bluuebunny/crossref_metadata_2025 huggingface dataset:
Whole-Body Operational Space Control for Locomotion and Manipulation
Authors: Sentis Luis
Published: March 2018

This article discusses the various researches being undertaken to study and develop Whole-Body Operational Space Control (WBOSC). The WBOSC emerges as a capable framework for real-time unified control of motion and force of humanoid robots. It could theoretically outperform high-speed industrial manipulators while providing the grounds for new types of service-oriented applications that require contact, by exploiting the rigid body dynamics of systems. By relying on joint torque sensors, WBOSC opens up the potential to interact with the physical environment using any part of the robot’s body while regulating the effective mechanical impedances to safe values. With ControlIt!, the developers provide a strict and easy way to use the WBOSC API consisting of compound tasks which define the operational space, and constraint sets that define the contacts with the environment as well as dependent degrees of freedom. ControlIt! is easy to connect to high level planners.
H2O Taking the Hydro out of Hydraulic Fracturing
Authors: Crawford Mark
Published: March 2018

This paper demonstrates the increasing use of waterless methods in oil and gas industry. Waterless methods aim to make unconventional oil and gas well more environmental friendly. While waterless fracturing is still relatively rare in the United States, it is more common in operations north of the border. Gas-energized fracturing has a significant advantage over traditional water-based methods: it requires less proppant, which saves money, and it can double oil and gas recovery from a well. Praxair, a supplier of industrial gases based in Danbury, Conn., has developed a system that relies on a different liquefied gas. Its DryFrac technology relies on liquid carbon dioxide that is mixed with sand and sent down the hole under high pressure. The experts point out that in places where hydraulic fracturing’s water use is becoming a real constraint to exploiting shale formations, it is likely that petroleum companies will find that it is worth it to make the commitment to waterless fracturing.
Go Fast With the Flow
Authors: Martin John
Published: March 2018

This article discusses various applications of computational fluid dynamics (CFD) in the field of swimming. Using known physics and fluid dynamics relationships, CFD allows complex fluid flow regimes and geometry to be simulated within a computer environment. The ability to obtain segment-specific fluid force data within a full body stroking model provides enormous amounts of information that would be unobtainable via current empirical testing techniques. CFD software imports a realistic geometry of the athlete, generates the geometry of the surrounding water and air, and meshes these geometries to represent the athlete’s body in its surroundings. For world-class swimmers, the pursuit of a record-breaking performance at the 2016 Rio Olympics may well depend on CFD modeling and other simulations just as much as the athlete's physical ability. Experts see several applications for CFD, as engineers and academics continue their research into swimming, and coaches, athletes, and support teams prep for new competitions and championships, including the 2016 Rio Games. The growth of CFD methodology in swimming will rely on the ability to obtain easy and accurate 3-D kinematics.
The Connected Life
Authors: Noor Ahmed K.
Published: March 2018

The article presents an overview of how connected or smart systems can help improve day-to-day lives and be beneficial for businesses as well. Connectivity opens a world of possibilities for improving occupant experience, reducing energy costs, and managing building equipment—three areas that can increase returns on real estate assets. Smart systems are expected to improve the efficiency of heat, light, sanitation, security, safety, and a host of services. The savings of energy alone could be significant. Connections between things and people, supported by networked processes, will enable everyone to turn vast amounts of heterogeneous data into practical information that can be used to do things that weren’t possible before, or to do familiar tasks better. Cognitive work and service assistants with deep learning and reasoning capabilities will support various human activities. The unprecedented communication can inspire creative thinking and collaborations among businesses and organizations.
From Fire to Water
Authors: Bahadur Vaibhav
Published: March 2018

This article presents the transformation of drilling and fracturing industry. More recent efforts have studied the use of flared gas to treat the flowback water that follows fracking. While the emergence of such technologies is encouraging, the solutions involve expensive infrastructure, which often reduces the economic advantage of flared gas utilization projects. Researchers are working to increase the performance of the condensers by coating the condenser tubes with water-shedding super-hydrophobic materials, which drain the condensed water and can increase the thermal performance by a factor of ten. The paper also discusses the benefits of a solution named atmospheric water harvesting (AWH). AWH can benefit oil-producing regions such as the Middle East and portions of Africa, which flare large volumes of gas, face perpetual water crises, and have year-round high humidity. The technology can also be positioned as an alternative to desalination in humid places with high flaring rates, but which lack brackish water sources that could be treated.
Back to the Sound Barrier
Authors: Freiherr Greg
Published: March 2018

This article explores efforts that are being put into developing a business jet called AS2 and various challenges in developing the same. Aerion’s 12-seat tri-engine AS2, unveiled in spring 2014, is designed to have a range up to 5000 nautical miles; reach 51,000 feet; and cruise at speeds between Mach 1.2 and Mach 1.6. About the time it is ready to fly commercially, possibly as early as 2023, the market could support annual sales of 30 supersonic business jets. NASA and Lockheed Martin have been exploring a variety of options for quieting sonic booms. In its Strategic Implementation Plan, released in 2015, NASA states that ‘the viability of commercial supersonic service depends on permissible supersonic flight over land.’ It is however noted that the success of the next generation of supersonic transport will ultimately come down to economics. Prospective buyers of supersonic business jets will include corporations and ultra-high net worth individuals.
Hot Plates
Authors: Langston Lee S.
Published: March 2018

