bluuebunny/crossref_metadata_2025 huggingface dataset:
Bio-Inspired Nonholonomic Tracking Control
Authors: Shoemaker Adam , Leonessa Alexander
Published: March 2014

The behavior of nature’s predators is considered for designing a high speed tracking controller for nonholonomic vehicles, whose dynamics are represented using a unicycle model. To ensure that the vehicle behavior closely resembles that of a predator, saturation constraints are added and accounted for using Lyapunov stability criterion. Following verification and comparison of the saturation constraints, the proposed algorithm is implemented on a testing platform. Based on the results presented, we believe the algorithm shows significant promise in high speed control and obstacle avoidance.
Navigation of an Underwater Remotely Operated Vehicle Based on Extended Kalman Filter
Authors: Martínez Blanca V. , Sierra Daniel A. , Villamizar Rodolfo
Published: March 2014

An algorithm to estimate positions, orientations, linear velocities and angular rates of an Underwater Remotely Operated Vehicle (UROV), based on the Extended Kalman Filter (EKF), is presented. The complete UROV kinematic and dynamic models are combined to obtain the process equation, and measurements correspond to linear accelerations and angular rates provided by an Inertial Measurement Unit (IMU). The proposed algorithm is numerically validated and its results are compared with simulated UROV states. A discussion about the influence of the covariance matrices on the estimation error and overall filter performance is also included. As a conclusion, the proposed algorithm estimates properly the UROV linear velocities and angular rates from IMU measurements, and the noise in estimated states is reduced in about one order of magnitude.
Ultra Sensitive Piezoelectric-Based Microcantilever Sensor Operating at High Modes for Detection of Ultrasmall Masses
Authors: Faegh Samira , Jalili Nader
Published: March 2014

Detection of ultrasmall masses such as proteins and pathogens has been made possible as a result of nano-technological advancements. Development of label-free and highly sensitive biosensors has enabled the transduction of molecular recognition into detectable physical quantities. MicroCantilever (MC)-based systems have played a widespread role in developing such biosensors. One of the most important drawbacks of the available biosensors their high cost. Moreover, biosensors are normally quipped with external devices such as actuator and read out systems which are bulky and expensive. A unique self-sensing detection technique is proposed in this paper in order to address the limitations of the measurement systems. A number of approaches have been reported for enhancing the sensitivity of MC-based systems including geometry modification, employing nanoparticle-enhanced MCs and operating MCs in lateral and torsional modes. Although being investigated, there have not been analytical high fidelity models describing comprehensive dynamics and behavior of MCs operating in high modes. In this study, a comprehensive mathematical modeling is presented for the proposed self-sensing detection platform operating at ultrahigh mode using distributed-parameters system modeling. Mode convergence theory was adopted to have an accurate level of estimation. An extensive experimental setup was built using piezoelectric MC operating at high mode which verified theoretical modeling results. Finally, the whole platform was utilized as a biosensor for detection of ultrasmall adsorbed mass along with the theoretical and experimental results and verification. It was proved that operating MC at ultrahigh mode increases the sensitivity of system to detect adsorbed mass as a result of increased quality factor.
System Level Dynamic Modeling Framework Being Developed at Clemson University’s Wind Turbine Drivetrain Testing Facility
Authors: Schkoda Ryan , Bulgakov Konstantin , Addepalli Kalyan Chakravarthy , Haque Imtiaz
Published: March 2014

This paper describes the system level, dynamic modeling and simulation strategy being developed at the Wind Turbine Drivetrain Testing Facility (WTDTF) at Clemson University’s Restoration Institute in North Charleston, SC, USA. An extensible framework that allows various workflows has been constructed and used to conduct preliminary analysis of one of the facility’s test benches. The framework dictates that component and subsystem models be developed according to a list of identified needs and modeled in software best suited for the particular task. Models are then integrated according to the desired execution target. This approach allows for compartmentalized model development which is well suited for collaborative work. The framework has been applied to one of the test benches and has allowed researches to begin characterizing its behavior in the time and frequency domain.
Model-Based Compensation for Burst Message Loss in Wireless Networked Control Systems: Experimental Results
Authors: Godoy Eduardo Paciência , Scorzoni Fernando , Colón Diego , Porto Arthur José Vieira
Published: March 2014

A recent trend in networked control systems (NCSs) is the use of wireless networks enabling interoperability between existing wired and wireless systems. One of the major challenges in these wireless NCSs (WNCSs) is to overcome the impact of the message loss that degrades the performance and stability of these systems. Moreover, this impact is greater when dealing with burst or successive message losses. This paper discusses and presents the experimental results of a compensation strategy to deal with this burst message loss problem in which a NCS mathematical model runs in parallel with the physical process, providing sensor virtual data in case of packet losses. Running in real-time inside the controller, the mathematical model is updated online with real control signals sent to the actuator, which provides better reliability for the estimated sensor feedback (virtual data) transmitted to the controller each time a message loss occurs. In order to verify the advantages of applying this model-based compensation strategy for burst message losses in WNCSs, the control performance of a motor control system using CAN and ZigBee networks is analyzed. Experimental results led to the conclusion that the developed compensation strategy provided robustness and could maintain the control performance of the WNCS against different message loss scenarios.
Multi-Objective Collision Avoidance
Authors: Ali Mohammad , Gray Andrew , Gao Yiqi , Hedrick J. Karl , Borrelli Francesco
Published: March 2014

