bluuebunny/crossref_metadata_2025 huggingface dataset:
Capsaicin combined with ice stimulation improves swallowing function in patients with dysphagia after stroke: A randomised controlled trial
Authors: Cui Feifei , Yin Qingmei , Wu Chao , Shen Meifen , Zhang Yijie , Ma Chen , Zhang Haiying , Shen Fang
Published: August 2020

Background

Dysphagia is a common condition after stroke, and it is associated with many complications. Early and effective treatments are essential to the prognosis of patients with dysphagia. We aimed to evaluate the effects and safety of capsaicin combined with ice stimulation in patients with dysphagia after stroke.

Methods

Patients with dysphagia admitted to our hospital from December 2017 to December 2019 were included. The control group received the ice stimulation, and the experimental group received the combined capsaicin and ice stimulation. The grade of water swallowing test (WST), standard swallowing assessment (SSA) scores and the serum substance P level was compared between control (ice only) and experimental group (capsaicin plus ice).

Results

No differences before treatment and significance following treatment in each group (before and after) and between groups (capsaicin plus ice vs ice only) were found (all P > .05); the SSA scores were significantly reduced after intervention for both groups (all P < .001), and after intervention, SSA score in experimental group was significantly less than that of control group (P < .001). After intervention, the number of patients graded as WST level I‐II in experimental group was significantly more than that of control group (P < .001); the serum substance P level was significantly increased after intervention for both groups (all P < .05), and after intervention, the serum substance P level in experimental group was significantly higher than that of control group (P = .007).

Conclusions

The combined use of capsaicin with ice stimulation is beneficial to the recovery of swallowing function of patients with dysphagia, which should be included into the clinical practice.
“TANGO” nocturia scanning tool: Turkish validity and reliability study
Authors: Culha Mehmet Gokhan , Culha Yeliz , Buyukyilmaz Funda , Turan Nuray , Bower Wendy
Published: August 2020

Background

The aim of this study is to evaluate the validity and reliability of the Targeting the Individual's Aetiology of Nocturia to Guide Outcomes (TANGO) screening tool, which is used to determine nocturia etiology.

Methods

Patients hospitalized in urology, orthopedics, and general surgery clinics between September 2019 and January 2020 were included in the study. Demographic characteristics of the participants such as age, gender, drug use, and nocturia severity were assessed by the researchers. The Turkish version of the TANGO questionnaire consisting of 22 questions was filled in by the patients. The patients were asked to repeat the same test 4 weeks later.

Results

A total of 124 patients were included in the study. The mean age of the patients participating in the study was 51.20 ± 18.50 (38‐82). The result of the reliability assessment showed that the total score intraclass correlation coefficient was 0.715 (individual item score weighted kappa coefficients, 0.696‐0.731) and the Cronbach's alpha coefficient was 0.727.

A total of 112 patients filled in the TANGO screening tool again after 4 weeks. The test‐retest reliability analysis kappa value was 0.75 (0.68‐0.83). In the validity analysis, a moderately positive correlation was observed between the TANGO‐Urinary Incontinence Score and the number of nocturia (r = 0.452, P = .003).

Conclusion

According to the validation study, the TANGO screening tool is valid and reliable to determine the nocturia etiology for the Turkish population.
High‐grade gliomas with isocitrate dehydrogenase wild‐type and 1p/19q codeleted: Atypical molecular phenotype and current challenges in molecular diagnosis
Authors: Zheng Linmao , Zhang Mengni , Hou Jing , Gong Jing , Nie Ling , Chen Xueqin , Zhou Qiao , Chen Ni
Published: August 2020

Glioma is the most common intracranial malignant tumor, with poor prognosis. The new World Health Organization (WHO) integrated classification (2016) for diffuse glioma is mainly based on the status of the isocitrate dehydrogenase (IDH) gene (IDH) mutation and 1p/19q codeletion, with diffuse glioma separated into three distinct molecular categories: chromosome 1p/19q codeletion/IDH mutant, 1p/19q intact /IDH mutant, and IDH wild‐type. Gliomas harboring 1p/19q codeletion but without IDH mutation are rare and cannot be classified according to the new revision of the WHO classification. Here we report three high‐grade gliomas with this atypical molecular phenotype, and describe their histological and immunohistochemical features, the status of mutations in TERT promopter, H3F3A, HIST1H3B, and BRAF, as well as MGMT promoter methylation, and prognosis. Considering morphology, molecular parameters, and patients prognosis, we found that high‐grade gliomas harboring 1p/19q codeletion but without IDH mutation were not typical glioblastoma multiforme (GBM) but were more likely to be GBM than anaplastic oligodendroglioma.
Complement factors and alpha‐fetoprotein as biomarkers for noninvasive prenatal diagnosis of neural tube defects
Authors: Dong Naixuan , Gu Hui , Liu Dan , Wei Xiaowei , Ma Wei , Ma Ling , Liu Yusi , Wang Yanfu , Jia Shanshan , Huang Jieting , Wang Chenfei , He Xuan , Huang Tianchu , He Yiwen , Zhang Qiang , An Dong , Bai Yuzuo , Yuan Zhengwei
Published: August 2020