This article presents an overview of use, advantages, and challenges related to ceramic gas turbines. The research shows that if these ceramic parts perform as promised, both operationally and economically, it could radically alter the jet engine industry. The promise of ceramics is that by taking advantage of their lower weight and superior high temperature properties, one could replace the complex air-cooled metal components with simpler ceramic components more tolerant of high temperatures. However, one difficulty engineers have had in developing ceramic components is the inability to put promising designs in production gas turbines for a true ‘beta’ test. GE plans to expand its application of ceramic matrix composites use in its 100,000-pound thrust GE9X engine, now under development for Boeing’s 777X airframe and scheduled to enter service in 2020. It will feature CMC combustion liners, high-pressure turbine stators, and first-stage shrouds. The jet engine industry has since developed successful composite fans; however, the inaugurating company got off to a rocky start.
Robotic Fish
Authors: Zhang Feitian , Lagor Francis D. , Lei Hong , Tan Xiaobo , Paley Derek A.
Published: March 2018

This article reviews different research and development work on robotic fishes. The Collective Dynamics and Control Laboratory at the University of Maryland has constructed two robotic fish to study bio-inspired flow sensing and control of underwater vehicles. Bio-inspired flow sensing and flow-relative control using distributed sensor measurements have been described and demonstrated with two underwater robots. Prototypes of the robotic fish have been designed for experiments to include a rigid airfoil-shaped robot and a flexible, self-propelled robot. The closed-loop control of the flexible robot comprised feedforward and feedback controls. The feedforward term accelerates the convergence of the tracking control, and the feedback term improves the tracking performance by reducing the steady-state error. Rheotaxis and speed-control experiments have demonstrated the effectiveness of the flow sensing and control algorithms. In ongoing work, teams are investigating a novel actuation approach using an internal reaction wheel for flexible fish propulsion.
Musculoskeletal System for Bio-Inspired Robotic Systems
Authors: Tadesse Yonas , Wu Lianjun , Saharan Lokesh K.
Published: March 2018

This article presents a research focused on developing musculoskeletal system for bio-inspired robotic systems. A musculoskeletal system is the fundamental structure that allows complex mobility of biological systems. This paper briefly describes the recently introduced twisted and coiled polymer (TCP) muscles and a novel design of musculoskeletal system based on ball and socket joint, as well as their application in a 3D printed humanoid robot. The challenge to develop such systems is multifaceted, including design, manufacturing, system integration, control methods, and energy usage. Some of the challenges in humanoid design are the degrees of freedom and the synergetic combination of hardware and software to perform a particular task. The other challenge is affordability of the platform. Most humanoids are very expensive. Since the TCP-based actuators are inexpensive and musculoskeletal systems inspired by biological systems are optimum for performance, they will address these problems. The bio-inspired ball and socket joint shown in the article can be cascaded to create complex robots, for example, for the shoulder joint of a humanoid.
A Decentralized, Communication-Free Force Distribution Method With Application to Collective Object Manipulation
Authors: Kalat Shadi Tasdighi , Faal Siamak G. , Onal Cagdas D.
Published: March 2018

We present a novel approach to achieve decentralized distribution of forces in a multirobot system. In this approach, each robot in the group relies on the behavior of a cooperative virtual teammate that is defined independent of the population and formation of the real team. Consequently, such formulation eliminates the need for interagent communications or leader–follower architectures. In particular, effectiveness of the method is studied in a collective manipulation problem where the objective is to control the position and orientation of a body in time. To experimentally validate the performance of the proposed method, a new swarm agent, Δρ (Delta-Rho), is introduced. A multirobot system, consisting of five Δρ agents, is then utilized as the experimental setup. The obtained results are also compared with a norm-optimal centralized controller by quantitative metrics. Experimental results prove the performance of the algorithm in different tested scenarios and demonstrate a scalable, versatile, and robust system-level behavior.
Chaos Synchronization of Fractional-Order Chaotic Systems With Input Saturation
Authors: Khamsuwan Pitcha , Sangpet Teerawat , Kuntanapreeda Suwat
Published: March 2018

This paper deals with the problem of master-slave synchronization of fractional-order chaotic systems with input saturation. Sufficient stability conditions for achieving the synchronization are derived from the basis of a fractional-order extension of the Lyapunov direct method, a new lemma of the Caputo fractional derivative, and a local sector condition. The stability conditions are formulated in linear matrix inequality (LMI) forms and therefore are readily solved. The fractional-order chaotic Lorenz and hyperchaotic Lü systems with input saturation are utilized as illustrative examples. The feasibility of the proposed synchronization scheme is demonstrated through numerical simulations.
Numerical Study of Heat Transfer Enhancement of Nano Liquid-Metal Fluid Forced Convection in Circular Tube
Authors: Zhou Xiaoming , Li Xunfeng , Cheng Keyong , Huai Xiulan
Published: March 2018

