bluuebunny/crossref_metadata_2025 huggingface dataset:
Prolonged water immersion alters resistance to sliding of aesthetic orthodontic coated wires
Authors: Lin Chin‐Yu , Kim Jun Sik , Lin Elias T. , Lin Elijah T.
Published: August 2020

Objective

The objective of this study was to compare the resistance to sliding of aesthetic orthodontic coated wires after prolonged water immersion for up to 4 weeks.

Setting and Sample Population

An in vitro study of commercially available orthodontic appliances.

Materials and Methods

Aesthetic coated stainless‐steel wires (Parylene‐coated, epoxy‐coated and Teflon‐coated) (0.019” × 0.025”) and an uncoated control were immersed in distilled‐deionized water for zero, two or four weeks at 37°C and then were subjected to resistance‐to‐sliding tests through a three‐bracket system of sapphire ceramic brackets (0.022” × 0.028” slot) and clear‐coloured elastic ligatures at a contact angle of 0° or 3°. Maximal and average resistance to sliding was analysed by a three‐way analysis of variance, two general linear models and a post hoc Tukey's honest significant difference test.

Results

Water immersion time, contact angle, wire group and their interactions had statistically significant effects on the resistance to sliding of tested orthodontic wires. Various coated wires had distinct timely changes in the maximal and average resistance to sliding after water immersion for 2 to 4 weeks. When compared to the uncoated control in most of the experimental conditions, epoxy‐coated wires had lower or non‐significant differences in resistance to sliding, while Parylene‐coated wire had higher resistances.

Conclusions

Prolonged water immersion for weeks alters the resistance to sliding of aesthetic orthodontic wires coated with Parylene, epoxy or Teflon. Based on their resistance to sliding, different designs in orthodontic biomechanics should be considered for the different aesthetic orthodontic coated wires.
Mapping and candidate gene screening of Cladosporium fulvum resistance gene Cf‐12 in tomato (Solanum lycopersicum) by high‐throughput sequencing
Authors: Chai Xinfeng , XU Xiangyang , Wang Dong , Xue Dongqi , Li Jingfu
Published: August 2020

Tomato leaf mould disease is a serious foliar disease caused by Cladosporium fulvum, resulting in a significant reduction in yield and quality, especially under protected cultivation. Finding new resistant genes against leaf mould has become one of the important goals of tomato breeding. Cf‐12‐tomato showed good resistance to several C. fulvum races. The Cf‐12 was mapped using re‐sequencing and BSA methods. Allelism test for Cf‐12, Cf‐5 and Cf‐9 was performed. The results showed that Cf‐12 is an independently assigned C. fulvum resistance gene. About 67,853 high‐quality polymorphic SNPs were found and 233 genes were annotated in three associated regions of 5.85 Mb on Chr. 6s. Three genes with typical Cf‐type characters encoding the leucine‐rich repeat receptor‐like protein were screened out. Using qRT‐PCR, structural and phylogenetic analysis, only the Solyc06g008265.1.1‐CGN7495 was finally identified. An effective InDel marker, InD‐3F/1R, was designed for MAS breeding. Our research provides new insights into the mapping of the Cf‐12, and provides a basis for Cf‐12 cloning and the Cf genetic evolution analysis.
Comparative outcome analysis of pediatric kidney transplant in posterior urethral valves children with or without pretransplant Mitrofanoff procedure
Authors: Rickard Mandy , Chua Michael E. , Zu’bi Fadi , Dos Santos Joana , Koyle Martin A. , Lorenzo Armando J. , Farhat Walid A.
Published: August 2020

Background

Urinary diversion using catheterizable channel among posterior urethral valve (PUV) patients may help to alleviate the functional concerns of the bladder on the allograft. Herein, we review our series of PUV patients undergoing renal transplants at a single institution to determine outcomes between those with and without pretransplant Mitrofanoff.

Methods

PUV cases in our transplant database from 2000 to 2017 were identified. Data collected included clinical demographics, presentation of PUV, bladder function, implementation of dialysis and donor type. Post‐transplant variables included graft function, and bladder function including incontinence and UTI development. Comparison between with vs without pretransplant Mitrofanoff patient groups was performed using Fisher's exact and t test analysis.

Results

Overall, 22 cases were analyzed. The majority (77%) had a prenatal diagnosis of PUV, and 23% had a symptomatic presentation. Pretransplant Mitrofanoffs were performed in 40.9% of cases. The overall age at transplant was 10 ± 5 years. Five percent experienced post‐transplant incontinence and 23% UTIs. No difference between groups was noted in variables including age at transplant, the timing of PUV diagnosis. Mitrofanoff group patients had more symptomatic febrile UTIs than those without Mitrofanoff (67% vs 15%; P = .03); however, there was no difference in post‐transplant UTI development. Furthermore, the Mitrofanoff group seems to have later onset of dialysis or need for transplant (age at the start of dialysis 36 ± 56 vs 156 ± 25 months, P < .001).

