218 research outputs found
Highway Cross Slope Measurement Using Airborne and Mobile LiDAR
Ensuring adequate pavement cross slope on highways can improve driver safety by reducing the potential for water sheeting and ponding. Collecting cross slope data is typically only based on small sample because efficient technology and means to collect accurate cross slope data has been evasive. The advent of Light Detection and Ranging (LiDAR) scanning technology has proven to be a valuable tool in the creation of 3D terrain models. Combined with other technologies such as Global Positioning Systems (GPS) and Inertial Measurement Unit devices (IMU) it is now possible to collect accurate 3D coordinate data in the form of a point cloud while the data collection system is moving. This study provides an evaluation of both Airborne LiDAR Scanning (ALS) and Mobile Terrestrial LiDAR Scanning (MTLS) systems regarding the accuracy and precision of collected cross slope data and documentation of procedures needed to calibrate, collect, and process this data.
ALS data was collected by a single vendor on a section of freeway in Spartanburg, South Carolina and MTLS data was collected by six vendors on four roadway sections in South Carolina. The MTLS cross slopes were measured on 23 test stations using conventional surveying methods and compared with the LiDAR-extracted cross slopes. Results indicate that both adjusted and unadjusted MTLS derived cross slopes meets suggested cross slope accuracies (±0.2%). Unadjusted LiDAR data did incorporate corrections from an integrated inertial measurement unit, and high accuracy real-time kinematic GPS, however, was not post-processed adjusted with ground control points.
Similarly, airborne LiDAR-extracted cross slopes was compared with conventional surveying measurement on five test stations along the freeway study section. Whereas, the ALS data accuracy was over the minimum acceptable error when two sides of the travel lanes were used to estimate the cross slope, the use of a fitted line to derive the cross slope provided accuracies similar to the MTLS systems.
The levels of accuracy demonstrate that MTLS and ALS can be reliable methods for cross slope verification. Adoption of LiDAR would enable South Carolina Department of Transportation (SCDOT) or other highway agencies to proactively address cross slope and drainage issues.
When rain falls on a pavement surface, the water depth that accumulates can result in hydroplaning. Previous research has not clearly defined a water depth at which hydroplaning occurs; however, there is considerable agreement that a water depth equal to 0.06 inches as the acceptable upper limit of water depth to minimize the possibility of hydroplaning. This research also explored the potential for hydroplaning with regard to the range of vehicle speed, tire tread depth, tire pressure, and pavement surface texture. Using the results of the sensitivity analysis to provide roadway context combined with MTLS derived cross slope data, SCDOT and other highway agencies can use a data driven approach to evaluate cross slopes and road segments that need corrective measures to minimize hydroplaning potential and enhance safety
Safety Evaluation of Shoulder Bypass Lanes at Unsignalized Intersections on Rural Two-Lane Roadways Using Cross Sectional Analysis
Construction of bypass lanes at rural intersections has typically been considered a low-cost highway safety improvement by the transportation community. However, this needs to be quantitatively evaluated so that the decisions could be made on whether to continue with adding bypass lanes. Highway safety analyses utilize two common approaches to evaluate the effectiveness of a geometric treatment: before-and-after study and cross-sectional study. This paper explains the results using a cross-sectional study approach, where intersections with bypass lanes were compared to intersections with no bypass lanes for which crash data were obtained for more than 1,100 intersections in Kansas. Both 3-legged and 4-legged intersections were taken into consideration separately by looking at intersection-related crashes and crashes within an intersection box. According to the results, the number of crashes and crash severities were lower at 3-legged intersections with bypass lanes compared with 3-legged intersections without bypass lanes, even though these reductions were not statistically significant at 95% level. When considering a 300-ft. intersection box, statistically significant crash reductions were observed at 4-legged intersections, for all considered crash and crash rate categories. When considering 90% level, crash reduction at 3-legged intersections was also statistically significant when considering a 300-ft. intersection box. Crash modification factors (CMFs) calculated to evaluate safety effectiveness of bypass lanes at unsignalized rural intersections in Kansas showed values less than 1.0 for almost all cases, indicating safety benefits of bypass lanes. Accordingly, it is beneficial to continue with the practice of adding shoulder bypass lanes at rural unsignalized intersections on two-lane roads where the traffic volumes are relatively low