Investigation of nano liquid-metal fluid (consists of liquid metal Ga and nanoparticles copper) as heat transfer medium in circular tube is performed for the first time. The numerical simulations of heat transfer enhancement of nano liquid-metal fluid in a circular tube subject to a constant wall heat flux are carried out, and the heat transfer performance is evaluated. The two-phase mixture model is used to simulate the flow of nanoparticles–liquid mixture for Reynolds number (Re) from 250 to 1000 and nanoparticle volume fraction (αp) from 0 to 0.1. The results show that the average heat transfer coefficient of nano liquid-metal fluid Ga–Cu is 23.8 times of that of nanofluid water–Cu at Re = 500 and αp = 0.04, and the average wall shear stress of Ga–Cu is 0.0154 Pa, whereas for water–Cu, it is 0.0259 Pa. As Re increases from 250 to 1000, the average heat transfer coefficient of water–Cu is improved by 40%, whereas for Ga–Cu, it is 45.4%. Based on the results in the paper, the nano liquid-metal fluid can be considered as an excellent heat transfer medium of forced convection in circular tube.
Control of Spray Evaporative Cooling in Automotive Internal Combustion Engines
Authors: Jafari S. , Dunne J. F. , Langari M. , Yang Z. , Pirault J.-P. , Long C. A. , Thalackottore Jose J.
Published: March 2018

A novel approach is proposed for precise control of two-phase spray evaporative cooling for thermal management of road vehicle internal combustion (IC) engines. A reduced-order plant model is first constructed by combining published spray evaporative cooling correlations with approximate governing heat transfer equations appropriate for IC engine thermal management. Control requirements are specified to allow several objectives to be met simultaneously under different load conditions. A control system is proposed and modeled in abstract form to achieve spray evaporative cooling of a gasoline engine, with simplifying assumptions made about the characteristics of the coolant pump, spray nozzle, and condenser. The system effectiveness is tested by simulation to establish its ability to meet key requirements, particularly concerned with precision control during transients resulting from rapid engine load variation. The results confirm the robustness of the proposed control strategy in accurately tracking a specified temperature profile at various constant load conditions, and also in the presence of realistic transient load variation.
Influence of Turbine Blade Leading Edge Profile on Film Cooling With Shaped Holes
Authors: Zhang Mingjie , Wang Nian , Chen Andrew F. , Han Je-Chin
Published: March 2018

This paper presents the turbine blade leading edge model film cooling effectiveness with shaped holes, using the pressure sensitive paint (PSP) mass transfer analogy method. The effects of leading edge profile, coolant to mainstream density ratio, and blowing ratio are studied. Computational simulations are performed using the realizable k–ɛ (RKE) turbulence model. Effectiveness obtained by computational fluid dynamics (CFD) simulations is compared with experiments. Three leading edge profiles, including one semicylinder and two semi-elliptical cylinders with an after body, are investigated. The ratios of major to minor axis of two semi-elliptical cylinders are 1.5 and 2.0, respectively. The leading edge has three rows of shaped holes. For the semicylinder model, shaped holes are located at 0 deg (stagnation line) and ±30 deg. Row spacing between cooling holes and the distance between impingement plate and stagnation line are the same for three leading edge models. The coolant to mainstream density ratio varies from 1.0 to 1.5 and 2.0, and the blowing ratio varies from 0.5 to 1.0 and 1.5. Mainstream Reynolds number is about 100,000 based on the diameter of the leading edge cylinder, and the mainstream turbulence intensity is about 7%. The results provide an understanding of the effects of leading edge profile on turbine blade leading edge region film cooling with shaped hole designs.
Fabrication and Performance Investigation of Three-Cell SOFC Stack Based on Anode-Supported Cells With Magnetron Sputtered Electrolyte
Authors: Solovyev Andrey , Ionov Igor , Lauk Alexander , Linnik Stepan , Shipilova Anna , Smolyanskiy Egor
Published: March 2018

A planar solid oxide fuel cell (SOFC) was fabricated using a commercial Ni/yttria-stabilized zirconia (YSZ) anode support, an YSZ/gadolinium-doped ceria (GDC) thin-film electrolyte, and a composite cathode of La0.6Sr0.4Co0.2Fe0.8O3/Gd0.1Ce0.9O1.95 (LSCF/GDC). A small, three-cell, SOFC stack is assembled using 10 cm × 10 cm single cells, metallic interconnects, and glass-based sealing. The stack performance was examined at various fuel flow rates of H2 + N2 and air at a fixed temperature of 750 °C. The three-cell stack with a crossflow design produced peak power density of 0.216 W/cm2 or about 39 W total power at 750 °C.
An Optimized Artificial Neural Network Unifying Model for Steady-State Liquid Holdup Estimation in Two-Phase Gas–Liquid Flow
Authors: Chaari Majdi , Seibi Abdennour C. , Hmida Jalel Ben , Fekih Afef
Published: March 2018

