bluuebunny/crossref_metadata_2025 huggingface dataset:
Saving Our Marine Archives
Authors: Dassié Emilie , DeLong Kristine , Kilbourne Hali , Williams Branwen , Abram Nerilie , Brenner Logan , Brahmi Chloé , Cobb Kim , Corrège Thierry , Dissard Delphine , Emile-Geay Julien , Evangelista Heitor , Evans Michael , Farmer Jesse , Felis Thomas , Gagan Michael , Gillikin David , Goodkin Nathalie , Khodri Myriam , Lavagnino Ana , LaVigne Michèle , Lazareth Claire , Linsley Braddock , Lough Janice , McGregor Helen , Nurhati Intan , Ouellette Gilman , Perrin Laura , Raymo Maureen , Rosenheim Brad , Sandstrom Michael , Schöne Bernd , Sifeddine Abdelfettah , Stevenson Samantha , Thompson Diane , Waite Amanda , Wanamaker Alan , Wu Henry
Published: February 2017

A concerted effort has begun to gather and preserve archives of marine samples and descriptive data, giving scientists ready access to insights on ancient environments.
Targeting bone morphogenetic protein signalling in midbrain dopaminergic neurons as a therapeutic approach in Parkinson's disease
Authors: O'Keeffe Gerard W. , Hegarty Shane V. , Sullivan Aideen M.
Published: February 2017

Parkinson's disease (PD) is the second most common neurodegenerative disease, characterized by the degeneration of midbrain dopaminergic (mDA) neurons and their axons, and aggregation of α-synuclein, which leads to motor and late-stage cognitive impairments. As the motor symptoms of PD are caused by the degeneration of a specific population of mDA neurons, PD lends itself to neurotrophic factor therapy. The goal of this therapy is to apply a neurotrophic factor that can slow down, halt or even reverse the progressive degeneration of mDA neurons. While the best known neurotrophic factors are members of the glial cell line-derived neurotrophic factor (GDNF) family, their lack of clinical efficacy to date means that it is important to continue to study other neurotrophic factors. Bone morphogenetic proteins (BMPs) are naturally secreted proteins that play critical roles during nervous system development and in the adult brain. In this review, we provide an overview of the BMP ligands, BMP receptors (BMPRs) and their intracellular signalling effectors, the Smad proteins. We review the available evidence that BMP–Smad signalling pathways play an endogenous role in mDA neuronal survival in vivo, before outlining how exogenous application of BMPs exerts potent effects on mDA neuron survival and axon growth in vitro and in vivo. We discuss the molecular mechanisms that mediate these effects, before highlighting the potential of targeting the downstream effectors of BMP–Smad signalling as a novel neuroprotective approach to slow or stop the degeneration of mDA neurons in PD.
Reference‐invariant permittivity and thickness measurement of lossy liquid materials
Authors: Hasar U.C. , Bute M.
Published: February 2017

A microwave method has been proposed to retrieve the complex permittivity and thickness of lossy dielectric liquids, which result in at least 10 dB attenuation, using reference‐plane‐invariant reflection scattering (S‐) parameters. The CST Microwave Studio simulation program was first used to validate the method. Then, the permittivity and thickness of lossy distilled water sample poured over a polyethylene sample holder were measured from reference‐invariant reflection‐only S‐parameter measurements at the X‐band. The method was compared with other methods in the literature to analyse its accuracy.
Low power‐consumption mid‐infrared distributed feedback quantum cascade laser for gas‐sensing application
Authors: Hashimoto J. , Yoshinaga H. , Mori H. , Tsuji Y. , Murata M. , Kato T. , Ekawa M. , Iguchi Y. , Katsuyama T.
Published: February 2017

A low power‐consumption distributed feedback quantum cascade laser (DFB‐QCL) is developed for gas‐sensing in 7 μm wavelength region. The threshold power‐consumption was as low as 0.93 W with the sufficient output power of 20 mW at 20°C under continuous‐wave condition. In addition, it maintained a single‐mode operation between −40 and 50°C without a mode‐hopping, leading to a total wavelength shift of 66 nm. This DFB‐QCL would be suitable for gas‐sensing application.
Ka‐band compact and high‐performance bandpass filter based on multilayer air‐filled SIW
Authors: Parment F. , Ghiotto A. , Vuong T.‐P. , Duchamp J.‐M. , Wu K.
Published: February 2017

A substantial reduction of substrate integrated waveguide (SIW) insertion loss can be achieved through the use of air as dielectric instead of usual dielectric material. However, air‐filled SIW (AFSIW) circuits exhibit larger footprint compared with their dielectric‐filled counterparts. A compact multilayer AFSIW bandpass ﬁlter is proposed to realise both high‐performance and small footprint. For demonstration purpose, a Ka‐band multilayer fourth‐order AFSIW bandpass filter has been designed and fabricated. Measured and simulated results are in good agreement. Retro‐simulations, taking into account fabrication tolerances, are also presented. Finally, a performance comparison with other multilayer technologies is presented.
Full 4‐port deembedding of differential transmission line interfaces by 2‐port reflection measurements with mode conversion excitation
Authors: Ritter P. , Möller M.
Published: February 2017

