The transportation demand is rapidly growing in metropolises, resulting in chronic traffic congestions in dense downtown areas. Adaptive traffic signal control as the principle part of intelligent transportation systems has a primary role to effectively reduce traffic congestion by making a real-time adaptation in response to the changing traffic network dynamics. Reinforcement learning (RL) is an effective approach in machine learning that has been applied for designing adaptive traffic signal controllers. One of the most efficient and robust type of RL algorithms are continuous state actor-critic algorithms that have the advantage of fast learning and the ability to generalize to new and unseen traffic conditions. These algorithms are utilized in this paper to design adaptive traffic signal controllers called actor-critic adaptive traffic signal controllers (A-CATs controllers). The contribution of the present work rests on the integration of three threads: (a) showing performance comparisons of both discrete and continuous A-CATs controllers in a traffic network with recurring congestion (24-hour traffic demand) in the upper downtown core of Tehran city, (b) analyzing the effects of different traffic disruptions including opportunistic pedestrians crossing, parking lane, non-recurring congestion, and different levels of sensor noise on the performance of A-CATS controllers, and (c) comparing the performance of different function approximators (tile coding and radial basis function) on the learning of A-CATs controllers. To this end, first an agent-based traffic simulation of the study area is carried out. Then six different scenarios are conducted to find the best A-CATs controller that is robust enough against different traffic disruptions. We observe that the A-CATs controller based on radial basis function networks (RBF (5)) outperforms others. This controller is benchmarked against controllers of discrete state Q-learning, Bayesian Q-learning, fixed time and actuated controllers; and the results reveal that it consistently outperforms them.
The medicinal properties attributed to Crocus sativus L. (saffron) are extensive. The safety of saffron is important in relation to its medicinal applications. This study was performed to elucidate the possible toxic effects of ethanolic extract of Crocus sativus L. stigma on liver, kidney and some hematological parameters in rats. Wistar rats were randomly assigned into four groups of eight animals each. Group 1 was treated with ISS as control and Groups 2 to 4 were treated with extract administered daily for 2 weeks intraperitoneally in doses of 0.35, 0.70 and 1.05 g kg −1 , respectively. Body weight of the animals were recorded on the first, seven and final days of the experiment. The haematological studies include total RBC count, total WBC count, Hb, %HCT, MCV, MCH and MCHC. Biochemical/serum profile studies include ALT, AST, urea, uric acid and creatinine. Tissue specimens of the liver and kidneys were subjected to histological examination using standard hematoxyline-eosin staining. The extract caused significant reductions in the Hb and HCT levels and total RBC count, although it showed any dose-dependent effect. Total WBC count showed significant dose-dependent increases in extract treated rats. Significant dose-dependent increased values of AST, ALT, urea, uric acid and creatinine were seen. Microscopically, there were mild to severe hepatic and renal tissue injuries supporting the biochemical analysis. The results indicated that extract of Crocus sativus L. stigma is toxic in high doses.
Purpose:To evaluate the effects of onion juice on sodium-selenite induced cataract formation.Materials and Methods:Thirty-two 10-day-old Wistar-albino rat pups were divided into four equal groups. Group 1 received only subcutaneous saline injection. In Group 2, sodium-selenite (30 nmol/g body weight) was injected subcutaneously. In Group 3, subcutaneous sodium-selenite was injected and one drop 50% diluted fresh juice of crude onion was instilled every 8 h into the right eye for 14 days; the left eye received no treatment. Group 4 rats were similar to those of Group 3, the only difference being that of undiluted fresh juice of crude onion. The development of cataract was assessed. Rat lenses were analyzed for total antioxidant (TA) level, and for activities of glutathione peroxidase (GPX) and superoxide dismutase (SOD).Results:Both eyes of all rats in Group 1 did not exhibit cataract formation. In Group 2, all rats developed Grade 3 cataract in the lenses of both eyes. The difference in exhibited cataract in the lens of the right eyes in all rats between Group 2 and any eyes of groups 3 or 4 were significant (P = 0.001). The mean TA level and mean activities of SOD and GPX in Group 2 rat lenses were significantly lower than the values in lenses of all rats in Group 1 (P = 0.001, 0.003, 0.001), and in the lenses of the right eyes of rats in Groups 3 and 4 (P = 0.001, 0.020, 0.001).Conclusion:Instillation of onion juice into the rat eyes can effectively prevent selenite-induced cataract formation. This effect was associated with increased TA level, SOD and GPX activities in the lens.
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