A Geo-Statistical Analysis of Road Mortality in the Enlarged EU

This paper aims at showing and understanding the spatial regional disparities hidden behind average national statistics on road fatalities in Europe; special attention is given on the EU last enlargement. The work is not limited on differences descriptions, but unveils what is hidden behind the observed infra-national heterogeneity in terms of road risk. It is indeed common practice to compare countries in terms of road safety performance and to rank them in terms of a risk indicator such as the mortality rate, which is often expressed by the number of fatalities due to road accidents per 100,000 inhabitants. Some countries are known for their very bad risk records and are often pointed out by national or international authorities, without any understanding of the regional differences hidden behind a national mean value. The data analysis shows that changes in the level of spatial aggregation of the data produce significant differences in the variables describing the level of road safety, and hence in operational recommendation and conclusions. Beside the differences in national conditions and polices, the regional differences in road environment characteristics, traffic performance, road user mix, travel speeds, seat-belt use, and availability of emergency care have been major contributors to these variations. Road safety professionals and decision makers should be aware of the differences existing when trying to reduce road toll of the country in sustainable and cost-effective way.

Pedestrian Risk Taking While Road Crossing: A Comparison of Observed and Declared Behaviour

AbstractThe objective of this research is the comparative analysis of observed and declared behaviour of pedestrians as regards road crossing in urban areas. A field survey was carried out, in which a panel of 75 young and middle-aged pedestrians (out of which 40 males) were asked to take 8 short walking trips (each one corresponding to a different walking and crossing scenario and involving one road crossing) in the Athens city centre in Greece. This allowed to record their crossing behaviour in different road and traffic conditions, including residential roads, main urban roads and major urban arterials. The same individuals were asked to fill in a questionnaire on their crossing behaviour and preferences at different road and traffic environments, as well as other related questions concerning their travel motivations, their mobility characteristics, their risk perceptions and preferences etc. A comparative analysis of their declared and observed crossing behaviour was carried out. More specifically, for each pedestrian, the rate of mid-block crossing and diagonal crossing during the walking tasks was calculated for the different road and traffic conditions. These were compared to their questionnaire responses on their crossing behaviour in different road and traffic conditions. The results suggest that, overall, pedestrians observed behaviour is in accordance with their declared behaviour. However, there is a non-negligible share of pedestrians, whose observed and declared behaviour were discordant, either at specific road and traffic conditions or overall. For instance, there were pedestrians who declared that they never cross at mid-block on major urban road but did so during the survey. Moreover, there were pedestrians who declared high frequency of mid-block crossing, but did not implement these crossing practices during the survey. The degree of discordance between pedestrian observed and declared behaviour was further analysed in relation to pedestrian demographics. A weak tendency was identified for female pedestrians to have more discordance between observed and declared crossing behaviour on residential roads, and the same was the case for young pedestrians in all road and traffic conditions. Overall, the results suggest that, while most pedestrians appear to have consistent declared and observed behaviour, there may all deviate from their general “profile” under specific conditions

Platelet-derived growth factor negatively regulates the insulin-like growth factor signaling pathway through the coordinated action of phosphatidylinositol 3-kinase and protein kinase C beta I

AbstractWe recently described that epidermal and fibroblast growth factors (EGF and FGF) regulate the IGF-I signaling pathway at the level of IRS-1 through the cooperative action of two independent signaling pathways; one dependent on phosphatidylinositol 3-kinase (PI 3-kinase) and the other on protein kinase D1 (PKD1) (Karam et al. [22]). To determine whether this mechanism could be generalized to another tyrosine kinase receptor-dependent growth factor, the effect of platelet-derived growth factor (PDGF) on the IGF-I signaling pathway was studied. PDGF inhibited IGF-I-stimulated IRS-1 tyrosine phosphorylation and subsequent IGF-I-induced PI 3-kinase activity, and stimulated IRS-1 serine 307 phosphorylation. These effects were mediated through a PI 3-kinase-dependent but extracellular signal-regulated kinase (ERK)-independent signaling pathway. However, PDGF-induced IRS-1 serine 307 phosphorylation was not sufficient per se to inhibit the IGF-I signaling but required another independent pathway. Noteworthy, although acutely stimulated by PDGF, and contrary to what we previously described (Karam et al. [22]), PKD1 did not associate with IRS-1and did not inhibit the IGF-I signaling in response to PDGF. However, we identified PKCβI as a new regulatory partner of PI 3-kinase for PDGF-induced inhibition of the IGF-I signaling pathway. Therefore, our results reinforce the idea that a coordinated action of two independent pathways seems absolutely necessary to negatively regulate IRS-1. Moreover, they also demonstrated that, depending of the cross-talk considered, subtle and specific regulatory mechanisms occur at the level of IRS-1 and that a unique regulatory model is not conceivable

Stress des étudiants et réussite universitaire : les conditions économiques, pédagogiques et psychologiques du succès

