bluuebunny/crossref_metadata_2025 huggingface dataset:
Reducing Sampling Uncertainty in Aeolian Research to Improve Change Detection
Authors: Webb Nicholas P. , Chappell Adrian , Edwards Brandon L. , McCord Sarah E. , Van Zee Justin W. , Cooper Bradley F. , Courtright Ericha M. , Duniway Michael C. , Sharratt Brenton , Tedela Negussie , Toledo David
Published: April 2019

Measurements of aeolian sediment transport support our understanding of mineral dust impacts on Earth and human systems and assessments of aeolian process sensitivities to global environmental change. However, sample design principles are often overlooked in aeolian research. Here we use high‐density field measurements of sediment mass flux across land use and land cover types to examine sample size and power effects on detecting change in aeolian transport. Temporal variances were 1.6 to 10.1 times the magnitude of spatial variances in aeolian transport for six study sites. Differences in transport were detectable for >67% of comparisons among sites using ~27 samples. Failure to detect change with smaller sample sizes suggests that aeolian transport measurements and monitoring are much more uncertain than recognized. We show how small and selective sampling, common in aeolian research, gives the false impression that differences in aeolian transport can be detected, potentially undermining inferences about process and impacting reproducibility of aeolian research.
Full-color emissive carbon-dots targeting cell walls of onion for in situ imaging of heavy metal pollution
Authors: Yao Zheng , Lai Zhiqiang , Chen Chengchi , Xiao Suting , Yang Peihui
Published: April 2019

Full-colour emissive carbon-dots were prepared and applied in targeting onion CWs for in situ imaging of heavy metal pollution.
Water-sensitive phase-transition of a carbon dot–calcium carbonate composite for moisture detection in organic solvents
Authors: Yu Haijun , Li Haoxiang , Chen Chao , Zhou Shengmin , Wang Ping
Published: April 2019

Sensitive and broad range water content detection in organic solvents based on phase transitions of a calcium carbonate nanocomposite is accomplished.
Base-enhanced electrochemical water oxidation by a nickel complex in neutral aqueous solution
Authors: Zhang Lu-Hua , Yu Fengshou , Shi Yumeng , Li Fei , Li Henan
Published: April 2019

Electrochemical water oxidation catalyzed by a homogeneous Ni complex at low overpotential in neutral media.
3D porous carbon networks with highly dispersed SiOx by molecular-scale engineering toward stable lithium metal anodes
Authors: Lu Zhitao , Liu Shaohong , Li Chuanfa , Huang Junlong , Wu Dingcai , Fu Ruowen
Published: April 2019

Benefiting from a high-porosity interconnected structure and lithiophilic SiOx nanodomains, CNT@SiOx–C shows great advantages as 3D hosts toward stable Li plating/stripping.
Papillae-like morphology of Ni/Ni(OH)2 hybrid crystals by stepwise electrodeposition for synergistically improved HER
Authors: Liu Yiheng , Wang Jianzhi , Tian Qifeng , Liu Manyu , Wang Xianming , Li Pan , Li Wei , Cai Ning , Chen Weimin , Yu Faquan
Published: April 2019

The stepwise electrodeposition of Ni/Ni(OH)2 dual composition resulted in 3D hierarchical nanoarrays with a papillae-like hybrid crystal structure.
Revealing the role of a surfactant in the nucleation and crystal growth of thiamine nitrate: experiments and simulation studies
Authors: Han Dandan , Wang Yan , Yang Yang , Gong Tingting , Chen Yifu , Gong Junbo
Published: April 2019

This work combines experiments and simulations to investigate the inhibition effects of a surfactant on the nucleation and crystal growth rate of thiamine nitrate.
Regulating the allocation of N and P in codoped graphene via supramolecular control to remarkably boost hydrogen evolution
Authors: Wu Hao , Chen Zhimin , Wang Ying , Cao Erping , Xiao Fei , Chen Shuo , Du Shichao , Wu Yiqun , Ren Zhiyu
Published: April 2019

Modulating the allocation of nitrogen and phosphorus in graphene by a judiciously designed supramolecular architecture achieved a record-low overpotential in nonmetallic doped graphene for the HER.
Integration of phosphine ligands and ionic liquids both in structure and properties – a new strategy for separation, recovery, and recycling of homogeneous catalyst
Authors: Jin Xin , Feng Jianying , Song Hongbing , Yao Jiajun , Ma Qingqing , Zhang Mei , Yu Cong , Li Shumei , Yu Shitao
Published: April 2019