Simplifying assumptions and empirical closure relations are often required in existing two-phase flow modeling based on first-principle equations, hence limiting its prediction accuracy and in some instances compromising safety and productivity. State-of-the-art models used in the industry still include correlations that were developed in the sixties, whose prediction performances are at best acceptable. To better improve the prediction accuracy and encompass all pipe inclinations and flow patterns, we propose in this paper an artificial neural network (ANN)-based model for steady-state two-phase flow liquid holdup estimation in pipes. Deriving the best input combination among a large reservoir of dimensionless Π groups with various fluid properties, pipe characteristics, and operating conditions is a laborious trial-and-error procedure. Thus, a self-adaptive genetic algorithm (GA) is proposed in this work to both ease the computational complexity associated with finding the elite ANN model and lead to the best prediction accuracy of the liquid holdup. The proposed approach was implemented using the Stanford multiphase flow database (SMFD), chosen for being among the largest and most complete databases in the literature. The performance of the proposed approach was further compared to that of two prominent models, namely a standard empirical correlation-based model and a mechanistic model. The obtained results along with the comparison analysis confirmed the enhanced accuracy of the proposed approach in predicting liquid holdup for all pipe inclinations and fluid flow patterns.
Terminal Synergetic Control for Blood Glucose Regulation in Diabetes Patients
Authors: Hachana A. , Harmas M. N.
Published: March 2018

In this paper, a new robust terminal synergetic control scheme is proposed to regulate blood glucose level in diabetic patients (type I diabetes), based on recently developed synergetic control and a terminal attractor technique. The technique presented has the advantage of using a continuous control law. Moreover, the proposed control scheme, besides being chattering free, has the characteristics of finite time convergence. Lyapunov synthesis is adopted to ensure controlled system stability. Simulation results of terminal synergetic control are compared to classic synergetic and second-order sliding mode control (SMC) performance, demonstrating that the proposed control method allows for rapidly achieving normoglycemia in type I diabetes patients.
Rotordynamic Force Coefficients of Volutes and Diffusers for Prediction of Turbomachinery Vibration
Authors: Mortazavi Farzam , Palazzolo Alan
Published: March 2018

The American Petroleum Institute (API) level II vibration stability analysis for impellers requires higher fidelity models to predict the dynamic forces of the whirling impeller. These forces are in turn required to predict the vibration stability, critical speeds, and steady-state vibration response of the shaft-bearing-seal-impeller system. A transient computational fluid dynamics (CFD)-based approach is proposed which is applicable to nonaxisymmetric turbomachinery components, such as the volute and/or diffuser vanes, unlike its predecessor models like the bulk-flow or the quasi-steady model. The key element of this approach is the recent advancements in mesh deformation techniques which permit less restrictive motion boundary conditions to be imposed on the whirling impeller. The results quantify the contributions of the volute and/or the diffuser to the total forces which guides the analyst on whether to include these components in the model. The numerical results obtained by this approach are shown to agree well with experimental measurements and to be superior to the earlier quasi-steady alternative in terms of accuracy. Furthermore, several volute shapes were designed and analyzed for the sensitivity of the solution to the geometrical properties of the volute. The design flow rotordynamic forces show a significant dependence on the presence of the volutes in the model, with the specific shape of the volute having a lesser influence. The dimensionless forces are shown to be almost independent of the spin speed.
Complete Characterization of a Highly Loaded Low Pressure Compressor at Different Reynolds Numbers for Computational Fluid Dynamics Simulations
Authors: Hadavandi Ruzbeh , Fontaneto Fabrizio , Desset Julien
Published: March 2018

Computational fluid dynamics (CFD) is nowadays extensively used for turbomachinery design and performance prediction. Nevertheless, compressors numerical simulations still fail in correctly predicting the stall inception and the poststall behavior. Several authors address such a lack of accuracy to the incomplete definition of the boundary conditions and of the turbulence parameters at the inlet of the numerical domain. The aim of the present paper is to contribute to the development of compressors CFD by providing a complete set of input data for numerical simulations. A complete characterization has been carried out for a state-of-art 1.5 stage highly loaded low-pressure compressor for which previous CFD analyses have failed to predict its behavior. The experimental campaign has been carried out in the R4 facility at the Von Karman Institute for Fluid Dynamics (VKI). The test item has been tested in different operative conditions for two different speed lines (90% and 96% of the design speed) and for two different Reynolds numbers. Stable and unstable operative conditions have been investigated along with the stalling behavior, its inception, and the stall-cell flow field. Discrete hot-wire traverses have been performed in order to characterize the spanwise velocity field and the turbulence characteristics.
Cold-Start Computational Fluid Dynamics Simulation of Spark-Ignition Direct-Injection Engine
Authors: Yang Xiaofeng , Kuo Tang-Wei , Singh Kulwinder , Hattar Rafat , Zeng Yangbing
Published: March 2018

Reliably starting the engine during extremely cold ambient temperatures is one of the largest calibration and emissions challenges in engine development. Although cold-start conditions comprise only a small portion of an engine's typical drive cycle, large amounts of hydrocarbon and particulate emissions are generated during this time, and the calibration of cold-start operation takes several months to complete. During the cold start period, results of previous cycle combustion event strongly influences the subsequent cycle due to variations in engine speed, residual fraction, residual wall film mass, in-cylinder charge and wall temperatures, and air flow distribution between cylinders. Including all these parameters in computational fluid dynamics (CFD) simulation is critical in understanding the cold start process in transient and cumulative manner. Measured cold start data of a production of four-cylinder spark-ignition (SI) direct-injection engine were collected for this study with an ambient temperature of −30 °C. Three-dimensional (3D) transient engine flow, spray, and combustion simulation over first three consecutive engine cycles is carried out to provide a better understanding of the cold-start process. Measured engine speed and one-dimensional (1D) conjugate heat transfer (CHT) model is used to capture realistic in-cylinder flow dynamics and transient wall temperatures for more accurate fuel–air mixing predictions. The CFD predicted cumulative heat release trend for the first three cycles matches the data from measured pressure analysis. The same observation can be made for the vaporized fuel mass as well. These observations are explained in the report.
Measurements of the Rotordynamic Response of a Rotor Supported on Porous Type Gas Bearing
Authors: Liu Wanhui , Feng Kai , Huo Yanwei , Guo Zhiyang
Published: March 2018