An approach is presented for the determination of the 4 × 4 transmission matrix of differential transmission line interfaces on a microchip fixture. Different settings of a simple calibration structure that extends the already available 50‐Ω on‐chip termination excite different transmission modes, which are used for the determination of the transmission matrix in mixed mode parameter form. Only reflection measurements at the two easily accessible connectors of the fixture are required, which enables an in‐situ deembedding of the chip performance while mounted.
Low‐power DSM‐UWB RFID‐based sensor system with low‐process sensitivity
Authors: Bao Dongxuan , Zou Zhuo , Qin Yajie , Zheng Li‐Rong
Published: February 2017

This Letter presents a RFID‐based sensor system targeting internet of everything (IOE) application. The system consists of a sensor tag with time‐domain sensor interface and a software defined radio receiver as the reader. In the proposed tag, a dual slope modulation (DSM) sensor interface combined with UWB transmitter (TX) is used to convert and transmit the sensing information in time domain. The sensor interface employs the DSM to reduce the output deviation caused by process variations. Moreover, the approach removes the need of time‐to‐digital converter (TDC) on tag and only three pulses are sent for each sample, resulting in significant power saving. On the reader side, the UWB pulses are detected and the intervals corresponding to the input signal are measured by a TDC. The UWB TX and DSM block of sensor tag is implemented in 0.18 μm CMOS process and FPGA, respectively. The system demonstrates 8‐bit ENOB at 98 kS/s sampling rate. The mean percentage error of output results is less than ±0.5% under ±10% process variation. The power consumption of the tag is 127 μW with an figures of merit (FoM) of 5 pJ/conv.step, which is suitable for wirelessly powered IOE application.
Self‐biasing memristor crossbar used for string matching and ternary content‐addressable memory implementation
Authors: Yakopcic C. , Bontupalli V. , Hasan R. , Mountain D. , Taha T.M.
Published: February 2017

A memristor crossbar‐based technique for highly parallel string matching is presented. An input string can be simultaneously compared against a bank of stored words, each having a different length, due to the self‐biasing nature of the crossbar circuit. This string matching system essentially acts as a ternary content‐addressable memory (TCAM). Owing to the high‐density nature of nanoscale memristor crossbars, this system can provide a significant area reduction when compared alternative TCAM designs while remaining competitive in terms of timing and energy.
Sparsity‐based SFCW‐GPR autofocusing imaging method under EM wave velocity uncertainty
Authors: Qu Lele , Ge Yanan , Yang Tianhong
Published: February 2017

To tackle the problem of the uncertainty of EM wave propagation velocity in the subsurface medium, a novel sparsity‐based autofocusing imaging method for stepped frequency continuous wave ground penetrating radar system is proposed. On the basis of the parametric sparse recovery method, the proposed imaging method exploits the sequential L0 and L2 norms minimisation strategy to simultaneously retrieve the EM wave propagation velocity information and the high‐quality focused image. Experimental results demonstrate the validity and effectiveness of the proposed imaging method.
Generalised benders decomposition‐based load optimisation in cellular and public WLAN interworking network
Authors: Zhou Fanqin , Li Wenjing , Feng Lei , Yu Peng , Meng Luoming
Published: February 2017

To realise load optimisation in cellular and public wireless local area network (WLAN) interworking network, a fairness preferred throughput maximisation (FPTM) optimisation model and a particular algorithm for it named joint UE‐AN association and resource allocation optimisation based on generalised benders decomposition are proposed in the study. The derived solution will give guidance on UE's access selection and resource allocation in cellular network to optimise the overall performance of the interworking network. Simulation results validate the performance on optimising access load in the interworking networks of FPTM model, which can practically enhance the effect of offloading from cellular network to WLAN and improve the total throughput.
Analysis of link availability and capacity in multiple‐input/single‐output‐Bose–Chaudhuri–Hocquenghem FSO systems under various turbulence conditions with pointing errors
Authors: Khodadadi Hamid R. , Ghezel Ayagh Mohammad H. , Chaman Motlagh Abolfazl
Published: February 2017

Free‐space optical (FSO) communication is highly sensitive to atmospheric turbulence. The gamma–gamma model has been used as it describes the behaviour of a wide range of atmospheric conditions with a good agreement. In this study, closed‐form expressions for calculating the bit error rate, the outage probability and ergodic capacity have been proposed for the gamma–gamma atmospheric turbulence channel with pointing errors. The performance of FSO for three turbulence mitigation techniques: aperture averaging, multiple‐input/single‐output and Bose–Chaudhuri–Hocquenghem block code have been investigated. Analytical results are depicted by using a realistic set of system parameter values, to lend a helpful insight into the performance of source–destination link distance of 10km in FSO communication system under atmospheric turbulence conditions.
Distributed outlier detection algorithm based on credibility feedback in wireless sensor networks
Authors: Feng Hailin , Liang Lun , Lei Hua
Published: February 2017

This study proposes a distributed outlier detection algorithm based on credibility feedback in wireless sensor networks. The algorithm consists of three stages, which are evaluating the initial credibility of sensor nodes, evaluating the final credibility based on credibility feedback and Bayesian theorem, and adjusting for the outlier set. Simulation results verify that the algorithm can achieve high detection accuracy and low false alarm rate, even in the situation that the network with a large number of outliers.
Jointly optimal rate control and total transmission power for cooperative cognitive radio system
Authors: Soleimanpour‐moghadam Mohadese , Talebi Siamak
Published: February 2017