Integration of phosphine ligand and ionic liquid – a new strategy for separation, recovery, and recycling of homogeneous catalyst.
Nickel(ii)-catalyzed C(sp2)–H sulfuration/annulation with elemental sulfur: selective access to benzoisothiazolones
Authors: Guo Jun-Ru , Gong Jun-Fang , Song Mao-Ping
Published: April 2019

The first Ni(ii)-catalyzed direct sulfuration/annulation of C(sp2)–H bonds with elemental sulfur was developed to afford structurally diverse benzoisothiazolones with benzimidazole skeletons in high yields.
Phase‐noise reduction by self‐injection locking in spatially extended tunnel‐diode oscillator
Authors: Narahara K.
Published: April 2019

A scheme is proposed for reducing phase noise in a spatially extended oscillator using tunnel‐diode (TD) transmission line. It is observed that a voltage edge oscillates on a TD line when supplied by an appropriate DC voltage at the end. When the TD line is bypassed by a linear transmission line, part of the oscillating edge is inputted to and moves on the linear line to interact with the oscillating edge at the another crosspoint. The proper length of the linear line makes the bypassed voltage arrive at the crosspoint at the same time as the oscillating edge. It results in significant phase‐noise reduction of the oscillating edge through self‐injection locking. Herein, the principle of operation is described with its experimental validation.
Multivariable optimisation approach for power allocation in OFDM‐DCSK system
Authors: Mobini Majid , Zahabi M. Reza
Published: April 2019

This study proposes some multivariable approaches for power allocation in orthogonal frequency multiple access‐based differential chaos shift keying (OFDM‐DCSK) system. The objective is to minimise the overall bit error rate (BER) under the total transmission power limit. There is some literature focusing on the power allocation for OFDM‐DCSK systems, but all of them have only addressed the case where the power allocated to the reference subcarrier is assumed to be equal to one to simplify the problem to a single‐variable optimisation problem. In this study, the authors simultaneously take the reference and data‐bearing subcarriers power into consideration. They formulate a multivariable optimisation problem and solve it using Lagrange relaxation to derive a closed form solution. As the main contribution, the problem is converted to a cubic equation which is solved theoretically. Since the equation is non‐convex, they solve it again using a genetic algorithm (GA)‐based method for additive white Gaussian noise channel as a case study. The heuristic algorithm validates the theoretical approach. As another conclusion, the simulation results indicate that both of the proposed approaches outperform algorithms relaxing the reference power in terms of the BER performance, but the analytical solution leads to less time complexity in comparison with the GA‐based method.
Survey on half‐ and full‐duplex relay based cooperative communications and its potential challenges and open issues using Markov chains
Authors: Kumar Rajeev , Hossain Ashraf
Published: April 2019

In this study, the authors address a brief survey on the half‐duplex (HD) and full duplex (FD) relay based cooperative communications. Some nodes in wireless communication acting as relays can share their resource with other nodes by exploiting relaying technologies to achieve cooperative communications. Generally, the buffer‐less HD relaying (HDR) limits the performance of a wireless system when the worst condition of transmitting and receiving channels of the relay occurs. The HDR is affected by pre‐log factor one‐half that reduces the spectral‐efficiency of the wireless system. Significantly, advanced technologies in self‐interference cancellation enable the FD relaying (FDR) in the cooperative wireless system to achieve high spectral efficiency. Recently, the buffer‐aided FDR provides significant performance gains by exploring the concepts of Markov chain of queuing theory at relay as compared to either buffer‐aided or buffer‐less HDR. Finally, they outline several research challenges associated with small size, interference management, and fading channel for FDR. In addition, some research challenges remain for further investigation that is related to physical‐layer security, FDR with a cross‐layer approach and two‐way buffer‐aided FDR.
Beam‐based uplink multi‐user detection for mmWave communications
Authors: Sheu Jeng‐Shin , Sheen Wern‐Ho , Wu Wei‐Cyuan , Chang Hong‐Rui
Published: April 2019

