bluuebunny/crossref_metadata_2025 huggingface dataset:
A Study on the Emissions of Alternative Aviation Fuels
Authors: Riebl Sebastian , Braun-Unkhoff Marina , Riedel Uwe
Published: September 2016

Currently, the aviation sector is seeking for alternatives to kerosene from crude oil, as part of the efforts combating climate change by reducing greenhouse gas (GHG) emissions, in particular carbon dioxide (CO2), and ensuring security of supply at affordable prices.

Several synthetic jet fuels have been developed including sustainable bio-kerosene, a low-carbon fuel. Over the last years, the technical feasibility as well as the compatibility of alternative jet fuels with today’s planes has been proven However, when burning a jet fuel, the exhaust gases are a mixture of many species, going beyond CO2 and water (H2O) emissions, with nitrogen oxides (NOx), carbon monoxide (CO), unburned hydrocarbons (UHC) including aromatic species and further precursors of particles and soot among them. These emissions have an impact on the local air quality as well as on the climate (particles, soot, contrails). Therefore, a detailed knowledge and understanding of the emission patterns when burning synthetic aviation fuels is inevitable.

In the present paper, these issues are addressed by studying numerically the combustion of four synthetic jet fuels (Fischer-Tropsch fuels). For reference, two types of crude-oil based kerosenes (Jet A-1 and Jet A) are considered, too. Plug flow calculations were performed by using a detailed chemical-kinetic model validated previously. The composition of the multi-component jet fuels were imaged by using the surrogate approach. Calculations were done for relevant temperatures, pressures, residence times, and fuel equivalence ratios φ.

Results are discussed for NOx, CO as well as benzene and acetylene as major soot precursors. According to the predictions, the NOx and CO emissions are within about ± 10% for all fuels considered, within the parameter range studied: T = 1800 K, T = 2200 K; 0.25 ≤ φ ≤ 1.8; p = 40 bar; t = 3 ms. The aromatics free GtL (Gas to Liquid) fuel displayed higher NOx values compared to Jet A-1/A. In addition, synthetic fuels show slightly lower (better) CO emission data than Jet A-1/A. The antagonist role of CO and NOx is apparent. Major differences were predicted for benzene emissions, depending strongly on the aromatics content in the specific fuel, with lower levels predicted for the synthetic aviation fuels. Acetylene levels show a similar, but less pronounced, effect.
Experimental Investigation on the Annular Sector Cascade of a High Endwall-Angle Turbine
Authors: Fu Weiliang , Gao Jie , Liang Chen , Wang Fukai , Zheng Qun , Zhou Endong
Published: September 2016

The flow in high endwall-angle turbine is complex, and it is different from the ordinary turbine flow in characteristics. In order to study the flow field characteristics of high endwall-angle turbines, the annular sector cascade experimental study of high endwall-angle turbines is carried out. The blade is studied experimentally in the form of annular sector cascade. The cascade includes 7 blades, and makes up 6 flow passages, in order to simulate full cascade flow. The experimental Mach number is adjusted by the way of changing inlet total pressure, and the Mach number influence (0.7, 0.8 and 0.9) on annular sector cascade flow is studied. Based on it, the inlet incidence angle (−15°, −7.5°, 0°, 7.5° and 15° )is changed with the way of changing sector straight pipes upstream of the cascade, and its influence on turbine flow fields is studied at the Mach number of 0.8. Here, five-hole probes are used to measure aerodynamic parameters distributions downstream of the cascade, and static pressure taps are positioned on the blade surface to measure surface static pressure distribution. The auto-traversing system and pressure sensors were operated by a self-compiled program based control program. The results indicate that there are two passage vortices inside the turbine cascade flow passage under the high Mach number condition, and the passage vortex near the high endwall-angle region is bigger. As Mach number increases, the passage vortices inside turbine cascade passage will become strong, and moves towards the blade mid-span. Besides, it is shown that the way of changing sector straight pipes can achieve the variation of inlet incidence angles. And, the blade profile with big leading-edge radius has good design and off-design performance. Detailed results and analyses are presented in the paper.
Effects of Fluidic Control of Air-Flow Distribution on Staged Lean Jet Engine Burner
Authors: Yoshida Seiji , Schneider Denis , Hassa Christoph
Published: September 2016

In this study, the effects of air-flow shifting between the pilot and main stages of a staged lean jet engine burner were investigated. A fluidic element attached in front of the swirlers was used to alter the air-flow split ratio between them, and the swirler and nozzle exit-section pressure loss behind the fluidic element was measured using an atmospheric isothermal test. The fluidic element did not fully recover the pressure loss in the burner inlet. However, it can also affect the losses, and cause an air shift between the pilot and main stage. Therefore, further combustion tests were conducted under two operating conditions: ground idle at 7% maximum take-off thrust and scaled cruise condition. Under ground idle conditions, increased pilot air flow improved the combustion efficiency for high fuel flow, and reduced pilot air flow improved it for low fuel flow. Staged and unstaged operations were also investigated under cruise conditions. In the staged operation, reduced pilot air flow increased the combustion efficiency, whereas in the unstaged operation, greater pilot air flow increased the combustion efficiency near the fueling mode switch-over point.
Analysis of High Pressure Turbine Nozzle Guide Vanes Considering Geometric Variations
Authors: Högner Lars , Nasuf Alkin , Voigt Paul , Voigt Matthias , Vogeler Konrad , Meyer Marcus , Berridge Christopher , Goenaga Frederic
Published: September 2016

Geometric variations caused by manufacturing scatter can influence the aerodynamic performance of turbomachinery components. In case of nozzle guide vanes (NGVs), the capacity is of particular importance due to its influence on the entire engine behaviour, since often the narrowest cross section of the turbine, which limits the capacity, is found in the first NGV stage.