Conclusion

Our study suggests that patients with early PUV diagnoses who develop symptomatic UTI may benefit from early creation of a Mitrofanoff cathetherizable channel, which is associated with delayed ESRD progression and need for dialysis.
Nanoinjection of neurotransmitters into the prothoracic ganglion of female cricket Acheta domesticus changes phonotactic selectivity
Authors: Atkins Gordon , Yoon James , Lee Kristin , Koo Rachel , Chung Kristin , Zdor John , Magno Darley , Cho Eun Byeol , Kim Cassie , Gonzalez‐Socoloske Daniel , Navia Benjamin
Published: August 2020

The phonotactic response by female crickets is influenced by Juvenile Hormone III, which affects selectivity to the syllable period of the calling song. This pathway is influenced by an inhibitory input in the prothoracic ganglion, possibly chloride‐mediated inhibition. In order to identify potential neurotransmitters involved in such pathway, we performed nanoinjection of five neurotransmitters into the prothoracic ganglion of virgin female Acheta domesticus. Phonotaxis for these females was evaluated before and after injections. All five neurotransmitters that were nanoinjected are known to bind to chloride channels. Nanoinjection of histamine significantly decreased phonotactic selectivity to the syllable period of the calling song while glycine, gamma aminobutyric acid, serotonin and saline controls did not. Octopamine significantly decreased phonotactic responses overall. The effect of histamine was tested further by nanoinjecting the antihistamine pyrilamine into the prothoracic ganglion of older unselected females, which resulted in increased phonotactic selectivity.
Xylella fastidiosa subspecies and sequence types detected in Philaenus spumarius and in infected plants in France share the same locations
Authors: Cunty Amandine , Legendre Bruno , de Jerphanion Pauline , Juteau Virginie , Forveille Aurélie , Germain Jean‐François , Ramel Jean‐Marie , Reynaud Philippe , Olivier Valérie , Poliakoff Françoise
Published: August 2020

In Europe, the meadow spittlebug Philaenus spumarius is the main known vector of the quarantine bacterium Xylella fastidiosa. So far detection and identification of X. fastidiosa has more often been performed from plant matrices than insects, mainly using a real‐time PCR and multilocus sequence typing (MLST) approach. Detection of X. fastidiosa in its insect vectors would enhance knowledge of the epidemiologic situation in France, specifically in the already infected Corsica and Provence‐Alpes‐Côte d’Azur (PACA) regions. The aim of this study was to validate a methodological approach to detect X. fastidiosa in P. spumarius, analysed individually or in groups of 10, using real‐time PCR and MLST, and to apply the approach to more than 4,000 individuals collected between 2015 and 2019 from infected areas. The corresponding results expanded our knowledge of the epidemiology of X. fastidiosa in France: (a) X. fastidiosa subsp. multiplex including the sequence types ST6 and ST7 were identified in the insect vector; (b) the rate of positive insects per infected area was as high as 33.3% in Corsica or 50% in the PACA region; (c) positive adults were found during winter; and (d) the bacterial load in P. spumarius (droplet digital PCR) usually ranged from 103 to 104 cells per insect, but could be as high as 105 or 106 cells per insect for some individuals (13%). The subspecies and sequence types detected in P. spumarius corresponded to the situation officially reported for plants in the same areas.
Evaluation of haemodynamic changes of uterine arteries using Doppler ultrasonography during different stages of pregnancy in Bos indicus cows
Authors: Hassan Mubbashar , Arshad Usman , Erdoğan Güneş , Ahmad Nasim
Published: August 2020

The objectives of the study were to evaluate haemodynamic changes and their relationships among ipsilateral (IPS) and contralateral (CONT) uterine arteries (UA) during different stages of pregnancy in Bos indicus cows. Multiparous pregnant cows (n = 40) having a gestation length 30.47 ± 0.54 (mean ± SD) days were randomly enrolled and subjected to Doppler ultrasonography sequentially at 1st, 2nd, 4th, 6th and 8th months of gestation. Blood flow indices including diameter of UA (mm), blood flow volume (BFVo, ml/min), blood flow velocity (BFVe, cm/s), time‐averaged maximum velocity (TAMV, cm/s), pulsatility index (PI) and resistance index (RI) were recorded. Data were analysed with mixed models using the PROC MIXED procedures, and Pearson correlation coefficients were calculated using the PROC CORR statement in SAS. The final statistical models included the fixed effects of side of UA, gestation month and the interaction between side of UA and gestation month. Results revealed that the mean diameter of the UA (12.13 ± 0.22 vs. 10.09 ± 0.22), BFVo (1236.33 ± 0.55 vs. 770.41 ± 0.55), BFVe (17.18 ± 0.42 vs. 15.58 ± 0.42) and TAMV (17.11 ± 0.44 vs. 15.77 ± 0.44) was higher (p < .05) in IPS as compared to CONT side of the UA in cows. However, PI and RI did not differ between IPS and CON arteries of uterus in cows. A very high and positive correlation (r = .89; p < .05) existed between the diameter of UA and BFVo starting from 1st to 8th months of gestation in IPS as well as CONT sides of UA. Moreover, TAMV was highly and positively correlated (r = .91; p < .05) with BFVe throughout the gestation. In conclusion, these haemodynamic changes in the UA could be used as a valuable validity tool to differentiate the compromised pregnancy in Bos indicus cows.
An integrated approach to determine three‐dimensional accretion geometries of tidal point bars: Examples from the Venice Lagoon (Italy)
Authors: Cosma* Marta , Yan Na , Colombera Luca , Mountney Nigel P. , D’Alpaos Andrea , Ghinassi* Massimiliano
Published: August 2020