To keep up with the dramatic proliferation of mobile traffic, the fifth‐generation (5G) systems adopt the millimetre‐wave (mmWave) frequency band together with a large‐scale antenna array. Although the use of large‐scale antenna array can effectively solve the problem of severe signal attenuation at high frequencies, it also derives other issues. For example, the system complexity on spatial domain becomes computationally prohibitive, because the system has to estimate all the channels of each antenna. Also, the ever‐growing data rates make the frequency selectivity of channels worst in the spatial domain. Recently, utilising the sparse characteristics of the mmWave band, beam‐domain signal processing has drawn increasing interest for future 5G systems. In this study, the authors design multi‐user data detection for the mmWave communication on beam domain. To effectively reduce the design complexity, they exploit the salient feature of channel sparsity to propose beam‐channel selection and user grouping. Results indicate that the beam‐channel selection is a critical step in the design of 5G systems since it can significantly decrease the complexity while maintaining the throughput. User grouping allows us to independently design detectors with lower complexity. Results show that the designed detectors can achieve a good trade‐off between throughput and complexity.
NOMA‐based cooperative relaying for secondary transmission in cognitive radio networks
Authors: Chu Yuzhi , Champagne Benoit , Zhu Wei‐Ping
Published: April 2019

In this study, the authors present and investigate a novel cooperative relaying scheme for cognitive radio networks (CRNs), which is based on non‐orthogonal multiple access (NOMA). In the proposed scheme, following the detection of an idle channel, the secondary base station transmits a power domain NOMA signal to a first nearby secondary user (SU). In addition to decoding its own signal, this user applies a decode‐and‐forward strategy to relay the signal intended to a second SU. In contrast to previous works, where the spectrum sensing and transmission phases are treated separately, the authors here consider both phases jointly in the design and analysis of the proposed scheme. To characterise performance of the latter, analytical expressions are derived for the outage probability and the ergodic rate of the two SUs by assuming a flat Rayleigh fading channel model. The performance of two traditional orthogonal multiple access schemes is also analysed for comparison. Simulation and numerical results are presented to demonstrate the effectiveness of the proposed cooperative relaying scheme for CRN, as well as the accuracy of the analytical results.
Eccentricity fault diagnosis indices for permanent magnet machines: state‐of‐the‐art
Authors: Faiz Jawad , Nejadi‐Koti Hossein
Published: April 2019

Eccentricity fault with 10% severity is probably the only existing fault in a brand new healthy electrical machine that is acceptable as a manufacturing tolerance. This fault can be developed due to a continuous pull between stator and rotor, even in a de‐energized machine. So, it must be diagnosed,and its severity monitored. The authors introduced and criticized various indices for eccentricity fault diagnosis. Advantages, drawbacks, and ambiguous points of each index and potential ground for improvement of these techniques are addressed. Moreover, different eccentric PM machine modelling techniques are reviewed and environmental factors affecting the eccentricity fault detection process are discussed. This survey covers all direct current and alternating current PM machines. It provides information about the researches performed since 1986 and it is helpful to newcomers to this field, artisans, and protection system designers. Considering the given information, the readers achieve enough understanding of the weaknesses and strong points of each eccentricity fault diagnosis index. Then, these indices are evaluated through assigning weight coefficients under various scenarios. Interested individuals can modify these weight coefficients based on the specifics of the application and decide which index is the most appropriate.
Sparsity measure based library aided unmixing of hyperspectral image
Authors: Das Samiran , Routray Aurobinda , Deb Alok Kanti
Published: April 2019

Availability of a large number of application‐specific spectral libraries has generated a great deal of interest in semi‐blind unmixing of the hyperspectral image in both remote sensing and signal processing community. This study presents a novel, semi‐supervised, parameter‐free algorithm which employs sparsity measures for library pruning. The overall algorithm includes sparsity criteria based library pruning and sparse inversion method for abundance computation. In the pruning process, each library element is removed from the spectral library and the corresponding sparse abundance matrix is computed. The library elements which lead to higher sparsity are adjudged as image endmembers, based on the assumption that elimination of actual image endmember enhances sparsity level. The authors also present a detailed exploration of standard sparsity measures. They calculate the abundance of the pruned library by maximising Gini index or pq‐norm sparsity, which satisfies the desirable sparsity properties and is easier to compute. The abundance calculation task is solved using the adaptive direction method of multipliers. The experimental results on several real and synthetic image datasets demonstrate the computational efficiency and proficiency the authors’ method in the presence of noise and highly coherent spectral library.
Image recovery and recognition: a combining method of matrix norm regularisation
Authors: Wang WeiGang , Song Wei , Wang GuangYuan , Zeng Guigen , Tian Feng
Published: April 2019