Within this scope, the present paper illustrates different methods in order to quantify the impact of geometric variations of high pressure turbine (HPT) NGVs with respect to capacity change during the development process. At first, in the design phase, a parametric CAD model of the NGV can be used to perform an initial assessment of the effect caused by different geometric variations onto capacity. The results of this study can for example be used to set the tolerances for the subsequent manufacturing process.

As soon as the first real hardware components become available, their geometry can nowadays be accurately captured using optical measurement techniques. Consequently, reverse engineering (RE) methods can be used to enable numerical assessment of geometric variability since manufacturing scatter is determined and incorporated into the subsequent CFD analysis. The process to perform this assessment is described in the second part of the paper and its results are compared to the initial CAD-based study. The investigation is conducted using an example of a state-of-the-art NGV stage provided by Rolls-Royce.
Model Based Diagnostics of AE-T100 Micro Gas Turbine
Authors: Mahmood Mariam , Martini Alessio , Traverso Alberto , Bianchi Enrico
Published: September 2016

The growing environmental impacts and dwindling supply of conventional fuels have led to the development of more efficient and clean energy systems. Micro gas turbines (mGT) have emerged as energy conversion technology, which offer promising features like high fuel flexibility, low emissions level, and efficient cogeneration of heat and power (CHP). Numerical simulation is a vital tool to predict the off-design performance of mGT cycles, and it also helps in cycle optimization. Starting from a model available at Ansaldo Energia, for steady state simulation of mGT T100 cycles based on user requirements, within the cooperation between University of Genova (Unige) and Ansaldo Energia, a new more comprehensive simulation tool has been developed through the incorporation of additional components, features, and involving a more detailed mathematical approach. The most important upgrades involved a number of different air path flows and the power electronics, which takes into account the power consumption from auxiliary components as well as the generator and inverter efficiencies.

Once the model has been verified against the existing tools, it was used in real operating conditions at the Ansaldo Energia test rig. The mGT performance has been assessed for different power levels, starting from 100 kW (nominal power) to 60 kW and then back to 100 kW, with 10 kW steps. The two tests at 100 kW operating conditions have been carried out with two different ambient temperatures: 20°C and 25°C, respectively. Data have been acquired under stable operating conditions, considering the recuperator cold outlet temperature as the stability indicator.

Finally the new model AE-T100 has been used also for diagnosis of the whole mGT cycle. The model has been successfully applied to a special mGT equipped with an on-purpose damaged recuperator, identifying the causes of performance degradation.
Numerical and Experimental Investigation of Heat Transfer in a Low Flow Single Stage Centrifugal Compressor
Authors: Cui Michael , Hohlweg William
Published: September 2016

Heat transfer is an integral part of centrifugal compressor working process. The heat transfer can be generated by compressed gas (internal heating) or external heat sources (external heating). The heat transfer affects compressor performance directly through two mechanisms: dissipate impeller shaft power to heat to generate thermal losses; add extra thermal energy (enthalpy) to working fluid to distort stage performance value. The impacts of both these mechanisms are inversely proportional to the flow coefficient of the compressor. To optimize the compressor design and to evaluate their performance accurately, the physical mechanisms that control thermal fluid flow and heat transfer inside centrifugal compressors need to be studied.

The current work investigates both internal and external heat transfer inside a single stage centrifugal compressor with low design flow coefficient. An integrated conjugate heat transfer (CHT) model of the compressor stage includes both the solid parts (impeller, guide vanes, and stationary walls) and the test gas. The heat transfer processes between the solid and fluid surfaces were quantified using the ANSYS CFX software. The stage studied was tested in a closed loop arrangement with both nitrogen and R134a gases over a range of speeds from choke to surge flow. The gas temperatures and pressures were measured throughout the flow path from inlet flange to discharge. The temperatures of the solid components were obtained for the regions with large temperature gradients. The concept of thermal losses is introduced to characterize the dissipation of the shaft work to heat. The fundamental physical mechanisms of thermal fluid flow inside the compressor are defined and the influence of heat transfer on the centrifugal compressor stage performance is quantified.
A Comparison of Turbulent Flame Speed Correlations for Hydrocarbon Fuels at Elevated Pressures
Authors: Burke Eoin M. , Güthe Felix , Monaghan Rory F. D.
Published: September 2016