Neural tube defects (NTDs) are serious congenital malformations. In this study, we aimed to identify more specific and sensitive maternal serum biomarkers for noninvasive NTD screenings. We collected serum from 37 pregnant women carrying fetuses with NTDs and 38 pregnant women carrying normal fetuses. Isobaric tags for relative and absolute quantitation were conducted for differential proteomic analysis, and an enzyme‐linked immunosorbent assay was used to validate the results. We then used a support vector machine (SVM) classifier to establish a disease prediction model for NTD diagnosis. We identified 113 differentially expressed proteins; of these, 23 were either up‐ or downregulated 1.5‐fold or more, including five complement proteins (C1QA, C1S, C1R, C9, and C3); C3 and C9 were downregulated significantly in NTD groups. The accuracy rate of the SVM model of the complement factors (including C1QA, C1S, and C3) was 62.5%, with 60% sensitivity and 67% specificity, while the accuracy rate of the SVM model of alpha‐fetoprotein (AFP, an established biomarker for NTDs) was 62.5%, with 75% sensitivity and 50% specificity. Combination of the complement factor and AFP data resulted in the SVM model accuracy of 75%, and receiver operating characteristic curve analysis showed 75% sensitivity and 75% specificity. These data suggest that a disease prediction model based on combined complement factor and AFP data could serve as a more accurate method of noninvasive prenatal NTD diagnosis.
Perspectives on utilization of macrophytes as feed ingredient for fish in future aquaculture
Authors: Naseem Shahida , Bhat Sami Ullah , Gani Adil , Bhat Farooz Ahmad
Published: August 2020

Aquaculture activity supplies high‐quality protein at affordable cost. A global call for foods of aquatic origin has heightened not only due to the zooming population growth, but also because of a choice of healthier foods for human beings. As the industry expands, it is facing the high cost of feeding because the key ingredients, that is fishmeal and fish oil, of aquadiet are very expensive. Identification of alternate foodstuffs that will remarkably minimize the expense of productivity of animal protein becomes a priority with due regard to environmental footprint. Alternative feed components are vital in partially or completely substituting unsustainable but high‐value components or constituents that will otherwise have direct competition with human use. Utilization of aquatic plants as a substitute for fish meal has the potential to revolutionize aquaculture in meeting global protein demand. A lot of money is spent on aquatic weed management, so this research idea tries to integrate both economic aspects and the environmental concerns. Macrophyte‐based feed ingredients have promising nutrient profile: crude protein ranges between 11% and 32%; lipid, 2.90% and 16.81%; and ash, 8% and 31%, a good array of amino acids; and a good amount of micro‐ and macronutrients that make them prosperous substituents for fish feed.
Crusading for Moral Authority: Christian Nationalism and Opposition to Science
Authors: Baker Joseph O. , Perry Samuel L. , Whitehead Andrew L.
Published: August 2020

Numerous studies show biblicist Christianity, religiosity, and conservative political identity are strong predictors of Americans holding skeptical attitudes toward publicly controversial aspects of science, such as human evolution. We show that Christian nationalism—meaning the desire to see particularistic and exclusivist versions of Christian symbols, values, and policies enshrined as the established religion of the United States—is a strong and consistent predictor of Americans’ attitudes about science above and beyond other religious and political characteristics. Further, a majority of the overall effect of political ideology on skepticism about the moral authority of science is mediated through Christian nationalism, indicating that political conservatives are more likely to be concerned with particular aspects of science primarily because they are more likely to be Christian nationalists. Likewise, substantial proportions of the well‐documented associations between religiosity and biblical “literalism” with views of science are mediated through Christian nationalism. Because Christian nationalism seeks to establish a particular and exclusivist vision of Christianity as the dominant moral order, adherents feel threatened by challenges to the epistemic authority undergirding that order, including by aspects of science perceived as challenging the supremacy of biblicist authority.
Fail‐safe aspects of oxygen supply
Authors: Duffin James
Published: August 2020

Key points

A fall in oxygen supply releases a remedial response that is otherwise prevented when the oxygen supply is sufficient; for example, the remedial function of HIF‐1α is released when oxygen levels fall.

Concept: the physiological responses initiated when oxygen supply is compromised operate in a fail‐safe manner. This concept is applied to two cases: the control of cerebral blood flow, and the detection of hypoxia by the carotid body.

The fail‐safe oxygen supply concept was tested with simple computer simulations to demonstrate its function and verify the ability to reproduce measured data.

The computer model reproduced published observations, suggesting that the fail‐safe concept can be considered as a principle that provides novel insight into the physiology of oxygen supply in these cases.