Low rates of lateral migration (centimetres to decimetres per year) combined with relatively high rates of vertical accretion (millimetres to centimetres per year) recorded in microtidal channels of the Venice Lagoon (Italy) give rise to point‐bar geometries and internal facies arrangements that differ substantially from widely accepted models of point‐bar sedimentary architecture. In this study, field data from the Venice Lagoon are combined with a three‐dimensional forward stratigraphic model, the ‘Point‐Bar Sedimentary Architecture Numerical Deduction’ (PB‐SAND), to predict the stratal geometries of point bars formed in aggradational settings. The PB‐SAND uses a combined geometric and stochastic modelling approach that can be constrained by field evidence. The model applied determines the geometry of four point bars generated by 9 to 11 m wide channels cutting through salt marshes. An iterative best‐fit modelling approach has been used to obtain multiple simulations for each case study, each of which fits the observations derived from the analysis of time‐series historical aerial photographs and 44 sedimentary cores. Results demonstrate how the geometry of the bars is determined by the development of two key stratal surfaces: the point‐bar brink and channel‐thalweg surfaces. These surfaces are defined by the progressive translation and vertical shift of the point‐bar brink (i.e. break of slope between bar top and bar slope) and the channel thalweg (i.e. deepest part of the channel) during bar evolution. The approach is used to: (i) reconstruct three‐dimensional point‐bar geometries; (ii) propose alternative reconstructions; (iii) provide insight to drive the acquisition of additional data to better constrain the proposed models; and (iv) provide insight into the mechanism of bar growth for slowly migrating channels in settings subject to relatively high rates of aggradation. This study highlights how interaction between styles of planform transformation and latero‐vertical shifts of meandering channels can determine the geometry of related sedimentary bodies.
Citizen‐agency versus state‐agency at the frontline in prisons and probation services: A systematic literature review
Authors: Sabbe Mathias , Moyson Stéphane , Schiffino Nathalie
Published: August 2020

Street‐level bureaucrats play a key role in the delivery of public services to the citizens with whom they interact. Using the Preferred Reporting Items for Systematic Review and Meta‐Analyses approach, we rely on a street‐level perspective to report a systematic review of 46 studies about officer–offender interactions in prisons and probation services. In doing so, we examine how correctional officers articulate state‐agency – whereby they focus on the implementation of rules and policies – and citizen‐agency – whereby their decisions regarding offenders are based on judgements of offenders' worth. Our results provide evidence that frontline work in prisons and probation services stems from a mix of citizen‐ and state‐agencies in which the former is prioritized over the latter: when rule enforcement allows it, correctional officers often make discretionary decisions based on professional judgements rooted in professional norms. In this respect, the managerial and actuarial approach to risk management and public protection involved by contemporary correctional reforms comes with new role expectations that conflict with correctional officers' rehabilitative ideals. At the same time, the literature provides many instances of officers coping with workload in order to meet policy objectives and organizational demands while maintaining satisfactory working conditions. In other words, there is an increasingly elaborate and fragile articulation of state‐ and citizen‐agencies at the frontline, in prisons and probations services. We conclude with some implications and an agenda for future research.
The determinants of real exchange rate volatility in South Africa
Authors: Mpofu Trust R.
Published: August 2020

This paper investigates the determinants of medium to long‐run real exchange rate volatility in South Africa over the period 1986–2015. The main objective of the paper is to analyse the impact of trade openness on real exchange rate volatility following conflicting results offered by empirical studies. Employing the Autoregressive Distributed Lag (ARDL) cointegration approach and using a variety of specifications and robustness tests, results show that trade openness has an impact on real exchange rate volatility. The interaction term of trade openness and the dummy variable for capital account liberalisation leads to a significant negative impact on real exchange rate volatility. Furthermore, findings indicate that volatility of output, commodity prices, money supply and government consumption, and the exchange rate regime significantly influence rand volatility.
Engine Combustion System Optimization Using Computational Fluid Dynamics and Machine Learning: A Methodological Approach
Authors: Badra Jihad A. , Khaled Fethi , Tang Meng , Pei Yuanjiang , Kodavasal Janardhan , Pal Pinaki , Owoyele Opeoluwa , Fuetterer Carsten , Mattia Brenner , Aamir Farooq
Published: August 2020