A test rig is built in this study to measure the rotordynamic response of a rotor supported on porous-type gas bearings. A rotor with a double impulse turbine at one end is driven by compressed air and supported on two porous type journal gas bearings and a pair of bump-type thrust gas bearings. The rotor is accelerated to ∼25 krpm and coasted down in the test. The rotor dynamic response is measured for different bearing supply pressures (i.e., 0.40 MPa, 0.45 MPa, and 0.50 MPa) and imbalance masses (i.e., 85 mg, 150 mg, and 215 mg). Synchronous and subsynchronous amplitudes are extracted from the rotor responses. The critical speed increases as the bearing supply pressure increases, but the damping ratio decreases. The onset speed of subsynchronous motion increases, and the subsynchronous amplitude decreases as the bearing supply pressure increases. The deceleration time is more than 5 min for a bearing supply pressure of 0.5 MPa, which reveals the very low drag friction of the porous gas bearings. The synchronous amplitude increases as the imbalance increases for all the tested bearing supply pressures. The critical speeds for different imbalances are almost the same, except for the out-of-phase imbalance condition under a bearing supply pressure of 0.50 MPa, in which the critical speed increases as the imbalance increases. The normalized synchronous amplitude shows the rotor-bearing system behaves almost in a linear fashion for all in-phase imbalance conditions. Nonlinear behavior is shown around the critical speed for the 215 mg out-of-phase imbalance condition under a bearing supply pressure of 0.50 MPa. The onset speed of the subsynchronous motion decreases as the imbalance increases under the in-phase imbalance condition. The predominant mode of vibration changes from cylindrical to conical and then back to cylindrical as the rotor speed decreases during the coast down test for the in-phase imbalance conditions. However, the rotor vibration mode is predominantly conical during the whole coast down test for the out-of-phase imbalance conditions.
An Investigation of Combustion Properties of Butanol and Its Potential for Power Generation
Authors: Methling Torsten , Richter Sandra , Kathrotia Trupti , Braun-Unkhoff Marina , Naumann Clemens , Riedel Uwe
Published: March 2018

Over the last years, global concerns about energy security and climate change have resulted in many efforts focusing on the potential utilization of nonpetroleum-based, i.e., bioderived, fuels. In this context, n-butanol has recently received high attention because it can be produced sustainably. A comprehensive knowledge about its combustion properties is inevitable to ensure an efficient and smart use of n-butanol if selected as a future energy carrier. In the present work, two major combustion characteristics, here laminar flame speeds applying the cone-angle method and ignition delay times applying the shock tube technique, have been studied, experimentally, and by modeling exploiting detailed chemical kinetic reaction models, at ambient and elevated pressures. The in-house reaction model was constructed applying the reaction model generation (RMG)-method. A linear transformation method recently developed, linTM, was exploited to generate a reduced reaction model needed for an efficient, comprehensive parametric study of the combustion behavior of n-butanol-hydrocarbon mixtures. All experimental data were found to agree with the model predictions of the in-house reaction model, for all temperatures, pressures, and fuel-air ratios. On the other hand, calculations using reaction models from the open literature mostly overpredict the measured ignition delay times by about a factor of two. The results are compared to those of ethanol, with ignition delay times very similar and laminar flame speeds of n-butanol slightly lower, at atmospheric pressure.
Classroom-Based Physical Activity and Sedentary Behavior Interventions in Adolescents: A Systematic Review and Meta-Analysis
Authors: McMichan Lauren , Gibson Ann-Marie , Rowe David A.
Published: March 2018

Background: It is reported that 81% of adolescents are insufficiently active. Schools play a pivotal role in promoting physical activity (PA) and reducing sedentary behavior (SB). The aim of this systematic review and meta-analysis was to evaluate classroom-based PA and SB interventions in adolescents. Methods: A search strategy was developed using the Population Intervention Comparison Outcome Study (PICOS) design framework. Articles were screened using strict inclusion criteria. Study quality was assessed using the Effective Public Health Practice Project quality assessment tool (http://www.ephpp.ca/tools.html). Outcome data for preintervention and postintervention were extracted, and effect sizes were calculated using Cohen’s d. Results: The strategy yielded 7574 potentially relevant articles. Nine studies were included for review. Study quality was rated as strong for 1 study, moderate for 5 studies, and weak for 3 studies. Five studies were included for meta-analyses, which suggested that the classroom-based interventions had a nonsignificant effect on PA (P = .55, d = 0.05) and a small, nonsignificant effect on SB (P = .16, d = −0.11). Conclusion: Only 9 relevant studies were found, and the effectiveness of the classroom-based PA and SB interventions varied. Based on limited empirical studies, there is not enough evidence to determine the most effective classroom-based methodology to increase PA and SB.
Unique genetic cassettes in a
Thermoanaerobacterium
contribute to simultaneous conversion of cellulose and monosugars into butanol
Authors: Li Tinggang , Zhang Chen , Yang Kun-Lin , He Jianzhong
Published: March 2018