Protective Effect of Coenzyme Q10 on Methamphetamine-Induced Apoptosis in Adult Male Rats
Background: The negative consequence of methamphetamine abuse is due to neuropathologic changes in the brain, which reduces dopaminergic neurons and result in damage to different brain areas. Neurotoxicity induced by methamphetamine increases the oxidative stress and associated with neuronal apoptosis. The role of the antioxidant coenzyme Q10 probably produces its neuroprotective effects. Therefore, the purpose of the present study was to examine the protective effect of coenzyme Q10 on methamphetamine-induced apoptosis in adult male rats.Materials and Methods: Fifty Wistar eight-week adult rats randomly divided into 5 groups: Healthy control, methamphetamine injection (Meth), methamphetamine injection and CoQ10 5mg/kg treatment (Meth+Post CoQ10 5mg/kg), methamphetamine injection and CoQ10 10mg/kg treatment (Meth+Post CoQ10 10mg/kg), methamphetamine injection and CoQ10 20mg/kg treatment (Meth+Post CoQ10 20mg/kg). Methamphetamine with a purity of 96% with a dosage of 20 mg/kg was injected Intraperitoneal. Coenzyme Q10 for three treatment groups was injected intraperitoneally for 14 days in a dosage of 5, 10 and 20 mg/kg/day. The protein expressions of Baxand Bcl2 were evaluated by western blotting technique.Results: Bax protein expression was significantly lower in Meth+Post CoQ10 5mg/kg (p=0.010) and so Meth+Post CoQ10 10mg/kg (p=0.004) comparing to Meth group. In addition, Bcl2 protein expression was significantly higher in Meth+Post CoQ10 5mg/kg comparing to Meth group (p=0.018). However, there were no significant differences between control and CoQ10 treatment groups. Bax/Bcl2 ratio was significantly lower in Meth+Post CoQ10 5mg/kg (p=0.005), Meth+Post CoQ10 10mg/kg (p=0.008) and Meth+Post CoQ10 20mg/kg (p=0.044) comparing to Meth group.Conclusion: We suggest that CoQ10 reduces the methamphetamine-induced apoptosis in the striatum of the rats through the reduction of apoptotic factors and increase of anti-apoptotic pathways
Na neizrazitoj logici zasnovano upravljanje frekvencijom za ODMRP u mobilnim ad hoc mrežama
On Demand Multicast Routing Protocol (ODMRP) is a popular solution designed for ad hoc networks with mobile hosts. Its efficiency, simplicity, and robustness to mobility render it one of the most widely used multicast routing protocols in Mobile Ad hoc NETworks (MANET). In ODMRP, there is no input rate control for upper layer traffic. So, it’s possible that high dense traffic flow causes congestion in networks. In this work, an enhancement to ODMRP is proposed referred to as fuzzy logic based Rate Control ODMRP (FRC-ODMRP). FRC-ODMRP attempts to adapt the arrival rate from upper layers to the state in the network by using feedback information from receivers of the multicast group. Accordingly, source comes up with a decision whether to increase or decrease its transmission rate based on information collected from the receivers. In this research, delay and packet delivery ratio reconsidered as indicators of congestion in addition to number of received packets. Simulation results demonstrate that FRC-ODMRP achieves significant performance improvements in comparison to conventional ODMRP and QoS-ODMRP. Indeed, it efficiently handles simultaneous traffic flows such that no one could dominate available bandwidth of networks.On Demand Multicast Routing Protocol (ODMRP) popularno je rješenje namijenjeno ad hoc mrežama s mobilnim domaćinima. Efikasnost, jednostavnost i robusnost u smislu mobilnosti učini su ovu metodu jednom od najraširenijih multicast protokola u ad hoc mobilnim mrežam (eng. MANET). Kod ODMRP-a nema upravljanja ulaznom frekvencijom za promet višeg sloja. Zbog toga je moguće da gusti promet uzrokuje zagušenje u mrežama. U ovome je radu predstavljeno poboljšanje ODMRP-a nazvano ODMRP zasnovan na fuzzy logici (FRC-ODRMP). FRC-ODRMP pokušava prilagoditi dolazne signale iz viših slojeva stanju u mreži koristeći povratnu informaciju od primatelja iz multicast grupe. Prilikom istraživanja dodatno je uzet omjer kašnjenja i dostavljenih paketa kao pokazatelj zagušenosti mreže uz broj dostavljenih paketa. Simulacijski rezultati pokazuju kako FRC-ODMRP značajno poboljšava performanse u odnosu na konvencionalni ODMRP i Qos-ODMRP. Dodatno, simultani promet efikasno je upravljan tako da nitko ne može dominirati dostupnom propusnošću mreže
Evaluation of Coordinated Ramp Metering (CRM) Implemented By Caltrans