An engineered fail‐safe system automatically prevents or mitigates the consequences of a system failure. This operational concept can be applied both to the delivery of oxygen to the brain during hypoxia and anaemia, and to the carotid body response to hypoxia and hypercapnia. I aimed to develop simple mathematical models of these fail‐safe processes and examine their ability to replicate experimental observations. The intent is to demonstrate the validity of applying the fail‐safe concept, not to reveal the details of the physiology involved. The model calculations are based on a single compartment of the relevant tissue in each case that is challenged with a decrease in oxygen supply. The model equation parameters were adjusted to reproduce experimental observations. The fail‐safe model of cerebral blood flow control yielded results similar in form to published experimental observations of the cerebral blood flow responses to hypoxia and anaemia. The fail‐safe model of carotid body glomus cell control of intracellular hydrogen ion concentration also yielded results similar in form to observations of carotid sinus nerve responses to hypoxia and hypercapnia. The ability of these simple models to simulate experimental observations demonstrates the applicability of the fail‐safe concept to oxygen delivery. I suggest that a fail‐safe view of oxygen delivery provides novel physiological insight.
Apparent Flexoelectricity Due to Heterogeneous Piezoelectricity
Authors: Yvonnet J. , Chen X. , Sharma P.
Published: August 2020

Recent work has highlighted how the phenomenon of flexoelectricity can masquerade as piezoelectricity. This notion can not only be exploited to create artificial piezoelectric-like materials without using piezoelectric materials but may also explain measurement artifacts in dielectrics. In this article, we show that the reverse is also possible and potentially advantageous in certain situations (such as energy harvesting). By constructing a computational homogenization approach predicated on the finite element method, we argue that composites made of piezoelectric phases can conspire to endow the material with a distinct overall flexoelectric-like response even though the native flexoelectricity of the constituent materials is negligible. Full finite element procedures for numerical evaluation of the different effective tensors, including the flexoelectric tensor, are provided. Numerical investigations are conducted, showing variation of the effective flexoelectric properties with respect to local geometry and properties of the composite in piezoelectric–piezoelectric and polymer–piezoelectric composites. We find that the flexoelectric response can be tuned to nearly five times higher than the constituents.
Analysis of Flangeability by Single-Stage SPIF and Press-Working in AA7075-O Sheet
Authors: Borrego Marcos , Morales-Palma Domingo , Vallellano Carpóforo
Published: August 2020

Recently, the research interest of hole-flanging has turned from conventional press-working to single-point incremental forming (SPIF) as a viable process for small- and medium-sized batches. Both technologies have been studied separately using different approaches and, therefore, most studies cannot be easily compared. Besides, some studies that measured the formability in SPIF using the classical limiting forming ratio (LFR) showed conflicting results that still need to be clarified. Under these circumstances, the aim of this work is to provide a better understanding of the deformation process and the material formability in hole-flanging by critically comparing both forming processes. To this end, a series of experimental tests on AA7075-O sheet of 1.6-mm thickness by press-working and single-stage SPIF, using forming tools with different profile radii, are analyzed. The material formability and flange geometry are compared and discussed in detail. The process limits are analyzed by using both the Forming Limit Diagram (FLD) and the LFR. The failure modes by necking and fracture are clearly identified and assessed on both processes along with the influence of the bending induced by the tools during the flange forming. Results conclude that the LFR is not an adequate parameter to compare formability between processes other than press-working and, accordingly, two additional variables based on either the flange height or the average thickness reduction are proposed to successfully analyze flangeability.
Effect of Tip Clearance on the Aeroelastic Stability of a Wide-Chord Fan Rotor
Authors: Dong Xu , Zhang Yingjie , Zhang Ziqing , Lu Xingen , Zhang Yanfeng
Published: August 2020

This research presents a series of simulations that investigate the effects of tip clearance on the aeroelastic stability of a wide-chord high-speed transonic fan rotor. The results show that the stall margin and the total pressure ratio decreases as the tip clearance increases. The effect of tip clearance on the blade loading can extend to 30% span. The phase of the influence coefficient without tip clearance is different from that with clearance, which causes the most unstable aerodynamic damping to shift in the nodal diameter. As the clearance increases from 0.25 mm to 2 mm, the damping decreases. The nonmonotonic behavior found by other researchers was not observed in this study. We conclude that the tip clearance affects the aeroelastic stability in two ways. The first is to change the blade loading so that the amplitude of the unsteady pressure increases or decreases, while the phase hardly changes, resulting in changes in aerodynamic damping. The second is to change the local flow so that the unsteady pressure amplitude and the phase change locally.
On the Positioning of a Piezoelectric Material in the Energy Harvesting From a Nonideally Excited Portal Frame
Authors: Rocha Rodrigo T. , Tusset Angelo M. , Ribeiro Mauricio A. , Lenz Wagner B. , Haura Junior Remei , Jarzebowska Elzbieta , Balthazar Jose M.
Published: August 2020

In this paper, we consider the application of the piezoelectric energy harvesting using a portal frame structure of two-degrees-of-freedom. The piezoelectric material is considered as a linear device using a capacitive mathematical model. The portal structure is of two-degrees-of-freedom considering with quadratic coupling between the first and second modes of vibration. 2:1 internal resonance between the first and second modes is set, which is a particular condition of this type of system due to the appearance of a saturation phenomenon. As this phenomenon causes the system to start vibrating from the second mode and, at steady-state, vibrates at the first mode, the objective of this work is to verify the energy uptake, considering the different positioning of a piezoelectric material, which is coupled to the supported beam and/or to the column. In addition, the structure is excited by a nonideal DC motor with a limited power supply. The results show a considerably nonlinear behavior due to the nonideal motor, and, with the saturation phenomenon, it is more efficient to collect energy by coupling the PZT to the column. The investigation of the stability of the system due to the piezoelectric coefficient Θ is also taken into account, which is carried out by numerical tools as phase planes, Poincare maps, bifurcation diagrams, and 0–1 test.
Numerical Modeling of Vascular Stresses During Lead Extraction: Subclavian vs. Femoral
Authors: Toloui Mostafa , Marshall Mark , Vatterott Pierce , Zhang Peter , Lahm Ryan , Lulic Thomas , Harris Megan
Published: August 2020

