The role of sagittal pelvic morphology in the development of adult degenerative scoliosis

Purpose Pelvic morphology dictates the alignment and biomechanics of the spine. Recent observations in different types of adolescent idiopathic scoliosis indicate that individual pelvic morphology is related to the spinal levels in which scoliosis develops: primary lumbar adolescent scoliosis is associated with a higher pelvic incidence (PI) than thoracic scoliosis and non-scoliotic controls. We hypothesize that adult degenerative scoliosis (ADS) of the lumbar spine follows the same mechanical principles and is associated with a high PI. Methods This study used an existing CT-scan database, 101 ADS patients were sex and age matched to 101 controls. The PI was measured by two observers with multi-planar reconstruction, perpendicular to the hip-axis according to a previously validated technique. Results The PI was 54.1° ± 10.8° in ADS patients and 47.7° ± 10.8° in non-scoliotic controls (p < 0.001). The median ADS curve apex was the disc L2-3 and median curve length was 4 vertebral levels. The mean supine Cobb angle was 21° ± 8° (ranged 10°–47°). There was no significant correlation between PI and the apex level (p = 0.883), the curve length (p = 0.418) or the Cobb angle (p = 0.518). Conclusions ADS normally develops de novo in the lumbar spine of patients with a higher PI than controls, similar to primary lumbar adolescent idiopathic scoliosis. This suggests a shared mechanical basis of both deformities. Pelvic morphology dictates spinal sagittal alignment, which determines the segments of the spine that are prone to develop scoliosis.

Potential of Driver Physiological Measures for Assessing Non-Urban Highway Geometry

Life is a complex phenomenon, mostly controlled by sympathetic and parasympathetic systems. And it is quite dynamic in response to numerous stimulations getting from a system called, human-vehicle-environmental ensemble. Geometry is one of the fundamental stimulus for a driver driving on a highway. His/her mental workload will be based on the input he/she gets from the above system. A system that provides an optimum workload will be the most efficient one. This study explored the capability of different physiological measures to assess the quality of geometric design of non-urban highways. Heart rate, galvanic skin resistance and rate of eye blinking and their variance from base condition were the candidate measures under consideration. Radius of curve, length of curve, length of tangent section, superelevation at curves, degree of curvature, deflection angle and minimum available sight distance at curves were the geometric variables considered. The study included driving experiments done on 114 horizontal curves of gradient less than 2 percentage, each curve being driven over by 30 car drivers. The subjects were equipped with sensors for collecting physiological measures and continuous logging of the data along with geometric coordinates made the database for study. The study revealed the relationship between significant geometric variables and workload measures. The study will be a contribution in the field of road safety auditing, planning and designing of non-urban highways.

Vertical Curve Computations Using a Developed Calculator

In this paper, an electronic calculator for vertical curve computations is developed in Microsoft Windows. The developed calculator used is successfully for vertical curve computations and requires entering the curve length, tangent grades, setting out interval, and the elevation of the intersection points. Computations of vertical curves by the developed calculator are faster, easier, accurate, and less subject to errors comparable to the traditional method of calculations. Finally, the results obtained by the traditional and developed methods are presented for checking the behavior of the developed calculator.

The Effect of Low Friction in Pavement Due to Floods and High-speed Vehicles in Increasing the Number of Rescue Vehicles' Driving Accidents

Background: The rescue operation is dangerous during floods when the street surface is wet and the rescue vehicles moving fast. Rural roads are known with a high percentage of run-off-the-road crashes and accidents, mostly affected by the unsuitable and inappropriate speed of the car and failure to keep a safe side distance from the highway alignment. Determining the length of the vertical curve and the stopping distance depends on the speed parameter in the geometric design. This parameter depends on the traffic flow and the vehicle driver. Materials and Methods: The calculation of distance visibility, especially in the vertical and horizontal curves, has a significant role in the geometric design of roads and the safety of roads and drivers. This study investigates changes in two critical parameters of friction surface of pavement and vehicles’ speed on the probability of accidents. In the present study, by changing the speed parameter, namely, increasing speed and decreasing friction, and reducing the distance of vision, the required vertical curve is calculated and compared with the existing curve length. Thus, when the curve length does not match the required arch length, the accident’s probability increases. Results: One of the study’s findings indicates that with a 5% decrease in the friction coefficient of the vertical curve, the probability of accident increases by about 20%. The results show that an approximately 10% increase in speed can raise the likelihood of a crash by 25% on average. Conclusion: The use of accident reduction-related strategies for rescue vehicles and ambulances will help the victims affected by natural disasters. The results showed that choosing the right speed is very important in flooded wet streets. Driving fast to speed up the relief operation not only increases the risk of traffic accidents but also slows down the relief of natural disasters. The results indicate the proper performance of the model created by the probabilistic method. Besides, this model’s use has the advantage of correctly identifying the factors affecting the increase in risk. Also, it helps to take the right measures to increase safety in the relief of natural disasters, especially floods.