The technology of image recovery, as a part of image processing, becomes more and more important. The robust principle component analysis (RPCA) serves as a key problem for low‐rank matrix recovery. However, the existing methods for solving the RPCA are mostly based on nuclear norm minimisation. These methods have the disadvantage that matrix's rank cannot be well approximated because they minimise all singular values. Moreover, these methods will lead to instability when images are highly correlated. In this study, the authors set up a novel model which combines the truncated nuclear norm with Frobenius norm to enhance solution accuracy and stability. Based on the idea of elastic‐net, which is composed of norm and norm, this model is based on elastic‐net of the singular values can be composed of the truncated nuclear norm and the square of Frobenius norm. In order to solve this problem, the TNNF algorithm was proposed based on the alternating direction method of multipliers. Compared with traditional methods, the numerical simulation results show that the proposed TNNF can achieve higher accuracy and better stability.
Characterising and predicting the movement of clouds using fractional‐order optical flow
Authors: Shakya Snehlata , Kumar Sanjeev
Published: April 2019

Estimating cloud motion with complex background through the sequence of satellite images plays an important role in weather forecasting. This motion can be used for characterization of clouds and predicting storms. Optical flow is used here for motion estimation which gives horizontal and vertical velocity components. Velocity field vector alone is not sufficient to analyze the cloud behavior for predicting extreme weather conditions and there is a need to develop some visual features for enhancing the weather prediction strategies. In this paper, we utilize the optical flow to localize the high alert regions. To have a better localization and motion signatures, we develop a fractional order technique to compute optical flow. Also, the localization is characterized by brightness of image, magnitude, directions, vorticity and irrotational components of the optical flow. We did analysis on sequence of images for Mumbai, India heavy rain that happened during August 28–29, 2017, cyclonic data sets for May 16, 2018, September 19–20, 2018 and October 14, 2018. Visual features show different patterns for extreme and normal weather situations. A study on interpolation and extrapolation of the image sequence is also presented. Optical flow based interpolation and Advection‐anisotropic‐diffusion based extrapolation model give promising results.
Deep‐network based method for joint image deblocking and super‐resolution
Authors: Li Xiaoguang , Sun Xu , Man Lam Kin , Zhuo Li , Li Jiafeng , Dong Ning
Published: April 2019

Many pieces of research have been conducted on image‐restoration techniques to recover high‐quality images from their low‐quality versions, but they usually aim to handle a single degraded factor. However, captured images usually suffer from various degradation factors, such as low resolution and compression distortion, in the procedures of image acquisition, compression, and transmission simultaneously. Ignoring the correlation of different degraded factors may result in the limited efficiency of the existing image‐restoration methods for captured images. A joint deep‐network‐based image‐restoration algorithm is proposed to establish a restoration framework for image deblocking and super‐resolution. The proposed convolutional neural network is made up of two stages. A deblocking network is constructed with two cascade deblocking subnets first, then, super‐resolution is performed by a very deep network with skipping links. Cascading these two stages forms a novel deep network. An end‐to‐end training scheme is developed, which makes the two stages be trained jointly so as to achieve better performance. Intensive evaluations have been conducted to measure the performance of the authors’ method both in general images and face images. Experimental results on several datasets demonstrate that the proposed method outperforms other state‐of‐the‐art methods, in terms of both subjective and objective performances.
High‐frequency current source converter for a direct drive powertrain in a wave energy converter
Authors: McDonald Stephen P. , Baker Nick J. , Pickert Volker
Published: April 2019

