Airborne organic micropollutant concentrations in mosses and humus as indicators for local versus long-range sources

The concentrations of HCB, PCB, and PAH in epiphytic mosses (Hylocomium splendens and Pleurozium schreberi) and forest humus were used to study the atmospheric exposure of conferous forests in a region in central Sweden. Air concentrations of HCB and PCB were monitored around an expected source. Moss contamination was used as a short-term exposure indicator, and humus contamination was assumed to indicate long-term exposure to HCB, PCB, and PAH.The level of HCB in mosses (0.4–1.7 ng/g, by dry weight, DW) complied well with background values. The levels of PCB measured as a sum of 7 identified PCB-congeners varied between 2–28 ng/g DW, with the highest levels in moss from the western part of the region, and decreasing concentrations from west to east. Around an expected PCB source in the southeastern part of the region the concentrations of PCB declined with increasing distance from the source area. The identified PAH concentrations in mosses varied between 39 and 730 ng/g DW. The PAH content in the mosses consisted mainly of nonvolatile PAH while the more volatile PAH were below the detection limit. The levels of HCB in humus were slightly more than in mosses (0.4–3.3 ng/g DW), and complied well with the background values. Sum PCB in the humus varied between 2 and 28 ng/g DW. The PAH in the humus were mainly nonvolatile PAH. The PAH concentrations in humus varied between 99 and 2600 ng/g DW. The air concentrations of PCB around the expected source (radius <1.5 km) were higher than background levels, and most likely caused the raised levels of PCB measured in the moss nearby.     

Influence of age-related stature on the frequency of body region injury and overall injury severity in child pedestrian casualties

OBJECTIVE: The current study aims to evaluate the influence of age-related stature on the frequency of body region injury and overall injury severity in children involved in pedestrian versus motor vehicle collisions (PMVCs). METHODS: A trauma registry including the coded injuries sustained by 1,590 1- to 15-year-old pedestrian casualties treated at a level-one trauma center was categorized by stature-related age (1-3, 4-6, 7-9, 10-12, and 13-15 years) and body region (head and face, neck, thorax, abdomen and pelvic content, thoracic and lumbar spine, upper extremities, pelvis, and lower extremities). The lower extremity category was further divided into three sub-structures (thigh, leg, and knee). For each age group and body region/sub-structure the proportion of casualties with at least one injury was then determined at given Abbreviated Injury Scale (AIS) severity levels. In addition, the average and distribution of the Maximum Abbreviated Injury Score (MAIS) and the average Injury Severity Score (ISS) were determined for each age group. The calculated proportions, averages, and distributions were then compared between age groups using appropriate significance tests. RESULTS: The overall outcome showed relatively minor variation between age groups, with the average +/- SD MAIS and ISS ranging from 2.3 +/- 0.9 to 2.5 +/- 1.0 and 8.2 +/- 7.2 to 9.4 +/- 8.9, respectively. The subjects in the 1- to 3-year-old age group were more likely to sustain injury to the head, face, and torso regions than the older subjects. The frequency of AIS 2+ lower extremity injury was approximately 20% in the 1- to 3-year-old group, but was twice as high in the 4- to 12-years age range and 2.5 times as high in the oldest age group. The frequency of femur fracture increased from 10% in the youngest group to 26% in the 4- to 6-year-old group and then declined to 14% in the 10- to 15-years age range. The frequency of tibia/fibula fracture increased monotonically with group age from 8% in the 1- to 3-year-old group to 31% in the 13- to 15-year-old group. CONCLUSIONS: While the overall outcome of child pedestrian casualties appears to be relatively constant across the pediatric stature range considered ( approximately 74-170 cm), subject height seems to affect the frequency of injury to individual body regions, including the thorax and lower extremities. This suggests that vehicle safety designers need not only account for the difference in injury patterns between adult and pediatric pedestrian casualties, but also for the variation within the pediatric group.     