Gasoline compression ignition (GCI) engines are considered an attractive alternative to traditional spark-ignition and diesel engines. In this work, a Machine Learning-Grid Gradient Ascent (ML-GGA) approach was developed to optimize the performance of internal combustion engines. ML offers a pathway to transform complex physical processes that occur in a combustion engine into compact informational processes. The developed ML-GGA model was compared with a recently developed Machine Learning-Genetic Algorithm (ML-GA). Detailed investigations of optimization solver parameters and variable limit extension were performed in the present ML-GGA model to improve the accuracy and robustness of the optimization process. Detailed descriptions of the different procedures, optimization tools, and criteria that must be followed for a successful output are provided here. The developed ML-GGA approach was used to optimize the operating conditions (case 1) and the piston bowl design (case 2) of a heavy-duty diesel engine running on a gasoline fuel with a research octane number (RON) of 80. The ML-GGA approach yielded >2% improvements in the merit function, compared with the optimum obtained from a thorough computational fluid dynamics (CFD) guided system optimization. The predictions from the ML-GGA approach were validated with engine CFD simulations. This study demonstrates the potential of ML-GGA to significantly reduce the time needed for optimization problems, without loss in accuracy compared with traditional approaches.
A Wire-Driven Multifunctional Manipulator for Single Incision Laparoscopic Surgery
Authors: Chowdhury A. M. Masum Bulbul , Cullado Michael J. , Shen Tao
Published: August 2020

Minimally Invasive Surgery (MIS) has gained popularity in current abdominal surgical procedures due to its reduced skin incision length, shortened recovery time and decreased postoperative complications. One trend is to enhance these benefits by developing technologies to expand the application of single incision laparoscopic surgery (SILS) which has even less incision and incision-related complication. However, the practical application of SILS has been constrained by many complexities, including fundamental procedure issues (e. g. limited space), as well as the issues related to surgical tools, such as lack of actuation force, weak tool tips, poor visualization and lack of dexterous multitasking tools. Due to this lack of multitasking tools, the surgical tools or robots have to be retracted, exchanged and reset multiple times during the surgery, increasing the surgical time, the risk of injury and the surgeon’s level of fatigue. This paper focuses on developing a multifunctional manipulator with an automatic tool changing capability to boost practical application of SILS. The manipulator uses a wire-driven method that minimizes the potential damage from sterilization since the electronic actuation and sensing components are located remotely from the end-effector which needs heat or chemical sterilization before surgery. The feasibility of the tool tip changing method has been demonstrated by experiments.
Classification of Left Atrial Appendage Morphology Using Deep Learning
Authors: Holm Mikayle A. , Deakyne Alex , Gaasedelen Erik , Upchurch Weston , Iaizzo Paul A.
Published: August 2020

Atrial fibrillation, a common cardiac arrhythmia, can lead to blood clots in the left atrial appendage (LAA) of the heart, increasing the risk of stroke. Understanding the LAA morphology can indicate the likelihood of a blood clot. Therefore, a classification convolutional neural network was implemented to predict the LAA morphology. Using 2D images of 3D models created from MRI scans of fixed human hearts and a pre-trained network, an 8.7% error rate was achieved. The network can be improved with more data or expanded to classify the LAA from the automatically segmented DICOM datasets and measure the LAA ostia.
Minimizing Cotton Ball Retention in Neurological Procedures
Authors: Bechtold Raphael , Garlow Benjamin , Liu Renee , Tandon Arushi , Szewc Alexandra , Zhu William , Musmanno Olivia , Gorelick Noah , Suk Ian , Huang Judy , Brem Henry , Manbachi Amir , Coles George
Published: August 2020

Neurosurgical operations are long and intensive medical procedures, during which the surgeon must constantly have an unobscured view of the brain in order to be able to properly operate, and thus must use a variety of tools to clear obstructions (like blood and fluid) from the operating area. Currently, cotton balls are the most versatile and effective option to accomplish this as they absorb fluids, are soft enough to safely manipulate the brain, act as a barrier between other tools and the brain, and function as a spacer to keep anatomies of the brain open and visible during the operation. While cotton balls allow neurosurgeons to effectively improve visibility of the operating area, they may also be accidentally left in the brain upon completion of the surgery. This can lead to a wide range of post-operative risks including dangerous immune responses, additional medical care or surgical operations, and even death. This project seeks to develop a unique medical device that utilizes ultrasound technology in order to minimize cotton retention after neurosurgical procedures in order to reduce undesired post-operative risks, and maximize visibility.
Improving Footwear Options for Persons With Lower Limb Amputations
Authors: Nickel Eric , Voss Gregory , Slater Billie , Mueller Emily , Hansen Andrew
Published: August 2020

Men and women with lower limb amputations struggle with managing the balance between prosthesis alignment and shoe heel rise. A novel prosthetic ankle-feet system is being developed to support a wider range of footwear options for men and women with lower limb amputations. Each rigid foot is customized to fit the footwear of choice and can be rapidly attached to (or released from) an ankle unit which remains attached to the prosthesis.

The ankle unit has a mass of 318g and is small enough to fit in the design volume of a 22cm foot across a range of heel rises. The ankle uses elastomeric bumpers arranged in a wiper design to maximize space efficiency.

Structural testing has shown that the 3D printed custom Nylon 12 feet withstood 4584N of forefoot loading without failure based on the ISO 10328 loading parameters, indicating suitable strength to support safe human use in the laboratory. The feet have a mass of 446g.