Changes in Target Vessel Anatomy Following Fenestrated Endovascular Aneurysm Repair: Midterm Results

Purpose: To analyze the changes in target vessel (TV) anatomy after fenestrated endovascular aneurysm repair (fEVAR) during midterm follow-up. Materials and Methods: A retrospective single-center study analyzed 56 patients (mean age 71±7 years; 49 men) who underwent fEVAR using custom-made stent-grafts (22 Zenith and 34 Anaconda) between June 2010 and July 2016. Advanta V12 (V12; 74, 53%) and BeGraft (BeG; 66, 47%) stent-grafts were used to bridge to the 140 TVs. Measurements of the TV deviation at the aortic origin, the vessel shift distal to the bridging stent-graft (BSG), and the outer and inner BSG curve lengths were performed after 3-dimensional reconstruction of the serial computed tomography angiography scans. The results of the measurements for the main devices, the TVs, and the bridging stent-grafts were compared using univariable and multivariable analysis. Results: Of the 140 BSGs examined (74 V12s and 66 BeGs), 393 measurements (38 celiac trunks, 102 superior mesenteric arteries, 121 left renal arteries, and 132 right renal arteries) were analyzed. The outer/inner BSG curve length ratio was larger after implantation of Zenith devices compared with Anaconda (p<0.001). The vessel shift distal to the BSG was significantly associated with the interaction of the TV and type of BSG only in the univariable analysis (p=0.001). There were no significant changes of the TV deviation at the aortic origin. Only the outer BSG curve length was significantly associated with TV complications (p=0.033). Median follow-up was 24 months (range 2–61). The BSG curve length ratio showed a significant increase over time (p<0.001) but did not differ between the BeG and V12 (p=0.381). Conclusion: No difference was found between the V12 and the BeG stent-grafts regarding anatomical TV changes during midterm follow-up after fEVAR. Both stent-grafts adapt to the TV anatomy over time, and moderate anatomical changes seem to be tolerated without increasing the risk for TV complications. The type of main device also influences the TV anatomy.

A Learning Trajectory to the Understanding of the Curve Length Concept

In this article, we present results of a research study focusing on the analysis of a hypothetical learning trajectory carried out with students taking a mathematics teaching degree. The aim of this study was to examine students’ understanding of the concept of curve length. The qualitative research was carried out with nine students participating in a course on Differential and Integral Calculus discipline of a private university in which that content was approached. The data were obtained through records of the students' worked out solutions, notes from observation recorded in the teacher's field diary and audio recordings made during the course development. From the analysis of the results, it can be inferred that the students showed gaps in their previous knowledge and difficulties on how to use that knowledge in the construction of new concepts; however, evidence was observed that the planned hypothetical learning trajectory facilitated, in part, the understanding of the concept of curve length.

Study Regarding the Imaging and Functional Evaluation in the Rehabilitation of Balance in Patients with Ischaemic Stroke

The present study is based on the paraclinical and functional evaluation of a sample of 66 subjects with ischaemic stroke, to monitor the evolution of their functional parameters. The tests concerning the variation of barycentre speed within the support polygon and the curve length were conducted using the GPS 400 Posturograph, which provided us with information related to the balance of the subjects in an orthostatic stance with eyes open, with eyes closed, looking to the right, looking to the left, head tilted to the right, head tilted to the left, head in extension. Our findings highlight the balance re-education capacity of the subjects with ischaemic stroke through individualised physical therapy programs.

Waveform adjustment for obtaining higher quality droplets based on a multi-satellite droplet monitoring system

In the field of printed electronics, there are many kinds of ink with a variety of performance and parameters. In order to generate high-quality droplets, it is necessary to eject droplet for testing in order to discover the appropriate excitation voltage and waveform shape. Consequently, a real-time and efficient droplet monitoring system is needed to monitor droplet formation quality. A multi-satellite droplet monitoring system is proposed in this paper. It can not only monitor the droplet with multiple satellites but also can generate the instantaneous droplet position curve, length curve and velocity curve. The waveform voltage and dwell time can be adjusted in real-time to obtain droplets with higher quality and efficiency.