bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitating the lateral skin stiffness by a new and versatile electro‐mechanical instrument. Preliminary studies
Authors: Nomura M. , Velleman D. , Pierre J. , Flament F.
Published: November 2016

Background

A new electro‐mechanical device for measuring the lateral stiffness of the skin is now available. It basically allows to recording the forces that the skin opposes to a lateral displacement (1–2 mm) of a pinching type movement. Preliminary assays of this device to various skin sites and an artificial substrate aimed at defining its major characteristics (sensitivity, reproducibility, variations according to skin site).

Methods

The calibration of the device (Khelometer®) and assessment of its reproducibility were carried out through the use of elastometer substrates of various stiffness's. The device was then used,in vivo, at different skin sites (scalp, inner and outer forearms, cheeks) of 213 healthy Japanese women of various ages. The short‐time effect of a hydrating regimen (7% glycerol) was recorded on the outer forearm.

Results

This new device offers an appreciable reproducibilityin vitroandin vivo(coefficient of variation of 2–4% and 5–14%, respectively). Unlike other biophysical methods, the Khelometer®can be easily applied onto the human scalp that shows a higher stiffness than the two other skin sites, increasing with age and presence of alopecia. In all the three studied skin sites, the impact of age leads to significantly higher lateral skin stiffness (LSS, expressed as N/mm) values. The latter were found significantly different between the two sides of the forearms where the outer (sun‐exposed) side showed statistically slightly higherLSS, than the unexposed inner side.LSSvalues found on cheeks (≈0.5 N/mm) were about four times lower than those of the scalp (≈2 N/mm) and about half those of forearms (≈1 N/mm). The effect of a 7% glycerol based formula was recorded 20 min post application onto the forearm, leading to a slight drop inLSS(approx. 15%) as compared to a vehicle‐applied skin site.

Conclusion

These preliminary studies clearly indicate that this new device, applicable to any skin site, offers appreciable assets such as sensitivity and reproducibility. Accordingly, it appears as a new approach in the non‐invasive biophysical measurements of the skin surface, in both advanced and applied research investigations.
Researching Authoritarianism in the Discipline of Democracy*
Authors: Ahram Ariel I. , Goode J. Paul
Published: November 2016

Object

This article examines the ways social science research approaches the study of authoritarian regimes and identifies ways to engage with regimes that are both deliberately opaque and oppressive.

Method

The article examines existing methodological prescriptions and practices as they pertain to the study of authoritarian regimes. These cover issues of data collection, research safety, subjective safety, and the positioning of knowledge about authoritarianism within the wider scope of social sciences.

Results

The article identifies three distinct but interrelated challenges in the study of authoritarian regimes: (1) access and timing, (2) data validity and integrity, and (3) ethical issues.

Conclusion

Methods commonly deployed in the study of democratic and open regimes cannot be readily deployed to the study of authoritarian ones. Greater reflexivity is needed to understand the methodological challenges inherent to the study of authoritarianism.
Eyes Wide Shut: Democratic Reversals, Scientific Closure, and the Study of Politics in Eurasia*
Authors: Goode J. Paul
Published: November 2016

Objectives

The article examines the relationship between democratic reversals and scientific closure. It focuses on the effects that authoritarian and hybrid regimes are likely to have on the ways scholars study them and conduct their fieldwork.

Method

Thematic content analysis of articles on Eurasian politics published over a 10‐year period, with particular attention paid to reported methods and fieldwork.

Results

Scientific closure had as much to do with research cycles in the discipline as with democratic reversals. Notions of the region as democratizing persisted into the 2000s as scholars recycled data and conceptual frames from the 1990s. Fieldwork‐driven research was more likely to detect autocratization.

Conclusion

While disciplinary consensus reframed the region as autocratizing, the field remains vulnerable to scientific closure. Aside from the challenges posed by autocracies for fieldwork, the new disciplinary consensus may deter qualitative fieldwork and innovation in studying authoritarianism in Eurasia.
Differential response at the seafloor during Palaeocene and Eocene ocean warming events at Walvis Ridge, Atlantic Ocean (ODP Site 1262)
Authors: Deprez Arne , Jehle Sofie , Bornemann André , Speijer Robert P.
Published: November 2016

The Latest Danian Event (LDE, c. 62.1 Ma) is an early Palaeogene hyperthermal or transient (<200 ka) ocean warming event. We present the first deep‐sea benthic foraminiferal faunal record to study deep‐sea biotic changes together with new benthic (Nuttallides truempyi) stable isotope data from Walvis Ridge Site 1262 (Atlantic Ocean) to evaluate whether the LDE was controlled by similar processes as the minor early Eocene hyperthermals. The spacing of the double negative δ13C and δ18O excursion and the slope of the δ18O–δ13C regression are comparable, strongly suggesting a similar orbital control and pacing of eccentricity maxima as well as a rather homogeneous carbon pool. However, in contrast to early Eocene hyperthermals, the LDE exhibits a remarkable stability of the benthic foraminiferal fauna. This lack of benthic response could be related to the absence of threshold‐related circulation changes or better pre‐adaptation to elevated deep‐sea temperatures, as the LDE was superimposed on a cooling trend, in contrast to early Eocene warming.
New soliton solutions of the system of equations for the ion sound and Langmuir waves
Authors: Tuluce Demiray Seyma , Bulut Hasan
Published: November 2016