Feedback from two women Veterans with lower limb amputations reinforced the importance of improving access to shoes with different heel rises. Future activities will include cyclic fatigue testing, additional weight reduction, and incorporating suggested design refinements.
A Novel Nonparametric Technique for Segmenting Multimode Hyperspectral Images Obtained From Non-Melanoma Skin Cancer Lesions
Authors: Geweid Gamal G. N. , Vasefi Fartash , Tavakolian Kouhyar
Published: August 2020

Keratinocyte Carcinoma, more traditionally known as Non-melanoma skin cancer (NMSC), is the most common cancer in humans. Incidence continues to increase despite increased public awareness of the harmful effects of solar radiation. In this paper, a non-parametric technique based on image registration will be applied to the multimode hyperspectral imaging system to segment Basal Cell Carcinoma (BCC) and Squamous cell carcinoma lesions (SCC). The aim is to enhance Mohs surgery by determining the actual borderlines of the desired area in the patient’s images, leading to increased efficiency and efficacy of the Mohs surgery. The proposed algorithm was applied to four sets of different Multimode hyperspectral Images with Non-Melanoma Skin. The experimental findings showed that the proposed algorithm is effective in Non-Melanoma skin detection. This could lead to improved image-guided excision of cancerous lesions with potential applications in robotic interventions.
Using Computational Modeling Derived From Micro CT Scanning for the Post-Implant Analyses of Various Cardiac Devices
Authors: Valenzuela Thomas , Zhingre Sanchez Jorge , Holm Mikayle , Iles Tinen , Iaizzo Paul
Published: August 2020

There are few medical devices currently utilized that have not had, at the very least, a second iteration. Medical device companies continually strive to improve their product to make it the best on the market. Medical devices are often optimized by defining the size of the device, making it more efficient and/or improving the device to tissue interface. Using the capabilities of the Visible Heart® Laboratories various cardiac devices can be implanted in reanimated swine and human hearts for the assessment of the various aforementioned parameters. After the implantation of these devices and assessment in functional anatomies, specimens were perfusion-fixed and then a micro-CT scanner was utilized to take high-resolution scans of the resultant device and tissue interfaces. These scans are used to generate high-resolution (∼20 microns) 3D models of the numerous implanted devices, measurement analyses, device simulations, and the creation of virtual reality scenes. All can then be used for detailed visual analyses. These abilities to render high-resolution models will allow medical device designers to closely evaluate their designs, in order to optimize their next iterations.
Current and Voltage Choice for North American Railroad Electrifications: 1895-1931
Authors: Allen John G.
Published: August 2020

The variety of currents and voltages adopted by North American railroads between 1895 and 1931 is sometimes seen as confusing. Railroads faced choices between direct current (DC) and alternating current (AC), as well as among different voltages. But closer analysis shows a clear order to the specifications chosen.

The technology options available at the time and the intended functions of these installations explain the specifications that railroads chose. Railroads electrifying fell into three basic groups: 1. Early adopters (usually requiring electrification for tunnels), 2. Railroads electrifying after 1910 for commuter service, and 3. Railroads that electrified for, or at least with freight service in mind.

Each of these faced very different sets of options, and made their choice of electrical specifications accordingly. There were four basic combinations of current and voltage: 1. Low-voltage DC delivered via third rail, 2. Medium-voltage DC, 3. Higher-voltage DC, and 4. AC (almost always single-phase at 11,000 Volts, 25 Hertz).

For railroads in a given category, the practicable choices were in fact limited to one or two options. Contrary to what is sometimes thought, the different electrical specifications reflected an underlying logic, not disorder.
Crash Energy Management Design for the LACMTA HR4000 Heavy Rail Vehicle
Authors: Wang Anbo , Liu Yanwen , Liu Xiaofang , Kirkpatrick Steven W. , Phan Virginia , Bocchieri Robert T.
Published: August 2020

The LACMTA HR4000 heavy rail vehicle was designed to meet the ASME RT-2 Safety Standard for Structural Requirements for Heavy Rail Transit Vehicles. The crash energy management (CEM) structures designed for this vehicle also provide unique performance characteristics through use of a staged combination of CEM technologies. The resulting design, using easily replaceable components, provides reduced repair costs for lower speed collisions, minimizes the number of cars damaged during a collision, while exceeding the RT-2 standard for safety to the operator. None of the CEM technologies used are novel, but their integrated design provides a unique performance in heavy rail vehicle design.

This paper provides an overview of the CEM design development. First, a general description of the CEM system function is provided, including the various CEM technologies used and how they interact during a collision. Then the 1-dimensional and 3-dimensional nonlinear dynamic models developed for optimizing the design are discussed. The CEM test program performed to demonstrate the system function and validate the modeling is described. Finally, the performance of the CEM system in train-to-train collision analyses is presented. Underframe testing was conducted for validation of the simulations.
An Evaluation of Passenger Mass Effects in Crashworthiness Analyses of Heavy Rail Vehicles
Authors: Kirkpatrick Steven W. , Bocchieri Robert T. , Zeigle Alexander , Liu Xiaofang , Liu Yanwen , Wang Anbo
Published: August 2020

The ASME RT-2 Safety Standard for Structural Requirements for Heavy Rail Transit Vehicles requires that crashworthiness analyses be performed for two primary collision scenarios. Both scenarios use a moving train colliding into a stopped train in their ready-to-run loading condition where no passenger mass is included in the analysis. This standard is now frequently cited in technical specifications for new vehicles by transit agencies in North America.