Cette recherche a pour objectif de mieux comprendre le processus de réussite ou d’échec des études universitaires à partir de deux facteurs essentiels : la situation matérielle et économique des étudiants et leurs méthodes de travail universitaire. Un panel de 98 étudiantes et étudiants de la première à la troisième année a été interrogé à plusieurs reprises au cours d’une année universitaire. Ils ont été choisis au hasard dans diverses disciplines des filières longues ou courtes en région parisienne, dans des métropoles régionales et dans des villes plus petites. Les données ont été recueillies par des questionnaires ad hoc sur les aspects pédagogiques et financiers et par des tests psychologiques pour mesurer le stress et l’anxiété. Le modèle transactionnel du stress s’est montré très fructueux et la méthode longitudinale a permis de corréler des variables recueillies à divers moments de l’année. C’est dans les métropoles régionales que se développe le plus favorablement une vie étudiante autonome. Mais plus que les conditions objectives, certaines variables psychologiques sont, dès le début de l’année, des indicateurs des résultats aux examens terminaux. Elles concernent la motivation et les évaluations que les étudiants font de leur situation tant économique que pédagogique ; elles portent sur les stratégies mises en œuvre pour faire face aux situations évaluées comme stressantes. Ainsi les « petits boulots » et le travail universitaire régulier se révèlent comme des conduites favorables à la réussite.Economic conditions of students as well as academic work methods were studied for a better understanding of the process of academic success or failure. A survey was carried out by following a panel of 98 college students (first and second/third year) on short and long courses in three types of universities, located in Paris, in main regional cities and in smaller cities. The sample was surveyed several times during an academic year using specific questionnaires on financial and pedagogical aspects. Stress and anxiety levels were also measured by tests. The transactional model of stress proved very productive and the longitudinal methodology permitted to study the correlation of variables collected at different times of the year. An autonomous living style is characteristic of big cities. However more so than objective conditions, certain psychological variables are, and this from the start of term, good indicators of the final results. They imply motivation, appraisal of economic and pedagogical situation by the students and coping strategies for situations perceived as stressful. It appears that odd jobs and regular academic work lead to success

The interurban DRAG-Spain model: the main factors of influence on road accidents in Spain

This paper presents the results of applying DRAG methodology to the identification of the main factors of influence on the number of injury and fatal accidents occurring on Spain’s interurban network. Nineteen independent variables have been included in the model grouped together under ten categories: exposure, infrastructure, weather, drivers, economic variables, vehicle stock, surveillance, speed and legislative measures. Highly interesting conclusions can be reached from the results on the basis of the different effects of a single variable on each of the accident types according to severity. The greatest influence revealed by the results is exposure, which together with inexperienced drivers, speed and an ageing vehicle stock, have a negative effect, while the increased surveillance on roads, the improvement in the technological features of vehicles and the proportion of high capacity networks have a positive effect, since the results obtained show a significant drop in accidents

Insulin-like Growth Factor II Signaling in Neoplastic Proliferation Is Blocked by Transgenic Expression of the Metalloproteinase Inhibitor Timp-1

Insulin-like growth factor (IGF) II is overexpressed in many human cancers and is reactivated by, and crucial for viral oncogene (SV40 T antigen, [TAg])–induced tumorigenesis in several tumor models. Using a double transgenic murine hepatic tumor model, we demonstrate that tissue inhibitor of metalloproteinase 1 (TIMP-1) blocks liver hyperplasia during tumor development, despite TAg-mediated reactivation of IGF-II. Because the activity of IGFs is controlled by IGF-binding proteins (IGFBPs), we investigated whether TIMP-1 overexpression altered the IGFBP status in the transgenic liver. Ligand blotting showed that IGFBP-3 protein levels were increased in TIMP-1–overexpressing double transgenic littermates, whereas IGFBP-3 mRNA levels were not different, suggesting that TIMP-1 affects IGFBP-3 at a posttranscriptional level. IGFBP-3 proteolysis assays demonstrated that IGFBP-3 degradation was lower in TIMP-1–overexpressing livers, and zymography showed that matrix metalloproteinases (MMPs) were present in the liver homogenates and were capable of degrading IGFBP-3. As a consequence of reduced IGFBP-3 proteolysis and elevated IGFBP-3 protein levels, dissociable IGF-II levels were significantly lower in TIMP-1–overexpressing animals. This decrease in bioavailable IGF-II ultimately resulted in diminished IGF-I receptor signaling in vivo as evidenced by diminished receptor kinase activity and decreased tyrosine phosphorylation of the IGF-I receptor downstream effectors, insulin receptor substrate 1 (IRS-1), extracellular signal regulatory kinase (Erk)-1, and Erk-2. Together, these results provide evidence that TIMP-1 inhibits liver hyperplasia, an early event in TAg-mediated tumorigenesis, by reducing the activity of the tumor-inducing mitogen, IGF-II. These data implicate the control of MMP-mediated degradation of IGFBPs as a novel therapy for controlling IGF bioavailability in cancer

An Analysis of Pedestrian Waiting Time at Uncontrolled Crosswalks Using Discrete Choice Model

A study of pedestrians crossing behavior is conducted at an uncontrolled mid-block crosswalk in Istanbul Turkey, to model the pedestrians waiting time, related to their behavior for making the crossing decision. This article focused on the issues encountered in the modeling of the operational behavior of pedestrians. The discrete choice framework is used because of its capacity to deal with individuals’ choice behavior. Pedestrians waiting time is classified into three levels, including low, medium, and high levels based on the level of service of pedestrians waiting time. The pedestrians’ behavior prediction has been improved by analyzing, taking into account three levels for pedestrian behavior