9 research outputs found
Delay-based Passenger Car Equivalent at Signalized Intersections in Iran
Due to their different sizes and operational characteristics, vehicles other than passenger cars have a different influence on traffic operations especially at intersections. The passenger car equivalent (PCE) is the parameter that shows how many passenger cars must be substituted for a specific heavy vehicle to represent its influence on traffic operation. PCE is commonly estimated using headway-based methods that consider the excess headway utilized by heavy vehicles. In this research, the PCE was estimated based on the delay parameter at three signalized intersections in Tehran, Iran. The data collected were traffic volume, travel time for each movement, signalization, and geometric design information. These data were analysed and three different models, one for each intersection, were constructed and calibrated using TRAF-NETSIM simulation software for unsaturated traffic conditions. PCE was estimated under different scenarios and the number of approach movements at each intersection. The results showed that for approaches with only one movement, PCE varies from 1.1 to 1.65. Similarly, for approaches with two and three movements, the PCE varies from 1.07 to 1.99 and from 0.76 to 3.6, respectively. In addition, a general model was developed for predicting PCE for intersections with all of the movements considered. The results obtained from this model showed that the average PCE of 1.5 is similar to the value recommended by the HCM (Highway Capacity Manual) 1985. However, the predicted PCE value of 1.9 for saturated threshold is closer to the PCE value of 2 which was recommended by the HCM 2000 and HCM 2010.</p
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A Study of Perceived Nature, Shade and Trees and Self-Reported Physical Activity in Denver
Introduction Integrating physical activity (PA) into daily routines has become a national priority following the American College of Sports Medicine/Centers for Disease Control’s statement on PA and health [1] and the U.S. Surgeon General’s Report on Physical Activity and Health [2]. [...]studies suggest the quality of landscape is a facet through which the surrounding environment may affect health behavior [23,24]. According to Leslie (2010), a majority of studies that show significant relationships between greenness and PA are those that collect perceived greenness measures (e.g., perception of trees, shade, and the presence of nature). Some studies also show that the level of the walkability of the neighborhood may affect its residences’ perception of the surrounding areas [52]. [...]the length of residency in the neighborhood is important because it can influence people’s relationships to the neighborhood environment and related perceptions of this place [53,54].</p
A Study of Perceived Nature, Shade and Trees and Self-Reported Physical Activity in Denver
(1) Background: Current evidence on the association between greenery and physical activity (PA) remains inconsistent. Most studies on this association use objective measures of greenness, which do not reveal people’s perceptions of greenness in neighborhoods, or the role of quality components of greenness, such as shade, trees, and the presence of nature on this association. (2) Methods: Drawing on data from the Neighborhood Environment and Health Survey—a cross-sectional population-based survey of Denver residents in 2007—we examined which measures of greenness (perceived and objective) correlated with the self-reported PA. We also assessed how components of perceived greenness, shade, trees and the presence of nature, correlated with PA. (3) Results: Perceived greenness, reflecting perception of trees, shade and the presence of nature, was positively associated with reported moderate–vigorous PA. Conclusion: Findings provide evidence that quality aspects of greenness affect people’s perception of the neighborhood in a way that relates to PA. The individual contributions of shade, trees, and the presence of nature in this association should be analyzed in future studies. Understanding the link between shade and trees and PA has implications for how to plan for walkability and sun safety at the neighborhood scale
The Effect of resistance training on GLUT4 expression in muscle tissue, glucose and insulin resistance in rats
Introduction: One of the most important glucose transporters is glucose transporter 4 (GLUT4), which can be expressed in insulin-sensitive tissues such as skeletal muscles. The purpose of this study was to investigate the effects of resistance training on GLUT4 gene expression and glycemic index in rats with type 2 diabetes.
Materials & Methods: Twenty-seven Wistar rats were selected; the rats were fed a high-fat diet for 6 weeks and then randomly divided into three groups: diabetic with resistance training (n=10), diabetic control (n=10), and obesity control (n=7).
Type 2 diabetes was induced by injection of a low dose of Streptozotocin (STZ) (30 mg/kg).
The resistance training program was performed for 6 weeks, five days per week. The glucose concentration was measured by glucose oxidase enzyme technology, serum insulin by the ELISA method, and real-time PCR was used to test the GLUT4 gene expression. For data analysis, independent t-test and one-way analysis of variance were used (α=0/ 05).
Findings: The results indicated that induction of diabetes reduced the GLUT4 gene expression in the gastrocnemius muscle tissue of diabetic rats (P=0.001). Also, GLUT4 gene expression increased in the diabetic training group compared with the diabetic control group (P=0.038). In addition, blood glucose and insulin resistance decreased significantly.
The content of GLUT4 gene expression was increased in the training group compared with the diabetic control group (p=0.001).
Discussion & Conclusions: Based on the findings of this study, it can be stated that the GLUT4 gene expression in rat gastrocnemius muscle tissue is reduced in diabetic rats. Also, resistance training could increase the GLUT4 gene expression and improve glucose transport and insulin resistance in type 2 diabetic rats. This could be due to improvement in the performance of glucose transporters by resistance training
Thyroid Storm Presenting as Psychosis
Thyroid storm is a life-threatening endocrine emergency with an incidence rate of 1% to 2%. It is a systemic condition of excessive thyroid hormone production and release leading to thermoregulatory, adrenergic, neuropsychiatric, cardiovascular, and abdominal manifestations. Although it is a rare condition, it carries a significant mortality rate. Hence, knowing the common and uncommon presentations of thyroid storm is important for its prompt diagnosis and treatment. In this article, we present an unusual case of a young woman who presented with psychosis as the manifesting symptom of thyroid storm. She did not respond adequately to conventional medical treatment, requiring plasmapheresis and a definitive thyroidectomy, which ultimately led to the return of patient’s baseline mental status and a dramatic recovery
Higher order aberration comparison between two aspherical intraocular lenses:MC6125AS and Akreos advanced optics
<b>AIM:</b> To compare higher order aberrations in two aspherical intraocular lenses (IOLs):Akreos advanced optics (AO) and Dr. Schmidt Microcrystalline 6125 aspheric anterior surface (MC6125AS) with each other.<b>METHODS:</b> Forty eyes of 39 patients underwent phacoemulsification and Akreos AO and MC6125AS were implanted in their eyes in a random manner. Three months post-operatively, higher order aberrations including spherical aberration, coma aberration, and total aberrations were measured and compared.<b>RESULTS:</b> The total aberration was 0.24±0.17 in eyes with Dr. Schmidt and 0.20±0.01 in eyes with Akreos AO (<i>P</i>=0.361). The mean of coma aberration was 0.17±0.21 and 0.09±0.86 in Dr. Schmidt and Akreos lenses, respectively (<i>P</i>=0.825). Total spherical aberration was almost the same in both groups (Mean:0.05, <i>P</i>=0.933). Best corrected visual acuity in Akreos AO (0.10±0.68) and Dr. Schmidt (0.09±0.67) did not differ significantly (<i>P</i>=0.700).<b>CONCLUSION:</b> There is no statistically significant difference in the higher order aberrations between these two aspherical lenses