In this study, the authors apply the multi‐objective optimisation (MOO) methods to the challenge posed by joint rate maximisation and total transmission power (TTP) minimisation in cooperative cognitive radio networks. The proposed MOO methods which are based on amplify and forward relaying strategy optimise the two conflicting objectives and, at same time, they maximise the rate quality and minimise the TTP allocated to the network relays simultaneously. The MOO problem under investigation is a non‐convex non‐linear combinatorial optimisation one that three MOO methods are presented for a desired solution. The explored methods are: weighted sum algorithm (which is based on a simplistic model), MOO fractional programming method (which has much in common with their MOO problem) and lexicographic algorithm (which is suitably adapted to complex combinatorial optimisation environments due to its robustness in avoiding trapping in local optima). Their simulation results confirm the proposed methods’ effectiveness for simultaneous rate maximisation and TTP minimisation as well as their superiority over counterpart algorithms.
Fingerprint localisation algorithm for noisy wireless sensor network based on multi‐objective evolutionary model
Authors: Fang Xuming , Nan Lei , Jiang Zonghua , Chen Lijun
Published: February 2017

Fingerprint localisation technology using received signal strength indication (RSSI) has become one of the hot spots in the research field of indoor positioning based on wireless sensor networks (WSNs). Due to the presence of the measurement noise of the RSSI, the weight of the calibration point in the current fingerprint positioning algorithm is not optimised. The authors propose a fingerprint localisation algorithm for noisy WSNs based on an innovative multi‐objective evolutionary model. The proposed algorithm at first employs the Kalman filter to filter the abnormal RSSI value, and then utilises a noise covariance estimator to perceive the noise covariance of the RSSI. Finally, the multi‐objective evolutionary model is used to search for the optimised weight of the calibration point via the filtered RSSI and the perceived noise covariance. That the novel evolutionary model can find the best fingerprint estimate with the optimised weight has been proven theoretically in this work. Extensive experimental results on an off‐the‐shelf WSN testbed show that the authors’ proposed algorithm improves the accuracy of the state‐of‐the‐art fingerprint positioning algorithm by at least 50% regardless of the placement of the target node, the number of beacon nodes, the size of the calibration cell, and the number of nearest neighbours.
Energy‐aware resource allocation for OFDMA wireless networks with hybrid energy supplies
Authors: Qin Meng , Yang Qinghai , Yang Jian , Park Daeyoung , Kwak Kyung Sup
Published: February 2017

In this study, the authors investigate the resource allocation for orthogonal frequency‐division multiple access (OFDMA) wireless networks, where the base station is powered by renewable energy and electric grid. To fully exploit the renewable energy, the authors propose an energy‐aware resource allocation (EARA) algorithm to maximise the network utility, which captures the tradeoff between the system throughput and the grid energy consumption. Specifically, the EARA algorithm only has to track the current system states (e.g. channel and queueing conditions) without requiring a relevant priori distribution knowledge, making it applicable for practical OFDMA wireless networks with unpredictable channel dynamics, renewable energy arrivals and stochastic traffics. Moreover, the performance achieved by the EARA algorithm is theoretically characterised. Most importantly, the authors develop an implementation architecture to take the EARA algorithm into practice, and also analyse the low implementation costs (e.g. low computational complexity, trivial signalling overhead etc.). Finally, simulation results verify the theoretical analysis and also demonstrate the advantages of the EARA algorithm.
Effect of composite channel aging on the spectral efficiency of multi‐pair massive multiple‐input multiple‐output amplify‐and‐forward relay networks
Authors: Chen Yuanyuan , Liu Chen , Wang Hairong , Zhu Wei‐Ping
Published: February 2017

This study investigates the spectral efficiency of multi‐pair massive multiple‐input multiple‐output amplify‐and‐forward relay networks by considering the composite channel aging effect. The rational of this work is that the channel aging effect caused by phase noise and node movements is an inevitable practical channel impairment in time‐varying fading channels and substantially degrades the performance. The proposed model comprises multiple sources and multiple destinations, each equipped with a single antenna, which communication via a relay equipped with a very large number of antennas by employing maximal‐ratio combining/maximum‐ratio transmission. Based on this model, the authors first derive a closed‐form lower bound expression for the achievable rate of per source–destination pair. Then, by using the derived expression, they study how the transmitted powers of each source and the relay can be reduced without compromising the spectral efficiency when the number of relay antennas approaches infinity. They also discuss the effect of channel aging coefficients, including Doppler shift and phase noise increment variance, on the asymptotic spectral efficiency under different power scaling laws. Both theoretical analysis and Monte Carlo simulations disclose that the channel aging effect does not affect the power scaling laws but degrades the spectral efficiency.
Hop‐by‐hop Relay Selection strategy for multi‐hop relay networks with imperfect CSI
Authors: Sun Hui , Naraghi‐Pour Mort
Published: February 2017

