A driving simulation study on the effects of different wine types on the performance of young drivers.

BACKGROUND: Alcohol consumption is responsible for a significant number of road fatalities. To contrast this phenomenon, a more responsible attitude to the wine consumption, especially among young, inexperienced drivers prone to risky behaviour on the road must be promoted. METHOD: This is a simplified single-blind, placebo-controlled experiment aimed at evaluating 44 young drivers monitored during a driving simulation following the consumption of natural and conventional wines, with a reference blood alcohol concentration (BAC) of 0.5 g/l. Two hypotheses are tested: (1) the legal consumption of wine has no significant impact on young drivers' performance in both ordinary and unusual road events; (2) natural and conventional wines are expected to produce negligible and acceptable impairments in young drivers the same BAC. Two reference groups (BAC = 0 g/l), one a placebo-controlled group with drivers treated with a dealcoholized wine, were included. RESULTS AND CONCLUSIONS: Significant differences between the groups in terms of perception and reaction times (PRT) to visual and auditory stimuli, and to speeding were observed, with young drivers treated with conventional wine displaying more aggressive behaviours. In contrast, participants treated with natural wine showed PRT which were not significantly different from those belonging to control groups. The gaze attention levels of wine treated drivers were found to be dose dependant, with young drivers of the two control groups and those of the treated ones with BAC < 0.3 g/l able to focus on wider area ahead and, thereby, collect more information from the road environment.

Investigation into passing behavior at passing zones to validate and extend the use of driving simulators in two-lane roads safety analysis.

A passing maneuver allows drivers to maintain their desired speed on two-lane highways. However, it entails a high risk of collision with vehicles travelling in the opposite direction. Investigating drivers' behavior while performing passing maneuvers could provide helpful information on the factors that influence this process. Driving simulators have become important tools for driving behavior research studies as they are safe, facilitate the controlled use of experimental variables, and generate detailed output data. It remains to be seen whether simulator results can be considered representative of real-life driving conditions. With respect to passing maneuvers, no study has made a comprehensive and direct comparison between drivers' passing behavior in the field and driver behavior observed in a simulated environment. In this validation study, a fixed-base interactive simulator was used to collect data from fifty-four participants (eighteen Iranians and thirty-six Italians) involved in several traffic scenarios on a two-lane rural highway segment (obtained by varying the speed of opposing vehicles, lead vehicles and headways in the opposite direction). A 3D model and its environmental characteristics were realized from the real segment which had previously been surveyed with drones to collect videos and derive data on real passing maneuvers. The results for the two-sided K-S test revealed no statistically significant difference in the accepted gap, effective accepted gap, perception reaction time, and time to collision variables between the field and the simulator at the 95 % confidence level. However, when conducting a one-sided K-S test, some statistical directional differences were found in the cases of the accepted gap and perception reaction time variables, which exhibited lower values in the field compared to the simulator again at the 95 % confidence level. Although the passing duration was statistically higher in the simulator than in the field, the shape of the two distributions was not statistically different. Analysis showed that differences in the passing duration are due to the lower passing vehicle speed and lower speed difference with the simulator than in the field, which are caused by truncating headways in the subject direction in the simulator. The cultural background of participants did not result in any discernible difference in passing behavior. The results would support a more extensive use of driving simulators in future passing behavior studies.

A driving simulation study to examine the impact of available sight distance on driver behavior along rural highways.

The available sight distance (ASD) is the maximum length of the roadway ahead visible to the driver. It is a fundamental factor in road geometry principles and is used by road designers to ensure safe driving conditions. However, designers do not know how a specific ASD may affect the longitudinal and transversal behavior of drivers engaged in negotiating curves. This paper focuses on analyzing driver longitudinal behavior along rural highways curves with limited visibility. A number of virtual sight condition scenarios were recreated and tested in the driving simulator. Three tracks were designed with various combinations of radii and sight obstructions (a continuous wall) along the roadside located at various offsets from the lane centerline, combinations which resulted with a minimum ASD of 56.6 m. Roadside factors capable of influencing the risk perception of drivers (e.g., traffic barriers, posted speed limit signs, vegetation) were all excluded from the simulations. Results indicate that speed and trajectory dispersion from the lane centerline depend linearly on ASD in the investigated range of curve radii (from 120 to 430 m). In general, when ASD increases, so does speed and the trajectories tend to be less dispersed around the lane centerline. As a result, in safety terms, any variation in ASD will have the polar opposite effect on safety related parameters. Furthermore, different curves with similar ASD values resulted in different speed and lateral control behaviors. Analysis from ANOVA support the same findings; in addition, radius, curve direction, and distance from trajectory to sight obstruction have been identified as significant independent parameters. Road designers should adjust the ASD and these parameters when seeking to encourage drivers to adopt appropriate behaviors. To optimize safe driving conditions, ASD should be designed so that it is slightly greater than the required sight distance, since excessive ASD values may encourage drivers to drive at inappropriate speeds.

