First-trimester biochemical and molecular diagnoses using chorionic villi: High accuracy in the U.S. collaborative study

The accuracy of biochemical and molecular prenatal diagnoses using chorionic villi as the fetal source was assessed by seven centres participating in the NICHD collaborative study on the safety and accuracy of chorionic villus sampling (CVS) and amniocentesis. Of 601 pregnancies studied, biochemical methods were used to determine the diagnosis in 283 fetuses at risk for 35 different metabolic disorders. Fifteen different lysosomal storage diseases accounted for 81 per cent of the biochemical prenatal diagnoses performed, with 57 per cent of these pregnancies at risk for Tay-Sachs disease. No errors were made in the biochemical diagnoses that predicted affected or unaffected fetuses. However, the diagnoses of certain disorders (e.g., mucopolysacchariodosis type IH, metachromatic leukodystrophy, and Krabbe disease) occasionally required confirmatory studies in cultured amniocytes because the enzyme results were inconclusive in direct and/or cultured villi or due to the presence of a pseudodeficiency allele. Of these, only the diagnosis of a fetus at risk for Krabbe disease remained inconclusive after special studies to discriminate between mutant and pseudodeficiency alleles. Recombinant DNA techniques were used to predict the diagnosis of 318 fetuses at risk for 16 different disorders in which the defective disease gene could be detected either directly or by linkage analysis to a nearby polymorphic marker. Of these, 32 per cent were for haemoglobinopathies, 25 per cent for cystic fibrosis, 24 per cent for Duchenne or Becker muscular dystrophy, and 7 per cent for haemophilias. Pregnancies at risk for known disorders with specific molecular lesions (e.g., sickle cell disease) were accurately diagnosed in direct and/or cultured villi. Diagnoses requiring analyses with closely linked polymorphic markers were occasionally uninformative or inconclusive. Maternal contamination was not reported in any biochemical or molecular-based diagnosis. These studies document the high accuracy and rapidity of both biochemical and mutation-specific prenatal diagnoses with direct and cultured chorionic villi.     

Transvaginal chorionic villus sampling using transabdominal ultrasound guidance

Transvaginal chorionic villus sampling (CVS) using concurrent transabdominal ultrasound guidance was performed in six women who desired CVS but could not be offered transcervical or transabdominal approaches because of uterine position and placental location. Satisfactory amounts of chorionic villi were obtained in all six cases with no maternal discomfort, an occurrence that contrasts with our experience in transvaginal CVS using endovaginal ultrasound guidance. We believe that transvaginal CVS using concurrent transabdominal ultrasound guidance warrants consideration as an alternative technique for first-trimester CVS in selected patients.     

CBM-CFS3: A model of carbon-dynamics in forestry and land-use change implementing IPCC standards

The scientific community, forest managers, environmental organizations, carbon-offset trading systems and policy-makers require tools to account for forest carbon stocks and carbon stock changes. In this paper we describe updates to the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3) implemented over the past years. This model of carbon-dynamics implements a Tier 3 approach of the Intergovernmental Panel on Climate Change (IPCC) Good Practice Guidance for reporting on carbon stocks and carbon stock changes resulting from Land Use, Land-use Change and Forestry (LULUCF). The CBM-CFS3 is a generic modelling framework that can be applied at the stand, landscape and national levels. The model provides a spatially referenced, hierarchical system for integrating datasets originating from different forest inventory and monitoring programs and includes a structure that allows for tracking of land areas by different land-use and land-use change classes. Ecosystem pools in CBM-CFS3 can be easily mapped to IPCC-defined pools and validated against field measurements. The model uses sophisticated algorithms for converting volume to biomass and explicitly simulates individual annual disturbance events (natural and anthropogenic). Several important scientific updates have been made to improve the representation of ecosystem structure and processes from previous versions of CBM-CFS. These include: (1) an expanded representation of dead organic matter and soil carbon, particularly standing dead trees, and a new algorithm for initializing these pools prior to simulation, (2) a change in the input data requirement for simulating growth from biomass to readily available merchantable volume curves, and new algorithms for converting volume to biomass, (3) improved prediction of belowground biomass, and (4) improved parameters for soil organic matter decay, fire, insect disturbances, and forest management. In addition, an operational-scale version of CBM-CFS3 is freely available and includes tools to import data in standard formats, including the output of several timber supply models that are commonly used in Canada. Although developed for Canadian forests, the flexible nature of the model has enabled it to be adapted for use in several other countries.     