Coordinated ramp metering (CRM) is a critical component of smart freeway corridors that rely on real-time traffic data from ramps and freeway mainline to improve decision-making by the motorists and Traffic Management Center (TMC) personnel. CRM uses an algorithm that considers real-time traffic volumes on freeway mainline and ramps and then adjusts the metering rates on the ramps accordingly for optimal flow along the entire corridor. Improving capacity through smart corridors is less costly and easier to deploy than freeway widening due to high costs associated with right-of-way acquisition and construction. Nevertheless, conversion to smart corridors still represents a sizable investment for public agencies. However, in the U.S. there have been limited evaluations of smart corridors in general, and CRM in particular, based on real operational data. This project examined the recent Smart Corridor implementation on Interstate 80 (I-80) in the Bay Area and State Route 99 (SR-99, SR99) in Sacramento based on travel time reliability measures, efficiency measures, and before-and-after safety evaluation using the Empirical Bayes (EB) approach. As such, this evaluation represents the most complete before-and-after evaluation of such systems. The reliability measures include buffer index, planning time, and measures from the literature that account for both the skew and width of the travel time distribution. For efficiency, the study estimates the ratio of vehicle miles traveled vs. vehicle hour traveled. The research contextualizes before-and-after comparisons for efficiency and reliability measures through similar measures from another corridor (i.e., the control corridor of I-280 in District 4 and I-5 in District 3) from the same region, which did not have CRM implemented. The results show there has been an improvement in freeway operation based on efficiency data. Post-CRM implementation, travel time reliability measures do not show a similar improvement. The report also provides a counterfactual estimate of expected crashes in the post-implementation period, which can be compared with the actual number of crashes in the “after” period to evaluate effectiveness
Comparing of Frequent Central Venous Catheter Insertion and Selection Procedure and its Complications
Background: Central venous catheterization is used for several goals in the emergency department. Common sites of insertion of central venous lines are the right and left jugular veins as well as the right and left subclavian veins. The aim of this study was to evaluate the tendency frequency of emergency medicine residents to choose central venous line insertion route and also to determine the post-procedure complications.
Methods: In this descriptive cross-sectional study, all patientswhounderwent central venous catheterization and were in the emergency ward of the Imam Reza hospital, Tabriz, Iran during March 21, 2015 to September 23, 2015 were included, preferences route of insertion and complications of both right and left jugular and subclavian veins were descriptively analyzed.
Results: Of all the 134 evaluated patients, 54.5% were catheterized in course of shock. 88.1% of patients underwent right jugular vein catheterization and only 4.5% experienced post-procedure complications. In 91.8% of cases, the decision-making was done by the physician and 75.4% of the catheterizations were fulfilled by second-year emergency medicine residents.
Conclusions: The most common route of catheterization was through the right jugular vein. Additionally, the most common complication was hematoma of the insertion site. In most of the cases, decision making was made by the physician and most of the catheterization procedures were fulfilled by second-year emergency medicine residents
Safety effectiveness of adding by-pass lanes at unsignalized rural intersections in Kansas
Master of ScienceDepartment of Civil EngineeringSunanda DissanayakeConstruction of by-pass lanes at rural intersections typically has been considered a low-cost safety improvement. Safety analysis utilizes two common approaches to evaluate treatment effectiveness: before-and-after study and cross-sectional study. This research performed paired sample t-test statistical analysis to estimate changes in total of crash frequency, crash rates, EPDO crash frequency, and EPDO crash rates at intersections, three to five years after adding a by-pass lane compared to identical time period before the by-pass lane was added. Crash data between 1990 and 2011 were obtained from Kansas Crash and Analysis Record System (KCARS) maintained by the Kansas Department of Transportation (KDOT). In order to perform a cross-sectional study, intersections with by-pass lanes were compared to intersections with no countermeasures; crash data were obtained for more than 1,100 intersections in the state of Kansas.
According to before-and-after study, addition of by-pass lanes improves safety at unsignalized rural intersections; crashes and their severities are reduced after adding by-pass lanes. But, these reductions are not statistically significant under 95% confidence level. However, when considering intersection related crashes, a statistically significant reduction in crash rates is happened after adding by-pass lanes at 3-legged intersections.
In cross-sectional study, crashes and their severities are lower at 3-legged intersections with the by-pass lanes versus 3-legged intersections without the by-pass lanes. However, these reductions are not statistically significant under 95% confidence level. When considering 300 feet intersection crash box, statistically significant reductions are happened at 4-legged intersection. In contrast, crashes and their severities increased at 4-legged intersections with the by-pass lanes, but these changes are not statistically significant under 95% confidence level.