The aim of this work is to provide insight into the state-of-the-art turbulent flame speed (ST) correlations and to determine the most appropriate correlations to use under different turbulent premixed combustion conditions. The accuracies of 16 correlations for ST are determined using a large volume of data over a range of conditions. Accuracy is based on a mean absolute percentage error (MAPE). The comparison is completed once using the original authors’ adjustable parameters and a second time using parameters proposed by the current work that minimize MAPE for four different groups of data. Based on the results of the analysis using the newly-suggested parameters, the five most accurate correlations are then further examined to evaluate their respective abilities to predict trends under various turbulent conditions. While many correlations perform well over the range of data (MAPE < 33%), no single correlation can predict all experimentally-observed trends for methane flames under these conditions. Further issues are found when predicting trends for larger hydrocarbons; ethane and propane. Although low errors are again found (MAPE < 25%), correlations are not generally able to replicate the observed trends of experimental data for C2H6 and C3H8. While it is commonly accepted that no single correlation can accurately predict ST, this work has shown that the correlation derived by Muppala provides the closest overall agreement to the data examined. However it cannot be defined as a general correlation. For this reason the authors have proposed to continue development of an ST modeling tool based on a modified version of the Cantera 1D freely propagating laminar flame speed (SL) code. Greater cooperation in the ST research community to expand the range of available experimental data and better enable direct comparison of data and correlations from different experiments is also recommended.
Quasi-3D Inverse Design of a Vaned 90-Degree Bent Diffuser for the Exit of a Centrifugal Compressor Impeller
Authors: Shumal Mohammad , Nili-Ahamadabadi Mahdi , Shirani Ebrahim
Published: September 2016

In the present study, the performance of a centrifugal compressor is improved by replacing the combination of vaned radial diffuser and axisymmetric vaneless 90-degree bend by a vaned 90-degree bent diffuser. It controls the outlet flow angle and reduces the overall diameter of the compressor. The optimum number of guide vanes inside the 90-degree bent diffuser is obtained using 3-D numerical simulation. Indeed, changing flow direction simultaneous with decreasing flow velocity through the 90-degree bent diffuser will increase the possibility of secondary flow and separation. Here, the meridional plane of the 90-degree bent diffuser is modified to reduce secondary flow and separation. Geometry modification process integrates Ball-Spine inverse design method as the shape modification algorithm and a quasi-3D analysis code as the flow solver. The current quasi-3D flow solver is in fact a 3-D flow solver that solves viscous flow between two virtual guide vanes located at a very close distance with free slip condition over them. In other words, in the current quasi-3D analysis, stream surfaces are the same as the virtual guide vanes and no slip condition is just applied on the hub and shroud. Shape modification process is carried out by improving the current hub and shroud pressure distribution and applying it to the inverse design algorithm. Spines directions are specified in a way that geometry would change only in the meriodional plane and guide vanes angle remain unchanged in the blade to blade plane through the geometry modification process. Having modified the meridional plane, the new vaned 90-degree bent diffuser is examined by the 3-D flow solver. Results show not only the secondary flow is reduced in the new 90-degree bent diffuser, but also its efficiency increases up to 2%. On the other hand, the overall diameter of the compressor decreases about 24%.
A Review on Gas Turbine Anomaly Detection for Implementing Health Management
Authors: Zhao Ningbo , Wen Xueyou , Li Shuying
Published: September 2016

With the rapid improvement of equipment manufacturing technology and the ever increasing cost of fuel, engine health management has become one of the most important parts of aeroengine, industrial and marine gas turbine. As an effective technology for improving the engine availability and reducing the maintenance costs, anomaly detection has attracted great attention. In the past decades, different methods including gas path analysis, on-line monitoring or off-line analysis of vibration signal, oil and electrostatic monitoring have been developed. However, considering the complexity of structure and the variability of working environments for engine, many important problems such as the accurate modeling of gas turbine with different environment, the selection of sensors, the optimization of various data-driven approach and the fusion strategy of multi-source information still need to be solved urgently. Besides, although a large number of investigations in this area are reported every year in various journals and conference proceedings, most of them are about aeroengine or industrial gas turbine and limited literature is published about marine gas turbine. Based on this background, this paper attempts to summarize the recent developments in health management of gas turbines. For the increasing requirement of predict-and-prevent maintenance, the typical anomaly detection technologies are analyzed in detail. In addition, according to the application characteristics of marine gas turbine, this paper introduces a brief prospect on the possible challenges of anomaly detection, which may provide beneficial references for the implementing and development of marine gas turbine health management.
Passive Control of Critical Speeds of a Rotating Shaft Using Eccentric Sleeves: Model Development
Authors: Kirk A. J. , Griffiths J. , Bingham C. , Knowles G. , Bickerton R.
Published: September 2016

This paper considers the passive control of lateral critical speeds in high-speed rotating shafts through application of eccentric balancing sleeves. Equations of motion for a rotating flexible shaft with eccentric sleeves at the free ends are derived using the extended Hamilton Principle, considering inertial, non-constant rotating speed, Coriolis and centrifugal effects. A detailed analysis of the passive control characteristics of the eccentric sleeve mechanism and its impact on the shaft dynamics, is presented. Results of the analysis are compared with those from three-dimensional finite element simulations for 3 practical case studies. Through a comparison and evaluation of the relative differences in critical speeds from both approaches it is shown that consideration of eccentric sleeve flexibility becomes progressively more important with increasing sleeve length. The study shows that the critical speed of high-speed rotating shafts can be effectively controlled through implementation of variable mass/stiffness eccentric sleeve systems.
Transient Thermal Response of the Media by Free Space Laser Heating in Heat Assisted Magnetic Recording
Authors: Xiong Shaomin , Smith Robert , Wang Na , Li Dongbo , Schreck Erhard , Canchi Sripathi , Dai Qing
Published: September 2016

