Prevalence of alcohol and drugs among Norwegian motor vehicle drivers: a roadside survey

The objective of the study was to determine the prevalence of alcohol, psychoactive medicinal drugs and illegal drugs among drivers in Norwegian road traffic. Drivers of motor vehicles were selected from April 2005 to April 2006 in the south-eastern part of Norway, surrounding, but not including the capital, Oslo. A stratified two-stage cluster sampling procedure was used. In the first stage, random road sites and time intervals were selected, and in the second stage, drivers were stopped by random at those sites and time intervals. Altogether about 12,000 drivers were asked to provide a sample of oral fluid (saliva) and answer a few questions. Samples of oral fluid were obtained from 88% of the drivers, of whom 30% were females and 70% males. The prevalence of each drug was estimated by a weighted average using weights adjusted for under- or over-sampling compared to traffic statistics. Alcohol or drugs were found in oral fluid samples of 4.5% of the drivers; alcohol in 0.4%, psychoactive medicinal drugs in 3.4%, and illegal drugs in 1.0%. Illegal drugs were found more frequently in samples from younger drivers, while psychoactive medicinal drugs were more frequently found in samples from older drivers. Psychoactive medicinal drugs were more prevalent among females than males, among drivers stopped on working days rather than weekends, and among those who reported annual driving distances less than 16,000km. The drugs found most frequently were zopiclone (1.4%), benzodiazepines (1.4%), codeine (0.8%), tetrahydrocannabinol (0.6%) and amphetamines (0.3%). Two or more drugs were found in 0.6% of the samples, corresponding to 15% of the drug-positive drivers.     

加州大学伯克利分校开发的结构可靠性分析软件介绍

介绍了加州大学伯克利分校开发的三种结构可靠性分析软件:CalREL,利用FORTRAN编制的全面结构可靠性分析软件;FERUM,采用Matlab编写,用于简单有限元模型节点的可靠性分析软件;Open Sees,一种面对对象的程序,根据结构可靠性能,模拟非线性结构响应。这些程序中的可靠性分析方法包括FORM,SORM,Monte Carlo模拟和各种重要的样本方法。此外,提出了变量重要性和敏感性测试。     

The influence of meteorological parameters on soil radon levels in permeable glacial sediments

The influence of meteorological parameters on soil radon concentrations in a permeable ice-marginal deposit in Kinsarvik, Norway, was investigated based on continuous measurements of soil radon concentrations, temperature, precipitation, wind speed, wind direction, air pressure and soil moisture content over a period of 10 months. The results show that the soil radon concentrations exhibit distinct seasonal and diurnal variations that predominantly are caused by changes in air temperature. Air flows between areas of different elevation occur in the ice-marginal deposit due to temperature differences between soil air and atmospheric air, and instantaneous changes in air flow direction were recorded when the atmospheric air temperature reached the average annual air temperature. Air pressure was found to be the second most important parameter influencing soil radon concentrations, while no apparent effect of precipitation, wind speed, wind direction or soil moisture was observed. Seasonal variations in indoor and soil radon levels were also investigated in a glaciofluvial deposit located 40 km southwest of Kinsarvik, and the close correlation between the seasonal variation patterns observed in the two areas suggests that the results of the Kinsarvik study also might be applicable to other areas of highly permeable building grounds where differences in terrain elevation exist.     

Biometrical modelling in genetics: are complex traits too complex?

The field of traditional biometrical genetics uses mixed-effects models to quantify the influence of genetic and environmental factors on a biological trait, based essentially on estimating within-family trait correlations. Such analyses provide a useful preview of what may be discovered with the emerging full-scale genotyping strategies. However, biometrical analyses require unrealistically large sample sizes to obtain a reasonable precision, particularly for dichotomous traits. In addition, it may be very difficult to separate genetic and environmental effects because environmental correlations are poorly understood. We illustrate these and other difficulties using population-based cousins and nuclear family data for birth weight, collected from the Medical Birth Registry of Norway.     

