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461.
This paper presents a methodology for the calculation of atmospheric stability classes in correlation with wind velocities for six sites of the Greek territory, namely Ellinikon (Athens), Elefsis, Megara, Heraklion, Chania and Patras, based on real data obtained from meteorological observations in these sites and on computations related with their geographic position. In addition to that, a comparison is presented of the atmospheric stability classes produced with online measurements for the Ellinikon (Athens) site with significant coincidence in the results.

These calculated values of the meteorological parameters (particularly of atmospheric stability) are most appropriate for uncertainty calculations in quantified risk assessments (QRAs) of hazardous installations sited in the above-mentioned areas, especially when risk and safety-related decisions need to be taken. Consequent results obtained with these parameters are more realistic compared to the “classical” assumption of D5/F2, which leads to significant diversification in the estimation of risk.  相似文献   

462.
PROBLEM: Injuries are the leading cause of death for adolescents in the United States. METHODS: This study longitudinally examined three psychological mediators of injury among 3,081 youths in agricultural settings: (a) safety consciousness, (b) dangerous risk taking, and (c) safety knowledge. These variables are examined within a nomological network of contextual variables. RESULTS: Cross-sectional results revealed that safety consciousness and dangerous risk taking were the strongest predictors of reported injury at Time 1 and Time 2. Safety knowledge had an unexpected negative association with injury, albeit weak. As predicted, participating in safety activities was positively associated with safety consciousness, and time spent working was strongly associated with safety knowledge. Furthermore, self-esteem had both positive and negative safety outcomes, suggesting a more complex functioning. Males exhibited fewer safety cognitions than females as predicted. Longitudinal data also revealed that injury at Time 1 and dangerous risk taking were the strongest predictors of Time 2 injury. IMPACT ON INDUSTRY: Results from this study emphasize the importance of assessing dangerous risk-taking perceptions when attempting to predict future injuries.  相似文献   
463.
PROBLEM: The expected substantial increase in people aged 65 or older is important for those concerned about transportation injuries. However, much of the previous research concentrates on older drivers and overlooks the fact that vehicle and crash factors may provide significant explanations of older occupant injury rates. METHOD: Differences across age groups are explored using two nationwide travel surveys, crash involvement, fatalities, and injuries from crash databases and an ordered probit model of injury severity. RESULTS AND DISCUSSION: Two noticeable differences that help explain injury risk are that older people are more likely to travel in passenger cars than younger people who frequently use light trucks, and that seriously injured older occupants are more likely to be involved in side-impact crashes than their younger counterparts. IMPACT: Increased attention to vehicle engagement in side-impact crashes and to vehicle technologies that can help drivers avoid side collisions would be particularly helpful for older occupants.  相似文献   
464.
We report a case of cystic hygroma and diffuse lymphangiectasia detected by sonogram at 12 weeks' gestation. Fetal karyotype was normal. At 20 weeks' gestation, herniation of the bowel into the chest was noted. At delivery, the infant was diagnosed as having Fryns' syndrome. This is the first reported case of Fryns' syndrome presenting with cystic hygroma.  相似文献   
465.
Serum levels of alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), and un-conjugated oestriol (uE3) were measured in serum samples of 4131 non-smoking and 1018 smoking women during the second trimester of pregnancy. The levels of all three analytes decreased with increasing body weight. The AFP median was significantly increased in smokers in a dose-response association; hCG decreased by 21 per cent and uE3 decreased by 3 per cent in smokers in a non-dose-related fashion. Regression functions for adjustment of serum levels for weight and smoking should be considered in risk estimation for Down syndrome in order to give a woman's individual risk more precisely.  相似文献   
466.
The pay-off of deserting and leaving a mate to care for the offspring alone is generally assumed to depend mainly on the availability of alternative mating partners and on the potential spawning rate of males and females. Eretmodus cyanostictus is a monogamous mouthbrooding cichlid in which the clutch is successively incubated first by the female and then by the male. It has been suggested that parents are constrained to monogamy due to low remating probabilities for both sexes. We tested this hypothesis by varying the sex ratio experimentally. Mate desertion by either sex was not significantly higher when additional potential mates were present (males: 8.3%, females: 0%) than when there were no other same-sex conspecifics present (males: 0%, females: 0%). Males lost their mate to a male intruder during their incubation in 26.7% of cases. Pair members were more active and showed more aggression when same-sex conspecifics were present. Behavioural differences between treatments were strongest during the incubation period of a given sex. If no desertion takes place, sexual conflict may be expressed also on a second level, the amount of parental care each parent provides. Indeed, males took the offspring later when additional females were present, although male incubation time did not differ between treatments. A hitherto undescribed display behaviour of females was clear evidence of a conflict about the timing of shift of young. In conclusion, offering alternative mating opportunities did not strongly favour mate desertion in E. cyanostictus. It rather revealed a conflict between mates about when to shift the young.Communicated by M. Abrahams  相似文献   
467.
