484 research outputs found

    Can Situational Action Theory Explain the Gender Gap in Adolescent Shoplifting? Results From Austria

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    Although shoplifting is one of the crimes with the smallest gender gap among all offense types, most studies still conclude that males steal from shops more frequently than females. The roots of the gendered distribution of shoplifting have not yet been satisfactorily explained. This work investigates whether situational action theory (SAT) can account for males’ greater involvement in shoplifting compared to females and if the propensity–exposure interaction that is at the heart of the theory applies to both genders. Results from a large-scale student survey conducted in Austria suggest that SAT generalizes to both genders and that it is well suited to explain why males are more likely to shoplift than females.The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The research underlying this article was funded under grant no. SPA03–56 by the Sparkling Science Research Program of the Austrian Federal Ministry of Science and Research

    The Effect of absorbing sites on the one-dimensional cellular automaton traffic flow with open boundaries

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    The effect of the absorbing sites with an absorbing rate β0\beta_{0}, in both one absorbing site (one way out) and two absorbing sites (two ways out) in a road, on the traffic flow phase transition is investigated using numerical simulations in the one-dimensional cellular automaton traffic flow model with open boundaries using parallel dynamics.In the case of one way out, there exist a critical position of the way out ic1 i_{c1} below which the current is constant for β0\beta_{0}<<β0c2\beta_{0c2} and decreases when increasing β0\beta_{0} for β0\beta_{0}>>β0c2\beta_{0c2}. When the way out is located at a position greater than ic2 i_{c2}, the current increases with β0\beta_{0} for β0\beta_{0}<<β0c1\beta_{0c1} and becomes constant for any value of β0\beta_{0} greater than β0c1\beta_{0c1}. While, when the way out is located at any position between ic1 i_{c1} and ic2 i_{c2} (ic1 i_{c1}<<ic2 i_{c2}), the current increases, for β0\beta_{0}<<β0c1\beta_{0c1}, with β0\beta_{0} and becomes constant for β0c1\beta_{0c1}<<β0\beta_{0}<<β0c2\beta_{0c2} and decreases with β0\beta_{0} for β0\beta_{0}>>β0c2\beta_{0c2}. In the later case the density undergoes two successive first order transitions; from high density to maximal current phase at β0\beta_{0}==β0c1\beta_{0c1} and from intermediate density to the low one at β0\beta_{0}==β0c2\beta_{0c2}. In the case of two ways out located respectively at the positions i1 i_{1} and i2 i_{2}, the two successive transitions occur only when the distance i2i_{2}-i1i_{1} separating the two ways is smaller than a critical distance dcd_{c}. Phase diagrams in the (ι,β0\alpha,\beta_{0}), (β,β0\beta,\beta_{0}) and (i1,β0i_{1},\beta_{0}) planes are established. It is found that the transitions between Free traffic, Congested traffic and maximal current phase are first order

    Temporal Modulation of the Control Parameter in Electroconvection in the Nematic Liquid Crystal I52

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    I report on the effects of a periodic modulation of the control parameter on electroconvection in the nematic liquid crystal I52. Without modulation, the primary bifurcation from the uniform state is a direct transition to a state of spatiotemporal chaos. This state is the result of the interaction of four, degenerate traveling modes: right and left zig and zag rolls. Periodic modulations of the driving voltage at approximately twice the traveling frequency are used. For a large enough modulation amplitude, standing waves that consist of only zig or zag rolls are stabilized. The standing waves exhibit regular behavior in space and time. Therefore, modulation of the control parameter represents a method of eliminating spatiotemporal chaos. As the modulation frequency is varied away from twice the traveling frequency, standing waves that are a superposition of zig and zag rolls, i.e. standing rectangles, are observed. These results are compared with existing predictions based on coupled complex Ginzburg-Landau equations

    Macroscopic traffic models from microscopic car-following models

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    We present a method to derive macroscopic fluid-dynamic models from microscopic car-following models via a coarse-graining procedure. The method is first demonstrated for the optimal velocity model. The derived macroscopic model consists of a conservation equation and a momentum equation, and the latter contains a relaxation term, an anticipation term, and a diffusion term. Properties of the resulting macroscopic model are compared with those of the optimal velocity model through numerical simulations, and reasonable agreement is found although there are deviations in the quantitative level. The derivation is also extended to general car-following models.Comment: 12 pages, 4 figures; to appear in Phys. Rev.