Probabilistic capacity models and seismic fragility estimates for RC columns subject to corrosion

In this paper, probabilistic drift and shear force capacity models are developed for corroding reinforced concrete (RC) columns. The developments represent a merger between a probabilistic model for chloride-induced corrosion, a time-dependent corrosion rate, and previously developed probabilistic models for drift and shear force capacity of pristine (undamaged) RC columns. Fragility estimates are obtained for an example corroding column by applying the developed models at given shear and drift demands. Model uncertainties in both the capacity and corrosion models are considered in the fragility estimation, in addition to uncertainties in environmental conditions, material properties, and structural geometry. Sensitivity analyses of the corroding RC column are carried out to identify the parameters to which the reliability of the example column is most sensitive. The developed models consider different combinations of chloride exposure condition, environmental oxygen availability, water-to-cement ratios, and curing conditions. They are applicable to both existing and new RC columns and may be employed for the prediction of service-life and life-cycle cost analysis of RC structures.     

The quantum confined Stark effect in silicon nanocrystals

The quantum confined Stark effect (QCSE) in Si nanocrystals embedded in a SiO(2) matrix is demonstrated by photoluminescence (PL) spectroscopy at room and cryogenic temperatures. It is shown that the PL peak position shifts to higher wavelengths with increasing applied electric field, which is expected from carrier polarization within the quantum dots. It is observed that the effect is more pronounced at lower temperatures due to the improved carrier localization at the lowest energy states of the quantum dots. Experimental results are shown to be in good agreement with phenomenological model developed for the QCSE model.     

Mixed-oxide (MOX) fuel performance benchmarks

Within the framework of the OECD/NEA Expert Group on Reactor-based Plutonium disposition (TFRPD), fuel modeling code benchmarks for MOX fuel were initiated. This paper summarizes the calculation results provided by the contributors for the first two fuel performance benchmark problems. A limited sensitivity study of the effect of the rod power uncertainty on code predictions of fuel centerline temperature and fuel pin pressure also was performed and is included in the paper.     

On the use of risk acceptance criteria in the offshore oil and gas industry

Risk acceptance criteria, as upper limits of acceptable risks, have been used for offshore activities on the Norwegian Continental Shelf for more than 20 years. The common thinking has been that risk analyses and assessments cannot be conducted in a meaningful way without the use of such criteria. The ALARP principle also applies, but the risk acceptance criteria have played a more active role in the assessment processes than seen for example in the UK. Recently there has, however, been a discussion about the suitability of risk acceptance criteria to assess and control risks. The purpose of this paper is to contribute to this discussion by presenting and discussing a risk analysis regime that is not based on the use of risk acceptance criteria at all. We believe that we can do better if cost-effectiveness (in a wide sense) is the ruling thinking rather than adoption of pre-defined risk acceptance limits. This means a closer resemblance with the ALARP principle as adopted in the UK and other countries, but is not a direct application of this practice. Also the building blocks of the common way of applying the ALARP principle are reviewed. The Norwegian offshore oil and gas industry is the starting point, but the discussion is to large extent general.     

Uncertainties in smart grids behavior and modeling: What are the risks and vulnerabilities? How to analyze them?

This paper looks into the future world of smart grids from a rather different perspective than usual: that of uncertainties and the related risks and vulnerabilities. An analysis of the foreseen constituents of smart grids and of the technological, operational, economical and policy-driven challenges is carried out to identify and characterize the related uncertainties and associated risks and vulnerabilities. The focus is on the challenges posed to the representation and treatment of uncertainties in the performance assessment of such systems, given their complexity and high-level of integration of novel technologies. A general framework of analysis is proposed.     

Higher order structure of short immunostimulatory oligonucleotides studied by atomic force microscopy

Immunostimulatory CpG-DNA activates the innate immune system by binding to Toll-like receptor 9. Structurally different CpG-containing oligonucleotides trigger a different type of immune response while activating the same receptor. We therefore investigated the higher order structure of two different classes of immunostimulatory CpG-DNA. Class A, which contains a partly self-complementary sequence and poly-G ends, forms duplexes and nanoparticles in salt solution, while class B, which does not contain these features and is purely linear, does not form a duplex or nanoparticles. Results obtained here by high-resolution atomic force microscopy of classes A and B CpG-DNA, reflect these differences in secondary structure. Detailed structural analysis of the atomic force microscopy topographs is presented for two different sample preparation methods.