Analysis of factors affecting the severity of crashes in urban road intersections.

Road crashes are events which depend on a variety of factors and which exhibit different magnitudes of outputs when evaluated with respect to the effects on road users. Despite a lot of research into the evaluation of crash likelihood and frequency, only a few works have focused exclusively on crash severity with these limited to sections of freeways and multilane highways. Hence, at present there is a large gap in knowledge on factors affecting the severity of crashes for other road categories, facilities, and scenarios. The paper deals with the identification of factors affecting crash severity level at urban road intersections. Two official crash records together with a weather database, a traffic data source with data aggregated into 5min intervals, and further information characterising the investigated urban intersections were used. Analyses were performed by using a back propagation neural network model and a generalized linear mixed model that enable the impact assessment of flow and other variables. Both methods demonstrate that flows play a role in the prediction of severity levels.

Fluoxetine alters feeding behavior and leptin levels in chronically-stressed rats.

Stress-induced alterations in feeding behavior are sexually dimorphic and have been related to changes in monoamine levels. Fluoxetine is commonly used as an antidepressant and has also been suggested as an adjunct to other strategies to treat obese individuals. Leptin may interact with stress hormones and with the brain serotonergic system, possibly affecting the feeding behavior of stressed rats. The aim of this study is to evaluate the interaction between chronic fluoxetine treatment and leptin levels in adult female Wistar rats submitted to chronic variable stress. After 30 days of stress, control and stressed groups were subdivided into two groups that received daily injections of vehicle or fluoxetine (8 mg/kg, i.p.). Body weight was evaluated before and after fluoxetine treatment. The animals gained weight with time, signifying that there is a difference in weight gain over time when fluoxetine-treated animals are, or not, subjected to the stress model. Both fluoxetine and stress induced a decrease in sweet food consumption. On the 60th day of fluoxetine treatment, leptin levels were decreased in fluoxetine-treated animals and there was no effect of stress. We conclude that chronic fluoxetine treatment induced a decreased intake of sweet food, as well as a reduction in leptin levels, and that this result could represent a compensatory response to reduced food intake rather than a direct anorectic mechanism. No interaction with chronic stress was observed.

Resistance to glucocorticoid-induced apoptosis in PLP peptide-specific T cell clones from patients with progressive MS.

Glucocorticoids (GC) are commonly used to treat inflammatory disorders such as multiple sclerosis (MS) and may exert their immunosuppressive activity by inducing apoptosis in activated lymphocytes. However, unlike relapsing-remitting MS patients, those with progressive disease respond poorly to GC treatment. The data in this communication indicate that PLP peptide-specific T cell clones from progressive, but not relapsing-remitting MS patients are resistant to GC-induced apoptosis in vitro, in a fashion associated with expression of B-7 co-stimulatory molecules. Thus, failure to respond to GC treatment may reflect defect in apoptosis that develop during the progressive stages of chronic inflammatory disease.

Accuracy of the diffusion equation to describe photon migration through an infinite medium: numerical and experimental investigation.