    Towards a Macroscopic Modelling of the Complexity in Traffic Flow

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    We present a macroscopic traffic flow model that extends existing fluid-like models by an additional term containing the second derivative of the safe velocity. Two qualitatively different shapes of the safe velocity are explored: a conventional Fermi-type function and a function exhibiting a plateau at intermediate densities. The suggested model shows an extremely rich dynamical behaviour and shows many features found in real-world traffic data.Comment: submitted to Phys. Rev.

    Life events and hemodynamic stress reactivity in the middle-aged and elderly

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    Recent versions of the reactivity hypothesis, which consider it to be the product of stress exposure and exaggerated haemodynamic reactions to stress that confers cardiovascular disease risk, assume that reactivity is independent of the experience of stressful life events. This assumption was tested in two substantial cohorts, one middle-aged and one elderly. Participants had to indicate from a list of major stressful life events up to six they had experienced in the previous two years. They were also asked to rate how disruptive and stressful they were, at the time of occurrence and now. Blood pressure and pulse rate were measured at rest and in response to acute mental stress. Those who rated the events as highly disruptive at the time of exposure and currently exhibited blunted systolic blood pressure reactions to acute stress. The present results suggest that acute stress reactivity may not be independent of stressful life events experience

    Long-lived states in synchronized traffic flow. Empirical prompt and dynamical trap model

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    The present paper proposes a novel interpretation of the widely scattered states (called synchronized traffic) stimulated by Kerner's hypotheses about the existence of a multitude of metastable states in the fundamental diagram. Using single vehicle data collected at the German highway A1, temporal velocity patterns have been analyzed to show a collection of certain fragments with approximately constant velocities and sharp jumps between them. The particular velocity values in these fragments vary in a wide range. In contrast, the flow rate is more or less constant because its fluctuations are mainly due to the discreteness of traffic flow. Subsequently, we develop a model for synchronized traffic that can explain these characteristics. Following previous work (I.A.Lubashevsky, R.Mahnke, Phys. Rev. E v. 62, p. 6082, 2000) the vehicle flow is specified by car density, mean velocity, and additional order parameters hh and aa that are due to the many-particle effects of the vehicle interaction. The parameter hh describes the multilane correlations in the vehicle motion. Together with the car density it determines directly the mean velocity. The parameter aa, in contrast, controls the evolution of hh only. The model assumes that aa fluctuates randomly around the value corresponding to the car configuration optimal for lane changing. When it deviates from this value the lane change is depressed for all cars forming a local cluster. Since exactly the overtaking manoeuvres of these cars cause the order parameter aa to vary, the evolution of the car arrangement becomes frozen for a certain time. In other words, the evolution equations form certain dynamical traps responsible for the long-time correlations in the synchronized mode.Comment: 16 pages, 10 figures, RevTeX

    Ultra-Long Pharmacokinetic Properties of Insulin Degludec are Comparable in Elderly Subjects and Younger Adults with Type 1 Diabetes Mellitus