Transvenous lead extraction is a critical and growing technique used to treat patients with chronically implanted pacemakers and defibrillators. This procedure is commonly executed via the subclavian vein or the femoral vein. Some physicians’ experiences indicate that the femoral approach results in fewer vascular tears. This study is aimed to present a physics-based comparative assessment of intravenous mechanical stresses for chronic lead management between the two approaches. Finite Element (FE) modeling is employed to quantify the vascular stress distributions. A full 3-D model including veins, heart, fibrotic scar regions and the lead was created to simulate the different lead extraction methods. Results: (1) highest stresses are generally in the vicinity of SVC lead attachments; (2) femoral approach results in a ∼uniform distribution of stress over the scar while the subclavian approach leads to patches of concentrated high stress; (3) 2–3 times higher maximum vascular stress during subclavian; (4) insignificant maximum stress at the apex for both; (5) inverse variation of stress levels with: (i) branch-to-scar distance for SVC method; and (ii)vein wall thickness in both methods. (6) lower stress levels for scars with longer attachment lengths. The importance and effectiveness of mechanical stress analysis in risk analysis for chronic lead management is illustrated. Overall, the localized intravascular wall stress is meaningfully higher for subclavian vs. femoral extraction with same SVC shear force. This may help explain the higher rate of SVC tears when extracting from the left subclavian approach. The individual anatomy (e.g. vascular angles) is a key factor in the resulting stress and this understanding may be critical when choosing an extraction approach and future lead design.
Stakeholder Engagement With Prototypes During Front-End Medical Device Design: Who Is Engaged With What Prototype?
Authors: Coulentianos Marianna J. , Rodriguez-Calero Ilka , Daly Shanna R. , Sienko Kathleen H.
Published: August 2020

Stakeholder engagement with prototypes during the front-end phases of medical device design can support problem identification, problem definition, and early concept generation. This study examined what prototypes were leveraged to engage specific types of stakeholders during front-end medical device design. Analysis of semi-structured interviews with 22 design practitioners in the medical device industry revealed some common associations of prototype choice for particular stakeholders. A few associations are highlighted: designers engaged users with physical three-dimensional (3D) prototypes, financial decision-makers with physical 3D and two-dimensional (2D) prototypes, government and regulatory stakeholders with 2D prototypes, and expert advisors with digital 3D prototypes. The rationale provided by practitioners revealed the intentional selection of prototype form for specific stakeholder engagements.
Magnetic Particle Spectroscopy-Based Handheld Device for Wash-Free, Easy-to-Use, and Solution-Phase Immunoassay Applications
Authors: Chugh Vinit Kumar , Wu Kai , Nair Abilash , di Girolamo Arturo , Schealler James , Vuong Hoang , Davies Will , Wall Adam , Whitely Emmet , Saha Renata , Su Diqing , Wang Jian-Ping
Published: August 2020

In recent years, magnetic particle spectroscopy (MPS) has emerged as a new technology for immunoassay applications. In MPS, alternating magnetic fields are applied to magnetic nanoparticles (MNPs). The magnetic responses of these nanoparticles are collected and recorded by a pair of specially designed pick-up coils. These magnetic responses contain higher harmonics that are specific to the physical changes of the nanoparticles such as the binding events of target analytes to nanoparticles. This volumetric-based bioassay method analyses the response signal from the whole nanoparticle suspension, thus, allows one step and wash-free immunoassay with minimum technical requirements. In this work, we developed a handheld MPS system as a future highly sensitive, cheap, in vitro, and easy-to-use point-of-care (POC) detection kit.
A System for the Objective Assessment of Hand Proprioceptive Function in Pediatric and Adult Populations
Authors: Oh Jinseok , Mahnan Arash , Xu Jiapeng , Holst-Wolf Jessica , Block Hannah , Konczak Jürgen
Published: August 2020

Proprioceptive signals from mechanoreceptors embedded in ligaments, tendons, and muscles are essential for the control of muscle tone and voluntary movement. Numerous neurological and orthopedic disorders are associated with proprioceptive dysfunction that impairs the control of balance and/or fine motor function. However, obtaining objective measures of proprioceptive function is difficult in most clinical settings, because available assessment methods rely on specialized equipment, expertise, or are too time-consuming. This paper presents a new tablet-based system that objectively measures finger position sense by implementing a psychophysical threshold search method. We here provide initial data that demonstrate the ease-of-use and efficacy of the system.
Effect of Coal Fouling on Railroad Ballast Under Direct Shear Loading Conditions
Authors: Dinesh Gundavaram , Hussaini Syed Khaja Karimullah
Published: August 2020