A hop‐by‐hop relay selection (RS) strategy for multi‐hop decode‐and‐forward cooperative relay networks referred to as Max‐DS is proposed. In this method, RS in each stage is only based on the channel state information (CSI) to relays in the next stage. In each stage, relays that successfully receive and decode the message from the previous stage form the candidate set for relaying, and among them, the relay with the largest number of ‘good’ channels to the next stage is selected for retransmission. It is shown that the proposed method can be implemented in a distributed manner without the need for a central controller. The authors analyse the performance of the proposed method in terms of end‐to‐end outage probability in the case of imperfect CSI of which the case of perfect CSI is a special case. Numerical results are presented from analysis which closely match those obtained from simulation. The results are compared with those from several other RS strategies, and show significant improvements.
Event‐triggered control for continuous‐time switched linear systems
Authors: Xiang Weiming , T. Johnson Taylor
Published: February 2017

The event‐triggered control problem for switched linear system is addressed in this study. The periodical sampling scheme and event‐triggering condition are incorporated in the closed‐loop. The feedback control updates its value only at sampling instants as long as event‐triggering condition is satisfied as well. In addition, the switchings are only allowed to occur at sampling instants and meanwhile the switching condition is satisfied. Three equivalent sufficient conditions are proposed to ensure the asymptotic stability of switched systems. In particular, one condition has a promising feature of affineness in system matrices, and as a consequence, it is extended to robust sampling case and ‐gain analysis. Several examples are provided to illustrate the authors' results.
Identification of dual‐rate sampled systems with time delay subject to load disturbance
Authors: Dong Shijian , Liu Tao , Wang Qing‐Guo
Published: February 2017

A discrete‐time model identification method is proposed for dual‐rate sampled systems with time delay subject to load disturbance with unknown dynamics. By viewing the output response arising from such load disturbance as a dynamic parameter for estimation, two recursive least‐squares identification algorithms are developed to estimate the linear model parameters and the load disturbance response, respectively, while the integer delay parameter is derived by using a one‐dimensional searching approach to minimise the output fitting error. An auxiliary model is constructed to estimate the unknown noise‐free output such that consistent estimation of the model parameters can be obtained under stochastic noise in the output measurement. Moreover, two adaptive forgetting factors are introduced to expedite the convergence rates of estimating the model parameters and the load disturbance response, respectively. Theoretical analysis is given to clarify the convergence of parameter estimation. Two illustrative examples are presented to demonstrate the effectiveness and merit of the proposed identification method.
Improved adaptive backstepping sliding mode control for generator steam valves of non‐linear power systems
Authors: Su Qingyu , Quan Wanzhen , Cai Guowei , Li Jian
Published: February 2017

The stability problem of steam valves in a single machine infinite bus system with thyristor controlled series compensation is addressed through the use of an improved adaptive backstepping method based on error compensation. The method combines sliding mode variable structure control, backstepping control and adaptive control. Initially, an excitation control input and error compensation are simultaneously obtained in the design of virtual control by adaptive backstepping and the Lyapunov method. The Lyapunov function is then constituted in stages to achieve subsystem stability, before obtaining a parameter updating law and a non‐linear control law for the closed‐loop system. The results for both systems show that the improved non‐linear backstepping sliding mode variable structure control approach can have four benefits. It can ensure that the system states are bounded, retain the faster stability of power systems, improve the speed of parameter identification and achieve real‐time parameter estimation. Finally, a simulation is presented to illustrate both the effectiveness and the feasibility of the improved control approach.
Square‐root Kalman‐like filters for estimation of stiff continuous‐time stochastic systems with ill‐conditioned measurements
Authors: Kulikov Gennady Yu. , Kulikova Maria V.
Published: February 2017

This study addresses the performance of the extended and extended‐cubature Kalman filters for state estimation of ill‐conditioned stiff continuous‐discrete stochastic systems. Stiff models arise naturally in practise as, for instance, the Van der Pol oscillator in electrical engineering and the Oregonator reaction in chemistry. Their accurate state estimation is a challenging task, which is made even more difficult by including ill‐conditioned measurements, here. The authors' goal is to study accuracy of these methods when the Van der Pol oscillator and the Oregonator reaction become increasingly ill‐conditioned. Thus, the authors determine efficient tools for estimation of stiff stochastic systems in the presence of round‐off and other disturbances. They examine both conventional filters and their square‐root forms. The square‐root methods are obtained in two ways, namely, by solving the square‐root moment differential equations and by square‐rooting the filter itself. They prove that only the square‐root filters grounded in the second approach (with use of stable orthogonal decompositions) are numerically stable and provide the highest state estimation accuracy in the ill‐conditioned stiff stochastic examples under consideration.
Stability analysis of non‐linear time‐varying systems by Lyapunov functions with indefinite derivatives
Authors: Zhou Bin
Published: February 2017

This study is concerned with stability analysis of non‐linear time‐varying systems by using Lyapunov function‐based approach. The classical Lyapunov stability theorems are generalised in the sense that the time‐derivative of the Lyapunov functions are allowed to be indefinite. The stability analysis is accomplished with the help of the scalar stable functions introduced in the author's previous study. Both asymptotic stability and input‐to‐state stability are considered. Particularly, for asymptotic stability, several concepts such as uniform and non‐uniform asymptotic stability, and uniform and non‐uniform exponential stability are studied. The effectiveness of the proposed theorems is illustrated by several numerical examples.
Reinforcement learning control of a single‐link flexible robotic manipulator
Authors: Ouyang Yuncheng , He Wei , Li Xiajing
Published: February 2017