We present a genome-level understanding of how cellulose is metabolized by
Thermoanaerobacterium
for biobutanol production.
Terahertz electrical writing speed in an antiferromagnetic memory
Authors: Olejník Kamil , Seifert Tom , Kašpar Zdeněk , Novák Vít , Wadley Peter , Campion Richard P. , Baumgartner Manuel , Gambardella Pietro , Němec Petr , Wunderlich Joerg , Sinova Jairo , Kužel Petr , Müller Melanie , Kampfrath Tobias , Jungwirth Tomas
Published: March 2018

We demonstrate terahertz electrical writing speed in an antiferromagnetic memory at an energy of the gigahertz speed writing.
Molecular engineering of Rashba spin-charge converter
Authors: Nakayama Hiroyasu , Yamamoto Takashi , An Hongyu , Tsuda Kento , Einaga Yasuaki , Ando Kazuya
Published: March 2018

Researchers report the discovery of a way for molecular engineering of Rashba spin-orbit devices.
Stretchable ultrasonic transducer arrays for three-dimensional imaging on complex surfaces
Authors: Hu Hongjie , Zhu Xuan , Wang Chonghe , Zhang Lin , Li Xiaoshi , Lee Seunghyun , Huang Zhenlong , Chen Ruimin , Chen Zeyu , Wang Chunfeng , Gu Yue , Chen Yimu , Lei Yusheng , Zhang Tianjiao , Kim NamHeon , Guo Yuxuan , Teng Yue , Zhou Wenbo , Li Yang , Nomoto Akihiro , Sternini Simone , Zhou Qifa , Pharr Matt , di Scalea Francesco Lanza , Xu Sheng
Published: March 2018

Ultrasound adds the third dimension to wearable sensors.
Antifungal Prophylaxis with Posaconazole Delayed-Release Tablet and Oral Suspension in a Real-Life Setting: Plasma Levels, Efficacy, and Tolerability
Authors: Lenczuk David , Zinke-Cerwenka Wilma , Greinix Hildegard , Wölfler Albert , Prattes Jürgen , Zollner-Schwetz Ines , Valentin Thomas , Lin Timothy C. , Meinitzer Andreas , Hoenigl Martin , Krause Robert
Published: March 2018

We continuously determined posaconazole plasma concentrations (PPCs) in 61 patients with hematological malignancies receiving posaconazole (PCZ) delayed-release tablets (DRT; 48 patients; median duration of intake, 92 days) and PCZ oral solution (OS; 13 patients; median duration of intake, 124 days). PCZ DRT and OS antifungal prophylaxis was efficient and well tolerated. Thirty-four of 48 patients (71%) receiving DRT always had PPCs of >0.7 mg/liter, while 14 of 48 patients (29%) had at least one PPC of ≤0.7 mg/liter. In patients receiving OS, 4 of 13 patients (31%) always had PPCs of >0.7 mg/liter, 6 of 13 patients (46%) had at least one PPC of ≤0.7 mg/liter, and 3 (23%) patients never reached a PPC of 0.7 mg/liter. In patients with at least one determined PPC, the mean proportion of all PPCs of >0.7 mg/liter was 91% for PCZ DRT, whereas it was 52% for PCZ OS (
P
= 0.001). In the per sample analysis, PPCs were significantly more likely to be >0.7 mg/liter in patients receiving DRT than in patients receiving OS (PPCs were >0.7 mg/liter in 91.4% [297/325] of patients receiving DRT versus 70.3% [85/121] of patients receiving OS;
P
< 0.001). Patients receiving PCZ DRT had higher proportions of PPCs of >0.7 mg/liter than patients receiving OS both in the per patient and in the per sample analyses. Two patients (3%) had side effects during PCZ prophylaxis, and one (2%) had fungal breakthrough infection. Therapeutic drug monitoring enables detection of extended periods of PPCs of ≤0.7 mg/liter (e.g., due to nonadherence or graft-versus-host disease), which may also be associated with the loss of protective intracellular PCZ concentrations, regardless of the PCZ formulation.
A Novel Glaesserella sp. Isolated from Pigs with Severe Respiratory Infections Has a Mosaic Genome with Virulence Factors Putatively Acquired by Horizontal Transfer
Authors: Watt Anne E. , Browning Glenn F. , Legione Alistair R. , Bushell Rhys N. , Stent Andrew , Cutler Ross S. , Young Neil D. , Marenda Marc S.
Published: March 2018