Heat assisted magnetic recording (HAMR) promises to deliver higher storage areal density than the current perpendicular magnetic recording (PMR) product. A laser is introduced to the HAMR system to heat the high coercively magnetic media above the Curie temperature (Tc) which is as high as 750 K in order to enable magnetic writing. The thermal response of the media becomes very critical for the success of the data writing process. In this paper, a new method is proposed to understand the transient thermal behavior of the HAMR media. The temperature response of the media is measured based on thermal erasure of the magnetically written signal. A lumped model is built to simplify the heat conduction problem to understand the transient thermal response. Finite element modeling (FEM) is implemented to simulate the transient thermal response of the media due to the laser pulse heating. The experimental and simulation results show fairly good agreement.
A Bioinspired Approach Combining L-Systems and Cellular Automata for Distributed Self-Reconfiguration of UBot Modular Robotic Systems
Authors: Bie Dongyang , Zhu Yanhe , Fan JiZhuang , Wang Xiaolu , Zhang Yu , Zhao Jie
Published: September 2016

Self-reconfiguration of Modular Self-Reconfigurable (MSR) robots is a fundamental primitive that can be used as part of higher-lever functionality. The biological principle of self-organizing and growth in both animals and plants is learned to solve the automatic planning of configuration and control methods. A bioinspired approach is proposed for distributed self-reconfiguration. This method aims at utilizing the self-organization and pattern emergence of the MSR robotic system, which is made of large quantity of modules to promote the system to reconfigure in the direction of adapting to environments and tasks. This mechanism is hybrid by combining Lindenmayer systems (L-systems) and Cellular Automata (CA). L-systems are introduced for defining global structure and providing topological description. Cellular Automata (CA) handle motion planning of distributed modules. This method is absolutely distributed and convergent to self-adaptive structures with desired organizing principles. The convergence of proposed method is verified through simulations and experiments on UBot robots.
Dual Si3N4 Charge Trapping Layer (SONNOS) Nonvolatile Memory With Ultra-Thin Body Trench Poly-Si Junctionless FET for 3D NAND Applications
Authors: Wu Yung-Chun , Lin Yu-Ru , Chiang Yi-Wei , Wang Wei-Cheng
Published: September 2016

This work presents the structure Junctionless FinFET (JLFinFET) based on ultra-thin body (UTB) with double stacked Si3N4 charge trapping layer (NN-CTL) Si-SiO2-Si3N4-Si3N4-SiO2-Si (SONNOS) nonvolatile memory (NVM). The device shows excellent transistor performances including steep sub-threshold swing (SS) of 76 mV/dec, favorable Vth, and high Ion/Ioff ratio (>107). For n-channel device, it shows excellent memory characteristics, high program/erase (P/E) performance, good endurance (>104 cycles) and an excellent 95∼99% electron retention at 85°C for 10 years.
A Real Time Cost Effective Geometry Calibration Method for Isocenter Tracking of a Rotating Gantry Using Optical Vision Sensors
Authors: Li Zheng Yuan , Ryo Sungsoo , Lee Hyuk Jin , Koo Ja Choon
Published: September 2016

In this paper, a real time and cost effective deformation sensor system is proposed to verify isocenter sphere of a dual-head radiation imaging device within its driving range. For the effectiveness in sensing, installation point was decided according to the finite element deformation analysis of the device model. The proposed sensor was implemented to the device, and then the result was evaluated by comparison with an optical tracker position data. In this method, attachable optical system were designed and implemented to the dedicated radiography system. From the attachment test relative deformation data of two orthogonal X-Ray tube and detector sets were obtained simultaneously by two image sensors attached on each of them. Laser spot orbits were obtained as a result, and were compared with optical tracker data results for verification. The proposed method significantly reduces costs and time spent for calibration process while satisfying micro scale precision requirements and it is applicable to other rotation mechanical system. Comprising devices costs much less than the manufacturing or purchasing a dedicated geometry phantoms, because this method only requires a low powered spot laser and a CMOS Camera plus additional optical devices.
Big Data Analytics: Prediction of Surface Defects on Steel Slabs Based on One Class Support Vector Machine
Authors: Hsu Chao-Yung , Kang Li-Wei , Weng Ming-Fang
Published: September 2016