Contamination of ballast generally occurs due to particle breakage, infiltration of other undesired materials from the surface or base of the ballast is one of the primary reason for track deterioration. In this context, large scale direct shear tests were conducted to examine the shear behavior of unstabilized and geogrid-stabilized fresh and coal fouled ballast. Fresh granite ballast with an average particle size (D50) of 42 mm and triaxial geogrid having 69 × 69 mm aperture were used in this study. Tests were conducted at different Void Contamination Index (VCI) values ranging from 0 to 60% at a constant shearing rate (Sr) of 3 mm/min and normal stress (σn) of 90 kPa. The test results revealed that the shear strength of ballast is highly influenced by the coal fouling. The friction (φ) and dilation angles (ψ) of unstabilized ballast is found to decrease from 63.06° to 55.55° and 17.7° to 11.22°, respectively as the VCI increases from 0 to 60%. It is further observed that the breakage of ballast (Bg, computed in terms of Marsal’s breakage) decreases from 9.37 to 3.98% with the presence of coal fines. However, the presence of geogrid was found to increase the friction angle and reduce the particle breakage and dilation of fresh and coal fouled ballast. These test results show the effectiveness of triaxial geogrid in stabilizing the fresh and coal fouled ballast.
Wheel-Rail Interface Condition Estimation via Acoustic Sensors
Authors: Shrestha Sundar , Koirala Anand , Spiryagin Maksym , Wu Qing
Published: August 2020

The surface roughness between the wheel and rail has a huge influence on the rolling noise level. The presence of the third body such as frost or grease at the wheel-rail interface contributes towards change in adhesion coefficient resulting in the generation of acoustic noise at various levels. Therefore, it is possible to estimate adhesion conditions between the wheel and rail from the analysis of audio patterns originating from wheel-rail interaction. In this study, a new approach to estimate adhesion condition is proposed which takes rolling noise as input.

Acoustic sensors (Behringer B-5 condenser microphone) for audio data acquisition were installed on a scaled bogie test rig. The cardioid configuration of the sensor was chosen for picking up the source signal while avoiding the surround sound. The test rig was operated at the speed of 40 and 60 rpm multiple times in both dry and wet friction conditions. The proposition behind running the setup several times was to get a large set of acoustic signals under different adhesion conditions because there exists no such dataset in the public repositories. 30 seconds interval of rolling noise data from the continuous audio signal was extracted as samples for the training W-RICE model. Each sample was pre-processed using the Librosa python package to extract seven basic features/signatures: zero-crossing rate, spectral centroid, spectral bandwidth, spectral roll-off, MFCCs (Mel-frequency cepstral coefficients), RMS (root-mean-square) energy and Chroma frequencies. These features were used as input to an MLP (Multi-Layered Perceptron) neural network and trained for four different classes (dry and wet conditions with speed of 40 rpm and 60 rpm each). MLP model training and testing were implemented in Keras deep learning library. MLPs can automatically learn useful and meaningful relationships among the input features for classifying the input audio sample to one of the output classes/categories. For four output categories considered, 100% classification accuracy was achieved on the test set while accuracies of 99.56%, 73.24%, and 63.59% were achieved for three validation sets consisting of audio samples of varying noise levels.
Discrete Element Modeling of Railway Ballast for Studying Railroad Tamping Operation
Authors: Dama Nilesh , Ahmadian Mehdi
Published: August 2020

The dynamic behavior of ballast particles during track tamping is studied by developing a computer simulation model using the Discrete Element Model (DEM) method. The simulation model is developed in a commercially available DEM software called PFC3D (Particle Flow Code 3D). The study primarily evaluates a complete tamping cycle as defined by insertion, squeeze, hold, and withdrawal. Using a Taguchi approach, the effect of Tine motion’s frequency and amplitude, insertion velocity, and squeeze velocity are evaluated on tamping effectiveness. The compactness of the ballast particles, as defined by the average number of contacts per particle (referred to “Coordination Number”) is used as a measure of the effectiveness of tamping. Setting up the DEM model and important elements such as selection and calibration of particle shapes, ballast mechanical properties, contact model, and parameters governing the contact force models are described in detail. The tamping process is evaluated using a half-track layout with a highly modular code that enables a high degree of adjustability to allow control of all parameters for improved simulation flexibility. A parametric study is performed to find the best values of tine motion parameters for improving tamping efficiency. A performance comparison is made between linear and elliptical tamping. The results indicate that smaller squeeze and release velocities of the tines yield better compaction. Of course, reducing the velocities would result in increased tamping time. Additionally, the results indicate that the linear motion of the tines potentially result in better compaction than elliptical motion, although the latter may require less insertion force (power) and cause less ballast damage.
Estimating the Inner Ring Defect Size and Residual Service Life of Freight Railcar Bearings Using Vibration Signatures
Authors: Lima Jennifer , Tarawneh Constantine , Aguilera Jesse , Cuanang Jonas
Published: August 2020