This study is based on new soliton solutions of the system of equations for the ion sound wave under the action of the ponderomotive force due to high-frequency field and for the Langmuir wave. The generalized Kudryashov method (GKM), which is one of the analytical methods, has been tackled for finding exact solutions of the system of equations for the ion sound wave and the Langmuir wave. By using this method, dark soliton solutions of this system of equations have been obtained. Also, by using Mathematica Release 9, some graphical simulations were designed to see the behavior of these solutions.
How and why are calcium currents curtailed in the skeletal muscle voltage‐gated calcium channels?
Authors: Flucher Bernhard E. , Tuluc Petronel
Published: November 2016

Voltage‐gated calcium channels represent the sole mechanism converting electrical signals of excitable cells into cellular functions such as contraction, secretion and gene regulation. Specific voltage‐sensing domains detect changes in membrane potential and control channel gating. Calcium ions entering through the channel function as second messengers regulating cell functions, with the exception of skeletal muscle, where CaV1.1 essentially does not function as a channel but activates calcium release from intracellular stores. It has long been known that calcium currents are dispensable for skeletal muscle contraction. However, the questions as to how and why the channel function of CaV1.1 is curtailed remained obscure until the recent discovery of a developmental CaV1.1 splice variant with normal channel functions. This discovery provided new means to study the molecular mechanisms regulating the channel gating and led to the understanding that in skeletal muscle, calcium currents need to be restricted to allow proper regulation of fibre type specification and to prevent mitochondrial damage.

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Closed-Loop Pressure Feedback Control of a Pressure-Driven Microdroplet Generator
Authors: Zeng Wen , Fu Hai , Li Songjing
Published: November 2016

To predict the size of droplets formed by pressure-driven flows, the droplet size as a nonlinear function of the pressure ratio is measured experimentally. The mathematical model of the pressure-driven microfluidic device is established, and by varying the volume of a container, comparative and quantitative measurements of the response speed and control accuracy of pressure-driven flows are presented. In particular, a closed-loop control system with feedback of the driven pressure is demonstrated, and the deviation between the measured and the predicted value of the driven pressure can be eliminated by using a PI controller. As a result, by accurately controlling the driven pressure of pressure-driven flows, monodisperse droplets with a desired size can be formed for pressure-driven microdroplet generators.
Suppression of High Frequency Oscillations on Suspension System of Snow Groomer With Evolutionary Algorithms Optimization
Authors: Marani Pietro , Ferrari Cristian
Published: November 2016

In current engineering practice for the design and dimensioning of hydropneumatic suspension systems, the effect of main parameters is considered; this approach can be used to implement approximate models basically suitable to describe low frequency and high amplitude oscillations of the machine.

The target of this study is a Snow Groomer, a tracked vehicle driven by diesel engines and equipped in front with a shovel and behind with a cutter. When the machine drives over a snowfield, it pushes snow ahead of it and, at the same time, smooths out any surface unevenness.

The suspension system is the key element to ensure the driver’s safety and comfort, the effectiveness of snow grooming and finally enhance the reliability of the machine components. The on-field testing had shown high frequency pressure oscillations transmitted from the sprocket to hydraulic system, propagated through the flexible hoses. Those Pressure Oscillations cause noise and can affect negatively the durability and reliability of the Machine. A lumped parameter non-linear dynamic model of the hydraulic circuit and of the machine interactions is built in Amesim environment, including Lax Wendroff wave propagation models, to make it able to catch the high frequency oscillations experienced in the test field.

Most of the design parameters are fixed (such as vehicle weight and hydraulic lines length), other parameters can be varied to study the optimal solution, these parameters define the “factors” of the optimization problem.

As a next step it is important to define the objectives of the optimization, in this case corresponding to various figures of merit describing the behavior of the system in different work conditions. The large number of factors included in the lumped parameter model generates an exponentially larger number of possible configurations. Moreover the relationship between factors and objective is not always possible to express with explicit mathematical models. Finally the presence of multiple and sometimes conflicting objectives forces more refined analysis methods to be adopted.

For the above mentioned reasons a Multi-objective Optimization method is proposed taking advantage of Evolutionary Algorithms and Pareto Front optimization. Two different architectural solutions are analyzed and optimized using two different algorithms, Non Sorting Genetic Algorithm II (NSGAII) and Multiple Object Swarm Particle Optimization Algorithm (MOPSO).