This paper presents a multi-objective safety system that is capable of avoiding unintended collisions with stationary and moving road obstacles, vehicle control loss as well as unintended roadway departures. The safety system intervenes only when there is an imminent safety risk while full control is left to the driver otherwise. The problems of assessing wether an intervention is required as well as controlling the vehicle motion in case an intervention is needed are jointly formulated as a single optimization problem, that is repeatedly solved in receding horizon. The novelty of the formulation lies in the ability of simultaneously avoiding moving obstacles while assessing the necessity thereof. The versatility of the proposed formulation is demonstrated through simulations showing its ability of avoiding a wide range of accident scenarios.
Battery Health Diagnostics Using Retrospective-Cost Subsystem Identification: Sensitivity to Noise and Initialization Errors
Authors: Zhou Xin , Ersal Tulga , Stein Jeffrey L. , Bernstein Dennis S.
Published: March 2014

Health management of Li-ion batteries requires knowledge of certain battery internal dynamics (e.g., lithium consumption and film growth at the solid-electrolyte interface) whose inputs and outputs are not directly measurable with noninvasive methods. Therefore, identification of those dynamics can be classified as an inaccessible subsystem identification problem. To address this problem, the retrospective-cost subsystem identification (RCSI) method is adopted in this paper. Specifically, a simulation-based study is presented that represents the battery using an electrochemistry-based battery charge/discharge model of Doyle, Fuller, and Newman augmented with a battery-health model by Ramadass. The solid electrolyte interface (SEI) film growth portion of the battery-health model is defined as the inaccessible subsystem to be identified using RCSI. First, it is verified that RCSI with a first-order subsystem structure can accurately estimate the film growth when noise or modeling errors are ignored. Parameter convergence issues are highlighted. Second, allowable input and output noise levels for desirable film growth tracking performance are determined by studying the relationship between voltage change and film growth in the truth model. The performance of RCSI with measurement noise is illustrated. The results show that RCSI can identify the film growth within 1.5% when the output measurement noise level is comparable to the change in output voltage between successive cycles due to film growth, or when the input measurement noise is comparable to the difference in current that results in a difference in voltage that is the same as the voltage change between successive cycles. Finally, the sensitivity of the performance of RSCI to initial condition errors in the battery charge/discharge model is investigated. The results show that when the initial conditions have an error of 1%, the identified results change by 7%. These results will help with selecting the appropriate sensors for the experiments with the hardware.
Rate Shaping Estimation and Control of a Piezoelectric Fuel Injector
Authors: Le Dat , Pietrzak Bradley W. , Shaver Gregory M.
Published: March 2014

Fuel injection rate shaping is one way to improve fuel efficiency and reduce harmful emissions in IC engines. Piezoelectrically actuated fuel injectors have a particularly fast response, which makes them capable of rate shaping operation. In this paper, a model-based closed-loop controller is designed to control the fuel injection rate passing through the nozzle of a piezoelectric fuel injector, by compensating for the injector’s nonlinear behavior. The performance of this controller is verified with simulation results.
Conceptual Design and Simulation of the Traction Control System of a High Performance Electric Vehicle
Authors: Núñez Juan Sebastián , Muñoz Luis Ernesto
Published: March 2014

This paper presents the conceptual design of the traction control system of a high performance electric vehicle with four driven wheels, intended to be used in quarter mile competitions. Different models of the longitudinal and vertical vehicle’s dynamics are presented, in order to consider the coupling dynamics of front and rear wheels. Two slip control strategies are proposed so as to maximize the traction forces of the wheels. The first one consists of a traditional control scheme applied to each wheel of the vehicle. Since the interaction between the tire and the road is often poorly known, the second controller proposed consists of a perturbation based extremum seeking control (PBESC), in order to maximize the traction force without knowledge of the road and the tire characteristics. Finally an auto tuning process based on low discrepancy sequences for both control systems is presented.
Nonparametric Identification of Hammerstein Systems Using Orthogonal Basis Functions as Ersatz Nonlinearities
Authors: Aljanaideh Khaled F. , Bernstein Dennis S.
Published: March 2014

In this paper, we present a technique for estimating the input nonlinearity of a Hammerstein system by using multiple orthogonal ersatz nonlinearities. Theoretical analysis shows that by replacing the unknown input nonlinearity by an ersatz nonlinearity, the estimates of the Markov parameters of the plant are correct up to a scalar factor, which is related to the inner product of the true input nonlinearity and the ersatz nonlinearity. These coefficients are used to construct and estimate the true nonlinearity represented as an orthogonal basis expansion. We demonstrate this technique by using a Fourier series expansion as well as orthogonal polynomials. We show that the kernel of the inner product associated with the orthogonal basis functions must be chosen to be the density function of the input signal.
Optimal Compression of a Generalized Prandtl-Ishlinskii Operator in Hysteresis Modeling
Authors: Zhang Jun , Merced Emmanuelle , Sepúlveda Nelson , Tan Xiaobo
Published: March 2014