When evaluating a collision scenario, it is a logical extension to consider including passenger weights. A collision has a greater risk of injury if more passengers are onboard. In addition, additional passenger weight increases the kinetic energy at a specific collision speed, which can contribute to the collision severity. The difficulty of including the passenger load is that the passengers are loosely coupled to the train collision response and have independent collision behaviors based on the passenger configurations relative to the vehicle interior. The corresponding occupant decelerations can occur over different time frames than the vehicle deceleration.

This paper describes a 1-dimensional lumped mass method for incorporating passenger weight into crashworthiness analysis. Each car in the train, the large car body mass is given the ready-to-run weight. The additional passenger load is divided into separate masses that are coupled to the car body using nonlinear springs. The separate passenger masses and attributes for the springs are derived from the specific seating layout of a car. Passengers are grouped by the various seating configurations with different timescales for coupling their mass into the car body.

Several collision analyses were performed with this 1D model for the LACMTA HR4000 heavy rail vehicle at the speeds specified in ASME RT-2 (24 and 40 km/h) at both the ready-to-run weight and at the maximum passenger weight. The influence on the crash dynamics and overall permanent stroke of the crash energy management (CEM) structures at each car interface is discussed. For the seating configuration used, a small fraction of the passenger mass is seen to influence the crash dynamics. This is because of the relatively long time it takes to couple much of the passenger mass into the car body relative to the short duration of the primary crash pulse on a car. Consequently, the addition of a large passenger weight did not require a commensurate increase in energy absorption capacity for the CEM structures of vehicle.
Design and Analysis of Elastic-Plastic Collision Post for Railway Vehicles
Authors: Liu Hongtao , Wang Jianran , Liu Xiaofang , Wang Kefei , Luo Qi , Liu Yanwen , Fang Ziwen , Hong Haifeng
Published: August 2020

Collision posts have been required at the front end of railway vehicles to provide protection against intrusion under collision in the US market since 1940s, though it is still not a standard required structure in the Europe and Asia markets. In this paper, typical front-end frame with and without collision posts of railway vehicles are compared to illustrate the pros and cons of collision posts in railway vehicles. Then two different front-end frames with collision posts are introduced in detail to discuss how to take the advantages of collision posts and avoid the drawbacks in different applications. In the first design, the collision posts are placed in front of the energy absorbing elements. When collision happens, the collision posts will deform first before the energy absorbing elements act. As a result, the collision posts and many carbody and cab structures, such as the front-end frame, underframe, cab interior and operator console may under repair even the collision speed is low. However, more space can be utilized for the cab and passenger compartment since the collision posts can be located at the very front of the vehicle. In the second design, there are two stages of energy absorbing elements and the collision posts are placed in the middle. The first stage of energy absorbing elements can absorb low-speed collision energy without damaging other structures and can be replaced easily. To make up for the extra space taken by the first stage energy absorbing elements, the shape and dimension of the collision posts have to be optimized. For both designs, finite element analysis has been used to analyze and optimize the design. Then full-scale test specimens are manufactured and tested to further validate the design and analysis. Based on the design, analysis and test results, an overall evaluation of collision post’s role in passenger protection and vehicle design has been generated.
Optimization of Railroad Bearing Health Monitoring System for Wireless Utilization
Authors: Cuanang Jonas , Tarawneh Constantine , Amaro Martin , Lima Jennifer , Foltz Heinrich
Published: August 2020

In the railroad industry, systematic health inspections of freight railcar bearings are required. Bearings are subjected to high loads and run at high speeds, so over time the bearings may develop a defect that can potentially cause a derailment if left in service operation. Current bearing condition monitoring systems include Hot-Box Detectors (HBDs) and Trackside Acoustic Detection Systems (TADS™). The commonly used HBDs use non-contact infrared sensors to detect abnormal temperatures of bearings as they pass over the detector. Bearing temperatures that are about 94°C above ambient conditions will trigger an alarm indicating that the bearing must be removed from field service and inspected for defects. However, HBDs can be inconsistent, where 138 severely defective bearings from 2010 to 2019 were not detected. And from 2001 to 2007, Amsted Rail concluded that about 40% of presumably defective bearings detected by HBDs did not have any significant defects upon teardown and inspection. TADS™ use microphones to detect high-risk bearings by listening to their acoustic sound vibrations. Still, TADS™ are not very reliable since there are less than 30 active systems in the U.S. and Canada, and derailments may occur before bearings encounter any of these systems.

