Persistence of Violation and Crash Behavior Over Time

This analysis examines the ability of previous offenses to predict future high-risk offenses, and similarly, the ability of crashes to predict future high-risk crashes, using the complete driver history data (up to 9 years) for a set of young Michigan subjects. As expected, those with previous ticketed offenses or reported crashes are at greater risk for future offenses or crashes; with a previous-year serious offense doubling the odds of serious offenses during the subsequent year, and a previous-year at-fault crash increasing the odds of subsequent-year at-fault crashes by nearly 50%. There is modest evidence that serious offenses and at-fault crashes may better predict subsequent behavior in females and in more experienced drivers. This latter finding is also evidenced by the fact that records of these young drivers are less predictive of subsequent driving history than is true for records of all drivers in general found in other studies. This suggests that, in the early stages of driving, offenses and crashes are, at least in part, attributable to inexperience, and hence, characteristic of all beginning drivers.     

Heavy metal contamination from mining sites in South Morocco: 2. Assessment of metal accumulation and toxicity in plants

Metalliferous soils cover a relatively large surface area in Morocco, and up to now no hyperaccumulating plants have been identified on these mining or these industrial sites. The aim of this work was to assess the extent of metal accumulation by plants found in three mining areas in southern Morocco with the ultimate goal of finding metal hyperaccumulating species by using the MetPAD biotest. The biotest helps to obtain information on the selective metal toxicity of aqueous extracts from the plants. A strong metal toxicity, as revealed by the biotest is an indication of a hyperaccumulating plant. Toxicity tests were run concurrently with chemicals analyses of metals in plants and their water extracts. The chemical analyses allow the determination of the hyperaccumulated metal(s). Specimens of the plant species mainly growing on and in the vicinity of the three mines were sampled with their corresponding soils. The results show that all plants analyzed had lower heavy metal content and toxicity despite the relatively very high soil concentrations. A comparison of our results with the criterion used to classify the hyperaccumulator plants indicates that plants we collected from mining sites were hypertolerant but not hyperaccumulators. This was confirmed by transfer factors generally lower than 1. Nevertheless, these tolerant plants species can be used as tools for revegetation for erosion control in metals-contaminated sites (phytostabilization).     

The role of personality characteristics in young adult driving

BACKGROUND: Motor vehicle injury is the major cause of mortality among young adults. Information about the individual characteristics of those who drive dangerously could enhance traffic safety programs. The goal of this research was to examine the association between various personality-related characteristics and risky driving behaviors. METHODS: Young adults in Michigan, USA (n = 5,362) were surveyed by telephone regarding several personality factors (risk-taking, hostility, aggression, tolerance of deviance, achievement expectations) and driving behaviors (competitive driving, risk-taking driving, high-risk driving, aggressive driving, and drink/driving). Michigan driver records were obtained to examine offenses, serious offenses, driving offense points, crashes and serious crashes in the three pre-interview years. Multivariate regression analyses, adjusting for age, race, and marital status were conducted separately by sex to identify personality factors related to driving. RESULTS: For men and women, greater risk-taking propensity, physical/verbal hostility, aggression, and tolerance of deviance were significant predictors of a competitive attitude toward driving, risk-taking driving, high-risk driving, driving aggression, and drink/driving. Greater risk-taking propensity, physical/verbal hostility, aggression, and to a small degree, expectations for achievement predicted higher numbers of offenses, serious offenses, and points. CONCLUSION: Traffic safety policies and programs could be enhanced through recognition of the role personality factors play in driving behavior and the incorporation of this knowledge into the design and implementation of interventions that modify the behaviors associated with them.     

Implementation of a medical command and control team in Switzerland

In case of a major incident or disaster, the advance medical rescue command needs to manage several essential tasks simultaneously. These include the rapid deployment of ambulance, police, fire and evacuation services, and their coordinated activity, as well as triage and emergency medical care on site. The structure of such a medical rescue command is crucial for the successful outcome of medical evacuation at major incidents. However, little data has been published on the nature and structure of the command itself. This study presents a flexible approach to command structure, with two command heads: one emergency physician and one experienced paramedic. This approach is especially suitable for Switzerland, whose federal system allows for different structures in each canton. This article examines the development of these structures and their efficiency, adaptability and limitations with respect to major incident response in the French‐speaking part of the country.     

Spatio-temporal variations of fluorescence properties of dissolved organic matter along the River Têt (Pyrénées-Orientales,France)

Fluorescence excitation-emission matrices showed the spectral signature of dissolved organic matter (DOM) downstream in the River Têt at all seasons corresponding to humic substances with maximum fluorescence emission λem=420–460 nm for excitations of λex=340–360 nm and the occasional presence of tryptophan, tracer of anthropogenic pressure, spectroscopically identified by λex/λem=310/350 nm. A factorial discriminant analysis, performed using the parameters selected (λex/λem pairs of wavelength), succeeded in a better discrimination of seasons than stations, and clearly showed the presence of two fluorophores. Fluorophore 1, with two absorption bands: λex=260–320 nm and 330–390 nm for λem=440–500 nm, and Fluorophore 2, with one absorption band: λex=300–360 nm for λem=410 nm, which are attributed to humic acid (HA) and fulvic acid (FA), respectively. Variations of DOM relative contents downstream in the River Têt, according to seasons and stations, showed high amounts of DOM (pedogenic character) along the river in the humid period, with the highest value obtained in the mountain section. In contrast, in summer, the DOM contents were low (aquagenic character). Moreover, DOM presents a relatively constant composition with a percentage of FA ranging from 40% at the mountain station to 48% at the mouth river, whatever the season.     

