165 research outputs found

    Travel Time Estimation on a Signalised Urban Networks using Cumulative Plots

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    This paper presents the development and testing of a methodology for estimation of average travel time on signalised urban networks. The methodology considers the classical analytical procedure, where average travel time on a study link is estimated as the average area between cumulative plots for the respective link. The challenge is to accurately estimate the plots based on the availability of data. The three different cases of data availability are considered: a) case-D, for only detector data; b) case- DS, for detector data and signal controller data; and c) case- DSS, for detector data, signal controller data and saturation flow rate. The performance of the methodology is evaluated under controlled environment considering different degree of saturation and different detection intervals. The performance for case-DS and for case-DSS is consistent whereas, the performance for case-D is highly sensitive to the signal phases in the detection interval

    Methodology for Travel Time Estimation on a Signalised Arterial

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    This paper presents the development and testing of a methodology for estimation of average travel time on signalised urban networks. The methodology considers the classical analytical procedure, where average travel time on a study link is estimated as the average area between cumulative plots for the respective link. The challenge is to accurately estimate the plots based on the availability of data. The three different cases of data availability are considered: a) case-D, for only detector data; b) case-DS, for detector data and signal controller data; and c) case- DSS, for detector data, signal controller data and saturation flow rate. The performance of the methodology is evaluated under controlled environment considering different degree of saturation and different detection intervals. The performance for case-DS and for case-DSS is consistent whereas, the performance for case-D is highly sensitive to the signal phases in the detection interval

    Improving travel time estimates from inductive loop and toll collection data with dempster-shafer data fusion

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    Dempster-Shafer data fusion can enhance travel time estimation for motorists and traffic managers. In this paper, travel time data from inductive loop road sensors and toll collection stations are merged through Dempster-Shafer inference to generate an improved estimate of travel time. The technique captures travel time data from the two sources and combines them by using Dempster's rule and belief values (also called probability mass) calculated from a confusion matrix. The most probable travel time over the monitored road section is selected as that with the largest belief. A case study is provided to illustrate application of the fusion technique with data gathered on winter Saturdays for 2 years: 2003 data are used to compute the confusion matrices and belief values, and 2004 data are used for validation

    Applicability of road safety indicators to assess driving risks under Swiss road conditions

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    Road traffic crash is a problem in every country. According to World Health Organization, in Europe there are about 127,000 people killed and at least some 2.4 million injured each year. Incident detection algorithms to detect incidents on motorways are well developed. Their objective is to detect incidents as soon as possible so that emergency services can get to the scene of the incident as soon as possible to reduce congestion, to provide medical help if needed and to increase safety of the affected area. Some crashes are traffic related and it may be possible to detect the state of the traffic where the risk of a crash is high. Based on this, premise safety indicators have been developed by [Aron et al, 2003], [Hayward, J. C., 1972], [Lee, C. et al, 2006], and [Pande, A. et al, 2006]. The derivation of these safety indicators are data driven and may be able to forecast the potential of a crash in real time. This study aims to assess the driving risks under Swiss road conditions by using safety indicators. Real traffic data from Automatic Traffic Counts installed on motorways and crash data have been collected in Vaud canton, Switzerland. This paper also discusses the applicability of the proposed safety indicators and the issues associated with their use

    Dnmt3a regulates emotional behavior and spine plasticity in the nucleus accumbens.

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    Despite abundant expression of DNA methyltransferases (Dnmts) in brain, the regulation and behavioral role of DNA methylation remain poorly understood. We found that Dnmt3a expression was regulated in mouse nucleus accumbens (NAc) by chronic cocaine use and chronic social defeat stress. Moreover, NAc-specific manipulations that block DNA methylation potentiated cocaine reward and exerted antidepressant-like effects, whereas NAc-specific Dnmt3a overexpression attenuated cocaine reward and was pro-depressant. On a cellular level, we found that chronic cocaine use selectively increased thin dendritic spines on NAc neurons and that DNA methylation was both necessary and sufficient to mediate these effects. These data establish the importance of Dnmt3a in the NAc in regulating cellular and behavioral plasticity to emotional stimuli