Visible surface defects are common in steel products, such as crack or scratch defects on steel slabs (a main product of the upstream production line in a steel production line). In order to prevent propagation of defects from the upstream to the downstream production lines, it is important to predict or detect the defects in earlier stage of a steel production line, especially for the defects on steel slabs. In this paper, we address the problem regarding the prediction of surface defects on continuous casting steel slabs. The main goal of this paper is to accurately predict the occurrence of surface defects on steel slabs based on the online collected data from the production line. Accurate prediction of surface defects would be helpful for online adjusting the process and environmental factors to promote producibility and reduce the occurrence of defects, which should be more useful than only inspection of defects. The major challenge here is that the amounts of samples for normal cases and defects are usually unbalanced, where the number of defective samples is usually much fewer than that of normal cases. To cope with the problem, we formulate the problem as a one class classification problem, where only normal training data are used. To solve the problem, we propose to learn a one-class SVM (support vector machine) classifier based on online collected process data and environmental factors for only normal cases to predict the occurrence of defects for steel slabs. Our experimental results have demonstrated that the learned one class SVM (OCSVM) classifier performs better prediction accuracy than the traditional two-class SVM classifier (relying on both positive and negative training samples) used for comparisons.
Simulation of Contact at Head and Multilayer Disk Interface Under Quasi-Static Condition
Authors: Hongrui Ao , Zhiying Han , Kai Zhang , Hongyuan Jiang
Published: September 2016

The reduction of head-media separation (HMS) results in a decreased flying height. Consequently, the contact probability between the slider and the lubricant layer or hard overcoat surface on the disks will increase greatly. Therefore, investigating the contact stress of the disk is vital for improving the reliability of the head disk interface. In this study, a rigid hemisphere sliding over a multilayer thin film half-space is implemented to simulate the contact between the recording slider and the magnetic storage multilayer disk under the quasi-static condition. The effects of different parameters such as normal load, friction coefficient and radius of slider on the von Mises, shear and principal stresses in the multilayer system are analyzed by using finite element method (FEM).
Experimental Investigation of the Effect of Hydrocarbon Oil Contamination on a Disk Surface
Authors: Seo Young Woo , Ovcharenko Andrey , Yan Yongqi , Talke Frank E.
Published: September 2016

Hydrocarbon oil is used to lubricate the spindle motor as well as the pivot actuator arm in current hard disk drives. Previous investigations using molecular dynamics have shown that hydrocarbon oil can contaminate the head-disk interface. In this paper, an experimental study is conducted to investigate the mechanism of hydrocarbon oil contamination on the disk surface using contact angle measurements, atomic force microscopy (AFM), ellipsometry, and gas chromatography mass spectrometry (GC-MS).
Dynamic sound scattering: Field fluctuation spectroscopy with singly scattered ultrasound in the near and far fields
Authors: Cowan M. L. , Page J. H. , Norisuye T. , Weitz D. A.
Published: September 2016

Dynamic sound scattering (DSS) is a powerful acoustic technique for investigating the motion of particles or other inclusions inside an evolving medium. In DSS, this dynamic information is obtained by measuring the field autocorrelation function of the temporal fluctuations of singly scattered acoustic waves. The technique was initially introduced 15 years ago, but its technical aspects were not adequately discussed then. This paper addresses the need for a more complete account of the method by describing in detail two different implementations of this sound scattering technique, one of which is specifically adapted to a common experimental situation in ultrasonics. The technique is illustrated by the application of DSS to measure the mean square velocity fluctuations of particles in fluidized suspensions, as well as the dynamic velocity correlation length. By explaining the experimental and analytical methods involved in realizing the DSS technique in practice, the use of DSS will be facilitated for future studies of particulate suspension dynamics and particle properties over a wide range of particle sizes and concentrations, from millimeters down to nanometers, where the use of optical techniques is often limited by the opacity of the medium.
Posttranslational mutagenesis: A chemical strategy for exploring protein side-chain diversity
Authors: Wright Tom H. , Bower Ben J. , Chalker Justin M. , Bernardes Gonçalo J. L. , Wiewiora Rafal , Ng Wai-Lung , Raj Ritu , Faulkner Sarah , Vallée M. Robert J. , Phanumartwiwath Anuchit , Coleman Oliver D. , Thézénas Marie-Laëtitia , Khan Maola , Galan Sébastien R. G. , Lercher Lukas , Schombs Matthew W. , Gerstberger Stefanie , Palm-Espling Maria E. , Baldwin Andrew J. , Kessler Benedikt M. , Claridge Timothy D. W. , Mohammed Shabaz , Davis Benjamin G.
Published: September 2016

Radicals push proteins beyond genes

Chemically modifying proteins after their translation can expand their structural and functional roles (see the Perspective by Hofmann and Bode). Two related methods describe how to exploit free radical chemistry to form carbon-carbon bonds between amino acid residues and a selected functional group. Wright
et al.
added a wide range of functional groups to proteins containing dehydroalanine precursors, with borohydride mediating the radical chemistry. Yang
et al.
employed a similar approach, using zinc in combination with copper ions. Together, these results will be useful for introducing functionalities and labels to a wide range of proteins.