There are currently two primary wayside detection systems for monitoring the health of freight railcar bearings in the railroad industry: The Trackside Acoustic Detection System (TADS™) and the wayside Hot-Box Detector (HBD). TADS™ uses wayside microphones to detect and alert the train operator of high-risk defects. However, many defective bearings may never be detected by TADS™ since a high-risk defect is a spall which spans about 90% of a bearing’s raceway, and there are less than 30 systems in operation throughout the United States and Canada. HBDs sit on the side of the rail-tracks and use non-contact infrared sensors to acquire temperatures of bearings as they roll over the detector. These wayside bearing detection systems are reactive in nature and often require emergency stops in order to replace the wheelset containing the identified defective bearing. Train stoppages are inefficient and can be very costly. Unnecessary train stoppages can be avoided if a proper maintenance schedule can be developed at the onset of a defect initiating within the bearing. Using a proactive approach, railcars with defective bearings could be allowed to remain in service operation safely until reaching scheduled maintenance.

The University Transportation Center for Railway Safety (UTCRS) research group at the University of Texas Rio Grande Valley (UTRGV) has been working on developing a proactive bearing condition monitoring system which can reliably detect the onset of bearing failure. Unlike wayside detection systems, the onboard condition monitoring system can continuously assess the railcar bearing health and can provide accurate temperature and vibration profiles to alert of defect initiation. This system has been validated through rigorous laboratory testing at UTRGV and field testing at the Transportation Technology Center, Inc. (TTCI) in Pueblo, CO. The work presented here builds on previously published work that demonstrates the use of the onboard condition monitoring system to identify defective bearings as well as the correlations developed for spall growth rates of defective bearing outer rings (cups). The system first uses the root-mean-square (RMS) value of the bearing’s acceleration to assess its health. Then, an analysis of the frequency domain of the acquired vibration signature determines if the bearing has a defective inner ring (cone) and the RMS value is used to estimate the defect size. This estimated size is then used to predict the residual life of the bearing. The methodology proposed in this paper can assist railroads and railcar owners in the development of a proactive and cost-efficient maintenance cycle for their rolling stock.
Effects of Non-Hertzian Contact Models on Derailment Simulation
Authors: Guan Qinghua , Liu Binbin , Bruni Stefano
Published: August 2020

The derailment of trains is a complex phenomenon that requires an elaborate contact model in simulation to better understand its mechanism. The CONTACT program is a well-known reference for wheel-rail contact modeling due to its high accuracy. However, its low computational efficiency restricts its applications especially in the context of a multi-body simulation. Therefore, a high computational efficient, simplified and approximate non-Hertzian contact is preferred in derailment simulation. The aim of this research is to verify the efficiency of a recently developed non-Hertzian wheel-rail contact model in derailment simulation, which is a combination of the Kik-Piotrowski model and the KBTNH that is a fast creep force solver for non-Hertzian contacts. To assess the performance of the non-Hertzian model in derailment simulation, the derailment coefficient for steady-state and quasi-steady conditions, the wheel/rail contact forces during flange contact, and the dynamics behaviors of the wheelset prior to the derailment are compared with the state of the art contact methods representing different levels of modeling complexity, accuracy and efficiency, namely the classical approach (Hertz theory+FASTSIM algorithm) and the ‘exact’ solver CONTACT.
Thermal Buckling in CWR Tracks: Critical Aspects of Experimental Techniques for Lateral Track Resistance Evaluation
Authors: Pucillo Giovanni Pio
Published: August 2020

After the introduction of continuous welded rail, thermal track buckling has been recognized to be one of the unsolved problem caused by this technological railroad improvement. In general, both weak ballast strength in the lateral direction and large alignment defects are the principal causes of such phenomenon.

In the UIC 720 Leaflet, which is the reference standard for the realization and maintenance of continuous welded rail tracks, two safety criteria against thermal track buckling are described: one is based on the maximum (ΔTmax) and minimum (ΔTmin) buckling temperatures, the other only on the minimum buckling temperature.

In the literature, it is found that a correlation exists between ΔTmax and the maximum (or peak, FP) lateral resistance value of the tie-ballast system, and, analogously, between ΔTmin and the minimum (or limit, FL) lateral resistance. For this reason, railway technicians had to paid special attention in the assessment of FP and FL.

Because FP concerns lateral displacements equal to 5÷10 mm, and FL occurs for lateral displacements greater than 80÷100 mm, some researchers have proposed to measure FP with a quasi-non-destructive experimental technique, the Single Tie Push Test (STPT), and, successively, to evaluate FL as a function of FP by empirical formulas, in place of the experimental evaluation of the full lateral resistance curve of the tie-ballast system.

Based on these considerations, a concerning issue arises whether it is sufficient, and above all safe, to use the simpler, less destructive, and less expensive STPT technique, which requires that only one tie is detached from the rails, or if it is necessary to perform lateral resistance tests on track panels composed by 4 to 6 ties, as in the case of the Discrete Cut Panel Pull Test (DCPPT).

For this purpose, in this paper the experimental results obtained in situ in full scale conditions with the two testing techniques are reported, and the differences obtained by performing tests with one, two, and four ties are analyzed with the aim of ensuring a safe evaluation of the main input parameters required for buckling temperatures calculation.