An unknown member of the family
Pasteurellaceae
was repeatedly isolated from 20- to 24-week-old pigs with severe pulmonary lesions reared on the same farm in Victoria, Australia. The etiological diagnosis of the disease was inconclusive. The complete genome sequence analysis of one strain, 15-184, revealed some phylogenic proximity to
Glaesserella
(
Haemophilus
)
parasuis
, the cause of Glasser's disease. However, the sequences of the 16S rRNA and housekeeping genes, as well as the average nucleotide identity scores, differed from those of all other known species in the family
Pasteurellaceae
. The protein content of 15-184 was composite, with 60% of coding sequences matching known
G. parasuis
products, while more than 20% had a closer relative in the genera
Actinobacillus
,
Mannheimia
,
Pasteurella
, and
Bibersteinia
. Several putative virulence genes absent from
G. parasuis
but present in other
Pasteurellaceae
were also found, including the
apxIII
RTX toxin gene from
Actinobacillus pleuropneumoniae
, ABC transporters from
Actinobacillus minor
, and iron transporters from various species. Three prophages and one integrative conjugative element were present in the isolate. Horizontal gene transfers might explain the mosaic genomic structure and atypical metabolic and virulence characteristics of 15-184. This organism has not been assigned a taxonomic position in the family, but this study underlines the need for a large-scale epidemiological and clinical characterization of this novel pathogen in swine populations, as a genomic analysis suggests it could have a severe impact on pig health.

IMPORTANCE
Several species of
Pasteurellaceae
cause a range of significant diseases in pigs. A novel member of this family was recently isolated from Australian pigs suffering from severe respiratory infections. Comparative whole-genome analyses suggest that this bacterium represents a new species, which possesses a number of virulence genes horizontally acquired from a diverse range of other
Pasteurellaceae
. While the possible contribution of other coinfecting noncultivable agents to the disease has not been ruled out in this study, the repertoire of virulence genes found in this organism may nevertheless explain some aspects of the associated pathology observed on the farm. The prevalence of this novel pathogen within pig populations is currently unknown. This finding is of particular importance for the pig industry, as this organism can have a serious impact on the health of these animals.
Caregiver experiences of racism and child healthcare utilisation: cross-sectional analysis from New Zealand
Authors: Paine Sarah-Jane , Harris Ricci , Stanley James , Cormack Donna
Published: March 2018

Objectives

Children’s exposure to racism via caregiver experience (vicarious racism) is associated with poorer health and development. However, the relationship with child healthcare utilisation is unknown. We aimed to investigate (1) the prevalence of vicarious racism by child ethnicity; (2) the association between caregiver experiences of racism and child healthcare utilisation; and (3) the contribution of caregiver socioeconomic position and psychological distress to this association.

Design

Cross-sectional analysis of two instances of the New Zealand Health Survey (2006/2007: n=4535 child–primary caregiver dyads; 2011/2012: n=4420 dyads).

Main outcome measures

Children’s unmet need for healthcare, reporting no usual medical centre and caregiver-reported dissatisfaction with their child’s medical centre.

Results

The prevalence of reporting ‘any’ experience of racism was higher among caregivers of indigenous Māori and Asian children (30.0% for both groups in 2006/2007) compared with European/Other children (14.4% in 2006/2007). Vicarious racism was independently associated with unmet need for child’s healthcare (OR=2.30, 95% CI 1.65 to 3.20) and dissatisfaction with their child’s medical centre (OR=2.00, 95% CI 1.26 to 3.16). Importantly, there was a dose–response relationship between the number of reported experiences of racism and child healthcare utilisation (eg, unmet need: 1 report of racism, OR=1.89, 95% CI 1.34 to 2.67; 2+ reports of racism, OR=3.06, 95% CI 1.27 to 7.37). Adjustment for caregiver psychological distress attenuated the association between caregiver experiences of racism and child healthcare utilisation.

Conclusions

Vicarious racism is a serious health problem in New Zealand disproportionately affecting Māori and Asian children and significantly impacting children’s healthcare utilisation. Tackling racism may be an important means of improving inequities in child healthcare utilisation.
Comparative analysis of methods for identifying multimorbidity patterns: a study of ‘real-world’ data
Authors: Roso-Llorach Albert , Violán Concepción , Foguet-Boreu Quintí , Rodriguez-Blanco Teresa , Pons-Vigués Mariona , Pujol-Ribera Enriqueta , Valderas Jose Maria
Published: March 2018

Objective

The aim was to compare multimorbidity patterns identified with the two most commonly used methods: hierarchical cluster analysis (HCA) and exploratory factor analysis (EFA) in a large primary care database. Specific objectives were: (1) to determine whether choice of method affects the composition of these patterns and (2) to consider the potential application of each method in the clinical setting.

Design

Cross-sectional study. Diagnoses were based on the 263 corresponding blocks of the International Classification of Diseases version 10. Multimorbidity patterns were identified using HCA and EFA. Analysis was stratified by sex, and results compared for each method.

Setting and participants

Electronic health records for 408 994 patients with multimorbidity aged 45–64 years in 274 primary health care teams from 2010 in Catalonia, Spain.

Results

HCA identified 53 clusters for women, with just 12 clusters including at least 2 diagnoses, and 15 clusters for men, all of them including at least two diagnoses. EFA showed 9 factors for women and 10 factors for men. We observed differences by sex and method of analysis, although some patterns were consistent. Three combinations of diseases were observed consistently across sex groups and across both methods: hypertension and obesity, spondylopathies and deforming dorsopathies, and dermatitis eczema and mycosis.