Science
, this issue pp.
597
and
623
; see also p.
553
Exploiting a host-commensal interaction to promote intestinal barrier function and enteric pathogen tolerance
Authors: Pedicord Virginia A. , Lockhart Ainsley A. K. , Rangan Kavita J. , Craig Jeffrey W. , Loschko Jakob , Rogoz Aneta , Hang Howard C. , Mucida Daniel
Published: September 2016

A secreted bacterial protein protects worms and mice from
Salmonella
pathogenesis.
Complete Genome Sequence of Feline Calicivirus Strain GX01-2013 Isolated from Household Cats in Guangxi, Southern China
Authors: He Ping , Zhou Huabo , Zhao Weifeng , He Jianqiao , Li Ruikai , Ding Yangbao , Chen Quanjiang , Liu Lin , Wei Zuzhang , Huang Weijian , Chen Ying
Published: September 2016

Here, we report the complete genome of a feline calicivirus (FCV) originating from household cats in Guangxi, southern China, in September 2013. To understand its genetic characteristics, we isolated FCV strain GX01-2013 from MDCK cells and determined its complete genome sequence.
Identification and Whole-Genome Sequencing of Four Enterovirus D68 Strains in Southern China in Late 2015
Authors: Chen Long , Shi Lei , Yang Hong , Gu Da-Yong , Meng Jun , Xu Yun-Qing , Yao Xiang-Jie , Zhang Hai-Long , Cheng Jin-Quan , Ma Han-Wu , Zhang Ren-Li , He Ya-Qing
Published: September 2016

Four enterovirus D68 (EV-D68) strains from four children with influenza-like illness were identified in Shenzhen, southern China, in late 2015. Here, we announce the availability of these viral genomes in GenBank. The genomic sequences of these EV-D68 strains showed the closest phylogenetic relationship to strains from northern China.
Complete Genome Sequence of the Intracellular Bacterial Symbiont TC1 in the Anaerobic Ciliate
Trimyema compressum
Authors: Shinzato Naoya , Aoyama Hiroaki , Saitoh Seikoh , Nikoh Naruo , Nakano Kazuma , Shimoji Makiko , Shinzato Misuzu , Satou Kazuhito , Teruya Kuniko , Hirano Takashi , Yamada Takanori , Nobu Masaru K. , Tamaki Hideyuki , Shirai Yumi , Park Sanghwa , Narihiro Takashi , Liu Wen-Tso , Kamagata Yoichi
Published: September 2016

A free-living ciliate,
Trimyema compressum
, found in anoxic freshwater environments harbors methanogenic archaea and a bacterial symbiont named TC1 in its cytoplasm. Here, we report the complete genome sequence of the TC1 symbiont, consisting of a 1.59-Mb chromosome and a 35.8-kb plasmid, which was determined using the PacBio RSII sequencer.
Faecal microbiota transplantation for recurringClostridium difficileinfection in a patient with Crohn's disease and ileorectal anastomosis
Authors: Oppfeldt Asser Mathiassen , Dahlerup Jens F , Christensen Lisbet A , Hvas Christian L
Published: September 2016

Faecal microbiota transplantation (FMT) is increasingly being used to treat refractory and recurringClostridium difficileinfection (CDI). Although FMT appears to be safe and highly effective in patients with a preserved colon and immunocompetence, its use in patients with inflammatory bowel disease (IBD) who are on immunomodulating therapies is controversial. In particular, patients who have undergone colectomy may have different treatment responses to FMT. In this case report, we describe the successful use of FMT in a female patient aged 19 years with Crohn's disease who underwent ileorectal anastomosis following colectomy. She had recurrent CDIs that were refractory to metronidazole, pulse-tapered vancomycin and fidaxomicin treatments. She underwent 2 FMTs, which were performed via sigmoidoscopy; her mother served as a donor. Follow-up was conducted for 12 months and indicated sustained remission of CDI.
Impact of the Nordic hamstring and hip extension exercises on hamstring architecture and morphology: implications for injury prevention
Authors: Bourne Matthew N , Duhig Steven J , Timmins Ryan G , Williams Morgan D , Opar David A , Al Najjar Aiman , Kerr Graham K , Shield Anthony J
Published: September 2016

Background

The architectural and morphological adaptations of the hamstrings in response to training with different exercises have not been explored.

Purpose

To evaluate changes in biceps femoris long head (BFLH) fascicle length and hamstring muscle size following 10-weeks of Nordic hamstring exercise (NHE) or hip extension (HE) training.

Methods

30 recreationally active male athletes (age, 22.0±3.6 years; height, 180.4±7 cm; weight, 80.8±11.1 kg) were allocated to 1 of 3 groups: (1) HE training (n=10), NHE training (n=10), or no training (control, CON) (n=10). BFLHfascicle length was assessed before, during (Week 5) and after the intervention with a two-dimensional ultrasound. Hamstring muscle size was determined before and after training via MRI.

Results

Compared withbaseline, BFLHfascicles were lengthened in the NHE and HE groups atmid-training(d=1.12–1.39, p<0.001) andpost-training(d=1.77–2.17, p<0.001) and these changes did not differ significantly between exercises (d=0.49–0.80, p=0.279–0.976). BFLHvolume increased more for the HE than the NHE (d=1.03, p=0.037) and CON (d=2.24, p<0.001) groups. Compared with the CON group, both exercises induced significant increases in semitendinosus volume (d=2.16–2.50, ≤0.002) and these increases were not significantly different (d=0.69, p=0.239).

Conclusion

NHE and HE training both stimulate significant increases in BFLHfascicle length; however, HE training may be more effective for promoting hypertrophy in the BFLH.
Effective psychological and psychosocial approaches to reduce repetition of self-harm: a systematic review, meta-analysis and meta-regression
Authors: Hetrick Sarah E , Robinson Jo , Spittal Matthew J , Carter Greg
Published: September 2016

Objective

To examine the efficacy of psychological and psychosocial interventions for reductions in repeated self-harm.