It is found that the limit lateral resistance depends neither on the chosen experimental technique, nor on the compaction level of the ballast bed, whereas the peak lateral resistance appears to be dramatically altered if it is evaluated by mean of the STPT, with serious risks of an unsafe evaluation of the buckling temperatures.
Broken Rail Prediction With Machine Learning-Based Approach
Authors: Zhang Zhipeng , Zhou Kang , Liu Xiang
Published: August 2020

Broken rails are the most frequent cause of freight train derailments in the United States. According to the U.S. Federal Railroad Administration (FRA) railroad accident database, there are over 900 Class I railroad freight-train derailments caused by broken rails between 2000 and 2017. In 2017 alone, broken rail-caused freight train derailments cause $15.8 million track and rolling stock damage costs to Class I railroads. The prevention of broken rails is crucial for reducing the risk due to broken rail-caused derailments. Although there is fast-growing big data in the railroad industry, quite limited prior research has taken advantage of these data to disclose the relationship between real-world factors and broken rail occurrence. This article aims to predict the occurrence of broken rails via machine learning approach that simultaneously accounts for track files, traffic information, maintenance history, and prior defect information.

In the prediction of broken rails, a machine learning-based algorithm called extreme gradient boosting (XGBoost) is developed with various types of variables, including track characteristics (e.g. rail profile information, rail laid information), traffic-related information (e.g. gross tonnage recorded by time, number of passing cars), maintenance records (e.g. rail grinding and track ballast cleaning), and historical rail defect records. Area Under the Curve (AUC) is used as the evaluation metric to identify the prediction accuracy of developed machine learning model. The preliminary result shows that the AUC for one year of the XGBoost-based prediction model is 0.83, which is higher than two comparative models, logistic regression and random forests. Furthermore, the feature importance discloses that segment length, traffic tonnage, number of car passes, rail age, and the number of detected defects in the past six months have relatively greater importance for the prediction of broken rails. The prediction model and outcomes, along with future research in the relationship between broken rails and broken rail-caused derailment, can benefit railroad practical maintenance planning and capital planning.
Wheel-Rail Contact Modelling for Locomotive Traction Control System Studies
Authors: Spiryagin Maksym , Wu Qing , Bosomworth Chris , Cole Colin , Hayman Mark , Persson Ingemar
Published: August 2020

Recent locomotive traction studies have been extensively focused on the development of wheel-rail contact models for application inside multibody software products to compute results which can be further used in the prediction of track damage indexes. These models are quite sufficient, but they have a significant disadvantage of slow computational speed. In order to use the same locomotive models for traction studies, a new concept of the model was studied. The main difference from existing models is the developed normal task approach that provides a transition from non-Hertzian to Hertzian contact patches and this innovation was validated against the results obtained in a parallel computation test implemented inside of the wheel-rail coupling based on the Extended Contact library. The test was performed with a multibody locomotive model running on tangent track. The first implementation of the developed wheel rail-coupling has been tested in a parallel mode with the Extended Contact library on a full mechatronic model of a locomotive and the results compared against each other. Discussion on the further development is provided.
On the Interpretation and Scope of the V&V 20 Standard for Verification and Validation in Computational Fluid Dynamics and Heat Transfer
Authors: Eça L. , Dowding K. , Roache P. J.
Published: August 2020

The goal of this paper is to summarize and clarify the scope and interpretation of the validation procedure presented in the V&V20-2009 ASME Standard. In V&V20-2009, validation is an assessment of the model error, without regard to the assessment satisfying validation requirements. Therefore, validation is not considered as a pass/fail exercise. The purpose of the validation procedure is the estimation of the accuracy of a mathematical model for specified validation variables (also known as quantities of interest, system responses or figures of merit) at a specified validation point for cases in which the conditions of the actual experiment are simulated. The proposed procedure can be applied to variables defined by a scalar.

For the sake of clarity, the paper reiterates the development and assumptions behind the V&V20-2009 procedure that requires the knowledge of the experimental values D and simulation values S at the set point and an estimate of the experimental, numerical and parameter uncertainties. The difference E between S and D is the centre of the interval that should contain the model error (with a certain degree of confidence) and the width of the interval is obtained from the validation uncertainty that is a consequence of the combination of the experimental, numerical and parameter uncertainties.

