Self-reported road traffic violations in France and how they have changed since 1983

Goals

The goal was to gain a picture of current driver behaviour, and of the links between committed violations and accident history. It was also to identify how driver behaviour has changed over the last 20 years.

Methods

A questionnaire-based cross-sectional study of a sample of 1161 drivers about the frequency of violations and the perception of the dangers and penalties associated with them was used in 2005. Self-reported violations and mental representations were also compared to the results of Biecheler who used similar methods (Biecheler-Fretel, 1983).

Results, conclusions

Road traffic violations are frequent in France, particularly among male drivers. Several violations are linked with history of accidents in our sample. Frequently or fairly frequently exceeding the speed limit by 10 km/h (a violation reported by almost 53% of our sample), increases accident occurrence by a factor of 1.4. Progress in drivers’ behaviour has been slow and nonuniform, and appears in part to be related to safety campaigns that have been run (seat belts, alcohol). The results could inform future campaigns. In particular, a campaign on the use of indicators would seem worthwhile.     

Discovery, biosynthesis, and structure elucidation of metabolites of a doping agent and a direct analogue, tetrahydrogestrinone and gestrinone, using human hepatocytes

Tetrahydrogestrinone (18a-homo-pregna-4,9,11-trien-17beta-ol-3-one, THG) is an anabolic androgenic steroid sold to athletes as an undetectable performance enhancer. Being an unapproved substance, no legitimate in vivo human excretion studies could be performed to identify urinary markers of this doping agent. In vitro systems were used as an alternative approach to study the human metabolism of THG and the gestrinone analogue, which is a marketed drug. Incubations of both compounds in the presence of human hepatocytes led to formation of oxidative and glucuroconjugated metabolites. Microgram quantities of the major in vitro metabolites were biosynthesized using human hepatocytes, characterized by HPLC/MS/MS, and their structures elucidated by NMR. Due to high structure similarity, both THG and gestrinone had an analogous in vitro metabolic pathway leading to successive addition of a hydroxyl and a beta-glucuronic acid at C-18. This in vitro metabolite of gestrinone was consistent with a previously reported major but unknown human urinary metabolite. The structure of another metabolite of THG was proposed to be a glucuroconjugate of an oxidative product with a hydroxyl group most likely at C-16epsilon. In vitro information reported therein could significantly impact the identification of new urinary markers of THG for doping control purposes.     

Mechanisms of scale formation and carbon dioxide partial pressure influence. Part I. Elaboration of an experimental method and a scaling model

Scale formation in industrial or domestic installations is still an important economic problem. The existence of a metastable domain for calcium carbonate supersaturated solutions and its breakdown are observed under conditions rarely well defined. In most cases it is the pH rise caused by the carbon dioxide loss that involves calcium carbonate precipitation. Before studying this problem, we suggest in this first part, a new model for the evolution of the calcocarbonic system that takes into account the hydrated forms of CaCO3: CaCO3 amorphous, CaCO3 x 6H2O (ikaite) and CaCO3 x H2O (monohydrate). According to this model, the precipitation of any one of these hydrated forms could be responsible for the breakdown of the metastable state. After this first step, the solids evolve into dehydrated forms. At first, the metastable domain spread of the calcium carbonate supersaturated solutions was studied by the elaboration of computer programs in which the formation of CaCO3(0)(aq) ion pairs was taken into account. These ion pairs are supposed to evolve through dehydration to form the various calcium carbonate solid form precursors. This thermodynamic study was then compared to the experimental methods of the critical pH. Here the pH rise was caused by adding sodium hydroxide under different conditions for sodium hydroxide addition speed, agitation mode and ageing of solutions. For the highest speed of sodium hydroxide addition, the CaCO3 ionic product reached the value of the amorphous calcium carbonate solubility product, and the reaction of the amorphous calcium carbonate precipitation was of the homogenous type. Decreasing the reagent's addition speed caused an extension of the titration time. Then, the breakdown of the metastable state was obtained with the CaCO3 x H2O heterogeneous precipitation. This clearly illustrates the probable ageing of the precursors of the solid states that are considered in this model.     

Large Woody Debris Structures for Sand-Bed Channels

Described is a method for channel erosion control and habitat rehabilitation featuring intermittent placement of structures made of large woody debris. This method is expressly tailored to address severe problems typical of incised channels with little sediment coarser than sand. In these types of environments, buoyancy forces are typically more important factors in woody debris stability than fluid drag. Buoyant forces are counteracted by the weight of the structure, earth anchors, and sediment deposits. Design concepts were tested in a demonstration project constructed along 2 km of channel draining a 37-km2 watershed. Large woody debris structures reduced velocities in the region adjacent to the bank toe and induced sediment deposition and retention. Construction costs per unit channel length were 23–58% of costs for recent stone bank stabilization projects within the same region. During the second year following construction, 31% of the structures failed during high flows, probably due to inadequate anchoring.     