The results of the optimization belonging to the Pareto Front will be analyzed to assess the expected improvement of the suspension performance and will be chosen as candidates for a new setting of the Snow Groomer. Furthermore a comparison in terms of effectiveness and speed in finding solutions will be given for the current simulation environment.
LQR Feedback Control Development for Wind Turbines Featuring a Digital Fluid Power Transmission System
Authors: Pedersen Niels H. , Johansen Per , Andersen Torben O.
Published: November 2016

Research within digital fluid power (DFP) transmissions is receiving an increased attention as an alternative to conventional transmission technologies. The use of DFP displacement machines entails a need for applicable control algorithms. However, the design and analysis of controllers for such digital systems are complicated by its non-smooth behavior. In this paper a control design approach for a digital displacement machine® is proposed and a performance analysis of a wind turbine using a DFP transmission is presented. The performance evaluation is based on a dynamic model of the transmission with a DFP motor, which has been combined with the NREL 5-MW reference wind turbine model. A classical variable speed control strategy for wind speeds below rated is proposed for the turbine, where the pump displacement is fixed and the digital motor displacement is varied for pressure control. The digital motor control strategy consists of a full stroke operation strategy, where a Delta-Sigma pulse density modulator is used to determine the chamber activation sequence. In the LQR-control design approach, the discrete behavior of the motor and Delta-Sigma modulator is described by a discrete linear time invariant model. Using full-field flow wind profiles as input, the design approach and control performance is verified by simulation in the dynamic model of the wind turbine featuring the DFP transmission. Additionally, the performance is compared to that of the conventional NREL reference turbine, transmission and controller.
Active Pneumatic Vibration Isolator With Pressure Feedback
Authors: Makaryants Georgy M. , Kosenkov Peter , Sverbilov Victor
Published: November 2016

This paper presents research on effectiveness of P-control algorithm with a pressure as an output signal for an active vibration isolator using pneumatic bellow. Pressure pulsation inside the pneumatic element of the vibration isolator is studied in the frequency range covering its sub resonant and resonant frequencies. Spectral analysis is used to compare the response to harmonic excitation of active pneumatic vibration isolator and that for the case with active control disabled. The minimal bore size of the control valve is defined to achieve a double advantage of the active system over the passive one in the frequency range including the vibration isolator resonant frequency. It is shown that to obtain this result, a fast-acting spool valve should be used. Moreover, at a low frequency range of a Hertz-level excitation signal, P-control algorithm demonstrates three times decrease of pressure pulsation amplitude. The analysis of experimental results shows that P-control algorithm with pressure output and the high response spool valve with the bore size as large as possible can be used for active pneumatic vibration isolator at the low frequency range.
Control of an Electrohydraulic Stewart Platform Manipulator as Vessels Motion Simulator
Authors: Manuel Lebrón García Rodrigo , Tumelero Valente Vítor , Sobczyk Mário Roland , Perondi Eduardo André
Published: November 2016

This work considers the use of Stewart Platforms with hydraulic actuators as a tool for developing motion control algorithms in open-sea applications, such as cargo transfers between ships and floating platforms, whose main goal is to attenuate the undesired relative oscillations caused by waves and tides. The Stewart Platform is one of the most representative examples of parallel manipulators, comprising two parallel bases connected by six linear actuators. The coordinated movement of these actuators allows both bases to have relative motions with six degrees of freedom, with superior precision and load/weight ratios when compared to serial manipulators. In this context, this work is motivated by the ongoing development of two coupled hydraulically driven Stewart Platforms. The first one is intended to emulate the movement of a ship deck under the influence of sea waves, while the second one, positioned on top of the first, will be used as a compensation device for controlling the motion imposed by the first one. This paper focuses on describing the design considerations of the lower platform. In the first part of the paper, we describe the main features of this research project. Then, we focus on its current development stage, which regards the mathematical modeling of the first platform and the design of its corresponding control algorithm. The proposed controller takes into consideration the manipulator’s mechanical and the actuators’ hydraulic dynamics, using the computed-torque control approach [9,10]. Lyapunov theory is used to guarantee the closed loop stability of the system. The control performance is verified by means of computer simulations results, which indicate that the proposed strategy yields good performance in leading the first platform to emulate a large range of motions that are compatible with vessel heave movements.
A Hybrid Feedback Linearization and Neural Network Control Algorithm Applied to a Hydraulic Actuator
Authors: Borges Fabio A. P. , Perondi Eduardo André , Cunha Mauro A. B. , Sobczyk Mario R.
Published: November 2016

This paper report a research investigation that proposes to replace the inversion set present in the traditional feedback linearization approach by an artificial neural network resulting in a hybrid composition approach with a neural network and an analytical term. The method is applied into a hydraulic actuator position system together with a friction compensation approach also built using neural networks. The control strategy used is based on a cascade methodology that consists of interpreting the hydraulic positioning system model as two interconnected subsystems: a mechanical subsystem driven by a hydraulic one. As experimental results have indicated a significant system behavior dependence on the oil temperature, its effects are also studied and the proposed method was improved by the inclusion of the oil temperature information as an input for the neural network functions. Experimental results show the effectiveness of the proposed controller and their advantages when compared with the traditional analytical schemes with feedback linearization approaches.
Heuristic Control Strategy of a Novel Hydraulic/Pneumatic Concept of Regenerative System for Commercial Hybrid Vehicles
Authors: da Silva Bravo Rafael Rivelino , De Negri Victor Juliano , de Oliveira Junior Amir Antônio Martins
Published: November 2016