In this study, the authors focus on the reinforcement learning control of a single‐link flexible manipulator and attempt to suppress the vibration due to its flexibility and lightweight structure. The assumed mode method and the Lagrange's equation are adopted in modelling to enhance the satisfaction of precision. Two radial basis function neural networks (NNs) are employed in the designed control algorithm, actor NN for generating a policy and critic NN for evaluating the cost‐to‐go. Rigorous stability of the system has been proven via Lyapunov's direct method. Through Matlab simulation and experiment on the Quanser flexible link platform, the superiority and feasibility of the reinforcement learning control are verified.
Game‐theoretic demand‐side management and closed‐loop control for a class of networked smart grid
Authors: Zhu Bing , Xia Kewei , Xia Xiaohua
Published: February 2017

A new systematic scheme is proposed for demand‐side management and control of a class of networked smart grid. The networked smart grid is modelled into an evolutionary game, and the theory of semi‐tensor product is applied to analyse its dynamic behaviours. By using a newly defined stacked form of structural matrix, a closed‐loop feedback control is designed to shape the structural matrix of the evolutionary game, such that the Nash equilibrium (with respect to minimum total cost) can be reached and maintained. Based on the proposed feedback control, a robust control can be designed for the smart grid to reach the Nash equilibrium in case of model uncertainties resulted from fake behaviours of some users. Examples are provided to illustrate the theoretical results.
Set of bilateral and radial symmetry shape descriptor based on contour information
Authors: Revollo Natalia V. , Delrieux Claudio A. , González‐José Rolando
Published: February 2017

Form and shape descriptors are among the most useful features for object identification and recognition. Even though there exists a widely used set of shape descriptors and underlying computational methods for their evaluation, frequently they fail to distinguish among very similar objects that they appear very different to the human eye. The authors propose a new set of shape descriptors based on a finer determination of the object symmetry axes, and a more accurate estimation of the bilateral and radial symmetries. These descriptors were thoroughly tested using several synthetic and real objects with varying degrees of symmetry. The methods for axes estimation and symmetry descriptors extraction outperform the widespread shape descriptors in recognising and identifying among very similar objects.
Patterns of approximated localised moments for visual loop closure detection
Authors: Erhan Can , Sariyanidi Evangelos , Sencan Onur , Temeltas Hakan
Published: February 2017

In the context of autonomous mobile robot navigation, loop closing is defined as the correct identification of a previously visited location. Loop closing is essential for the accurate self‐localisation of a robot; however, it is also challenging due to perceptual aliasing, which occurs when the robot traverses in environments with visually similar places (e.g. forests, parks, office corridors). In this study, the authors apply the local Zernike moments (ZMs) for loop closure detection. When computed locally, ZMs provide a high discrimination ability, which enables the distinguishing of similar‐looking places. Particularly, they show that increasing the density over which the local ZMs are computed improves loop closing accuracy significantly. Furthermore, they present an approximation of ZMs that allows the usage of integral images, which enable real‐time operation. Experiments on real datasets with strong perceptual aliasing show that the proposed ZM‐based descriptor outperforms state‐of‐the‐art methods in terms of loop closure accuracy. They also release the source‐code of the implementation for research purposes.
Multiple Laplacian graph regularised low‐rank representation with application to image representation
Authors: Shu Zhenqiu , Fan Hongfei , Huang Pu , Wu Dong , Ye Feiyue , Wu Xiaojun
Published: February 2017

Recently, low‐rank representation (LRR)‐based techniques have manifested remarkable results for data representation. To exploit the latent manifold structure of data, the graph regulariser is incorporated into the model of LRR. However, it is critical to construct an appropriate graph model and set the corresponding parameters. In addition, this procedure is usually time‐consuming and proved to be overfitting when using cross validation or discrete grid search. Two novel LRR‐based methods, called multiple graph regularised LRR and multiple hypergraph regularised LLR, are proposed to represent the high‐dimensional data. To guarantee the smoothness along the estimated manifold, the multiple graph regulariser and the multiple hypergraph regulariser are incorporated into the traditional LRR method, respectively, which results in a unified framework. Moreover, the augmented Lagrange multiplier is adopted to solve the proposed models. Extensive experiments on real image datasets show the effectiveness of the proposed methods.
Lossless image compression algorithm and hardware architecture for bandwidth reduction of external memory
Authors: Li Shizhong , Yin Haibing , Fang Xiangzhong , Lu Huijuan
Published: February 2017

In high definition (HD) video coders, huge memory access bandwidth is the major throughput bottleneck. Lossless embedded compression is an efficient solution to alleviate the bandwidth burden, in which image are compressed before writing into local memory and decompressed after retrieving from local memory. This study proposes a hardware‐oriented lossless image compression algorithm, supporting block and line random access flexibly for adapting diverse hardware video codec architectures. The major contributions are characterised as follows. First, block or pixel‐level adaptive prediction is proposed to fully utilise the image spatial correlation by employing adaptive mode decision. Second, multiple‐range semi‐fixed (SF) variable length coding (VLC) is employed to describe the prediction residue, and adaptive block size selection is employed for SF VLC to fully utilise the statistical redundancy. In addition, Huffman VLC is further employed to represent the control syntax elements. Third, four‐stage pipeline hardware architecture is proposed to implement the proposed algorithm. Simulation results show that the proposed algorithm achieves competitive rate compression performance compared with reference algorithms. The proposed hardware architecture is verified supporting real‐time processing for quad‐HD videos at the frequency of 166 MHz. The proposed work achieves reducing memory access bandwidth by ∼55.2%, which is useful for hardwired video coding.
Frequency‐ and time‐domain analysis of a novel UWB reconfigurable microstrip slot antenna with switchable notched bands
Authors: Oraizi Homayoon , Valizade Shahmirzadi Nooshin
Published: February 2017