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    BACKGROUND: Management of diabetes in elderly subjects is complex and careful management of glucose levels is of particular importance in this population because of an increased risk of diabetes-related complications and hypoglycaemia. OBJECTIVE: The aim of this study was to evaluate the pharmacokinetic and pharmacodynamic properties of insulin degludec (IDeg), a basal insulin with an ultra-long duration of action, in elderly subjects with type 1 diabetes compared with younger adults. METHODS: This trial was a randomised, double-blind, two-period, crossover trial conducted in a single centre and included both inpatient and outpatient periods. Subjects were men and women aged 18–35 years inclusive (younger adult group) or ≥65 years (elderly group) with type 1 diabetes who received IDeg (0.4 U/kg) via subcutaneous injection in the thigh once-daily for six days. Following 6-day dosing, a 26-hour euglycaemic glucose clamp procedure was conducted to evaluate the steady-state pharmacodynamic effects of IDeg. Blood samples were taken for pharmacokinetic analysis up to 120 h post-dose. Pharmacokinetic endpoints included the total exposure of IDeg, ie the area under the IDeg serum concentration curve during one dosing interval at steady state (AUC(IDeg,τ,SS)) (τ = 0–24 h, equal to one dosing interval) and the maximum IDeg serum concentration at steady state (C(max,IDeg,SS)). Pharmacodynamic endpoints included the total glucose-lowering effect of IDeg, ie the area under the glucose infusion rate (GIR) curve at steady state (AUC(GIR,τ,SS)), and the maximum GIR at steady state (GIR(max,IDeg,SS)). RESULTS: Total exposure (AUC(IDeg,τ,SS)) and maximum concentration (C(max,IDeg,SS)) of IDeg were comparable between elderly subjects and younger adults. Estimated mean age group ratios (elderly/younger adult) for AUC(IDeg,τ,SS) and C(max,IDeg,SS) and corresponding two-sided 95 % confidence intervals (CIs) were 1.04 (95 % CI 0.73–1.47) and 1.02 (95 % CI 0.74–1.39), respectively. Mean AUC(IDeg,0–12h,SS)/AUC(IDeg,τ,SS) was 53 % in both younger adult and elderly subjects, showing that in both age groups IDeg exposure was evenly distributed across the first and second 12 h of the 24-hour dosing interval. No statistically significant differences were observed between younger adult and elderly subjects with regard to AUC(GIR,τ,SS) (the primary endpoint of this study) and GIR(max,IDeg,SS). Estimated mean age group ratios (elderly/younger adult) for AUC(GIR,τ,SS) and GIR(max,IDeg,SS) and corresponding two-sided 95 % CIs were 0.78 (95 % CI 0.47–1.31) and 0.80 (95 % CI 0.54–1.17), respectively. Duration of action was beyond the clamp duration of 26 h in all subjects. CONCLUSIONS: The exposure of IDeg at steady state during once-daily dosing was similar in younger adult and elderly subjects. The glucose-lowering effect of IDeg was numerically lower in elderly subjects compared with younger adults, but no significant differences were observed between age groups. The ultra-long pharmacokinetic and pharmacodynamic properties of IDeg observed in younger adults were preserved in elderly subjects with type 1 diabetes. Clinical trials.gov number: NCT0096441

    Combination of simulation and model-checking for the analysis of autonomous vehicles’ behaviors: A case study

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    International audienceAutonomous vehicles’ behavioural analysis represents a major challenge in the automotive world. In order to ensure safety and fluidity of driving, various methods are available, in particular, simulation and formal verification. The analysis, however, has to cope with very complex environments depending on many parameters evolving in real time. In this context, none of the aforementioned approaches is fully satisfactory, which lead us to propose a combined methodology in order to point out suspicious behaviours more efficiently. We illustrate this approach by studying a non deterministic scenario involving a vehicle, which has to react to some perilous situation

    New Insights into Traffic Dynamics: A Weighted Probabilistic Cellular Automaton Model

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    From the macroscopic viewpoint for describing the acceleration behavior of drivers, this letter presents a weighted probabilistic cellular automaton model (the WP model, for short) by introducing a kind of random acceleration probabilistic distribution function. The fundamental diagrams, the spatio-temporal pattern are analyzed in detail. It is shown that the presented model leads to the results consistent with the empirical data rather well, nonlinear velocity-density relationship exists in lower density region, and a new kind of traffic phenomenon called neo-synchronized flow is resulted. Furthermore, we give the criterion for distinguishing the high-speed and low-speed neo-synchronized flows and clarify the mechanism of this kind of traffic phenomena. In addition, the result that the time evolution of distribution of headways is displayed as a normal distribution further validates the reasonability of the neo-synchronized flow. These findings suggest that the diversity and randomicity of drivers and vehicles has indeed remarkable effect on traffic dynamics.Comment: 12 pages, 5 figures, submitted to Europhysics Letter
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