The Prandtl-Ishlinskii (PI) model is a popular hysteresis model that has been widely applied in smart materials-based systems. Recently, a generalized PI model is formulated that is capable of characterizing asymmetric, saturated hysteresis. The fidelity of the model hinges on accurate representation of envelope functions, play operator radii, and corresponding weights. For a given number of play operators, existing work has typically adopted some predefined play radii, the performance of which could be far from optimal. In this paper, novel schemes based on entropy and relative entropy (Kullback-Leibler divergence) for optimal compression of a generalized PI model are proposed to best represent the original hysteresis model subject to a given complexity constraint, i.e., the number of play operators. The overall compression performance is expressed as a cost function, and is optimized using dynamic programming. The proposed compression schemes are applied to the modeling of the asymmetric hysteresis between resistance and temperature of a vanadium dioxide (VO2) film, and the effectiveness is further demonstrated in a model verification experiment. In particular, under the same complexity constraint, an entropy-based compression scheme and a Kullback-Leibler divergence-based compression scheme result in modeling errors around 37% and 48%, respectively, of that under a uniform compression scheme.
Development of Nonlinear Control Algorithms for Shaking Table Tests
Authors: Yang T. Y. , Li Kang , Lin Jian Yuan , Li Yuanjie
Published: March 2014

Shaking table testing method is one of the main sources of experimental means to evaluate the dynamic response of structural systems under earthquake loads. The experimental technique produces nearly realistic prototype conditions, giving important insight into critical issues such as collapse mechanisms, component failures, acceleration amplifications, residual displacements and post-earthquake capacities. Traditional tuning of shaking table relies on the use of linear controllers, which are designed to regulate linear systems. With most of the specimens being tested to highly nonlinear states (to understand the structural response under extreme loads), traditional linear controllers can no longer control the shaking table effectively. This results in experimental errors between commanded and measured shaking table movements which may produce an unintended response of the tested structure. Ultimately, it may result in a pre-mature failure of the specimen. To address this issue, a Lyapunov–based nonlinear control algorithm is utilized to develop an enhanced shaking table control system, which is based on nonlinear models accounting for the nonlinear response of the hydraulic actuator and specimens. A one-sixth-scaled model has been developed and constructed in the laboratory at the University of British Columbia, Vancouver. Advanced nonlinear system identification techniques have been developed to create the numerical model capable of recreating the nonlinearity experienced by the laboratory setup. Simulation results indicate that the developed nonlinear control algorithm can be used to achieve excellent tracking, even when the tested structure behaves nonlinearly. The example also demonstrates the ability of the nonlinear controller to compensate for disturbances in the actuating force applied to the shaking table. Thus, the proposed nonlinear shaking table control algorithm is not only a viable alternative, but also a way to significantly improve the quality of shaking table tests.
Robust Control of an HVAC System via a Super-Twisting Sliding Mode Technique
Authors: Kianfar Kaveh , Izadi-Zamanabadi Roozbeh , Saif Mehrdad
Published: March 2014

This paper presents design and implementation of a super twisting sliding mode control for superheat temperature and evaporating temperature of refrigerant fluid in an evaporator of HVAC (Heating-Ventilation and Air Conditioning)-Refrigeration system. Based on a nonlinear model of the evaporator two control approaches are presented. The first approach is based on a Multi-Input Multi Output (MIMO) system in which there are two control inputs; inlet mass flow and outlet mass flow rate, and the outputs are the length of two phase flow and evaporating temperature of refrigerant. The second approach considers the system as a Single input single output (SISO) one, and by using inlet mass flow, superheat temperature is controlled. In the first approach, by implementing a feedback linearization method the two control inputs are decoupled. By decoupling the effects of both inputs, the two state variables of system are controlled separately and effectively. By applying sliding mode control robustness against the disturbances and uncertainties is guaranteed. Super-twisting algorithm is applied as a remedy for chattering problem in classical sliding mode control and achieving finite time convergence. Controller and model of systems are simulated using MATLAB and Simulink. The results of simulations show the effectiveness of designed controller in presence of uncertainties.
Rate-Based Contractive Model Predictive Control of Diesel Air Path
Authors: Huang Mike , Nakada Hayato , Polavarapu Srinivas , Butts Ken , Kolmanovsky Ilya
Published: March 2014

A model predictive control (MPC) strategy is developed for the diesel engine air path. The objective is to regulate the intake manifold pressure (MAP) and exhaust gas recirculation rate (EGR rate) to the specified set-points by coordinated control of the Variable Geometry Turbine (VGT), and EGR valve. The approach taken enforces a decay in a flexible Lyapunov function so that a computationally simple MPC controller can be constructed using a single-step prediction and control horizon. A rate-based framework is also utilized to achieve zero-steady state tracking in the presence of model and plant mismatch. Closed-loop simulation results are reported.
Perturbing Structural Design Towards Minimizing Variation in Vibratory Response
Authors: Zhou K. , Tang J.
Published: March 2014