A novel reconfigurable microstrip slot antenna with capability of switchable frequency notched bands for ultra‐wide‐band (UWB) applications is presented. The feed line is tapered to provide UWB matching condition. Two parasitic elements are attached to two sides of patch having a square slot for improvement of frequency band response. An inverted Γ‐shaped parasitic element is placed inside the slot in patch to produce a notch at wireless local area network (WLAN) frequency band (5.1–5.7 GHz). A rectangular split ring resonator is placed on the back side of microstrip slot antenna to produce a notch at downlink X‐band for satellite communication systems (7.2–7.8 GHz). Reconfigurability of proposed antenna is obtained by placing PIN diodes at appropriate places to achieve four different operations, namely UWB coverage, UWB coverage with single band notch at WLAN, UWB coverage with single band notch at downlink X‐band and UWB coverage with double band notch at WLAN and downlink X‐band. The first case achieves fractional bandwidth of 123% (3.1–13 GHz). Antenna performance is studied in frequency and time domains. The bias circuits of PIN diodes are placed on antenna structure and are considered in simulations. A prototype model of proposed antenna is fabricated and measured to demonstrate its desirable features.
Preparation of phase transfer functional catalysts and their application in viscosity reduction of heavy oils
Authors: Feng Yaoyao , Li Yiguang , Li Qiuye , Li Xiaohong , Zhang Zhijun
Published: February 2017

Four kinds of nanosilica‐supported metallic and metatitanic acid nanocatalysts were synthesised as potential phase transfer catalysts for enhancing heavy oil recovery via a liquid‐reduction method. The catalysts were carried by water and transferred into oil phase, and the catalytic performance of catalysts for the aquathermolysis reaction and viscosity reduction of the extra‐heavy oil recovered at Shengli Oilfield (Dongying, China) was investigated. At a mass fraction of 1%, an aquathermolysis reaction temperature of 150°C and an aquathermolysis time of 36 h, the as‐synthesised silica/zero valence iron and nickel (denoted as SiO2/Fe/Ni) catalyst was able to reduce the apparent viscosity of the two kinds of heavy oils by 79.3 and 77.6%, showing promising application in the industrial production of heavy crude oil.
Potassium Hydroxide Catalysed Intermolecular Aza-Michael Addition of 3-Cyanoindole to Aromatic Enones
Authors: Yang Jingya , Li Tianyuan , Zhou Hongyan , Li Nana , Xie Dongtai , Li Zheng
Published: March 2017

Indole is one of the utmost important heterocycles as it is an essential nucleus of many pharmaceutical compounds. Its aza-Michael reaction, however, is underdeveloped because of the moiety’s inherent characteristics. Here, a potassium hydroxide catalysed intermolecular aza-Michael reaction of 3-cyanoindole with aromatic enones is described. A variety of chalcone derivatives are well tolerated and afford the corresponding N-adducts in moderate to high yields. The use of a cheap catalyst, low catalyst loading, mild reaction temperature, and good substrate tolerance make this procedure a direct and facile method for the preparation of N1-functionalized indoles.
Safety and Efficacy of a Novel “Hybrid Closure” Technique in Large-Bore Arteriotomies
Authors: Amponsah Michael , Tayal Rajiv , Khakwani Zain , Sinclair Michael , Wasty Najam
Published: February 2017

The “preclose” technique employing two Perclose (P) devices is well established for large-bore artery (LBA) hemostasis. Occasionally, only one Perclose deploys successfully during the initial preclose because of arterial calcification necessitating the use of the crossover balloon technique to achieve hemostasis at the LBA. We sought to determine if the combined use of one Perclose and either one Angioseal or one Mynx vascular closure device (VCD) is a safe alternative closure technique large-bore arteriotomy closure.

In total, 40 patients underwent high-risk percutaneous coronary intervention (HRPCI) with Impella support, of whom 38 had common femoral artery (CFA) arteriotomies and 2 underwent percutaneous axillary arteriotomy (AA). Prior to Impella insertion, one Perclose device was predeployed. At the end of HRPCI, Impella was removed and a 0.035″ wire was inserted through the Impella sheath. This sheath was then withdrawn over the wire, and partially deployed Perclose was fully deployed. A 6-Fr sheath was advanced over a 0.035″ wire into the CFA or AA, achieving hemostasis and reducing the LBA to a 6-Fr size. The 6-Fr arteriotomy was closed with a 6-Fr Mynx or Angioseal VCD. Patients were followed at day 1 and day 30.

Hybrid closure was successful in 38 of 40 cases. In one case of Mynx balloon rupture, hemostasis was achieved with heparin reversal and manual compression. In the case of Perclose failure, crossover balloon tamponade at arteriotomy site and external manual compression achieved hemostasis. Patients were free of complications at day 1 and day 30.