To develop and implement improved instruments for flood risk management in Germany, the national research programme ‘Risk management of extreme flood events’ (RIMAX), funded by the German Federal Ministry of Education and Research (BMBF), was initiated. More than 30 joint projects are in progress under this framework since January 2005. An extended brochure which provides information regarding all projects currently funded by the RIMAX research programme is available from the RIMAX-website (www.rimax-hoch wasser.de). Intensive research has been carried out during the first two years of the funding initiative and several workshops were held to enhance the scientific discussion and the communication between the numerous projects. To develop communication pathways between research and practice RIMAX was presented at the ‘acqua alta 2006’, a trade fair for flood prevention and disaster management. Furthermore, a working group from the German Association for Water, Wastewater and Waste (DWA) is in the process of forming which aims at supporting the transfer of research results into practice. In 2006, five additional projects commenced. However, most of the projects funded in 2005 concentrate on the completion of their research and publishing their findings. A RIMAX-wide concept for the documentation and presentation of the results is currently developed by the coordinating team. More information and current news are available from the RIMAX-website (www.rimax-hochwasser.de).  相似文献   
468.
469.
Acetone extracts of engine exhaust particulate matter (PM) and of vapor-phase semi-volatile organic compounds (SVOCs) collected from a set of 1998-2000 model year normal emitter diesel engine automobile or light trucks and from a set of 1982-1996 normal emitter gasoline engine automobiles or light trucks operated on the California Unified Driving Cycle at 22 [degree]C were assayed for in vitro genotoxic activities. Gasoline and diesel PM were comparably positive mutagens for Salmonella typhimurium strains YG1024 and YG1029 on a mass of PM extract basis with diesel higher on a mileage basis; gasoline SVOC was more active than diesel on an extracted-mass basis, with diesel SVOC more active on a mileage basis. For chromosomal damage indicated by micronucleus induction in Chinese hamster lung fibroblasts (V79 cells), diesel PM expressed about one-tenth that of gasoline PM on a mass of extract basis, but was comparably active on a mileage basis; diesel SVOC was inactive. For DNA damage in V79 cells indicated by the single cell gel electrophoresis (SCGE) assay, gasoline PM was positive while diesel PM was active at the higher doses; gasoline SVOC was active with toxicity preventing measurement at high doses, while diesel SVOC was inactive at all but the highest dose.  相似文献   
470.
In recent years, many states have sought to set soil standards for hazardous waste sites. For example, Michigan and Oregon have had soil standards for several years, and within the last three years Massachusetts, New Jersey, Pennsylvania, and Texas have derived soil standards; while Illinois and several other states are in the process of developing soil standards. In general, soil cleanup standards are set to protect against leaching to groundwater and direct contact with soil. This article reviews several agencies' protocols and presents a sensitivity analysis of parameters used to establish these soil cleanup standards. Major issues examined in this article include land use (residential versus commercial/industrial) and exposure parameters used for deriving soil cleanup standards for direct contact. Soil cleanup standards are developed considering exposure routes such as ingestion, dermal contact, inhalation of vapors, and fugitive dust. Other factors such as chemical/physical properties are also considered. For example, many states use Toxicity Characteristic Leaching Procedure (TCLP) or EPA Method 1312 Synthetic Precipitation Leaching Procedure (SPLP) to derive soil standards protective of leaching to groundwater. The results indicate that factors such as leaching and certain exposure assumptions play a key role in determining soil cleanup standards. Exposure pathways were examined by performing a sensitivity analysis using a generic equation to consider exposure from ingestion, dermal contact, and inhalation of soil in deriving soil cleanup standards. The sensitivity analysis indicates that selection of exposure parameters such as toxicity values and soil-to-skin adherence factors contribute more substantially than others. These two factors are also among those values with the greatest uncertainty. Selection of exposure pathways is also important for the derivation of soil cleanup standards. For example, inhalation is the most significant exposure pathway for volatile organic compounds such as toluene, yet many states do not evaluate this exposure route. These findings are based on the mathematical models used by the agencies, and no judgments are made on the validity of the models. The results of this analysis can help focus attention on the most sensitive parameters as federal government reforms environment policies (i.e., CERCLA and RCRA) and the development of national soil cleanup standards is debated.  相似文献   
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