In this paper, the operational conditions of a new hydraulic/pneumatic system conception for medium and heavy-duty vehicles are evaluated. The design comprises a hydraulic system, coupled to a pneumatic system, with ability to recover braking energy in driving cycles characterized by frequent stop-and-go, and also on highways with small inclinations. In order to evaluate the potential of the hybrid system, the vehicle is subjected to a driving cycle, whose route is comprised in part by a road in the horizontal plane, and in part by a road with slope. A heuristic control strategy is presented, whose approach is based on a mathematical model built in platform-MATLAB/SIMULINK and supported by maps of performance and efficiency and physical parameters of the components. The control strategy provides five operating modes for the vehicle in order to meet the different traffic conditions, in accordance with the driving cycle analyzed. As the trip occurs, is required the hybrid system supply the pneumatic auxiliaries of the vehicle employing the regenerated energy stored in the accumulators preferably, or the power generated from internal combustion engine when the accumulators are empty. The simulating results prove the effectiveness of the control strategy to command the hybrid system properly, as well as the ability of the vehicle to achieve the requirements of performance and maintaining a high overall efficiency of the engine.
Aspects of Parameter Sensitivity for Series Hydraulic Hybrid Light-Weight Duty Vehicle Design
Authors: Baer Katharina , Ericson Liselott , Krus Petter
Published: November 2016

Hybridization of a vehicle’s drivetrain can in principle help to improve its energy efficiency by allowing for recuperation of kinetic energy and modulating the engine’s load. How well this can be realized depends on appropriate sizing and control of the additional components. The system is typically designed sequentially, with the hardware setup preceding the development and tuning of advanced controller architectures. Taking an alternative approach, component sizing and controller tuning can be addressed simultaneously through simulation-based optimization.

The results of such optimizations, especially with standard algorithms with continuous design variable ranges, can however be difficult to realize, considering for example limitations in available components. Furthermore, drive-cycle based optimizations are prone to cycle-beating. This paper examines the results of such simulation-based optimization for a series hydraulic hybrid vehicle in terms of sensitivity to variations in design parameters, system parameters and drive cycle variations. Additional relevant aspects concerning the definition of the optimization problem are pointed out.
Methods for Measuring the Life of the MFC as Sensor and Actuator at High Temperature
Authors: Pandey Akash , Arunachalakasi Arockiarajan
Published: November 2016

Macro fiber Composite (MFC) having various applications in active control, vibration control and transducers are subjected to high temperature and continuous loading (mechanical or electrical), which leads to the deterioration in its sensing and actuating properties. Hence, the fatigue study is important. For studying deterioration in the sensing performance, experiments were performed using 4 point bending setup, with MFC pasted on the steel beam in the area of constant stress. When compared to the room temperature, experimental observation shows that MFC exhibit much accelerated rate of degradation at 70° C. Similarly, degradation of actuation performance at high temperature (70° C) was studied using cantilever setup with MFC pasted at the top of the cantilever beam. The tip deflection was measured as the parameter to represent the actuation performance of MFC. Comparing experimental results for room temperature and 70° C, it was found that actuation fatigue life is not much affected at the higher temperature.
Finite Element Analysis of Electroactive Polymer and Magnetoactive Elastomer Based Actuation for Origami-Inspired Folding
Authors: Zhang Wei , Ahmed Saad , Masters Sarah , Ounaies Zoubeida , Frecker Mary
Published: November 2016

With the development of smart materials such as electroactive polymers and magnetoactive elastomers, active origami structures, where desired folded shapes can be achieved using external electric and magnetic stimuli, are showing promising potential in many engineering applications. In this study, finite element analysis (FEA) models are developed in 3-D using COMSOL Multiphysics software for unimorph bending and folding actuated using a single external field, and a bi-fold configuration which is actuated using multi-field stimuli. The objectives of the study are: 1) to investigate folding behavior and effects of geometric parameters, and 2) to maximize actuation for a given stimulus. Experimentally determined mechanical pressures and moments are applied as external loads to simulate electric and magnetic fields, respectively. Good agreement is obtained in the tip displacement and folding angles between the simulation and experiments, which demonstrates the effectiveness of the FEA model.
Sound Transmission Loss of Adaptive Sandwich Panels Treated With MR Fluid Core Layer
Authors: Hemmatian Masoud , Sedaghati Ramin
Published: November 2016

This study aims to investigate the sound transmission loss (STL) capability of sandwich panels treated with Magnetorheological (MR) fluids at low frequencies. An experimental setup has been designed to investigate the effect of the intensity of the applied magnetic field on the natural frequencies and STL of a clamped circular plate. A multilayered uniform circular panel comprising two elastic face sheets and MR fluid core layer is fabricated. It is shown that as the applied magnetic field increases, the fundamental natural frequency of the MR sandwich panel increases. Moreover, the STL of the panel at the resonance frequency considerably increases under applied magnetic field. Furthermore, an analytical model for the STL of the finite multilayered panels with MR core layer is developed and compared with the experimental measurements. The MR core layer is treated as a viscoelastic material with complex shear modulus. It is shown that good agreement exists between the analytical and experimental results. Parametric study has also been conducted to investigate the effect of face sheets and core layers’ thickness.
A Single Fiber Bragg Grating Sensor for the Simultaneous Measurement of Strain and Temperature
Authors: Singh Abhay K. , Huang Haiying , Zhu Yupeng , Han Ming
Published: November 2016