Design

We conducted a systematic review, meta-analysis and meta-regression to examine the efficacy of psychological and psychosocial interventions to reduce repeat self-harm in adults. We included a sensitivity analysis of studies with a low risk of bias for the meta-analysis. For the meta-regression, we examined whether the type, intensity (primary analyses) and other components of intervention or methodology (secondary analyses) modified the overall intervention effect.

Data sources

A comprehensive search of MEDLINE, PsycInfo and EMBASE (from 1999 to June 2016) was performed.

Eligibility criteria for selecting studies

Randomised controlled trials of psychological and psychosocial interventions for adult self-harm patients.

Results

Forty-five trials were included with data available from 36 (7354 participants) for the primary analysis. Meta-analysis showed a significant benefit of all psychological and psychosocial interventions combined (risk ratio 0.84; 95% CI 0.74 to 0.96; number needed to treat=33); however, sensitivity analyses showed that this benefit was non-significant when restricted to a limited number of high-quality studies. Meta-regression showed that the type of intervention did not modify the treatment effects.

Conclusions

Consideration of a psychological or psychosocial intervention over and above treatment as usual is worthwhile; with the public health benefits of ensuring that this practice is widely adopted potentially worth the investment. However, the specific type and nature of the intervention that should be delivered is not yet clear. Cognitive–behavioural therapy or interventions with an interpersonal focus and targeted on the precipitants to self-harm may be the best candidates on the current evidence. Further research is required.
25-year trends in gender disparity for obesity and overweight by using WHO and IOTF definitions among Chinese school-aged children: a multiple cross-sectional study
Authors: Song Yi , Wang Hai-Jun , Dong Bin , Ma Jun , Wang Zhiqiang , Agardh Anette
Published: September 2016

Objectives

We sought to explore 25-year trends of gender disparity in the prevalence of obesity and overweight both in urban and rural areas among Chinese children from 1985 to 2010.

Methods

Data included 1 280 239 children aged 7–18 years enrolled in the Chinese National Survey on Students's Constitution and Health (CNSSCH), which is the largest nationally representative sample of school-aged children in China. Obesity and overweight were defined according to both WHO and the International Obesity Task Force (IOTF) definitions. Logistic regression was used to estimate the prevalence OR (POR) of gender for obesity and overweight prevalence in different surveys.

Results

The prevalence of obesity increased (WHO definition: from 0.10% to 4.3%; IOTF definition: from 0.03% to 2.2%) over the past 25 years in urban and rural areas among Chinese children and it was much higher among boys than girls at each survey point (p<0.01). The increasing trend was significant in all age subgroups (p<0.01). Although the prevalence of obesity continuously increased in boys and girls, the changing pace was more rapid in boys than in girls. PORs of boys versus girls for obesity also increased over time, and the estimates of PORs were higher in urban areas than in rural areas at each survey point.

Conclusions

The gradually increasing gender disparity in urban and rural areas suggests that the prevalence of obesity and overweight in boys, and especially in urban boys, contributes to a large and growing proportion of obese and overweight children.
Prescriber preferences for behavioural economics interventions to improve treatment of acute respiratory infections: a discrete choice experiment
Authors: Gong Cynthia L , Hay Joel W , Meeker Daniella , Doctor Jason N
Published: September 2016

Objective

To elicit prescribers' preferences for behavioural economics interventions designed to reduce inappropriate antibiotic prescribing, and compare these to actual behaviour.

Design

Discrete choice experiment (DCE).

Setting

47 primary care centres in Boston and Los Angeles.

Participants

234 primary care providers, with an average 20 years of practice.

Main outcomes and measures

Results of a behavioural economic intervention trial were compared to prescribers' stated preferences for the same interventions relative to monetary and time rewards for improved prescribing outcomes. In the randomised controlled trial (RCT) component, the 3 computerised prescription order entry-triggered interventions studied included: Suggested Alternatives (SA), an alert that populated non-antibiotic treatment options if an inappropriate antibiotic was prescribed; Accountable Justifications (JA), which prompted the prescriber to enter a justification for an inappropriately prescribed antibiotic that would then be documented in the patient's chart; and Peer Comparison (PC), an email periodically sent to each prescriber comparing his/her antibiotic prescribing rate with those who had the lowest rates of inappropriate antibiotic prescribing. A DCE study component was administered to determine whether prescribers felt SA, JA, PC, pay-for-performance or additional clinic time would most effectively reduce their inappropriate antibiotic prescribing. Willingness-to-pay (WTP) was calculated for each intervention.

Results

In the RCT, PC and JA were found to be the most effective interventions to reduce inappropriate antibiotic prescribing, whereas SA was not significantly different from controls. In the DCE however, regardless of treatment intervention received during the RCT, prescribers overwhelmingly preferred SA, followed by PC, then JA. WTP estimates indicated that each intervention would be significantly cheaper to implement than pay-for-performance incentives of $200/month.