The accuracy of results obtained from the diffusion equation (DE) has been investigated for the case of an isotropic point source in a homogeneous, weakly absorbing, infinite medium. The results from the DE have been compared both with numerical solutions of the radiative transfer equation obtained with Monte Carlo (MC) simulations and with cw experimental results. Comparisons showed that for the cw fluence rate, discrepancies are of the same order as statistical fluctuations on MC results (within 1%) when the distance r from the source is > 2/mu(s)', (mu(s)' is the reduced scattering coefficient). For these values of r, discrepancies for the time-resolved fluence rate are of the same order of statistical fluctuations (within 5%) when the time of flight is t > 4t0 with to time of flight for unscattered photons. For shorter times the DE overestimates the fluence discrepancies are larger for larger values of the asymmetry factor. As to the specific intensity, for small values of r the MC results are more forward peaked than expected from the DE, and the forward peak is stronger for photons arriving at short times. We assumed r > 2/mu(s)' and t > 4t0 for the domain of validity of the DE and we determined the requirements for which the simplifying assumptions necessary to obtain the DE, expressed by two inequalities, are fulfilled. Comparisons with cw experimental results showed a good agreement with MC results both at high and at small values of r mu(s)', while the comparison with the DE showed significant discrepancies for small values of r mu(s)'. Using MC results we also investigated the error made on the optical properties of the medium when they are retrieved using the solution of the DE. To obtain accuracy better than 1% from fitting procedures on time-resolved fluence rate data it is necessary to disregard photons with time of flight < 4t0. Also from cw data it is possible to retrieve the optical properties with good accuracy: by using the added absorber technique discrepancies are < 1%, both on mu(s)' and on mu(a), if the absorption coefficient is small (mu(a)/mu(s)' < 0.005).

Independence of the diffusion coefficient from absorption: experimental and numerical evidence.

We investigated the dependence of the diffusion coefficient on the absorption coefficient by studying the propagation of light emitted by an isotropic source in an infinitely extended medium. Comparisons with both experimental and numerical results showed that the diffusion equation gives a better description of photon migration when the diffusion coefficient is assumed to be independent of absorption.

Leukocyte infiltration and collagenolysis in cervical tissue from intrapartum sheep.

Sheep uterine cervices and cervical mucus were heavily infiltrated by neutrophils during labour, whereas samples of cervices obtained from non-pregnant controls had no infiltrate. The neutrophilic infiltrate of the sheep uterine cervix at term was not homogeneously distributed throughout the organ: luminal mucus contained more neutrophils than tissues which, in turn, displayed a differential distribution, the superficial subepithelial layer being more heavily infiltrated than the deeper submucous layers. A widespread collagenolysis was observed in the sheep uterine cervix at term. The homogeneous morphological aspect of degradation of collagen fibres throughout the whole cervical stroma contrasted with the above-mentioned differential distribution of neutrophils. On the basis of previous reports showing that collagenolysis follows the leukocytic invasion of human and rat cervices at term, a possible role for the neutrophilic infiltrate of the sheep uterine cervix is discussed.

Classification of species in the genus Penicillium by Curie point pyrolysis/mass spectrometry followed by multivariate analysis and artificial neural networks.

Curie point pyrolysis/mass spectrometry of Penicillium species was performed with 530 degrees C Curie point foils. The mass spectra were submitted to principal component analysis, canonical variates analysis and hierarchical cluster analysis, producing a final dendrogram by the use of average linkage clustering. By this approach a successful classification of the species Penicillium italicum, P. expansum and P. digitatum originating from fruits was obtained. Isolates of the same species grouped together in the dendrogram, while the different species were distinguished. Also when grown on two different agar media, replicates of the same species grouped together. Likewise, a satisfactory classification was achieved by multivariate analysis of the data for various isolates of the cheese-associated fungi Aspergillus versicolor, P. discolor, P. roqueforti, P. solitum, P. verrucosum, P. commune and P. palitans. However, some difficulties appeared in distinguishing the closely related species P. commune and P. palitans. Such difficulties became greater on including more isolates and limiting the analysis to five of the species. The use of back-propagation artificial neural networks, in contrast, resulted in a correct classification in all cases. Thus, it is concluded that Curie point pyrolysis/mass spectrometry is useful in chemotaxonomic studies of the closely related species in the genus Penicillium.

Comparison between bladder wall's strain analysis and CMG in clinical urodynamics: preliminary report.

On the basis of data obtained in previous experimental investigations, the application of a new physical entity, "strain" (sigma), was evaluated in bladder dynamics. In this preliminary study 12 cases of urodynamically evaluated subjects are reported; the significance of the traditional P(V) curves is critically compared with the new sigma (V) curve, proposed by the authors.