In this paper, we have introduced the bandwidth of a Tilted Fiber Bragg Grating (TFBG) as a measurand and combine it with the central Bragg wavelength to address its cross-sensitivity with temperature and strain. We have developed a method for coating the TFBG with a thermochromic material and characterized the coated TFBG sensor under temperature and strain variations. We observed that the spectral bandwidth is sensitive only to the temperature change while the central Bragg wavelength is sensitive to both the strain and temperature. Therefore, we can measure the temperature from the TFBG bandwidth alone and measure the strain from the TFBG central wavelength after compensating for temperature induced wavelength change.
The Application Potentials of Shape Memory Alloys in Hand Tools
Authors: Langbein Sven , Czechowicz Alexander , Zobel Frank , Dültgen Peter
Published: November 2016

Shape memory alloys show remarkable potentials as actuators and elastic elements. Due to their compact design smallest actuators with multifunctional properties can be implemented in small installation space, even in hand tools. The publication focuses on a comparison between technical SMA specifications and future perspectives regarding hand tools and portable automated tool systems. Within this publication two examples of innovative systems are discussed: A haptic information feedback system based on SMA wires implemented in handles for communication between user and tool is presented as well as an automated installation ring opener.
The Effect of Transmembrane Potential on the Gating of MscL Channels in Droplet Interface Bilayers
Authors: Najem Joseph S. , Sukharev Sergei , Leo Donald J.
Published: November 2016

The ability to functionalize droplet interface bilayers (DIBs) with the MscL channel and its mutants has been demonstrated. In previous work, the V23T gain of function mutant of MscL produced consistent activation when harmonic axial compressions were applied to the aqueous droplets supporting the lipid bilayer, where the channels settle. The deformation of the droplets results, at maximum compression, in an increase in surface area, and thus an increase in tension at the water-lipid-oil interface. This increase in monolayer tension was found to be the product of the relative change in surface area of each of the droplets and the compressibility modulus of the DPhPC monolayer (∼120 mN/m). The tension increase at the water-lipid-oil interface almost doubles to make up the increase in tension in the bilayer interface, resulting in activation of the incorporated MscL channels. However, it was found that the application of a relatively high transmembrane potential (∼100 mV), from an external power source, is a requirement for the activation of the V23T-MscL channels. Here, we investigate and analyze the impact of transmembrane potential on the activity of MscL channels in both a droplet interface bilayer system and E. coli spheroplast via patch-clamp. We demonstrate that the channels became more susceptible to gating upon the application of a negative potential, compared to when a positive potential is applied, proving their sensitivity to voltage polarity.
Electromechanical Behavior and Microstructure of Highly Sensitive Polyaniline/Ethylene Vinyl Acetate Composite Piezo-Resistive Materials
Authors: Polpaya Indu Chanchal , Rao C. Lakshmana , Varughese Susy
Published: November 2016

The unique micro/nano-structure of an intrinsically conducting polymer can be tuned to get higher gauge factors (GF) and reliability, which make them better materials for piezo-resistive applications than conducting carbon based composites and metallic composites. This work reports a highly sensitive conducting polyaniline (PANI)-based composite film that showed a GF ∼66. This high GF was achieved by forming a particular microstructure of conducting PANI particles in a free standing film of PANI-DBSA/EVA. The paper also attempts to explain the mechanism for the observed high sensitivity using the electronic percolation theory, shape and size of the conducting particles and the changes in the microstructure, due to strain. The high sensitivity, high stability during cyclic loading and low electrical hysteresis together with high mechanical strength make PANI-DBSA/EVA conducting composite film a promising material for piezo-resistive strain sensing applications.
Active Sensing and Damage Classification for Wave Energy Converter Structural Composites
Authors: Farinholt Kevin , Desrosiers Michael , Kim Mark , Friedersdorf Fritz , Adams Stephen , Beling Peter
Published: November 2016

Ocean resources have the potential to provide a large source of renewable energy for communities around the globe. Technologies such as wave energy converters must be designed to operate remotely in harsh environmental conditions. These structures are exposed to widely varying structural loads, and there is interest in developing monitoring systems that can identify the presence of damage, estimate its severity, and provide maintenance or control recommendations that could protect the system from failure. The research presented in this paper focuses on using the electromechanical impedance response of piezoelectric transducers to monitor the health of composite materials similar to those used in the fabrication of several wave energy converters. Techniques have been developed to detect and classify discrete damage events such as holes and slots within composite plates, as well as fatigue damage that evolves due to manufacturing flaws such as delamination and laminate waves. Using data collected over a frequency range of 100 Hz to 100 kHz, a series of genetic algorithms and statistical modeling techniques were used to classify damage type and severity. Plate studies with discrete damage (holes, notches) provided a large dataset of 113 observations comprised of seven distinct classes, one baseline and six damage severities. Random forest techniques were used to classify this population, with accuracies of 93.4% obtained. Fatigue studies of rectangular composite beams containing manufacturing defects (delamination, laminate waves), produced a measurement population of 14 instances comprised of six distinct classes. Framing this problem as the time evolution of damage due to fatigue loads allowed the use of hidden Markov models to differentiate the type of manufacturing flaw present, with results indicating 85.7% accuracy given this limited dataset.
Dynamic Model of Tendon-Driven Robotic Chains Forming a Shape-Shifting Surface
Authors: Lasagni Matteo , Römer Kay
Published: November 2016

This paper presents Kinematics and Dynamics of a Shape-Shifting Surface, a robotic system able to take on the shape of arbitrary connected 3D surfaces. Such a surface, which we introduced and described in previous work, consists of piecewise controllable chains in turn composed of serially connected foldable “robotic particles”. Aiming at a high resolution rendering, where tiny particles need to be combined in a large number, a tendon-driven design is a lightweight and scalable solution.