The Crash Modification Factors were calculated to evaluate safety effectiveness of adding by-pass lanes at unsignalized rural intersections. The calculated CMFs less than 1.0, indicate a reduction in crashes after implementation of by-pass lanes. Finally, this study concluded that expected crashes at intersections with by-pass lanes are lower than intersections without by-pass lanes
Evaluation of Group Consulting on Pregnancy Anxiety: A Randomized Clinical Trial
Introduction: Anxiety is a disorder of mental health in pregnant women reported by 20 percent of health care providers and is accompanied by adverse pregnancy outcomes. This study aimed to determine the effect of obstetric counseling on the anxiety of pregnant women. Methods: In this randomized, double-blind controlled trial, 90 pregnant women attending to Sheibani Health Care Center in Tehran aging from 18 to 35 years old and with a gestational age of 8 to 18 weeks were evaluated first pregnancy. They were randomly assigned to counseling (group counseling with routine perinatal care) and control (only routine perinatal care) groups. The group counseling was designed according to different needs of pregnancy for five sessions in five weeks (a duration of 60 to 90 minutes for each session). The questionnaires of demographic information, Beck Depression, and Spielberg spiel Berger State-trait anxiety were used. The data analysis was performed by SPSS software version 13 using parametric and non-parametric tests. Results: According to the results, there was a significant difference between post-intervention scores in state anxiety (P = 0.014); however, there was no significant difference in trait anxiety (P = 0.19). Also, the changes in trait anxiety were more in the consoling group compared with the control group (P = 0.002), which is also seen for the state anxiety group (P = 0.0001). Conclusions: It is concluded from this study that group counseling is effective in the reduction of state anxiety and trait anxiety in pregnant women
Molecular and Structural Stability of Infliximab: Spray-Dried Powder versus Freeze-Dried Cake.
he current study compared the stability of Infliximab powder following 2 drying procedures namely spray drying and freeze drying.
Introduction: Infliximab as a chimeric anti-TNFα monoclonal antibody was approved for the treatment of inflammatory diseases namely Crohn's disease and rheumatoid arthritis. In prospect of preparing stable formulation of Infliximab, freeze drying and spray drying were compared as processing method.
Methods and Results: Spray-dried formulation was prepared in the presence of Trehalose and Sucrose besides Cysteine. Powders were characterized via SEC-HPLC to quantify the level of induced aggregates/fragments after process along with upon 1 and 3 months of storage at 45̊C. Kinetic of aggregation and fragmentation was calculated for each sample. FTIR-spectroscopic assessments were employed to determine the secondary structure of antibody. Trehalose generated more stable particle within spray drying, with least aggregation and fragmentation rate constants of 0.22 and 0.27 (1/month). Combination of Cysteine and Trehalose significantly reduced aggregation upto 0.87, 1.07 and 2.26 % after process, up on 1 and 3 months of storage (rate constant of aggregation of 0.14,(1/month)). Fragmentation was 0.31, 0.38 and 0.98 % respectively with 0.17 (1/month) rate constant of fragmentation. The induced aggregates in Remicade were 0.11, 0.18 and 0.32% (aggregation rate constant:0.15 (1/month)) and fragments were 0.1, 0.14 and 0.29% after process, 1 month and 3 months at 45̊C (fragmentation rate constant of 0.15 (1/month)). The conformation of antibody was shown to be composed of 66.68% and 69.43% beta-sheet in spray-dried powder and freeze-dried cake (Remicade®) respectively.
Conclusions: This study demonstrated that, both spray drying and freeze drying may be efficient for powder production of Infliximab with regards to molecular and structural stability after storage at high temperatures
The Ability of Triple Antibiotic Paste and Calcium Hydroxide in Disinfection of Dentinal Tubules
Introduction: The purpose of this in vitro study was to compare the ability of triple antibiotic paste (TAP) to calcium hydroxide (CH) in disinfecting dentinal tubules. Material and Methods: Sixty root blocks were obtained from extracted single-rooted human teeth. The root canals were enlarged with Gates-Glidden drills up to size 3 and were contaminated with Enterococcus. faecalis (E. faecalis), and then left for 21 days. The contaminated blocks were treated with saline (as negative control), CH or TAP. Dentin debris was obtained at the end of first and 7th days, using Gates-Glidden drills sizes 4 and 5 from two different depths of 100 and 200 µm. The vital bacterial load was assessed by counting the number of colony forming units (CFUs). The data was analyzed with the Kruskal-Wallis H and Dunn Post-Hoc tests. The Wilcoxon Signed Ranks test was used to check for differences in bacterial growth at both depths (P<0.05). Results: In comparison with CH, the TAP significantly decreased the number of CFUs in both depths and time intervals (P<0.001), while the CH group showed a moderate antibacterial effect. Conclusion: TAP is more effective in disinfecting the canal against E. faecalis compared to CH
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