Carbonyl sulfide,dimethyl sulfide and carbon disulfide in the Pearl River Delta of southern China: Impact of anthropogenic and biogenic sources

Reduced sulfur compounds (RSCs) such as carbonyl sulfide (OCS), dimethyl sulfide (DMS) and carbon disulfide (CS₂) impact radiative forcing, ozone depletion, and acid rain. Although Asia is a large source of these compounds, until now a long-term study of their emission patterns has not been carried out. Here we analyze 16 months of RSC data measured at a polluted rural/coastal site in the greater Pearl River Delta (PRD) of southern China. A total of 188 canister air samples were collected from August 2001 to December 2002. The OCS and CS₂ mixing ratios within these samples were higher in autumn/winter and lower in summer due to the influence of Asian monsoon circulations. Comparatively low DMS values observed in this coastal region suggest a relatively low biological productivity during summer months. The springtime OCS levels in the study region (574 ± 40 pptv) were 25% higher than those on other East Asia coasts such Japan, whereas the springtime CS₂ and DMS mixing ratios in the PRD (47 ± 38 pptv and 22 ± 5 pptv, respectively) were 3–30 times lower than elevated values that have been measured elsewhere in East Asia (Japan and Korea) at this time of year. Poor correlations were found among the three RSCs in the whole group of 188 samples, suggesting their complex and variable sources in the region. By means of backward Lagrangian particle release simulations, air samples originating from the inner PRD, urban Hong Kong and South China Sea were identified. The mean mixing ratio of OCS in the inner PRD was significantly higher than that in Hong Kong urban air and South China Sea marine air (p < 0.001), whereas no statistical differences were found for DMS and CS₂ among the three regions (p > 0.05). Using a linear regression method based on correlations with the urban tracer CO, the estimated OCS emission in inner PRD (49.6 ± 4.7 Gg yr^?1) was much higher than that in Hong Kong (0.32 ± 0.05 Gg yr^?1), whereas the estimated CS₂ and DMS emissions in the study region accounted for a very few percentage of the total CS₂ and DMS emission in China. These findings lay the foundation for better understanding sulfur chemistry in the greater PRD region of southern China.     

Guidelines for copper in sediments with varying properties

A major weakness of sediment quality guidelines (SQGs) is their poor ability to predict how toxicity thresholds change for different sediment types. Using species sensitivity distributions (SSDs) of copper effects data, new guidelines were derived for copper in non-sulfidic marine sediments in which organic carbon (OC) and particle size strongly influence copper bioavailability. The derived SQGs varied in a predictable manner with changes in sediment particle size and organic carbon (OC), and were shown to offer a significant improvement on the existing ‘single value’ SQG. Adequate protection for all benthic organisms is expected to be achieved for a OC-normalised copper concentration of 3.5 mg Cu g⁻¹ OC in the <63 μm sediment fraction. For short-term exposures, the equivalent acute guideline is 11 mg < 63 μm Cu g⁻¹ OC. The new SQGs incorporate a high degree of conservatism owing to the use of copper-spiked sediments and laboratory-based bioassays that were expected to result in greater metal exposure of organisms to bioavailable copper than would be expected for field-contaminated sediments with similar total copper concentrations. SQGs that vary with sediment properties were prepared in an easily referenced tabular format.     

Vertical distributions of non-methane hydrocarbons and halocarbons in the lower troposphere over northeast China

Vertical distributions of air pollutants are crucial for understanding the key processes of atmospheric transport and for evaluating chemical transport models. In this paper, we present measurements of non-methane hydrocarbons (NMHCs) and halocarbons obtained from an intensive aircraft study over northeast (NE) China in summer 2007. Most compounds exhibited a typical negative profile of decreasing mixing ratios with increasing altitude, although the gradients differed with different species. Three regional plumes with enhanced VOC mixing ratios were discerned and characterized. An aged plume transported from the northern part of the densely populated North China Plain (NCP; i.e. Beijing–Tianjin area) showed relatively higher levels of HCFC-22, 1,2-dichloroethane (1,2-DCE) and toluene. In comparison, the plume originating from Korea had higher abundances of CFC-12, tetrachloroethene (C₂Cl₄) and methyl chloride (CH₃Cl), while regional air masses from NE China contained more abundant light alkanes. By comparing these results with the earlier PEM-West B (1994) and TRACE-P (2001) aircraft measurements, continuing declining trends were derived for methyl chloroform (CH₃CCl₃), tetrachloromethane (CCl₄) and C₂Cl₄ over the greater China–northwestern Pacific region, indicating the accomplishment of China in reducing these compounds under the Montreal protocol. However, the study also provided evidence for the continuing emissions of several halocarbons in China in 2007, such as CFCs (mainly from materials in stock) and HCFCs.     