However, improper actuation strategies might expose the system to undesired forces, which can compromise its integrity and stability. To tackle this problem, optimal actuation and planning strategies are required to anticipate unacceptable situations. To this end, a dynamic model is derived to predict the reaction of the system subject to control actions. Being the system both tendon-driven and under-actuated, we have to overcome a number of challenges in deriving this model.
Electroelastic Bandgap Formation in Locally Resonant Metamaterial Beams With Piezoelectric Shunts: A Modal Analysis Approach
Authors: Sugino Christopher , Leadenham Stephen , Ruzzene Massimo , Erturk Alper
Published: November 2016

Metamaterials made from flexible structures with piezoelectric laminates connected to resonant shunt circuits can exhibit vibration attenuation properties similar to those of their purely mechanical locally resonant counterparts. Thus, in analogy to purely mechanical metamaterials, electroelastic metamaterials with piezoelectric resonators can exhibit vibration attenuation bandgaps. To enable the effective design of these locally resonant electroelastic metamaterials, the electromechanical behavior of the piezoelectric patches must be reconciled with the modal behavior of the electroelastic structure. To this end, we develop a novel argument for the formation of bandgaps in bimorph piezoelectric beams, relying on modal analysis and the assumption of infinitely many segmented shunted electrodes (unit cells) on continuous piezoelectric laminates bracketing a substrate. As a case study, the frequency limits of the locally resonant bandgap that forms from resonant shunting is derived, and a design guideline is presented to place the bandgap in a desired frequency range. This method can be easily extended to more general circuit impedances, and can be used to design shunt circuits to obtain a desired frequency response in the main structure.
Synchronized Switch Harvesting on Inductor Interface to Promote Piezoelectric Stack Energy Harvesting From Human Walking
Authors: Zhang Jinxiao , Liu Haili , Wang Ya
Published: November 2016

In this paper, a self-supported power conditioning circuit is developed for a footstep energy harvester, which consists of a monolithic multilayer piezoelectric stack with a force amplification frame to extract electricity from human walking locomotion. Based on a synchronized switch energy harvesting on inductance (SSHI) interface and a peak detector topology, the power conditioning circuit is designed to optimize the power flow from the piezoelectric stack to the energy storage device under real-time human walking excitation instead of a simple sine waveform input, as reported in most literatures. The unique properties of human walking locomotion and multilayer piezoelectric stack both impose complications for circuit design. Three common interface circuits, e.g. standard energy harvesting (SEH) circuit, series-SSHI and parallel-SSHI are compared in experiments to find which one is the best suit for the real-time-footstep energy harvester. Experimental results show that the use of parallel-SSHI circuit interface produces 85% more power than the SEH counterpart, while the use of series-SSHI circuit demonstrates the similar performance in comparison to the SEH interface. The reasons for such a huge efficiency improvement by using the parallel-SSHI interface are detailed in this paper.
Algorithms for the Real-Time Compensation of Hysteresis in MR Actuators Caused by Partially Filled Shear Gaps
Authors: Maas Jürgen , Hegger Christian
Published: November 2016

Magnetorheological fluids (MRF) are suspensions of fine, magnetically polarizable particles in a non-magnetic carrier fluid. Under the influence of a magnetic field the particles form chains in the direction of the field lines, whereby the resulting shear stress can be changed high dynamical, largely linear with a good reproducibility by several orders of magnitude. Furthermore, the MRF technology provides a drag torque-free operation by a magnetically induced MR-fluid movement control, resulting in new perspectives regarding the increase of energy-efficiency with improved switching dynamics and comfort for applications e.g. in the powertrain of vehicles. A certain drawback of the MR-fluid control is a hysteresis behavior of the torque generation with respect to the controlling current caused by the partially filled shear gaps. In addition, the hysteresis depends on the rotational speed due to the resulting centrifugal forces, so that the influence of this external disturbance must be compensated, too. In order to obtain a linearized force characteristic of the actuator, a modified Prandtl-Ishlinskii approach for the hysteresis compensation is designed, parametrized and validated by experiments within this paper.
Ticks collected from Chilbal Island, Jeollanam Province, Republic of Korea, during 2014–2015
Authors: Kim Heung-Chul , Kwon Young-Soo , Kim Mi-Ran , Park Chang-Uk , Yun Seok-Min , Lee Won-Ja , Chong Sung-Tae , Klein Terry A. , Robbins Richard George
Published: November 2016