Evaluating common drivers for color,iron and organic carbon in Swedish watercourses

The recent browning (increase in color) of surface waters across much of the northern hemisphere has important implications for light climate, ecosystem functioning, and drinking water treatability. Using log-linear regressions and long-term (6–21 years) data from 112 Swedish watercourses, we identified temporal and spatial patterns in browning-related parameters [iron, absorbance, and total organic carbon (TOC)]. Flow variability and lakes in the catchment were major influences on all parameters. Co-variation between seasonal, discharge-related, and trend effects on iron, TOC, and absorbance were dependent on pH, landscape position, catchment size, latitude, and dominant land cover. Large agriculture-dominated catchments had significantly larger trends in iron, TOC, and water color than small forest catchments. Our results suggest that while similarities exist, no single mechanism can explain the observed browning but show that multiple mechanisms related to land cover, climate, and acidification history are responsible for the ongoing browning of surface waters.     

Simulated Impacts of Climate Change on Current Farming Locations of Striped Catfish (Pangasianodon hypophthalmus; Sauvage) in the Mekong Delta,Vietnam

In Vietnam, culturing striped catfish makes an important contribution to the Mekong Delta’s economy. Water level rise during rainy season and salt intrusion during dry season affect the water exchange and quality for this culture. Sea level rise as a consequence of climate change will worsen these influences. In this study, water level rise and salt water intrusion for three sea level rise (SLR) scenarios (i.e., +30, +50, and +75 cm) were simulated. The results showed that at SLR +50, the 3-m-flood level would spread downstream and threaten farms located in AnGiang, DongThap and CanTho provinces. Rising salinity levels for SLR +75 would reduce the window appropriate for the culture in SocTrang and BenTre provinces, and in TienGiang’s coastal districts. Next to increasing dikes to reduce the impacts, the most tenable and least disruptive option to the farming community would be to shift to a salinity tolerant strain of catfish.     

Plant and Soil Responses to High and Low Diversity Grassland Restoration Practices

The USDA’s Conservation Reserve Program (CRP) has predominantly used only a few species of dominant prairie grasses (CP2 practice) to reduce soil erosion, but recently has offered a higher diversity planting practice (CP25) to increase grassland habitat quality. We quantified plant community composition in CP25 and CP2 plantings restored for 4 or 8 years and compared belowground properties and processes among restorations and continuously cultivated soils in southeastern Nebraska, USA. Relative to cultivated soils, restoration increased soil microbial biomass (P = 0.033), specifically fungi (P < 0.001), and restored soils exhibited higher rates of carbon (C) mineralization (P = 0.010). High and low diversity plantings had equally diverse plant communities; however, CP25 plantings had greater frequency of cool-season (C₃) grasses (P = 0.007). Older (8 year) high diversity restorations contained lower microbial biomass (P = 0.026), arbuscular mycorrhizal fungi (AMF) biomass (P = 0.003), and C mineralization rates (P = 0.028) relative to 8 year low diversity restorations; older plantings had greater root biomass than 4 year plantings in all restorations (P = 0.001). Low diversity 8 year plantings contained wider root C:N ratios, and higher soil microbial biomass, microbial community richness, AMF biomass, and C mineralization rate relative to 4 year restorations (P < 0.050). Net N mineralization and nitrification rates were lower in 8 year than 4 year high diversity plantings (P = 0.005). We attributed changes in soil C and N pools and fluxes to increased AMF associated with C₄ grasses in low diversity plantings. Thus, reduced recovery of AMF in high diversity plantings restricted restoration of belowground microbial diversity and microbially-mediated soil processes over time.     

Factorial validity of the Maslach burnout inventory—Dutch version (MBI‐NL) among dentists

Burnout is considered to be a long‐term reaction to occupational stress. It is characterized by emotional exhaustion, depersonalization, and diminished personal accomplishment. The most widely used instrument to measure burnout is the Maslach Burnout Inventory (MBI), developed by Maslach and Jackson (1986). From this instrument, Schaufeli and van Dierendonck (1995a) developed a somewhat modified Dutch version: the MBI‐NL. Burnout among dentists has hardly been studied. Since the professions that the MBI‐NL was developed upon are quite different from dentistry, the aim of this study was to test the three‐factor structure of the MBI‐NL against alternative structures among dentists. Both principal components analysis (PCA) and confirmatory factor analysis (CFA) were examined in a representative sample of 709 Dutch general dental practitioners (75 per cent response rate). The three‐factor structure shows the best fit to the underlying data, while other psychometric qualities are very satisfactory. It is concluded that the three‐factor structure of the MBI‐NL is superior to alternative structures, and that the MBI‐NL is a highly suitable instrument to measure burnout among dentists. Copyright © 1999 John Wiley & Sons, Ltd.     