Wave energy converters (WECs) generally use a mechanical solution such as hydraulics or gearing to optimise the extraction of energy from the incoming waves prior to converting it into electrical energy via a high‐speed rotating generator. This simplifies the electrical power conversion system (EPCS) design and facilitates the use of mechanical energy storage such as springs, compressed air, or hydraulic accumulators. The naturally peaky nature of the WEC power can thus be reduced and there is potential to tune the resonant frequency of the WEC. The potential design of a current source converter (CSC) for an integrated low‐speed direct‐drive power take‐off (PTO) for a WEC is described here. Silicon carbide (SiC) devices which enable high switching frequencies with a beneficial reduction in passive component dimensions are considered. Issues such as fault tolerance, protection, and parasitic inductance are investigated leading to an improved layout proposal.
Three‐phase fixed‐frequency interleaved (LC)(L)‐type series‐resonant converter with a capacitive output filter
Authors: Almardy Mohamed , Bhat Ashoka K.S.
Published: April 2019

A three‐phase interleaved (LC)(L)‐type dc–dc series‐resonant converter with a capacitive output filter using fixed frequency control is proposed. The converter operations for different modes during different intervals have been presented using the operating waveforms. The converter is analysed using the approximate analysis approach, and the design procedure is illustrated with a design example. PSIM simulation results for the designed converter are given for load and input voltage variations. It is shown that the converter operates in zero‐voltage switching (ZVS) at the minimum input voltage and for different load conditions. On the other hand, at the maximum input voltage from full load to light load, leading switches operate with ZVS, whereas lagging switches operate with zero‐current switching (ZCS).
Effects of phase leg reactor, submodule capacitor, number of submodules and switching frequency on harmonics in modular multilevel converters
Authors: Bissal Ara , Ali Waqas , Colak Ilknur
Published: April 2019

The modular multilevel converter (M2C) will play an important role in the future especially for high‐voltage and high‐power applications where controllability is a key factor. Although a lot of research has been carried out on this topic, little has been done to understand how different system parameters, like the arm reactor, the submodule capacitor, number of submodules and switching frequency, influence the performance of the converter. In this study, a robust model of a M2C was presented and used to perform an extensive parametric sweep versus the variables mentioned above. It has been shown that by implementing an anti‐windup scheme, the model remains stable over a large range of parameters. It has also been shown that an optimum knee point exists in all total harmonic distortion (THD) graphs versus inductance, capacitance, number of submodules and switching frequency. Finally, it has been shown that to decrease THD, the number of submodules can be increased while making sure the effective arm capacitance is maintained constant.
Fluid flow measurement in rotor ventilation ducts
Authors: Micallef Christopher , Degabriele Joseph , Camilleri Darren
Published: April 2019

Engineers are constantly developing different ways to cool electrical machines more efficiently. Ventilation ducts/channels are common in the stators of large electrical machines. Lately ventilation ducts on rotors of electrical machines are also being introduced. While measurement of fluid velocities inside stationary ventilation ducts, such as those present in and around the stator core of electrical machines, are relatively easy, measurement of fluid velocities inside rotating ventilation ducts, such as those present on the rotors of electrical machines, is quite challenging. This study describes a method which enables the measurement of fluid velocities inside rotating ducts on the rotor of electrical machines.
Sizing guidelines for grid‐connected decentralised energy storage systems: single house application
Authors: Panagiotou Konstantina , Klumpner Christian , Sumner Mark
Published: April 2019

Nowadays, the existing hierarchical, centrally controlled power grid faces new challenges due to the increase penetration of renewable sources, the need of implementing demand‐side management and the 2020 and 2050 environmental targets. A promising concept which can successfully contribute to addressing the environmental concerns and energy challenges of the twenty‐first century is the grid‐connected decentralised energy systems that embed significant amount of renewable generation and allow reverse power flow from distribution grids into the transmission network. Despite their benefits, decentralised energy storage systems are not yet widely spread due to several implementation and designing barriers. The design obstacle which is being addressed in this study includes the determination of the optimal size of the energy storage system components in terms of battery size and rating of the power converter for a single house application. In order to generalise the findings, nine different real houses were considered. Thus, the most financially beneficial battery and power converter combination for nine existing UK houses with installed PV roof‐top system were identified in this study.
Experimental results from a Thomson‐coil actuator for a vacuum interrupter in an HVDC breaker
Authors: Baudoin Antoine , Hátsági Bence , Álvarez Miguel , Ängquist Lennart , Nee Simon , Norrga Staffan , Modeer Tomas
Published: April 2019