Kinetic studies of imazapyr photolysis and characterization of the main photoproducts

The fate of imazapyr (2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)nicotinic acid), a broad-spectrum herbicide in the imidazolinone family, has been studied upon UV irradiation. Most of the photoproducts occurring during the photodegradation have been characterized by means of liquid chromatography and mass spectrometry coupled techniques (LC-MS). The use of high resolution mass spectrometry has allowed to maximize the chemical information obtained from a single LC-MS analysis. The degradation of a 10?ppm imazapyr solution leads to pyridine derivatives which remain in solution during 50–100?h while the imazapyr is completely degraded after 6?h.     

Patterns of mussel recruitment in southern Africa: a caution about using artificial substrata to approximate natural recruitment

Quantifying sessile marine invertebrate recruitment often requires destructive sampling or extrapolation from artificial substrata, the latter introducing the danger of artifacts. We measured intertidal mussel recruitment into mussel beds and into brushes at three-month intervals for five years across 3,200 km of southern Africa and determined substrata effects on recruitment rate. Recruitment into mussel beds showed a strong, coast-wide gradient, with high recruitment on the West coast, diminishing on the South coast, and increasing slightly on the East coast. At scales of 10 s of km, brushes reflected natural temporal recruitment variability, with a strong significant linear correlation between recruitment into brushes and into mussel beds. However, the relationship became semi-logarithmic when comparing among locations at a scale of 100 s of km. Artificial substrata thus reflect local natural settlement well but may be a poor indicator of it when spatial scales are large, particularly when mussel bed topography is complex, or localities have very different recruitment densities.     

Regional scale variability in sediment and nutrient delivery from small agricultural watersheds

Although many studies have pointed out the various controlling factors of sediment and nutrient delivery on a plot or watershed scale, little is known on the spatial variability of sediment and nutrient delivery on a regional scale. This study was conducted to reveal regional variations in sediment-associated nutrient delivery in central Belgium. Sediment deposited in 13 small retention ponds was sampled and analyzed for total phosphorus (TP), K, Mg, and Ca content. The TP content of the sediment deposits varied from 510 to 2001 mg P per kg sediment. Nutrients are predominantly fixed on the very fine sediment fraction (<16 microm), which is the reason why the nutrient trap efficiency of the ponds is only a fraction of the sediment trap efficiency. Average nutrient trap efficiency of the studied ponds varies between 4 and 31%, whereas sediment trap efficiency varies between 10 and 72%. For watersheds ranging from 7 to 4873 ha, sediment yield ranged between 1.2 and 20.6 Mg ha(-1) yr(-1), whereas TP export varied from 1.8 to 39.7 kg ha(-1) yr(-1). The observed spatial variability in nutrient losses is primarily attributed to regional variations in erosion and sediment yield values and to a far lesser degree to the spatial variations in fertilizer application. Redistribution of manure in the framework of an agricultural policy may increase the rate of nutrient delivery by ways of erosion and sediment transport.     

Soil-to-root transfer and translocation of polycyclic aromatic hydrocarbons by vegetables grown on industrial contaminated soils

Polycyclic aromatic hydrocarbons (PAHs) are possible contaminants in some former industrial sites, representing a potential risk to human health if these sites are converted to residential areas. This work was conducted to determine whether PAHs present in contaminated soils are transferred to edible parts of selected vegetables. Soils were sampled from a former gasworks and a private garden, exhibiting a range of PAH concentrations (4 to 53 to 172 to 1263 and 2526 mg PAHs kg-1 of dry soil), and pot experiments were conducted in a greenhouse with lettuce (Lactuca sativa L. var. Reine de Mai), potato (Solanum tuberosum L. var. Belle de Fontenay), and carrot (Daucus carota L. var. Nantaise). At harvest, above- and below ground biomass were determined and the PAH concentrations in soil were measured. In parallel, plates were placed in the greenhouse to estimate the average PAH-dust deposition. Results showed that the presence of PAHs in soils had no detrimental effect on plant growth. Polycyclic aromatic hydrocarbons were detected in all plants grown in contaminated soils. However, their concentration was low compared with the initial soil concentration, and the bioconcentration factors were low (i.e., ranging from 13.4 x 10(-4) in potato and carrot pulp to 2 x 10(-2) in potato and carrot leaves). Except in peeled potatoes, the PAH concentration in vegetables increased with the PAH concentration in soils. The PAH distribution profiles in plant tissues and in soils suggested that root uptake was the main pathway for high molecular weight PAHs. On the opposite, lower molecular weight PAHs were probably taken up from the atmosphere through the leaves as well as by roots.     

Basic principles and ecological consequences of changing water regimes on nitrogen cycling in fluvial systems

Understanding the environmental consequences of changing water regimes is a daunting challenge for both resource managers and ecologists. Balancing human demands for fresh water with the needs of the environment for water in appropriate amounts and at the appropriate times are shaping the ways by which this natural resource will be used in the future. Based on past decisions that have rendered many freshwater resources unsuitable for use, we argue that river systems have a fundamental need for appropriate amounts and timing of water to maintain their biophysical integrity. Biophysical integrity is fundamental for the formulation of future sustainable management strategies. This article addresses three basic ecological principles driving the biogeochemical cycle of nitrogen in river systems. These are (1) how the mode of nitrogen delivery affects river ecosystem functioning, (2) how increasing contact between water and soil or sediment increases nitrogen retention and processing, and (3) the role of floods and droughts as important natural events that strongly influence pathways of nitrogen cycling in fluvial systems. New challenges related to the cumulative impact of water regime change, the scale of appraisal of these impacts, and the determination of the impacts due to natural and human changes are discussed. It is suggested that cost of long-term and long-distance cumulative impacts of hydrological changes should be evaluated against short-term economic benefits to determine the real environmental costs.