Hybrid closure with one Perclose and either one Mynx or one Angioseal VCD is safe and effective for LBA closure.
Complications and Cost Analysis of Intraoperative Arterial Complications in Head and Neck Free Flap Reconstruction
Authors: Chu Michael , Nelson Jonas , Basta Marten , Gerety Patrick , Kanchwala Suhail , Wu Liza , Chang Catherine
Published: February 2017

Background Microvascular anastomotic patency is fundamental to head and neck free flap reconstructive success. The aims of this study were to identify factors associated with intraoperative arterial anastomotic issues and analyze the impact on subsequent complications and cost in head and neck reconstruction.

Methods A retrospective review was performed on all head and neck free flap reconstructions from 2005 to 2013. Patients with intraoperative, arterial anastomotic difficulties were compared with patients without. Postoperative outcomes and costs were analyzed to determine factors associated with microvascular arterial complications. A regression analysis was performed to control for confounders.

Results Total 438 head and neck free flaps were performed, with 24 (5.5%) having intraoperative arterial complications. Patient groups and flap survival between the two groups were similar. Free flaps with arterial issues had higher rates of unplanned reoperations (p < 0.001), emergent take-backs (p = 0.034), and major surgical (p = 0.002) and respiratory (p = 0.036) complications. The overall cost of reconstruction was nearly double in patients with arterial issues (p = 0.001). Regression analysis revealed that African American race (OR = 5.5, p < 0.009), use of vasopressors (OR = 6.0, p = 0.024), end-to-side venous anastomosis (OR = 4.0, p = 0.009), and use of internal fixation hardware (OR =3.5, p = 0.013) were significantly associated with arterial complications.

Conclusion Intraoperative arterial complications may impact complications and overall cost of free flap head and neck reconstruction. Although some factors are nonmodifiable or unavoidable, microsurgeons should nonetheless be aware of the risk association. We recommend optimizing preoperative comorbidities and avoiding use of vasopressors in head and neck free flap cases to the extent possible.
Shear Stress Induces Change in Extracellular Signal-Regulated Kinase 5 Levels with Sustained Activation under Disturbed and Continuous Laminar Flow
Authors: Shalaby S. , Chitragari G. , Sumpio B. , Sumpio B.
Published: February 2017

Extracellular signal-regulated kinase 5 (ERK5) has been reported to regulate endothelial integrity and protect from vascular dysfunction under laminar flow. Previously reported research indicates that under laminar flow ERK5 is activated with production of atheroprotective molecules. However, the characterization of ERK5 activation and levels under different flow patterns has not been investigated.

Confluent HUVECs were serum-starved then seeded on glass slides. HUVECs incubated in 1% FBS were exposed to continuous laminar flow (CLF), to-and-fro flow (TFF), or pulsatile forward flow (PFF) in a parallel plate flow chamber. At the end of experimentation, cell lysates were immunoblotted with antibodies to phospho-ERK5 and total ERK5. ERK5 activation was assessed by the levels of phosphorylated ERK5. The densitometric mean ± SEM is calculated and analyzed by ANOVA. p < 0.05 is considered significant.

Levels of ERK5 decreased with all flow conditions with the largest decrease in TFF flow condition. TFF and CLF exhibited sustained ERK5 phosphorylation in HUVECs stimulated for up to 4 hours. PFF had transient phosphorylation of ERK5 at 2 hours, which then became undetectable at 4 hours of exposure to flow. Also, TFF and CLF both showed decreased levels at 4 hours, suggesting a decrease in activation for these flow conditions.

Exposure of HUVEC to different types of shear stress results in varying patterns of activation of ERK5. Activation of ERK5 with TFF suggests a role in the pathogenesis of atherosclerosis and vascular remodeling under disturbed flow conditions.
UK science mired in uncertainty about Brexit
Authors: Feder Toni
Published: March 2017

The most immediate concern is that the country remain attractive and welcoming for foreign researchers and students.
Field-based screening identifies resistance to Sunn pest (Eurygaster integriceps) feeding at vegetative stage in elite wheat genotypes
Authors: Emebiri Livinus , El Bousshini Mustapha , Tan Mui-Keng , Ogbonnaya Francis C.
Published: February 2017