Researchers from the University Transportation Center for Railway Safety (UTCRS) have developed an advanced algorithm that can accurately and reliably monitor the condition of the bearings via temperature and vibration measurements. This algorithm uses the vibration measurements collected from accelerometers on the bearing adapters to determine if there is a defect, where the defect is within the bearing, and the approximate size of the defect. Laboratory testing is performed on the single bearing and four bearing test rigs housed at the University of Texas Rio Grande Valley (UTRGV). The algorithm uses a four second sample window of the recorded vibration data and can reliably identify the defective component inside the bearing with up to a 100% confidence level. However, about 20,000 data points are used for this analysis, which requires substantial computational power. This can limit the battery life of the wireless onboard condition monitoring system. So, reducing the vibration sample window to conduct an accurate analysis should result in a more optimal power-efficient algorithm. A wireless onboard condition monitoring module that collects one second of vibration data (5,200 samples) was manufactured and tested to compare its efficacy against a wired setup that uses a four second sample window. This study investigates the root-mean-square values of the bearing vibration and its power spectral density plots to create an optimized and accurate algorithm for wireless utilization.
Application of Virtualization to Implement the Automatic Train Supervision System of a Communications Based Train Control System
Authors: Chy John
Published: August 2020

Capacity improvement and obsolescence management are the primary reasons for deploying Communications Based Train Control (CBTC) technology to replace conventional track circuit-based signaling systems like in New York City Transit (NYCT), Baltimore Maryland Transit Administration (MTA) or the San Francisco Bay Area Rapid Transit District (BART). Resignaling projects without stopping revenue operations are highly complex and are referred as brownfield train control projects.

The Automatic Train Supervision (ATS) subsystem in a CBTC System is responsible for monitoring and regulating train operations. The ATS’ responsibilities include functions such as identifying trains, tracking and displaying trains, setting speed restrictions and work zones, automatic and manual routing capabilities. In addition, the ATS serves as the Human Machine Interface (HMI) between Train Controllers at the Operations Control Center (OCC).

One of the challenges in brownfield train control projects is fitting a CBTC ATS subsystem into an already existing Operations Control Center (OCC). The console in the operating theater will need to host both the existing system and the new CBTC ATS workstation. Similarly, the technical rooms may already be at capacity but still need to accommodate the CBTC system in addition to the legacy system for the transition period.

Transferring the OCC to a new building is often part of the modernization program and is the ideal method to mitigate space constraints. However, CBTC deployment is not always associated with transfer to a new larger building with a large OCC theater. Transfer to the new OCC with more space may be done before the CBTC deployment or at the same time as the CBTC revenue service. When there is no new larger OCC, solutions need to be investigated to accommodate both the legacy system and the new CBTC at the existing OCC.

Advancements in virtual technology provides a more efficient solution that reduces the amount of physical space an ATS needs in the OCC without compromising communication and processing speed or capabilities.

This paper describes the different equipment and functionalities of an ATS subsystem and the challenge of fitting each piece into an existing OCC while keeping the legacy system. The paper then discusses the basic technology behind networking, defining the concept of machine virtualization at a high level, and how all these technologies may be used to solve the ATS challenges faced during CBTC resignaling projects.
Producing and Measuring the 3rd Body Layer
Authors: Harrison Harold
Published: August 2020

Decades of measuring friction conditions at the wheel-rail interface have resulted in widely varying answers produced by different measurement methods and devices. This variation is a result of many factors, some of which are difficult to quantify and control, especially under field conditions. One of these variables is the presence of an unknown 3rd body layer material, whose accumulation on the wheel and rail surfaces affect the value of independent tests performed to quantify the nominal state of wheel on rail in actual operating conditions. This paper describes a series of tests undertaken to understand the creation of the 3rd body layer from the starting point of clean wheel and rail surfaces and how that can lead to new standard practices for field testing. A 2 × 2 matrix of wheel and rail conditions is defined to help formalize the discussion of the production and measurement of the 3rd body layer.

Case 1 is the nominal virgin state of the two materials. This is actually fairly hard to produce. Almost any process and/or handling will leave some films on both surfaces. Lab tests typically start in this state after cleaning/degreasing the surfaces following machining or sanding.

Cases 2 and 3 are potentially the same (clean wheel or rail), however, the more likely case is Case 2 where some existing location on actual track is chosen to determine its current state, thus the use of a Tribometer using a clean wheel.

Case 4 represents the nominal state of most track with passing vehicles where the current environmental/ambient conditions encourage a particular set of 3rd body wear products.

This formalization helps reveal the prior common practices that have produced assumptions of what is the ‘correct’ value and how that has created a bias in one’s thinking of what really exists in normal revenue service. This issue is particularly consequential in attempting to quantify the benefit of the friction modifiers that are being adopted across the railroad industry.
Vibration Control of a Rigid and Flexible High-Speed Railway Vehicle
Authors: Türkay Semiha , Leblebici Aslı S.
Published: August 2020

In this paper, the vertical carbody dynamics of the railway vehicle excited by random track inputs are investigated. The multi-objective ℋ∞ controllers for carbody weight of the actual, heavy and a mass confined in a polytopic range have been designed with the aim of reducing the wheel forces, heave, pitch and roll body accelerations of the vehicle. Later, the carbody mass is modelled as a free-free Euler Bernoulli beam and the low frequency flexural vibrations of the train body are examined. An omnibus ℋ∞ controller is synthesized to suppress both the rigid and low frequencies flexible modes of the railway vehicle. The performances of the ℋ∞ controllers are verified by using the passive and active suspension responses on the right and left rail track disturbances that are represented by the power spectral density functions authenticated for the stochastic real track data collected from the Qinhuangdao-Shenyang passenger railway line in China. Simulation results showed that all controllers exhibit a very good performance by effectively reducing the car-body accelerations in vicinity of the resonanat frequencies while keeping the wheel-rail forces in the allowable limit.
Full Function Sampling of Uncertain Correlations
Authors: Irick Kevin W. , Engerer Jeff , Lance Blake , Roberts Scott A. , Schroeder Ben
Published: August 2020