Real structures are always subject to uncertainties due to material imperfection, machining tolerance, and assemblage error, etc. These uncertainties lead to variations in structural vibratory responses. In order to reduce the likelihood of unexpected failures in structures, we need to minimize the response variations, which is the underlying idea of robust design. In this paper, we present an inverse sensitivity-based algorithm that allows us to tailor the structural design such that, under the same level of uncertainties, the response variations can be effectively reduced. We first develop a direct relation between the structural uncertainties and the response variations including the means and variances. We then formulate an optimal identification algorithm that will yield design perturbation to minimize the response variances while maintaining the mean values. Case analyses are carried out to validate the validity and efficiency of the new algorithm.
Spatio-Temporal Estimation of Wildfire Growth
Authors: Sharma Balaji R. , Kumar Manish , Cohen Kelly
Published: March 2014

This work presents a methodology for real-time estimation of wildland fire growth, utilizing afire growth model based on a set of partial differential equations for prediction, and harnessing concepts of space-time Kalman filtering and Proper Orthogonal Decomposition techniques towards low dimensional estimation of potentially large spatio-temporal states. The estimation framework is discussed in its criticality towards potential applications such as forest fire surveillance with unmanned systems equipped with onboard sensor suites. The effectiveness of the estimation process is evaluated numerically over fire growth data simulated using a well-established fire growth model described by coupled partial differential equations. The methodology is shown to be fairly accurate in estimating spatio-temporal process states through noise-ridden measurements for real-time deploy ability.
Design of a Minimally Actuated Medical Exoskeleton With Mechanical Swing-Phase Gait Generation and Sit-Stand Assistance
Authors: Tung Wayne Yi-Wei , McKinley Michael , Pillai Minerva V. , Reid Jason , Kazerooni Homayoon
Published: March 2014

Lower-extremity powered exoskeletons have traditionally used four to ten powered degrees of freedom to provide gait assistance for individuals with spinal cord injury (SCI). Systems with numerous high-impedance powered degrees of freedom commonly suffer from cumbersome walking dynamics and decreased utility due to added weight and increased control complexity. We propose a new approach to powered exoskeleton design that minimizes actuation and control complexity by embedding intelligence into the hardware. This paper describes a minimalistic system that uses a single motor for each exoskeleton leg in conjunction with a bio-inspired hip-knee coupling mechanism to enable users to walk, sit, and stand. Operating in concert with a custom orthotic knee joint, the exoskeleton hip joint has been designed to mimic the biarticular coupling of human leg muscles thus allowing a single actuator to power both hip and knee motions simultaneously. The implementation of this design resulted in a system that provides comparable performance to existing exoskeletons. This system has been tested on paraplegic subjects and has successfully enabled patients to stand up, sit down, and ambulate in numerous real world situations.
Control of Voluntary and Involuntary Nerve Impulses for Hemiparesis Rehabilitation and MRI Study
Authors: Lacey Lauren , Buharin Vasiliy , Turkseven Melih , Shinohara Minoru , Ueda Jun
Published: March 2014

In order for stroke victims to gain functional recovery of their hemiparetic limbs, facilitation techniques such as the repetitive facilitation exercise, or RFE, have been developed. Currently, there is a lack of understanding of the neural mechanisms associated with these types of facilitation techniques. To better understand the neural mechanisms associated with the RFE a functional magnetic resonance imaging (fMRI) study should be conducted. This paper presents initial experimental results testing the feasibility of implementing an fMRI-compatible actuator to facilitate a myotatic reflex in synchronization with the patient’s intention to move the hemiparetic limb. Preliminary data from a healthy individual demonstrated the feasibility of overlapping the long latency component of the afferent myotatic reflex with descending nerve impulses in a time window of 15ms. In addition, to implement the RFE into an fMRI-compatible device, a pneumatic actuation time delay due to long transmission line was evaluated. The results may be used for the assessment of the RFE using an fMRI-compatible robotic device in the future.
Nonlinear Controller Design With Bandwidth Consideration for a Novel Compressed Air Energy Storage System
Authors: Saadat Mohsen , Shirazi Farzad A. , Li Perry Y.
Published: March 2014

Maintaining the accumulator pressure regardless of its energy level and tracking the power demanded by the electrical grid are two potential advantages of the Compressed Air Energy Storage (CAES) system proposed in [1, 2]. In order to achieve these goals, a nonlinear controller is designed motivated by an energy-based Lyapunov function. The control inputs of the storage system include displacement of the pump/motor in the hydraulic transformer and displacement of the liquid piston air compressor/expander. While the latter has a relatively low bandwidth, the former is a faster actuator with a higher bandwidth. In addition, the pneumatic path of the storage vessel that is connected to the liquid piston air compressor/expander has a high energy density, whereas the hydraulic path of the storage vessel is power dense. The nonlinear controller is then modified to achieve a better performance for the entire system according to these properties. In the proposed approach, the control effort is distributed between the two pump/motors based on their bandwidths: the hydraulic transformer reacts to high frequency events, while the liquid piston air compressor/expander performs a steady storage/regeneration task. As a result, the liquid piston air compressor/expander will loosely maintain the accumulator pressure ratio and the pump/motor in the hydraulic transformer will precisely track the desired generator power. This control scheme also allows the accumulator to function as a damper in the storage system by absorbing power disturbances from the hydraulic path generated by wind gusts.
Approximations for Partial Differential Equations Appearing in Li-Ion Battery Models
Authors: Chaturvedi Nalin A. , Christensen Jake F. , Klein Reinhardt , Kojic Aleksandar
Published: March 2014