Sunn pest (Eurygaster integriceps Puton) is currently widely distributed in West and Central Asia and Eastern Europe, but has not been found in Australia, Western Europe or North America. Climate warming is known to promote the expansion of its range of distribution, and it is expected that the insect could spread into new territories. Varieties of wheat (Triticum aestivum) carrying resistance remain an important component of managing the biosecurity risk of any potential incursion. Previous studies have identified sources of Sunn pest resistance in wheat, but there is little information on the genes that confer the resistance. This research used field-based, artificial infestation cages to evaluate 204 elite wheat varieties for Sunn pest resistance, at Terbol, Lebanon. A significant (P < 0.001) difference in resistance was observed among the wheat germplasm, with 19 varieties rated as resistant to moderately resistant and 17 as highly susceptible. Three of the elite varieties showed very little damage, a status similar to that of the resistant check, ICBW-209273. In parallel, the research carried out a genome-wide scan with single-nucleotide polymorphism (SNP) markers to identify chromosome regions and putative genes associated with resistance. Association mapping identified SNP markers with significant associations on chromosomes 2D, 4B and 5B. When these markers were projected onto the wheat population sequencing-based (POPSEQ) reference map, they tended to map close to the location of wheat height-reducing genes. The phenotypic variation explained by the identified markers ranged from 7% to 11%, and collectively, they explained 23.9% of the variation or 45% of the generalised heritability. Marker-trait association was confirmed in two independent, doubled-haploid wheat populations, derived from crosses involving wheat landraces from Afghanistan, where Sunn pest is recognised as an endemic problem. In the two wheat populations, the analyses validated the strong association between wsnp_BF483640B_Ta_2_2 and resistance to Sunn pest damage at the vegetative stage. This study demonstrates existence of genetic resistance to Sunn pest feeding at the vegetative stage in elite wheat germplasm. The study also identified and validated SNP markers that could be useful tools for transfer of resistance into new wheat cultivars.
Boron detection and quantification based on the absorption spectra of pyridoxine and its boron complex
Authors: Chen Fuming , Ai Ye , Yang Hui Ying
Published: March 2017

Environmental contextBoron, an essential element for human health and the growth of animals and plants, can also be harmful when intake is excessive. Herein, a simple and efficient method for determining boron species in aqueous samples has been developed based on the optical absorption of the pyridoxine or boron–pyridoxine complex. This rapid method is suitable for online analysis, with great significance to drinking water and industrial water treatment.
AbstractA simple and efficient method for the determination of boron species in aqueous samples is presented based on the optical behaviour of the pyridoxine or boron–pyridoxine complex. The boron concentration in the sample is proportional to the absorption intensity of the boron–pyridoxine complex, and is inversely proportional to that of free pyridoxine. The calibration plot is linear in the range of 0–8mgL–1 boron element within a pH 5.72–9.30 range. The method was developed for freshwaters, but is also applicable to seawater without significant interference from other commonly occurring ions in water such as Na+, K+, Cl–, Zn2+, Mn2+, Co2+, Ni2+, NO3–, and SO42–. This simple and rapid method is suitable for incorporation into an online analyser, which will be of great significance to the water treatment industry.
A survey of swainsonine content in Swainsona species
Authors: Cook Daniel , Gardner Dale R. , Welch Kevin D. , Allen Jeremy G.
Published: February 2017

The indolizidine alkaloid swainsonine is an inhibitor of α-mannosidase and mannosidase II that causes lysosomal storage disease and alters glycoprotein processing. Several plant species worldwide contain swainsonine, grazing these plants may cause severe toxicosis in livestock, leading to a chronic disease characterised by altered behaviour, depression, weight loss, decreased libido, infertility and death. Swainsona is a large genus of the Fabaceae family with all species but one being endemic to Australia. Swainsonine has previously been reported to be, or expected to be, present in 26 Swainsona species in Australia. Methods of detection in these 26 species were a jack bean α-mannosidase inhibition assay, gas chromatography, or gas or liquid chromatography coupled with mass spectrometry. Seven of these 26 Swainsona species are reported to be toxic, and for three of these no chemical assay for swainsonine has been undertaken. Only 1 of the 26 species has been analysed for swainsonine using modern instrumentation such as gas or liquid chromatography coupled with mass spectrometry. Using both liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry, 248 specimens representing 41 Swainsona species were screened in the present study for swainsonine. Swainsonine was detected in 9 of the 41 Swainsona species, eight of which had not been determined to contain swainsonine previously using modern instrumentation. The list of swainsonine-containing taxa reported here will serve as a reference for diagnostic purposes and risk assessment.
Emergence of communities and diversity in social networks
Authors: Han Xiao , Cao Shinan , Shen Zhesi , Zhang Boyu , Wang Wen-Xu , Cressman Ross , Stanley H. Eugene
Published: February 2017

Significance

Understanding how communities emerge is a fundamental problem in social and economic systems. Here, we experimentally explore the emergence of communities in social networks, using the ultimatum game as a paradigm for capturing individual interactions. We find the emergence of diverse communities in static networks is the result of the local interaction between responders with inherent heterogeneity and rational proposers in which the former act as community leaders. In contrast, communities do not arise in populations with random interactions, suggesting that a static structure stabilizes local communities and social diversity. Our experimental findings deepen our understanding of self-organized communities and of the establishment of social norms associated with game dynamics in social networks.
Localization of the gate and selectivity filter of the full-length P2X7 receptor
Authors: Pippel Anja , Stolz Michaela , Woltersdorf Ronja , Kless Achim , Schmalzing Günther , Markwardt Fritz
Published: February 2017

Significance

The P2X7 receptor (P2X7R) was the first ion channel that was suggested to transform from cation selective into nonselective by undergoing a dilatation in the diameter of its transmembrane pathway following sustained activation. This change requires that the selectivity filter behave as a dynamic structure. Here, we used a single-channel analysis of cysteine substitution mutants to find that the gate and selectivity filter of P2X7R are colocalized and primarily determined by one single residue, S342. We found the agonist-opened selectivity filter to be completely stable over time, indicating that use-dependent dilatation of the channel diameter does not occur. Instead, P2X7R exhibits striking susceptibility to remain in the open state for longer when the channel pore contains slowly or nonpermeating cations.