Recent developments in high‐voltage direct current transmission technology and the plans for multi‐terminals motivate research efforts on the fast DC breaker. A novel concept to interrupt current up to several kiloamperes within a few milliseconds is presently under development, using a vacuum interrupter together with power electronics to create an artificial zero‐crossing in the current through the switch. To achieve this objective, one critical component in the concept is an ultra‐fast linear mechanical actuator. A prototype has been developed based on a Thomson coil. The experimental results are presented and show how a contact gap in a vacuum interrupter was effectively created in a controlled manner. Current of several kiloamperes was successfully interrupted within 3 ms, thanks to the high‐speed operation of the linear actuator.
Influence of stator and rotor geometric parameters on rotor bar current waveform and performance of IMs
Authors: Gundogdu Tayfun , Zhu Zi‐Qiang , Mipo Jean‐Claude , Personnaz Sophie
Published: April 2019

In this study, the influence of the stator and rotor geometric parameters on the rotor bar current waveform and performance characteristics of a squirrel‐cage induction machine (IM), based on a slot/pole number combination (48‐stator slot/8‐pole/52‐rotor slot), with the same winding layout, stator outer diameter, stack length, stator current, and rated speed as the Toyota Prius 2010 interior permanent magnet machine, is investigated. In order to reveal the individual influence of each parameter, parametric analyses have been conducted for each geometric parameter, and the corresponding variations of torque, torque ripple, power losses, and efficiency are numerically studied. It has been shown that in addition to rotor slot width, rotor slot depth, and stator slot width, corresponding to rotor tooth width, rotor tooth height, and stator tooth width, respectively, have a significant effect on the bar current waveform and performance characteristics while the slot opening widths have the least effect.
Electronic power steering system – A mechatronic model for simulative analysis of power consumption
Authors: Reiland Nikolaus , Miernik Christian , Gerling Dieter
Published: April 2019

Dynamic modelling of electronic power steering (EPS) systems is an essential part of vehicle dynamics simulation during the development process in automotive industry. Most of existing models focus on mechanical or driving‐comfort issues (i.e. steering ripple analysis) but do not consider precise modelling of the power consumption of the system. However, correct dimensioning of board net components requires accurate predictions of the system's power demand as early as possible. In order to fill this gap, this article presents both modelling and parameter identification of a steering system with a simple mechanical module and a detailed representation of the electrical subsystem. Accuracy of the developed modelling approach is validated against test bench and vehicle measurements.
Schwannomatosis of the Spinal Accessory Nerve: A Case Report
Authors: Morshed Ramin , Lee Anthony , Lee Young , Chin Cynthia , Jacques Line
Published: April 2019

Schwannomatosis is a distinct syndrome characterized by multiple peripheral nerve schwannomas that can be sporadic or familial in nature. Cases affecting the lower cranial nerves are infrequent. Here, the authors present a rare case of schwannomatosis affecting the left spinal accessory nerve. Upon genetic screening, an in-frame insertion at codon p.R177 of the Sox 10 gene was observed. There were no identifiable alterations in NF1, NF2, LZTR1, and SMARCB1. This case demonstrates a rare clinical presentation of schwannomatosis in addition to a genetic aberration that has not been previously reported in this disease context.
Differentially synchronized spiking enables multiplexed neural coding
Authors: Lankarany Milad , Al-Basha Dhekra , Ratté Stéphanie , Prescott Steven A.
Published: April 2019

Significance

The nervous system processes phenomenal amounts of information. This processing must be conducted efficiently. In telecommunications systems, efficiency is increased by transmitting multiple signals through a single communication channel, or multiplexing. Neurons also multiplex. Here, we demonstrate a strategy for multiplexing different features of aperiodic stimuli: Cortical neurons use the rate of asynchronous spiking to encode stimulus intensity while using the timing of synchronous spikes to encode abrupt changes in stimulus intensity. This is possible because high-contrast features (e.g., edges) evoke spikes that transiently synchronize across neurons, whereas low-contrast features evoke sustained asynchronous spiking whose rate is proportional to stimulus intensity. Differentially synchronized spiking evoked in the same neurons by different stimulus features enables the formation of multiplexed representations.
In vivo selective inhibition of TRPC6 by antagonist BI 749327 ameliorates fibrosis and dysfunction in cardiac and renal disease
Authors: Lin Brian Leei , Matera Damian , Doerner Julia F. , Zheng Nan , del Camino Donato , Mishra Sumita , Bian Hong , Zeveleva Svetlana , Zhen Xiaoguang , Blair Nathaniel T. , Chong Jayhong A. , Hessler David P. , Bedja Djahida , Zhu Guangshuo , Muller Grace K. , Ranek Mark J. , Pantages Lynn , McFarland Mary , Netherton Matthew R. , Berry Angela , Wong Diane , Rast Georg , Qian Hu Sheng , Weldon Steven M. , Kuo Jay J. , Sauer Achim , Sarko Chris , Moran Magdalene M. , Kass David A. , Pullen Steven S.
Published: April 2019