Li-ion based batteries are believed to be the most promising battery system for HEV/PHEV/EV applications due to their high energy density, lack of hysteresis and low self-discharge currents. However, designing a battery, along with its Battery Management System (BMS), that can guarantee safe and reliable operation, is a challenge since aging and other mechanisms involving optimal charge and discharge of the battery are not sufficiently well understood. In a previous article [1], we presented a model that has been studied in [2]–[5] to understand the operation of a Li-ion battery. In this article, we continue our work and present an approximation technique that can be applied to a generic battery model. These approximation method is based on projecting solutions to a Hilbert subspace formed by taking the span of an countably infinite set of basis functions. In this article, we apply this method to the key diffusion equation in the battery model, thus providing a fast approximation for the single particle model (SPM) for both variable and constant diffusion case.
Modeling the Effects of Heat Transfer Processes on Material Strain and Tension in Roll to Roll Manufacturing
Authors: Lu Youwei , Pagilla Prabhakar R.
Published: March 2014

This paper develops governing equations for material strain and tension based on a temperature distribution model when the flexible materials (often called webs) are transported on rollers through heat transfer processes within roll-to-roll (R2R) processing machines. Heat transfer processes are employed widely in R2R systems that contain process operations such as printing, coating, lamination, etc., which require heating/cooling of the moving web material. The heat transfer processes introduce the thermal expansion/contraction of the material and changes in the elastic modulus. Thus, the temperature distribution in the moving material affects the strain distribution in the material. Because of change in strain as well as modulus as a function of temperature, tension in the material resulting from elastic strain is also affected by heating/cooling of the web. To obtain the temperature distribution, two basic heat transfer modes are considered: web wrapped on a heat transfer roller and the web span between two consecutive rollers. The governing equations for strain is then obtained using the law of conservation of mass considering the temperature effects. Subsequently, a governing equation for web tension is obtained by assuming the web is elastic with the modulus varying with temperature; an average modulus is considered for defining the constitutive relation between web strain and tension. Since it is difficult to obtain measurement of tension using load cell rollers within heat transfer processes, a tension observer is designed. To evaluate the developed governing equations, numerical simulations for a single tension zone consisting of a heat transfer roller, a web span, and a driven roller are conducted. Results from these numerical model simulations are presented and discussed.
Comprehensive Battery Equivalent Circuit Based Model for Battery Management Application
Authors: Tong Shijie , Klein Matthew P. , Park Jae Wan
Published: March 2014

This paper presents a comprehensive control oriented battery model. Described first is an equivalent circuit based battery model which captures particular battery characteristics of control interest. Then, the model categorizes the battery dynamics based on their different time constants (transient, long-term, life-time). This model uses a 2-D map representing the temperature and state-of-charge dependent model parameters. Also, the model uses new battery state-of-charge and state-of-health definitions that are more practical for a real battery management system. Battery testing and simulation on various types of batteries and use scenarios was completed to validate that the model is easy to parameterize, computationally efficient and of adequate accuracy.
Comparison of Ultrasound Muscle Stiffness Measurement and Electromyography Towards Validation of an Algorithm for Individual Muscle Control
Authors: Brown Ellenor , Aomoto Kazuya , Ikeda Atsutoshi , Ogasawara Tsukasa , Yoshitake Yasuhide , Shinohara Minoru , Ueda Jun
Published: March 2014

The ability to control individual muscle activity is widely applicable in clinical diagnostics, training, and rehabilitation. Inducing muscle patterns that amplify abnormal muscle coordination can assist with early diagnosis of neuromuscular disorders. Individual muscle control also allows for targeted exercise of muscles weakened by disease, injury, or disuse. The goals of this research are to test a system for individual muscle control and introduce the use of muscle ultrasound as an alternative to electromyography (EMG). The system integrates a computational model of the right upper extremity with a robotic manipulator to predict and control muscle activity. To test the system, subjects gripped the manipulator and isometrically resisted loads applied to the hand. Muscle activity was measured via EMG and ultrasound. The system was able to induce the desired direction of muscle activity change but with limited precision. EMG measurement appeared susceptible to error due to crosstalk in the forearm.
Simplicity Does Not Always Lead to Enlightenment: A Critical Commentary on “Adaptation Processes Affecting Performance in Elite Sport”
Authors: Tamminen Katherine A. , Crocker Peter R.E.
Published: March 2014