    BAZ1B in Nucleus Accumbens Regulates Reward-Related Behaviors in Response to Distinct Emotional Stimuli

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    ATP-dependent chromatin remodeling proteins are being implicated increasingly in the regulation of complex behaviors, including models of several psychiatric disorders. Here, we demonstrate that Baz1b, an accessory subunit of the ISWI family of chromatin remodeling complexes, is upregulated in the nucleus accumbens (NAc), a key brain reward region, in both chronic cocaine-treated mice and mice that are resilient to chronic social defeat stress. In contrast, no regulation is seen in mice that are susceptible to this chronic stress. Viral-mediated overexpression of Baz1b, along with its associated subunit Smarca5, in mouse NAc is sufficient to potentiate both rewarding responses to cocaine, including cocaine self-administration, and resilience to chronic social defeat stress. However, despite these similar, proreward behavioral effects, genome-wide mapping of BAZ1B in NAc revealed mostly distinct subsets of genes regulated by these chromatin remodeling proteins after chronic exposure to either cocaine or social stress. Together, these findings suggest important roles for BAZ1B and its associated chromatin remodeling complexes in NAc in the regulation of reward behaviors to distinct emotional stimuli and highlight the stimulus-specific nature of the actions of these regulatory proteins

    Monitoring of IVF birth outcomes in Finland: a data quality study

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    BACKGROUND: The collection of information on infertility treatments is important for the surveillance of potential health consequences and to monitor service provision. STUDY DESIGN: We compared the coverage and outcomes of IVF children reported in aggregated IVF statistics, the Medical Birth Register (subsequently: MBR) and research data based on reimbursements for IVF treatments in Finland in 1996–1998. RESULTS: The number of newborns were nearly equal in the three data sources (N = 4331–4384), but the linkage between the MBR and the research data revealed that almost 40% of the reported IVF children were not the same individuals. The perinatal outcomes in the three data sources were similar, excluding the much lower incidence of major congenital anomalies in the IVF statistics (157/10 000 newborns) compared to other sources (409–422/10 000 newborns). CONCLUSION: The differences in perinatal outcomes in the three data sets were in general minor, which suggests that the observed non-recording in the MBR is most likely unbiased

    Histone arginine methylation in cocaine action in the nucleus accumbens

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    Repeated cocaine exposure regulates transcriptional regulation within the nucleus accumbens (NAc), and epigenetic mechanisms - such as histone acetylation and methylation on Lys residues - have been linked to these lasting actions of cocaine. In contrast to Lys methylation, the role of histone Arg (R) methylation remains underexplored in addiction models. Here we show that protein-R-methyltransferase-6 (PRMT6) and its associated histone mark, asymmetric dimethylation of R2 on histone H3 (H3R2me2a), are decreased in the NAc of mice and rats after repeated cocaine exposure, including self-administration, and in the NAc of cocaine-addicted humans. Such PRMT6 down-regulation occurs selectively in NAc medium spiny neurons (MSNs) expressing dopamine D2 receptors (D2-MSNs), with opposite regulation occurring in D1-MSNs, and serves to protect against cocaine-induced addictive-like behavioral abnormalities. Using ChIP-seq, we identified Src kinase signaling inhibitor 1 (Srcin1; also referred to as p140Cap) as a key gene target for reduced H3R2me2a binding, and found that consequent Srcin1 induction in the NAc decreases Src signaling, cocaine reward, and the motiv ation to self-administer cocaine. Taken together, these findings suggest that suppression of Src signaling in NAc D2-MSNs, via PRMT6 and H3R2me2a down-regulation, functions as a homeostatic brake to restrain cocaine action, and provide novel candidates for the development of treatments for cocaine addiction. Keywords: histone arginine (R) methylation; drug addiction; medium spiny neurons; ChIP-seq; Sr
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