Conclusions

Prescribing behaviour and stated preferences are not concordant, suggesting that relying on stated preferences alone to inform intervention design may eliminate effective interventions.

Trial registration number

NCT01454947; Results.
Lactate minimum underestimates the maximal lactate steady-state in swimming mice
Authors: Rodrigues Natalia Almeida , Torsoni Adriana Souza , Fante Thais , dos Reis Ivan Gustavo Masselli , Gobatto Claudio Alexandre , Manchado-Gobatto Fúlvia Barros
Published: September 2016

The intensity of lactate minimum (LM) has presented a good estimate of the intensity of maximal lactate steady-state (MLSS); however, this relationship has not yet been verified in the mouse model. We proposed validating the LM protocol for swimming mice by investigating the relationship among intensities of LM and MLSS as well as differences between sexes, in terms of aerobic capacity. Nineteen mice (male: 10, female: 9) were submitted to the evaluation protocols for LM and MLSS. The LM protocol consisted of hyperlactatemia induction (30 s exercise (13% body mass (bm)), 30 s resting pause and exhaustive exercise (13% bm), 9 min resting pause and incremental test). The LM underestimated MLSS (mice: 17.6%; male: 13.5%; female: 21.6%). Pearson’s analysis showed a strong correlation among intensities of MLSS and LM (male (r = 0.67, p = 0.033); female (r = 0.86, p = 0.003)), but without agreement between protocols. The Bland−Altman analysis showed that bias was higher for females (1.5 (0.98) % bm; mean (MLSS and LM): 4.4%–6.4% bm) as compared with males (0.84 (1.24) % bm; mean (MLSS and LM): 4.5%–7.5% bm). The error associated with the estimated of intensity for males was lower when compared with the range of means for MLSS and LM. Therefore, the LM test could be used to determine individual aerobic intensity for males (considering the bias) but not females. Furthermore, the females supported higher intensities than the males. The differences in body mass between sexes could not explain the higher intensities supported by the females.
Dynamics of tax evasion through an epidemic-like model
Authors: Brum Rafael M. , Crokidakis Nuno
Published: September 2016

In this work, we study a model of tax evasion. We considered a fixed population divided in three compartments, namely honest tax payers, tax evaders and a third class between the mentioned two, which we call susceptibles to become evaders. The transitions among those compartments are ruled by probabilities, similarly to a model of epidemic spreading. These probabilities model social interactions among the individuals, as well as the government’s fiscalization. We simulate the model on fully-connected graphs, as well as on scale-free and random complex networks. For the fully-connected and random graph cases, we observe that the emergence of tax evaders in the population is associated with an active-absorbing nonequilibrium phase transition, that is absent in scale-free networks.
Proposal for a material with negative thermal expansion
Authors: Abdullah Mikrajuddin
Published: September 2016

I propose a model of a material that exhibits negative thermal expansion (NTE) properties and criteria for the occurrence of linear and volumetric NTE. I derived the criteria for an arbitrary force between rigid units in the material. These criteria are also discussed specifically for the Lennard–Jones (6–12) potential and in more detail for metal–organic framework (MOF) materials comprising rigid units connected by organic linkers. Qualitatively, the model predictions can explain some observed results. Surprisingly, the model can produce equations for the transition temperature from NTE to positive thermal expansion (PTE), [Formula: see text] K, which is exactly the same as the temperature at which the glass transition begins to occur in most polymers, i.e., [Formula: see text] K.
Estimation of Synchronization Patterns of Chaotic Systems in Cartesian Product Networks with Delay Couplings
Authors: Oooka Kanaru , Oguchi Toshiki
Published: September 2016

This paper considers synchronization problems in networks of chaotic systems with time-delayed couplings. First of all, we show that synchronization patterns can be estimated from eigenvectors of the graph Laplacian related to the scaling method for synchronization conditions. Then, we consider synchronization in Cartesian product networks. By combining the proposed estimation method with the properties of the Cartesian product, we can easily detect synchronization patterns emerging in the Cartesian product networks from the eigenvalues of the original networks. Some numerical examples are provided to demonstrate the validity of the proposed estimation method.
Exact Traveling Wave Solutions and Bifurcations for a Shallow Water Equation Modeling Surface Waves of Moderate Amplitude
Authors: Zhu Wenjing , Li Jibin
Published: September 2016

In this paper, we consider the traveling wave solutions for a shallow water equation. The corresponding traveling wave system is a singular planar dynamical system with one singular straight line. On the basis of the theory of the singular traveling wave systems, we obtain the bifurcations of phase portraits and explicit exact parametric representations for solitary wave solutions and smooth periodic wave solutions, as well as periodic peakon solutions. We show the existence of compacton solutions of the equation under different parameter conditions.
Extremal charged Vaidya and its near horizon geometry
Authors: Sadeghian S. , Shafiekhani A.
Published: September 2016

Recently [Formula: see text]-dimensional spherically symmetric charged Vaidya black hole solution has been constructed. We observe that this nonstationary solution admits extremal limit and study its near horizon geometry. We show that the symmetry of the near horizon geometry is [Formula: see text]. Our analysis shows that the theorems for the near horizon geometry of stationary extremal black holes, may be extended to nonstationary cases.