The 65th Medical Brigade and Public Health Command District-Korea, in collaboration with the Migratory Birds Center, National Park Research Institute, conducted a migratory bird tick-borne disease surveillance program on Chilbal Island, a small, remote, uninhabited island in southwestern Jeollanam Province, Republic of Korea (ROK), during 2014–2015. Ticks were collected by dragging vegetation and from nest soil and litter of the Ancient Murrelet, Synthliboramphus antiquus, and Swinhoe’s Storm Petrel, Hydrobates monorhis, using Tullgren funnels. A total of 115 ticks belonging to three genera and three species were collected. Ornithodoros sawaii (98.3%, 113 ticks) was the most frequently collected tick species, followed by Ixodes signatus (0.9%, 1 nymph) collected from nest soil and litter, and Haemaphysalis flava (0.9%, 1 male) collected by tick drag.
Internalization of secreted antigen–targeted antibodies by the neonatal Fc receptor for precision imaging of the androgen receptor axis
Authors: Thorek Daniel L. J. , Watson Philip A. , Lee Sang-Gyu , Ku Anson T. , Bournazos Stylianos , Braun Katharina , Kim Kwanghee , Sjöström Kjell , Doran Michael G. , Lamminmäki Urpo , Santos Elmer , Veach Darren , Turkekul Mesruh , Casey Emily , Lewis Jason S. , Abou Diane S. , van Voss Marise R. H. , Scardino Peter T. , Strand Sven-Erik , Alpaugh Mary L. , Scher Howard I. , Lilja Hans , Larson Steven M. , Ulmert David
Published: November 2016

A radiolabeled antibody against a secreted antigen uses Fc receptor–mediated internalization for cancer imaging and therapy.
Muscling out gene mutations
Authors: Whitehead Kathryn A.
Published: November 2016

An adenovirus system that delivers gene-editing components rescues dystrophin expression in Duchenne muscular dystrophy muscle cells.
Using
In Vitro
Dynamic Models To Evaluate Fluoroquinolone Activity against Emergence of Resistant Salmonella enterica Serovar Typhimurium
Authors: Lee Seung-Jin , Awji Elias Gebru , Park Na-hye , Park Seung-Chun
Published: November 2016

The objectives of this study were to determine pharmacokinetic/pharmacodynamic (PK/PD) indices of fluoroquinolones that minimize the emergence of resistant
Salmonella enterica
serovar Typhimurium (
S
. Typhimurium) using
in vitro
dynamic models and to establish mechanisms of resistance. Three fluoroquinolones, difloxacin (DIF), enrofloxacin (ENR), and marbofloxacin (MAR), at five dose levels and 3 days of treatment were simulated. Bacterial killing-regrowth kinetics and emergence of resistant bacteria after antibacterial drug exposure were quantified. PK/PD indices associated with different levels of antibacterial activity were computed. Mechanisms of fluoroquinolone resistance were determined by analyzing target mutations in the quinolone resistance-determining regions (QRDRs) and by analyzing overexpression of efflux pumps. Maximum losses in susceptibility of fluoroquinolone-exposed
S
. Typhimurium occurred at a simulated AUC/MIC ratio (area under the concentration-time curve over 24 h in the steady state divided by the MIC) of 47 to 71. Target mutations in
gyrA
(S83F) and overexpression of
acrAB-tolC
contributed to decreased susceptibility in fluoroquinolone-exposed
S
. Typhimurium. The current data suggest AUC/MIC (AUC/mutant prevention concentration [MPC])-dependent selection of resistant mutants of
S
. Typhimurium, with AUC/MPC ratios of 69 (DIF), 62 (ENR), and 39 (MAR) being protective against selection of resistant mutants. These values could not be achieved in veterinary clinical areas under the current recommended therapeutic doses of the fluoroquinolones, suggesting the need to reassess the current dosing regimen to include both clinical efficacy and minimization of emergence of resistant bacteria.
Inhibition of Plasmodium Liver Infection by Ivermectin
Authors: Mendes António M. , Albuquerque Inês S. , Machado Marta , Pissarra Joana , Meireles Patrícia , Prudêncio Miguel
Published: November 2016

Avermectins are powerful endectocides with an established potential to reduce the incidence of vector-borne diseases. Here, we show that several avermectins inhibit the hepatic stage of
Plasmodium
infection
in vitro
. Notably, ivermectin potently inhibits liver infection
in vivo
by impairing parasite development inside hepatocytes. This impairment has a clear impact on the ensuing blood stage parasitemia, reducing disease severity and enhancing host survival. Ivermectin has been proposed as a tool to control malaria transmission because of its effects on the mosquito vector. Our study extends the effect of ivermectin to the early stages of mammalian host infection and supports the inclusion of this multipurpose drug in malaria control strategies.
Nephrotoxicity during Vancomycin Therapy in Combination with Piperacillin-Tazobactam or Cefepime
Authors: Rutter W. Cliff , Cox Jessica N. , Martin Craig A. , Burgess Donna R. , Burgess David S.
Published: November 2016