The paper presents the alternatives to address parameter uncertainty and expands upon the interpretation of the final result. The paper also includes two examples demonstrating the application of the V&V20-2009 validation procedure including one problem from V&V10.1-2012 on solid mechanics.
Ageism in the Fitness and Health Industry: A Review of the Literature
Authors: Jin Bora , Harvey Idethia Shevon
Published: August 2020

This review aims to understand how age-related stereotypes against older adults’ physical capabilities influence their ability to engage in regular physical activity. The authors wanted to know how people construe ageism in the fitness and health arena, how ageism manifests in this field, and how ageism influences older adults’ learning and practicing physical activity. Data was extracted using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. Twenty-two empirical studies met the selection criteria. The findings revealed that the attributes of ageism fell into either self-imposed or other-directed ageism categories and manifested as implicit or explicit ageism. The study also identified the following four themes: (a) perceptions of aging and exercise, (b) exercise motivation, (c) opportunities for older adults, and (d) ambiguous positionality as older exercisers. The research provides evidence for the existence of ageism against older exercisers. Further research considering the implication of ageism within the exercising industry is necessary.
Chapter 2: Perceived Benefits and Challenges of Physical Educators’ Use of Social Media for Professional Development and Learning
Authors: Carpenter Jeffrey P. , Harvey Stephen
Published: August 2020

Purpose: This study investigated the benefits and challenges described by physical educators who had actively used social media professionally for an average of more than 6 years.Method: The data were collected through semistructured individual and focus group interviews, with an international sample of physical educators (N = 48). The data were analyzed through an open coding process to develop themes.Results: Diverse benefits and challenges associated with social media use were identified and organized in alignment with a social ecological model. The benefits included enhanced knowledge, skills, teaching, student learning, and access to professional community. The challenges included managing the quantity of available content, the risks of context collapse, and navigating the cultures and discourse of online spaces.Discussion: A deeper understanding of the benefits and challenges of physical educators’ social media use can enable stakeholders to act in more strategic ways as they navigate the promise and the peril of social media.
Chapter 8: Research Ruminations and New Frontiers for Social Media Use for Professional Development and Learning in Physical Education and Sport Pedagogy
Authors: Carpenter Jeffrey P. , Harvey Stephen
Published: August 2020

This chapter compares and contrasts the findings of the preceding empirical monograph chapters. The findings from these chapters are addressed in terms of how they illustrate the positives, negatives, and tensions that can be associated with social media use for professional development and learning. Across the various chapters, similarities in findings as well as apparent contradictions are discussed. By illuminating the potential and the perils of social media use and misuse, a pragmatic summary of the findings can inform wise use and nonuse of social media for professional development and learning by those involved in the field of physical education and sport pedagogy. Although prior literature and this monograph have begun to address some aspects of social media use in physical education and sport pedagogy, much remains to be explored. Topics, social media tools, methods, and theory that could be taken up or expanded upon in future research to advance the field are suggested.
Population Pharmacokinetic Study of Ceftriaxone in Elderly Patients, Using Cystatin C-Based Estimates of Renal Function To Account for Frailty
Authors: Tan Shu Jin , Cockcroft Matthew , Page-Sharp Madhu , Arendts Glenn , Davis Timothy M. E. , Moore Brioni R. , Batty Kevin T. , Salman Sam , Manning Laurens
Published: August 2020

Ceftriaxone is widely used for respiratory and urinary infections in elderly and frail patients, but there are few pharmacokinetic studies. A prospective population pharmacokinetic study of ceftriaxone in adults over 65 years old was undertaken. Dried blood spots collected at baseline (predose) and 0.5, 1, 4, 8, and 24 h after administration of 1 g of ceftriaxone were assayed using a validated liquid chromatography-mass spectroscopy analytical method. Frailty was classified using the Edmonton frailty scale and grip strength via a hand dynamometer.
A Trimeric Autotransporter Enhances Biofilm Cohesiveness in Yersinia pseudotuberculosis but Not in Yersinia pestis
Authors: Calder Joshua T. , Christman Nicholas D. , Hawkins Jessica M. , Erickson David L.
Published: August 2020

The evolution of
Yersinia pestis
from its
Y. pseudotuberculosis
ancestor involved gene acquisition and gene losses, leading to differences in biofilm production. Characterizing the unique biofilm features of both species may provide better understanding of how each adapts to its specific niches. This study identifies a trimeric autotransporter, YadE, that promotes biofilm stability of
Y. pseudotuberculosis
but which has been inactivated in
Y. pestis
, perhaps because it is not compatible with the Hms polysaccharide that is crucial for biofilms inside fleas. We also reveal that the Rcs signaling cascade, which represses Hms expression, activates YadE in
Y. pseudotuberculosis
. The ability of
Y. pseudotuberculosis
to use polysaccharide or YadE protein for cell-cell adhesion may help it produce biofilms in different environments.
Uncovering the Role of the E1 Protein in Different Stages of Human Papillomavirus 18 Genome Replication
Authors: Piirsoo Alla , Kala Martin , Sankovski Eve , Ustav Mart , Piirsoo Marko
Published: August 2020

Human papillomavirus (HPV) infections pose serious medical problem. To date, there are no HPV-specific antivirals available due to poor understanding of the molecular mechanisms of virus infection cycle. The infection cycle of HPV involves initial amplification of the viral genomes and maintenance of the viral genomes with a constant copy number, followed by another round of viral genome amplification and new viral particle formation. The viral protein E1 is critical for the initial amplification of the viral genome. However, E1 involvement in other phases of the viral life cycle has remained controversial. In the present study, we show that at least two different replication modes of the HPV18 genome are undertaken simultaneously during the maintenance and vegetative amplification phases, i.e., replication of the majority of the HPV18 genome proceeds under the control of the host cell replication machinery without E1 function, whereas a minority of the genome replicates in an E1-dependent manner.