Noninformative Bayesian testing and neutral Bayes factors

Summary In contrast with usual point estimation settings, there is no well-defined notion of noninformative Bayesian, procedures for tests of two-sided hypotheses. In this paper, we examine the behavior of the answers associated with the (point estimation) Jeffreys priors and show that, in some cases, they coincide numerically with the classical p-values. This partial equivalence between noninformative and classical answers is also exhibited with neutral Bayes factors. This new evaluation, which determines the cut-off point between acceptance and rejection of the null hypothesis, actually leads to a procedure similar to the (so-called) Jeffreys answere and thus supports the use of a noninformative improper prior. This interpretation thus brings a partial rehabilitation of some p-values as noninformative answers.     

Analysis of the diffractional properties of dual-period apodizing gratings: theoretical and experimental results

We present an analysis of the diffractional properties of dual-period apodizing gratings. In a previous paper we used these components to obtain single-lateral-mode and dual-longitudinal-mode emission from a broad-area diode laser. We now calculate the diffracted field for a monochromatic beam incident on the grating by using an analytical model. Predictions of the model are compared with experimental measurements made with several dual-period gratings. We also discuss the situation in which a dual-period grating is used as an external coupler of a diode laser in a two-wavelength emission regime.     

Determination of refractive indices of opaque rough surfaces

The refractive indices of optical materials are usually determined from spectrophotometric and ellipsometric measurements of specular beams. When the roughness of the interfaces increases, the energy in the specularly reflected and transmitted beams decreases and scattering becomes predominant. For strong roughness (compared to the incident wavelength) a surface does not exhibit specular reflection or transmission, making difficult the determination of the refractive index. We describe two techniques, based on scattering measurements, that one can use to determine the refractive indices of opaque inhomogeneous media.     

Varations in maize pollen emission and deposition in relation to microclimate

The coexistence of genetically modified (GM) crops with conventional crops has become a subject of debate and inquiry. Maize (Zea mays L.) is one of the most cultivated crop plants in the world and there is a need to assess the risks of cross-pollination. Concentration and deposition rate downwind from different-sized maize crops were measured during three flowering seasons, together with micrometeorological conditions in the surrounding environment. Pollen release started once the air vapor pressure deficit (VPD) increases above 0.2 to 0.5 kPa. Moreover, the dynamics of release was correlated with the dynamics of VPD surrounding the tassels. Horizontal deposition appeared to follow a power law over short distance downwind from the source, and the dispersal distance increased with the source canopy height and the roughness length of the downwind canopy. This work also provides a data set containing both pollen measurements and contrasting weather conditions to validate dispersal models and further investigate maize pollen dispersal processes.     

Balsam Fir Foliar Chemistry in Middle and Lower Crowns and Spruce Budworm Growth, Development, Food and Nitrogen Utilization

The impact of current-year foliage from the middle or lower crown section of balsam fir trees on larval growth, development, nitrogen, and food utilization was studied with laboratory rearing experiments, gravimetric analyses, and foliage chemical analyses. Pupal dry weight, pupal nitrogen weight, and total development times were not affected by feeding on current-year foliage from either the middle or the lower crown section. However, the nutritive and, particularly, allelochemical profiles were significantly different between crown levels and influenced spruce budworm food utilization, depending on development stage. Newly molted fifth instars feeding since post-diapause on middle crown foliage had lower dry weight and nitrogen weight than those fed lower crown foliage. This apparently resulted from the high monoterpene content in the mid-crown foliage. At the end of the fifth instar, however, insects from both crown levels had similar larval dry weights and nitrogen weights. Larvae fed middle crown foliage compensated with several mechanisms that led to increased relative nitrogen accumulation rate (RNAR) including increased efficiencies of conversion of ingested and digested nitrogen (ECIN, ECDN). Sixth-instar development time was nearly two days shorter for larvae fed middle crown foliage compared to those fed lower crown foliage. A higher relative consumption rate (RCR) due to the high content of two phagostimulatory components (soluble sugars and β-pinene) may account for reduced sixth-instar development time. Larvae from the middle crown section had higher relative growth rates (RGR) and RNAR than those from the lower crown. Pupal development time was also longer in the lower crown. The existence of spruce budworm flexibility to adapt to foliar biochemistry variations by developing compensatory mechanisms enables larvae to exploit the whole tree crown.