Recent reports have demonstrated that vancomycin (VAN) may lead to an increase in the incidence of acute kidney injury (AKI) when it is combined with antipseudomonal beta-lactams. This study compared the incidence of AKI associated with VAN plus piperacillin-tazobactam (TZP) or cefepime (FEP). This was a retrospective, matched cohort study that was conducted at an academic medical center between September 2010 and September 2014 and that included adult patients without severe chronic or structural kidney disease, dialysis, pregnancy, cystic fibrosis, or a hospital transfer receiving TZP-VAN or FEP-VAN for at least 48 h. The primary outcome was the difference in the AKI incidence between the TZP-VAN and FEP-VAN groups, evaluated using the risk, injury, failure, loss of kidney function, and end-stage kidney disease (RIFLE) criteria. Patients in the two groups were matched on the basis of age, sex, severity of illness, baseline creatinine clearance, hypotension, number of nephrotoxicity risk factors, and intravenous contrast exposure. In total, 4,193 patients met all inclusion criteria (3,605 received TZP-VAN and 588 received FEP-VAN). The unadjusted AKI incidence was 21.4% in patients receiving TZP-VAN, whereas it was 12.6% in patients receiving FEP-VAN (
P
< 0.001). After the patients were matched, 1,633 patients receiving TZP-VAN and 578 patients receiving FEP-VAN were evaluated. The AKI incidence remained higher in patients receiving TZP-VAN than in those receiving FEP-VAN (21.4% versus 12.5%,
P
< 0.0001). This trend remained true for all classifications of the RIFLE criteria. After controlling for remaining confounders, TZP-VAN therapy was associated with 2.18 times the odds of AKI than FEP-VAN therapy (95% confidence interval, 1.64 to 2.94 times) in logistic regression. AKI was significantly more common in patients receiving vancomycin in combination with piperacillin-tazobactam than in those receiving vancomycin in combination with cefepime. This finding reinforces the need for the judicious use of combination empirical antimicrobial therapy.
IncP Plasmid Carrying Colistin Resistance Gene
mcr-1
in Klebsiella pneumoniae from Hospital Sewage
Authors: Zhao Feifei , Feng Yu , Lü Xiaoju , McNally Alan , Zong Zhiyong
Published: November 2016

A
Klebsiella pneumoniae
strain of sequence type 313 (ST313) recovered from hospital sewage was found carrying the plasmid-borne colistin resistance gene
mcr-1
, which was bracketed by two copies of the insertion sequence IS
Apl1
on a 57-kb self-transmissible IncP-type plasmid of a new IncP-1 clade. The carriage of
mcr-1
on a self-transmissible broad-host-range plasmid highlights that
mcr-1
has the potential to spread beyond the
Enterobacteriaceae
family.
MetQ of Neisseria gonorrhoeae Is a Surface-Expressed Antigen That Elicits Bactericidal and Functional Blocking Antibodies
Authors: Semchenko Evgeny A. , Day Christopher J. , Seib Kate L.
Published: November 2016

Neisseria gonorrhoeae, the causative agent of the sexually transmitted infection (STI) gonorrhea, is a growing public health threat for which a vaccine is urgently needed. We characterized the functional role of the gonococcal MetQ protein, which is the methionine binding component of an ABC transporter system, and assessed its potential as a candidate antigen for inclusion in a gonococcal vaccine. MetQ has been found to be highly conserved in all strains investigated to date, it is localized on the bacterial surface, and it bindsl-methionine with a high affinity. MetQ is also involved in gonococcal adherence to cervical epithelial cells. Mutants lacking MetQ have impaired survival in human monocytes, macrophages, and serum. Furthermore, antibodies raised against MetQ are bactericidal and are able to block gonococcal adherence to epithelial cells. These data suggest that MetQ elicits both bactericidal and functional blocking antibodies and is a valid candidate antigen for additional investigation and possible inclusion in a vaccine for prevention of gonorrhea.
Associations of specific types of sports and exercise with all-cause and cardiovascular-disease mortality: a cohort study of 80 306 British adults
Authors: Oja Pekka , Kelly Paul , Pedisic Zeljko , Titze Sylvia , Bauman Adrian , Foster Charlie , Hamer Mark , Hillsdon Melvyn , Stamatakis Emmanuel
Published: November 2016

Background/Aim

Evidence for the long-term health effects of specific sport disciplines is scarce. Therefore, we examined the associations of six different types of sport/exercise with all-cause and cardiovascular disease (CVD) mortality risk in a large pooled Scottish and English population-based cohort.

Methods

Cox proportional hazards regression was used to investigate the associations between each exposure and all-cause and CVD mortality with adjustment for potential confounders in 80 306 individuals (54% women; mean±SD age: 52±14 years).

Results

Significant reductions in all-cause mortality were observed for participation in cycling (HR=0.85, 95% CI 0.76 to 0.95), swimming (HR=0.72, 95% CI 0.65 to 0.80), racquet sports (HR=0.53, 95% CI 0.40 to 0.69) and aerobics (HR=0.73, 95% CI 0.63 to 0.85). No significant associations were found for participation in football and running. A significant reduction in CVD mortality was observed for participation in swimming (HR=0.59, 95% CI 0.46 to 0.75), racquet sports (HR=0.44, 95% CI 0.24 to 0.83) and aerobics (HR=0.64, 95% CI 0.45 to 0.92), but there were no significant associations for cycling, running and football. Variable dose–response patterns between the exposure and the outcomes were found across the sport disciplines.

Conclusions

These findings demonstrate that participation in specific sports may have significant benefits for public health. Future research should aim to further strengthen the sport-specific epidemiological evidence base and understanding of how to promote greater sports participation.