goal of clinical research. In clinical trials, the processes leading to publication can be complex from choice and prioritization of analytic topics through to journal submission and revisions. As little literature exists on the publication process for multicenter trials, we describe the development, implementation, and effectiveness of such a process in a multicenter trial. Methods The Hepatitis C Antiviral Long-Term Treatment against Cirrhosis (HALT-C) trial included a data coordinating center (DCC) and clinical centers that recruited and followed more than 1,000 patients. Publication guidelines were approved by the steering committee, and the publications committee monitored the publication process from selection of topics to publication. Results A total of 73 manuscripts were published in 23 peer-reviewed journals. When manuscripts were closely tracked, the median time for analyses and drafting of manuscripts was 8 months. The median time for data analyses was 5 months and the median time for manuscript drafting was 3 months. The median time for publications committee review, submission, and journal acceptance was 7 months, and the median time from analytic start to journal acceptance was 18 months. Conclusions Effective publication guidelines must be comprehensive, implemented early in a trial, and require active management by study investigators. Successful collaboration, such as in the HALT-C trial, can serve as a model for others involved in multidisciplinary and multicenter research programs. [ABSTRACT FROM AUTHOR]

A method is proposed to relate essentially instantaneous roadside measurements of vehicle exhaust emissions, with emission results generated over a type approval driving cycle. An urban remote sensing data set collected in 2008 is used to define the dynamic relationship between vehicle specific power and exhaust emissions, across a range of vehicle ages, engine capacities, and fuel types. The New European Driving Cycle is synthesized from the remote sensing data using vehicle specific power to characterize engine load, and the results compared with official published emissions data from vehicle type approval tests over the same driving cycle. Mean carbon monoxide emissions from gasoline-powered cars ≤3 years old measured using remote sensing are found to be 1.3 times higher than published original type approval test values; this factor increases to 2.2 for cars 4-8 years old, and 6.4 for cars 9-12 years old. The corresponding factors for diesel cars are 1.1, 1.4, and 1.2, respectively. Results for nitric oxide, hydrocarbons, and particulate matter are also reported. The findings have potential implications for the design of traffic management interventions aimed at reducing emissions, fleet inspection and maintenance programs, and the specification of vehicle emission models. [ABSTRACT FROM AUTHOR]

This paper provides an assessment of the tools required to fulfil the air quality management role now expected of local authorities within the UK. The use of a range of pollution monitoring tools in assessing air quality is discussed and illustrated with evidence from a number of previous studies of urban background and roadside pollution monitoring in Leicester. A number of approaches to pollution modelling currently available for deployment are examined. Subsequently, the modelling and monitoring tools are assessed against the requirements of local authorities establishing air quality management areas. Whilst the paper examines UK-based policy, the study is of wider international interest. [ABSTRACT FROM AUTHOR]

In London, the recent analysis of ambient measurements has shown that directly emitted (primary) nitrogen dioxide has increasehttp://bkstrm. Epnet. Com:8080/ai/images/save. GifSaved as a fraction of total nitrogen oxides from road transport sources. These increases appear to be mostly due to certain after-treatment devices, such as oxidation catalysts and particle filters fitted to diesel vehicles. This study uses a constrained simple chemical model to predict hourly concentrations of at a busy roadside site in central London to investigate the dependence of peak hourly concentrations of on the level of assumed primary emitted by road vehicles. The model performance is shown to be good across the full range of hourly and concentrations over seven years. Monte Carlo simulations are used to predict future hourly concentrations and the probability of exceeding the EU hourly limit value for by considering the model errors, uncertainties in future trends and the inter-annual variability of meteorology. It is shown that if the emission ratio of 22. 0% by volume, as calculated at the end of 2004, is sustained into the future, it is likely that the hourly EU limit value will not be met. However, the probability of not meeting the limit value in 2010 depends strongly on the meteorological year and varies from 16% to 88% depending on the year considered. This work shows that further increases in the ratio beyond those observed at the end of 2004 would considerably increase the probability of the EU hourly limit for being exceeded. Additionally, the analysis of road network emissions in London shows that many other roads are likely to be at risk from exceeding the hourly limit value. Further work is required to improve the quantification of in vehicle exhausts to determine the likely future risks of exceeding the hourly limit value in other European cities. [Copyright &y& Elsevier]

Abstract: Plans to build a third runway at London Heathrow (LHR) airport have been held back because of concerns that the development would lead to annual mean concentrations of nitrogen dioxide (NO2) in excess of the EU Directive limit value, which must be met by 2010. The dominant effect of other sources of NO x close to the airport, primarily from road traffic, makes it difficult to detect and quantify the contribution made by the airport to local NO x and NO2 concentrations. This work presents approaches that aim to detect and quantify the airport contribution to NO x concentrations for a network of seven measurement sites close to the airport. Two principal approaches are used. First, a graphical technique using bivariate polar plots that develops the idea of a pollution rose is used to help discriminate between different source types. The sampling uncertainties associated with the technique have been calculated through a randomised re-sampling approach. Second, the unique pattern of aircraft activity at LHR enables data filtering techniques to be used to statistically verify the presence of aircraft sources. It is shown that aircraft NO x sources can be detected to at least 2.6km from the airport, even though the airport contribution at that distance is very small. Using these approaches, estimates have been made of the airport contribution to long-term mean concentrations of NO x and NO2. At the airfield boundary we estimate that approximately 27% of the annual mean NO x and NO2 is due to airport operations. At background locations 2–3km downwind of the airport we estimate that the upper limit of the airport contribution to be less than 15% (<10μgm−3). This work also provides approaches that would help validate and refine dispersion modelling studies used for airport assessments. [Copyright &y& Elsevier]