Conclusions

This study showed that multimorbidity patterns vary depending on the method of analysis used (HCA vs EFA) and provided new evidence about the known limitations of attempts to compare multimorbidity patterns in real-world data studies. We found that EFA was useful in describing comorbidity relationships and HCA could be useful for in-depth study of multimorbidity. Our results suggest possible applications for each of these methods in clinical and research settings, and add information about some aspects that must be considered in standardisation of future studies: spectrum of diseases, data usage and methods of analysis.
Frequency of reporting on patient and public involvement (PPI) in research studies published in a general medical journal: a descriptive study
Authors: Price Amy , Schroter Sara , Snow Rosamund , Hicks Melissa , Harmston Rebecca , Staniszewska Sophie , Parker Sam , Richards Tessa
Published: March 2018

Objectives

While documented plans for patient and public involvement (PPI) in research are required in many grant applications, little is known about how frequently PPI occurs in practice. Low levels of reported PPI may mask actual activity due to limited PPI reporting requirements. This research analysed the frequency and types of reported PPI in the presence and absence of a journal requirement to include this information.

Design and setting

A before and after comparison of PPI reported in research papers published inThe BMJbefore and 1 year after the introduction of a journal policy requiring authors to report if and how they involved patients and the public within their papers.

Results

Between 1 June 2013 and 31 May 2014,The BMJpublished 189 research papers and 1 (0.5%) reported PPI activity. From 1 June 2015 to 31 May 2016, following the introduction of the policy,The BMJpublished 152 research papers of which 16 (11%) reported PPI activity. Patients contributed to grant applications in addition to designing studies through to coauthorship and participation in study dissemination. Patient contributors were often not fully acknowledged; 6 of 17 (35%) papers acknowledged their contributions and 2 (12%) included them as coauthors.

Conclusions

Infrequent reporting of PPI activity does not appear to be purely due to a failure of documentation. Reporting of PPI activity increased after the introduction ofThe BMJ’s policy, but activity both before and after was low and reporting was inconsistent in quality. Journals, funders and research institutions should collaborate to move us from the current situation where PPI is an optional extra to one where PPI is fully embedded in practice throughout the research process.
Risks of all-cause mortality and major kidney events in patients with new-onset primary open-angle glaucoma: a nationwide long-term cohort study in Taiwan
Authors: Chou Chu-Lin , Hsieh Tsung-Cheng , Chen Jin-Shuen , Fang Te-Chao
Published: March 2018

Objective

Cardiovascular risk factors are associated with primary open-angle glaucoma (POAG) in the general population. However, long-term mortality and major kidney events in patients with new-onset POAG remain unclear.

Methods

Using the Taiwan National Health Insurance Research Database between 1997 and 2011, 15 185 patients with a new diagnosis of POAG were enrolled and propensity score matched (1:1) with 15 185 patients without ocular disorders (WODs). All-cause mortality and major kidney events were analysed by a multivariate Cox proportional hazards regression model and a competing risk regression model.

Results

The risk of all-cause mortality was significantly higher in patients with new-onset POAG than in those WODs (adjusted HR (aHR) 2.11, 95% CI 1.76 to 2.54; p<0.001). Patients with POAG had higher risks of acute renal failure (ARF) (competing risk aHR 2.58, 95% CI 1.88 to 3.55; p<0.001) and end-stage renal disease (ESRD) (competing risk aHR 4.84, 95% CI 3.02 to 7.77; p<0.001) than those WODs.

Conclusions

Our data demonstrate that POAG is a risk of all-cause mortality, ARF and ESRD, thus needing to notice mortality and major kidney events in patients with new-onset POAG.
Speak up-related climate and its association with healthcare workers’ speaking up and withholding voice behaviours: a cross-sectional survey in Switzerland
Authors: Schwappach David , Richard Aline
Published: March 2018

Objectives

To determine frequencies of healthcare workers (HCWs) speak up-related behaviours and the association of speak up-related safety climate with speaking up and withholding voice.

Design

Cross-sectional survey of doctors and nurses. Data were analysed using multilevel logistic regression models

Setting

4 hospitals with a total of nine sites from the German, French and Italian speaking part of Switzerland.

Participants

Survey data were collected from 979 nurses and doctors.

Main outcome measures

Frequencies of perceived patient safety concerns, of withholding voice and of speaking up behaviour. Speak up-related climate measures included psychological safety, encouraging environment and resignation.

Results

Perceived patient safety concerns were frequent among doctors and nurses (between 62% and 80% reported at least one safety concern during the last 4 weeks depending on the single items). Withholding voice was reported by 19%–39% of HCWs. Speaking up was reported by more than half of HCWs (55%–76%). The frequency of perceived concerns during the last 4 weeks was positively associated with both speaking up (OR=2.7, p<0.001) and withholding voice (OR=1.6, p<0.001). An encouraging environment was related to higher speaking up frequency (OR=1.3, p=0.005) and lower withholding voice frequency (OR=0.82, p=0.006). Resignation was associated with withholding voice (OR=1.5, p<0.001). The variance in both voicing behaviours attributable to the hospital-site level was marginal.

Conclusions

Our results strengthen the importance of a speak up-supportive safety climate for staff safety-related communication behaviours, specifically withholding voice. This study indicates that a poor climate, in particular high levels of resignation among HCWs, is linked to frequent ‘silence’ of HCWs but not inversely associated with frequent speaking up. Interventions addressing safety-related voicing behaviours should discriminate between withholding voice and speaking up.