The new gold rush: fueling ethanol production while protecting water quality

Renewable fuel production, particularly grain-based ethanol, is expanding rapidly in the USA. Although subsidized grain-based ethanol may provide a competitively priced transportation fuel, concerns exist about potential environmental impacts. This contribution focuses on potential water quality implications of expanded grain-based ethanol production and potential impacts of perennial-grass-based cellulosic ethanol. Expanded grain-based ethanol will increase and intensify corn production. Even with recommended fertilizer and land conservation measures, corn acreage can be a major source of N loss to water (20-40 kg ha(-1) yr(-1)). A greater acreage of corn is estimated to increase N and P loss to water by 37% (117 million kg) and 25% (9 million kg), respectively, and measures to encourage adoption of conservation practices are essential to mitigate water quality impairments. Dried distiller's grains remaining after ethanol production from corn grain are used as animal feed and can increase manure P content and may increase N content. Cellulosic fuel-stocks from perennials such as switchgrass and woody materials have the potential to produce ethanol. Although production, storage, and handling of cellulosic materials and conversion technology are limitations, accelerating development of cellulosic ethanol has the potential to reduce dependence on grain fuel-stocks and provide water quality and other environmental benefits. All alternative fuel production technologies could have environmental impacts. There is a need to understand these impacts to help guide policy and help make programmatic and scientific decisions that avoid or mitigate unintended environmental consequences of biofuel production.     

A new urban boundary layer and dispersion parameterization for an emergency response modeling system: Tests with the Joint Urban 2003 data set

A new urban parameterization for a fast-running dispersion prediction modeling system suitable for emergency response situations is introduced. The parameterization represents the urban convective boundary layer in the dispersion prediction system developed by the National Atmospheric Release Advisory Center (NARAC) at Lawrence Livermore National Laboratory. The performance of the modeling system is tested with data collected during the field campaign Joint Urban 2003 (JU03), held in July 2003 in Oklahoma City, Oklahoma. Tests were performed using data from three intense operating periods held during daytime slightly unstable to unstable conditions. The system was run in operational mode using the meteorological data that would be available operationally at NARAC to test its effectiveness in emergency response conditions. The new parameterization considerably improves the performance of the original modeling system, by producing a better degree of pattern of correspondence between predictions and observations (as measured by Taylor diagrams), considerably reducing bias, and better capturing directional effects resulting in plume predictions whose shape and size better resemble the observations (via the measure of effectiveness). Furthermore, the new parameterization shows similar skills to urban modeling systems of similar or greater complexity. The parameterization performs the best at the three JU03 sensor arcs (1, 2, and 4 km downwind the release points), with fractional bias values ranging from 0.13 to 0.4, correlation values from 0.45 to 0.71, and centered root-mean-square error being reduced more than 50% in most cases. The urban parameterization has been tested with grid increments of 125, 250, 500 and 1000 m, performing best at 250 and 500 m. Finally, it has been found that representing the point source by a Gaussian distribution with an initial spread of particles leads to a better representation of the initial spread induced by near-source buildings, resulting in lower bias and improved correlation in downtown Oklahoma City.     

Results from a national survey of Crown prosecutors and defense counsel on impaired driving in Canada: A “System Improvements” perspective

Introduction

This article summarizes the main findings from a study designed to examine the legal process in Canada as it applies to alcohol-impaired driving from the point of view of Crown prosecutors and defense counsel, and to identify evidentiary or procedural factors that may impact the legal process, the rights of the accused, and interactions of all parts in the legal process.

Method

The data in this study were collected by means of a survey that was mailed out to the population of Crown prosecutors and defense counsel in Canada. In total, 765 prosecutors and 270 defense lawyers or an estimated 33% of all Canadian prosecutors and 15% of defense lawyers completed and returned the questionnaire. The "systems improvement" paradigm was used to interpret the findings and draw conclusions. Such an approach acknowledges the importance of the context in which countermeasures are implemented and delivered and the structures or entities used to deliver countermeasures to a designated target group.

Results

Results on type of charges and breath alcohol concentration, caseload, case outcomes, case preparation time, conviction rate at trial and overall conviction rate, reasons for acquittals and time to resolve cases are described.

Discussion

The findings from this national survey suggest that there are important challenges within the criminal justice system that impede the effective and efficient processing of impaired driving cases. Some of these challenges occur as a function of practices and policies, while others occur as a function of legislation.

Impact on industry

This study illustrates that a "system improvements" approach that acknowledges the importance of all elements of the criminal justice system and the interaction between those elements, can be beneficial in overcoming the alcohol-impaired driving problem.