Drugs and driving

The authors present a global overview on the issue of drugs and driving covering four major areas: (1) Epidemiology and Prevalence--which reviews epidemiological research, summarizes available information, discusses the methodological shortcomings of extant studies, and makes recommendations for future research to better define prevalence and epidemiology; (2) Effects of Medicinal and Illegal Drugs on Driving Performance--focuses on the six classes of drugs most often found in impaired and injured drivers, draws conclusions regarding the risk of these drugs to traffic safety and discusses the need for additional research; (3) Toxicological Issues--discusses ways to identify drug users via behavioral testing and analytical techniques, reviews the approaches used by different countries, screening and confirmation techniques, alternative specimens (e.g., urine, oral fluid, sweat), and how rapid roadside testing could be coupled with behavioral and laboratory testing in an effective approach to identifying and prosecuting drugged drivers; (4) Driving Under the Influence of Drugs [DUID] Laws--provides an overview of DUID laws in the United States and Europe, discusses the basic tenets of these laws, the various types of DUID statutes, the reasons why many existing laws hinder the prosecution of drugged drivers and the rationale for developing per se legislation as a strategy to more effectively manage the drugged driver problem.     

Ethnic differences in determinants of participation and non-participation in prenatal screening for Down syndrome: A theoretical framework

Objective To develop a theoretical framework for analysing ethnic differences in determinants of participation and non-participation in prenatal screening for Down syndrome. Methods We applied Weinstein's Precaution Adoption Process (PAP) Model to the decision of whether or not to participate in prenatal screening for Down syndrome. The prenatal screening stage model was specified by reviewing the empirical literature and by data from seven focus group interviews with Dutch, Turkish and Surinamese pregnant women in the Netherlands. Results We identified 11 empirical studies on ethnic differences in determinants of participation and non-participation in prenatal screening for Down syndrome. The focus group interviews showed that almost all stages and determinants in the stage model were relevant in women's decision-making process. However, there were ethnic variations in the relevance of determinants, such as beliefs about personal consequences of having a child with Down syndrome or cultural and religious norms. Discussion The prenatal screening stage model can be applied as a framework to describe the decision-making process of pregnant women from different ethnic backgrounds. It provides scope for developing culturally sensitive, tailored methods to guide pregnant women towards informed decision-making on participation or non-participation in prenatal screening for Down syndrome. Copyright © 2007 John Wiley & Sons, Ltd.     

瑞典水文变化-气候变化影响模拟

温室效应加剧导致的气候变化将会引起水文系统的变化.随着气候要素的变化,水文变化将会在全球呈现出区域差异性.因此,有必要开展局地和区域尺度上的水文变化影响研究,评价不同区域将会受到怎样的影响.本研究旨在对广泛的瑞典流域上气候变化的水文影响(响应)进行评估.我们采用不同的方法,将气候模型中产生的气候变化信号转换输入到水文模型中.利用瑞典区域气候模拟计划(SWECLIM)生成的区域气候情景,我们进行了几次水文模型模拟研究.得出的基本结论是根据流域的地理位置处于瑞典北部或南部,气候变化对河道水流的分区影响是显著不同的.此外,预测的水文变化不仅与用于确定区域气候模型边界条件的全球气候模型的选择有关,而且与人为气体排放情景的选取有关.     

Inspiring England's urban fringes: multi-functionality and planning

The urban fringe has been described as 'planning's last frontier'; a zone of transition and interface between town and country where a broad variety of land uses and activities come together, and where development pressure is often intense. In this paper, we argue that the urban fringe possesses special characteristics, making it more than simply a transitional landscape. These characteristics centre on patterns of land use, biodiversity and leisure/development opportunity which are unique to the urban edge and to land extending away from built-up areas. The uniqueness, diversity and particular dynamics of the urban fringe demands a special brand of planning and management response. Therefore we suggest that the principle of 'multi-functionality' provides a framework for action, showing how diversity can be managed and supported. Through brief case studies, we demonstrate how functional interactions at the urban fringe might be promoted in the future.