Empirically-based correlations are commonly used in modeling and simulation but rarely have rigorous uncertainty quantification that captures the nature of the underlying data. In many applications, a mathematical description for a parameter response to some input stimulus is often either unknown, unable to be measured, or both. Likewise, the data used to observe a parameter response is often noisy, and correlations are derived to approximate the bulk response. Practitioners frequently treat the chosen correlation — sometimes referred to as the “surrogate” or “reduced-order” model of the response — as a constant mathematical description of the relationship between input and output. This assumption, as with any model, is incorrect to some degree, and the uncertainty in the correlation can potentially have significant impacts on system responses. Thus, proper treatment of correlation uncertainty is necessary. In this paper, a method is proposed for high-level abstract sampling of uncertain data correlations. Whereas uncertainty characterization is often assigned to scalar values for direct sampling, functional uncertainty is not always straightforward. A systematic approach for sampling univariable uncertain correlations was developed to perform more rigorous uncertainty analyses and more reliably sample the correlation space. This procedure implements pseudo-random sampling of a correlation with a bounded input range to maintain the correlation form, to respect variable uncertainty across the range, and to ensure function continuity with respect to the input variable.
Trends and applicant characteristics in New Zealand: Radiation oncology versus radiology
Authors: Alamri Yassar , Alsahli Khalid , Ravindran Danus
Published: August 2020

Introduction: Previous research has projected future shortages in radiation oncologistsin Australia. Anecdotal evidence also suggests a similar pattern in New Zealand, howevershortages in the radiology workforce have not been forecast to date. The present study aimed to examine the trends in applications for radiation oncology and radiology positions in New Zealand.Methods: Data were collected on vocational training applicants and senior medical officer (SMO, consultant) positions from 2009 to 2016. Data were obtained from publicly-available data on the New Zealand Ministry of Health and Royal Australian and New Zealand College of Radiologists (RANZCR) websites.Results: Compared with radiation oncology, applications to radiology significantly outnumbered the available positions—a trend that escalated between 2009 and 2016. In addition, the radiation oncology SMO workforce in New Zealand attracted progressively fewer local graduates (i.e., more international medical graduates) compared with radiology over the period studied.Conclusions: This is the first study to shed light on trends in applications to the two specialties overseen by RANZCR in New Zealand. Future efforts should focus on attracting more trainees to radiation oncology and addressing factors underlying the apparent discrepancies between the two specialties, as well as the mental health and wellbeing of trainees.
Let’s talk about discourse analysis for health professional education: What, why and how
Authors: Woodward-Kron Robyn
Published: August 2020

Much of healthcare is facilitated through interactive talk and writing: diagnosing, collaboratively making treatment decisions, conducting treatment, coordinating care, handing over care. For junior health professionals, learning the valued patterns of talk and writing—the discursive practices of healthcare—is part of becoming a health professional. Discourse analysis of texts, written and spoken, can make visible to health professional educators what the valued interactional patterns are and how junior members learn the discursive practices through interaction with more senior colleagues. It can also illuminate “troubles” in communication, such as barriers, power imbalances and misalignment. Doing discourse analysis requires an understanding of how texts work and a meaningful, systematic approach to representing and analysing data. This paper introduces genre theory, a form of discourse analysis that distinguishes between text types according to their social purpose and contextual variables, including what the text is about, who is involved and how the text is organised. This paper outlines some principles of genre analysis and practical “how to” guidelines. It also provides suggestions about how findings of genre analysis can inform teaching in health professional education.
Vitamin K Analogs Influence the Growth and Virulence Potential of Enterohemorrhagic Escherichia coli
Authors: Kijewski Anne , Witsø Ingun Lund , Iversen Hildegunn , Rønning Helene Thorsen , L'Abée-Lund Trine , Wasteson Yngvild , Lindbäck Toril , Aspholm Marina
Published: August 2020

Enterohemorrhagic
E. coli
(EHEC) can cause serious illness and deaths in humans by producing toxins that can severely damage our intestines and kidneys. There is currently no optimal treatment for EHEC infections, as antibiotics can worsen disease development. Consequently, the need for new treatment options is urgent. Environmental factors in our intestines can affect the virulence of EHEC and help our bodies fight EHEC infections. The ruminant intestine, the main reservoir for EHEC, contains high levels of vitamin K, but the levels are variable in humans. This study shows that vitamin K analogs can inhibit the growth of EHEC and/or production of its main virulence factor, the Shiga toxin. They may also inhibit the spreading of the Shiga toxin encoding bacteriophage. Our findings indicate that vitamin K analogs have the potential to suppress the development of serious disease caused by EHEC.