This paper is a critical commentary on the article “Adaptation Processes Affecting Performance in Elite Sport” (Schinke, Battochio, Lidor, Tenenbaum, Dube, & Lane, 2012). We review relevant literature and highlight theoretical and conceptual concerns regarding Schinke et al.’s model, particularly regarding their characterization of adaptation as a process versus an outcome, and the role of appraisals, emotions, emotional regulation, coping, and Fiske’s (2004) core motives within their model of adaptation. Adaptation or adjustment among elite athletes is a valuable area of research in sport psychology; however, Schinke et al.’s model oversimplifies the adaptation process and has limited utility among sport psychology researchers and practitioners.
Adaptation Revisited: An Invitation to Dialogue
Authors: Schinke Robert J. , Tenenbaum Gershon , Lidor Ronnie , Lane Andrew M.
Published: March 2014

Within this opportunity to dialogue in commentary exchange about a previously conceived adaptation model, published in the Journal of Clinical Sport Psychology, we revisit the utility of our model (Schinke et al., 2012a) and consider Tamminen and Crocker’s (2014) critique of our earlier writing. We also elaborate on emotion and emotion regulation through explaining hedonistic and instrumental motives to regulate emotions. We draw on research from general and sport psychology to examine emotion regulation (Gross, 2010). We argue that when investigating emotion, or any topic in psychology, the process of drawing from knowledge in a different area of the discipline can be useful, especially if the existing knowledge base in that area is already well developed. In particular, we draw on research using an evolutionary perspective (Nesse & Ellsworth, 2009). Accounting for these issues, we clarify the adaptation framework, expand it, and arguably offer a model that has greater utility for use with athletes in relation to training and competition cycles and progressions throughout their career. We also clarify for the readership places of misinterpretation by the commentary authors, and perhaps, why these have resulted.
Serodiagnosis as Adjunct Assay for Pertussis Infection in São Paulo, Brazil
Authors: Vaz-de-Lima Lourdes R. A. , Martin Monte D. , Pawloski Lucia C. , Leite Daniela , Rocha Karen C. P. , de Brito Cyro A. , Vaz Tânia M. I. , Martins Luciano Moura , Alvarenga Danielly P. , Ribeiro Ana F. , Carvalhanas Telma R. M. P. , Nakasaki Rosa M. D. , Oliveira Silvia S. , Waldman Eliseu A. , Tondella Maria Lucia
Published: March 2014

Pertussis remains an important public health problem in many countries despite extensive immunization. Cultures and real-time PCR (RT-PCR) assays are the recommended pertussis diagnostic tests, but they lack sensitivity at the later stage of the disease. This study introduces the IgG anti-pertussis toxin enzyme-linked immunosorbent assay (PT ELISA) in our routine diagnosis to improve disease burden estimation. Serum samples and nasopharyngeal swabs (n= 503) were collected at the same time from patients presenting with cough illness suspected of being pertussis and tested by the PT ELISA and culture and/or RT-PCR, respectively. Patients were separated into three age groups: group 1, <1 year (n= 260; mean age, 3 months), group 2, 1 to 6 years (n= 81; mean age, 3 years), and group 3, ≥7 years (n= 162; mean age, 26 years). The times (means) from cough onset to specimen collection were 16, 24, and 26 days, respectively. In group 1, 83 (82.2%) of 101 positive cases were positive for pertussis by culture/RT-PCR, while 40 (39.6%) tested positive by PT ELISA. In group 2, 6 (19.4%) of 31 positive cases were culture/RT-PCR positive, and 29 (93.6%) were seropositive. In group 3, 13 (13.8%) of 94 positive cases were positive by culture/RT-PCR and 91 (96.8%) were positive by serology. Culture/RT-PCR detected more cases of pertussis in infants (P< 0.0001), whereas the PT ELISA detected more cases in adolescents and adults (P< 0.0001). The timing between cough onset and specimen collection or recent vaccination may have partially affected our results. Serology is a suitable, cost-effective, and complementary pertussis diagnostic tool, especially among older children, adolescents, and adults during the later disease phase.
Outer Ear Canal Infection with Rhabditis sp. Nematodes in a Human
Authors: Teschner Magnus , Würfel Waldemar , Sedlacek Ludwig , Suerbaum Sebastian , Tappe Dennis , Hornef Mathias Walter
Published: March 2014

Here we report the first human case of an outer ear canal infection with a free-living nematode of the genus
Rhabditis
. Otomicroscopy revealed viable worms in the outer ear canal of a patient suffering from chronic otorrhea and hearing loss. The nematode was identified by microscopy and internal transcribed spacer (ITS)-PCR.
Propionibacterium acnes and Staphylococcus lugdunensis Cause Pyogenic Osteomyelitis in an Intramedullary Nail Model in Rabbits
Authors: Gahukamble Abhay Deodas , McDowell Andrew , Post Virginia , Salavarrieta Varela Julian , Rochford Edward Thomas James , Richards Robert Geoff , Patrick Sheila , Moriarty Thomas Fintan
Published: March 2014