Significance

Transient receptor potential canonical 6 (TRPC6) is an important mediator of pathological hypertrophy and fibrosis, contributing to renal and cardiac disease. However, no selective TRPC6 inhibitor with in vivo efficacy has been developed and tested to determine if nongenetic channel suppression ameliorates disease in intact animals. We developed and tested an orally bioavailable TRPC6-specific inhibitor, BI 749327, revealing its capacity to improve cardiac function and reduce chamber dilation and fibrosis in the context of abnormal hemodynamic stress. Similarly, BI 749327 suppressed myofibroblast activation and fibrosis in a renal disease model. These data support BI 749327 as a representative of a therapeutic class for treating cardiac and renal disease and provide a tool for studying the biological function of TRPC6.
Dynamic super-resolution structured illumination imaging in the living brain
Authors: Turcotte Raphaël , Liang Yajie , Tanimoto Masashi , Zhang Qinrong , Li Ziwei , Koyama Minoru , Betzig Eric , Ji Na
Published: April 2019

Significance

The brain is composed of cells that continually communicate with one another via electric and chemical signals. To understand nerve cells in a physiological context, we must study them in vivo, for which optical microscopy is an essential tool. In particular, much of this communication takes place at the nanoscale level and requires in vivo super-resolution microscopy. We applied adaptive optics to correcting sample-induced optical aberrations and optimized image acquisition and reconstruction to combat sample motion, which allowed us to adapt super-resolution structured illumination microscopy to in vivo imaging in the brains of zebrafish larvae and mice. With these optimizations, we were able to image dynamic processes at dendrites and synapses in the mouse brain at nanoscale resolution in vivo.
scMerge leverages factor analysis, stable expression, and pseudoreplication to merge multiple single-cell RNA-seq datasets
Authors: Lin Yingxin , Ghazanfar Shila , Wang Kevin Y. X. , Gagnon-Bartsch Johann A. , Lo Kitty K. , Su Xianbin , Han Ze-Guang , Ormerod John T. , Speed Terence P. , Yang Pengyi , Yang Jean Yee Hwa
Published: April 2019

Concerted examination of multiple collections of single-cell RNA sequencing (RNA-seq) data promises further biological insights that cannot be uncovered with individual datasets. Here we present scMerge, an algorithm that integrates multiple single-cell RNA-seq datasets using factor analysis of stably expressed genes and pseudoreplicates across datasets. Using a large collection of public datasets, we benchmark scMerge against published methods and demonstrate that it consistently provides improved cell type separation by removing unwanted factors; scMerge can also enhance biological discovery through robust data integration, which we show through the inference of development trajectory in a liver dataset collection.
Directional soliton and breather beams
Authors: Chabchoub Amin , Mozumi Kento , Hoffmann Norbert , Babanin Alexander V. , Toffoli Alessandro , Steer James N. , van den Bremer Ton S. , Akhmediev Nail , Onorato Miguel , Waseda Takuji
Published: April 2019

Significance

Understanding the fundamental dynamics of directional and localized waves is of significant importance for modeling ocean waves as well as predicting extreme events. We report a theoretical framework, based on the universal (2D + 1) nonlinear Schrödinger equation, that allows the construction of slanted solitons and breathers on the water surface. Our corresponding wave flume observations emphasize and uniquely reveal that short-crested localizations can be described as a result of nonlinear wave dynamics, complementing the linear superposition and interference arguments as has been generally suggested for directional ocean waves.
Hit and run versus long-term activation of PARP-1 by its different domains fine-tunes nuclear processes
Authors: Thomas Colin , Ji Yingbiao , Wu Chao , Datz Haily , Boyle Cody , MacLeod Brett , Patel Shri , Ampofo Michelle , Currie Michelle , Harbin Jonathan , Pechenkina Kate , Lodhi Niraj , Johnson Sarah J. , Tulin Alexei V.
Published: April 2019