Propionibacterium acnes
and coagulase-negative staphylococci (CoNS) are opportunistic pathogens implicated in prosthetic joint and fracture fixation device-related infections. The purpose of this study was to determine whether
P. acnes
and the CoNS species
Staphylococcus lugdunensis
, isolated from an “aseptically failed” prosthetic hip joint and a united intramedullary nail-fixed tibial fracture, respectively, could cause osteomyelitis in an established implant-related osteomyelitis model in rabbits in the absence of wear debris from the implant material. The histological features of
P. acnes
infection in the
in vivo
rabbit model were consistent with localized pyogenic osteomyelitis, and a biofilm was present on all explanted intramedullary (IM) nails. The animals displayed no outward signs of infection, such as swelling, lameness, weight loss, or elevated white blood cell count. In contrast, infection with
S. lugdunensis
resulted in histological features consistent with both pyogenic osteomyelitis and septic arthritis, and all
S. lugdunensis
-infected animals displayed weight loss and an elevated white blood cell count despite biofilm detection in only two out of six rabbits. The differences in the histological and bacteriological profiles of the two species in this rabbit model of infection are reflective of their different clinical presentations: low-grade infection in the case of
P. acnes
and acute infection for
S. lugdunensis
. These results are especially important in light of the growing recognition of chronic
P. acnes
biofilm infections in prosthetic joint failure and nonunion of fracture fixations, which may be currently reported as “aseptic” failure.
Adenovirus E1A Recruits the Human Paf1 Complex To Enhance Transcriptional Elongation
Authors: Fonseca Gregory J. , Cohen Michael J. , Mymryk Joe S.
Published: March 2014

During infection by human adenovirus (HAdV), the proteins encoded by the early region 1A (E1A) gene bind and appropriate components of the cellular transcriptional machinery to activate the transcription of viral early genes. Previously, we identified roles for the human Bre1 (hBre1) and hPaf1 complexes in E1A-mediated transcriptional activation of HAdV early genes. Here we show that E1A binds hBre1 directly and that this complex targets the hPaf1 complex via the Rtf1 subunit. Depletion of hPaf1 reduces E1A-dependent activation of transcription from the E2e, E3, and E4 viral transcription units, and this does not result from a reduced ability of RNA polymerase II to be recruited to the promoter-proximal regions of these genes. In contrast, depletion of hPaf1 reduces the occupancy of RNA polymerase II across these transcription units. This is accompanied by reductions in the level of H3K36 trimethylation, a posttranslational histone modification associated with efficient transcriptional elongation, and the number of full-length transcripts from these genes. Together, these results indicate that E1A uses hBre1 to recruit the hPaf1 complex in order to optimally activate viral early transcription by enhancing transcriptional elongation.

IMPORTANCE
This work provides the mechanism by which the hPaf1 complex contributes to E1A-dependent activation of early gene transcription. The work also demonstrates that E1A induces gene expression by stimulating transcriptional elongation, in addition to its better-characterized effects on transcriptional initiation.
Novel Permissive Cell Lines for Complete Propagation of Hepatitis C Virus
Authors: Shiokawa Mai , Fukuhara Takasuke , Ono Chikako , Yamamoto Satomi , Okamoto Toru , Watanabe Noriyuki , Wakita Takaji , Matsuura Yoshiharu
Published: March 2014

Hepatitis C virus (HCV) is a major etiologic agent of chronic liver diseases. Although the HCV life cycle has been clarified by studying laboratory strains of HCV derived from the genotype 2a JFH-1 strain (cell culture-adapted HCV [HCVcc]), the mechanisms of particle formation have not been elucidated. Recently, we showed that exogenous expression of a liver-specific microRNA, miR-122, in nonhepatic cell lines facilitates efficient replication but not particle production of HCVcc, suggesting that liver-specific host factors are required for infectious particle formation. In this study, we screened human cancer cell lines for expression of the liver-specific α-fetoprotein by using a cDNA array database and identified liver-derived JHH-4 cells and stomach-derived FU97 cells, which express liver-specific host factors comparable to Huh7 cells. These cell lines permit not only replication of HCV RNA but also particle formation upon infection with HCVcc, suggesting that hepatic differentiation participates in the expression of liver-specific host factors required for HCV propagation. HCV inhibitors targeting host and viral factors exhibited different antiviral efficacies between Huh7 and FU97 cells. Furthermore, FU97 cells exhibited higher susceptibility for propagation of HCVcc derived from the JFH-2 strain than Huh7 cells. These results suggest that hepatic differentiation participates in the expression of liver-specific host factors required for complete propagation of HCV.

IMPORTANCE
Previous studies have shown that liver-specific host factors are required for efficient replication of HCV RNA and formation of infectious particles. In this study, we screened human cancer cell lines for expression of the liver-specific α-fetoprotein by using a cDNA array database and identified novel permissive cell lines for complete propagation of HCVcc without any artificial manipulation. In particular, gastric cancer-derived FU97 cells exhibited a much higher susceptibility to HCVcc/JFH-2 infection than observed in Huh7 cells, suggesting that FU97 cells would be useful for further investigation of the HCV life cycle, as well as the development of therapeutic agents for chronic hepatitis C.
Hint of Lyme, an uncommon cause of syncope
Authors: Manek Megha , Kulkarni Abhishek , Viera Anthony
Published: March 2014

A 20-year-old Caucasian male patient presented after a single episode of syncope. His heart rate was 40 beats per minute. ECG showed new onset complete heart block. A temporary pacer was placed. He had a macular rash on the body from past 2 weeks and was diagnosed with contact dermatitis. Erythema migrans was considered as differential for rash. Lyme titre was ordered and found to be positive. After antibiotic therapy and observation on telemetry, his heart block resolved. He was subsequently discharged and a follow-up ECG revealed persistent normal sinus rhythm.
Intra-articular osteoid osteoma of the distal humerus: a diagnostic challenge
Authors: Challawar Nikhil Subhash , Shah Hitesh Hasmukhlal
Published: March 2014

Osteoid osteoma rarely presents in an intra-articular or juxta-articular location, leading to synovitis and flexion deformity, which can easily mislead the diagnosis. We present a case of an intra-articular osteoid osteoma of the distal humerus in a 19-year-old woman with pain and flexion deformity of the elbow. Although radiographs were normal, a nidus was demonstrated on CT scan. Appropriate surgical treatment provided relief to the patient and the diagnosis was confirmed on histopathology. Thus, an intra-articular osteoid osteoma may be mistaken for more common causes of synovitis unless there is an index of suspicion and appropriate imaging is undertaken.
Steroids In caRdiac Surgery (SIRS) trial: acute kidney injury substudy protocol of an international randomised controlled trial
Authors: Garg Amit X , Vincent Jessica , Cuerden Meaghan , Parikh Chirag , Devereaux P J , Teoh Kevin , Yusuf Salim , Hildebrand Ainslie , Lamy Andre , Zuo Yunxia , Sessler Daniel I , Shah Pallav , Abbasi Seyed Hesameddin , Quantz Mackenzie , Yared Jean-Pierre , Noiseux Nicolas , Tagarakis Georgios , Rochon Antoine , Pogue Janice , Walsh Michael , Chan Matthew T V , Lamontagne Francois , Salehiomran Abbas , Whitlock Richard ,   on behalf of the SIRS Investigators
Published: March 2014

Introduction

Steroids In caRdiac Surgery trial (SIRS) is a large international randomised controlled trial of methylprednisolone or placebo in patients undergoing cardiac surgery with the use of a cardiopulmonary bypass pump. At the time of surgery, compared with placebo, methylprednisolone divided into two intravenous doses of 250 mg each may reduce the risk of postoperative acute kidney injury (AKI).

Methods and analysis

With respect to the study schedule, over 7000 substudy eligible patients from 81 centres in 18 countries were randomised in December 2013. The authors will use a logistic regression to estimate the adjusted OR of methylprednisolone versus placebo on the primary outcome of AKI in the 14 days following surgery (a postoperative increase in serum creatinine of ≥50%, or ≥26.5 μmol/L, from the preoperative value). The stage of AKI will also be considered, as will the outcome of AKI in those with and without preoperative chronic kidney disease. After receipt of grant funding, the authors began to record additional perioperative serum creatinine measurements in consecutive patients enrolled at substudy participating centres, and patients were invited to enroll in a 6-month serum creatinine collection. In these trial subpopulations, the authors will consider the outcome of AKI defined in alternate ways, and the outcome of a 6-month change in kidney function from the preoperative value.

Ethics and dissemination

The authors were competitively awarded a grant from the Canadian Institutes of Health Research for this SIRS AKI substudy. Ethics approval was obtained for additional serum creatinine recordings in consecutive patients enrolled at participating centres. The additional kidney data collection first began for patients enrolled after 1 March 2012. In patients who provided consent, the last 6-month kidney outcome data will be collected in 2014. The results will be reported no later than 2015.

Clinical Trial Registration

NumberNCT00427388.
Management and treatment of feline tarsal injuries
Authors: Kulendra Elvin , Arthurs Gareth
Published: March 2014

Feline tarsal injuries are common, particularly in male cats, and can result from dog bites, road traffic accidents or falls from heights. Complete physical and orthopaedic examinations are required to reliably identify all injuries in these cases, but life‐threatening injuries must take precedence over orthopaedic trauma. This article discusses the management and treatment of injuries to the feline tarsus.
P1DSOM — A FAST SEARCH ALGORITHM FOR HIGH-DIMENSIONAL FEATURE SPACE PROBLEMS
Authors: SAGHEER ALAA , TSURUTA NAYOUKI , TANIGUCHI RIN-ICHIRO
Published: March 2014

The self-organizing map (SOM) is a traditional neural network algorithm used to achieve feature extraction, clustering, visualization and data exploration. However, it is known that the computational cost of the traditional SOM, used to search for the winner neuron, is expensive especially in case of treating high-dimensional data. In this paper, we propose a novel hierarchical SOM search algorithm which significantly reduces the expensive computational cost associated with traditional SOM. It is shown here that the computational cost of the proposed approach, compared to traditional SOM, to search for the winner neuron is reduced into O(D1 + D2 + ⋯ + DN) instead of O(D1 × D2 × ⋯ × DN), where Dj is the number of neurons through a dimension dj of the feature map. At the same time, the new algorithm maintains all merits and qualities of the traditional SOM. Experimental results show that the proposed algorithm is a good alternate to traditional SOM, especially, in high-dimensional feature space problems.