Significance

Little is known about how multiple functions of a single protein are coordinated in a living cell. PARP-1 is a multidomain nuclear protein that plays a critical role in regulating developmental processes including apoptosis, DNA repair, epigenetic marking of chromatin, assembly of higher-order chromatin structures, and transcriptional activation. Using deletional isoforms of PARP-1 in in vivo and in vitro experiments, we have demonstrated that the multiple domains of PARP-1 cooperate in response to interactions with different PARP-1 targets, leading either to short-term activation of the enzyme or to prolonged and sustained activity. This sustained activity produces accumulation of pADPr in the surrounding chromatin, leading to prolonged chromatin loosening.
Peppermint (Mentha piperita L.) extract effectively inhibits cytochrome P450 3A4 (CYP3A4) mRNA induction in rifampicin-treated HepG2 cells
Authors: Kobayashi Tsukasa , Sugaya Kouichi , Onose Jun-Ichi , Abe Naoki
Published: April 2019

Interaction between foods and drugs is an important consideration in pharmaceutical therapy. Therefore, here, we examined the suppressive effects of the extracts from seven edible herbs on the induction of CYP3A4 gene expression in rifampicin-treated HepG2 cells. We evaluated the structure and suppressive activity of the most effective active compound isolated from dried peppermint (Mentha piperita L.). The structure of the compound was identified as that of pheophorbide a based on spectroscopic data. It suppressed the induction of CYP3A4 mRNA expression by rifampicin in a dose-dependent manner. Quantitative high-performance liquid chromatography showed that 2 g of dry leaves 0.43 mg in one cup of peppermint tea. These findings demonstrate that pheophorbide a suppresses the induction of CYP3A4 mRNA expression in rifampicin-treated HepG2 cells. Pheophorbide is known to cause photosensitivity. However, the effective dose of pheophorbide a that had a suppressive effect was very low, indicating a high safety margin.

Abbreviations: DAD: diode array detector; DMEM: Dulbecco’s modified Eagle's medium; ELISA: enzyme-linked immunosorbent assay; HPLC: high-performance liquid chromatography; PCR: polymerase chain reaction; PXR: pregnane X receptor; CAR: constitutive androstane receptor; AHR: aryl hydrocarbon receptor; TLC: thin-layer chromatography
Monitoring residual 36 h post‐match neuromuscular fatigue in rugby union; a role for postural control?
Authors: Troester Jordan C. , Duffield Rob
Published: April 2019

The present study investigated single‐leg balance and landing measures, respectively, at the beginning of a weekly micro‐cycle 36 h after a match compared to 48 h rest without any match load. Twenty‐seven professional rugby union players performed balance and landing tests on a 1000 Hz force plate across three in‐season micro‐cycles either with or without match loads in the prior 36 h. Participants were further sub‐divided into higher and lower match load groups to investigate changes in balance and landing variables. Differences between rested and 36 h post‐match single‐leg balance sway velocity were trivial in all cases, except for the higher‐load group on the dominant leg, which were possibly impaired 36 h post‐match (ES ± 90% CL = 0.68 ± 0.66). Differences between rested and 36 h post‐match single‐leg landing measures of relative impulse on the non‐dominant leg were possibly lower (0.36 ± 0.34), with possible impairment observed on both legs in the higher load group 36 h post‐match (0.39 ± 0.33; 0.49 ± 0.42). Differences in landing measures of peak force and time to stabilisation were mainly trivial (ES < 0.20). Postural control measures at 36 h post‐match are comparable to a rested state; though impairment of sway velocity on the dominant leg and landing impulse may indicate residual neuromuscular fatigue resulting from increased match exposure.
Acute isolated utricular lesion
Authors: Pavlovic Dusan
Published: April 2019

Since new diagnostic tools enabled us to measure all five vestibular sensors, various forms of vestibular neuritis has been described. Here the patient with unilateral acute vestibular loss due to isolated utricular lesion has been presented. Acute utricular lesion could be missed if the attention hasn't been paid to clinical signs of graviceptive lesion and could be easily confirmed with modern vestibular diagnostic tools.
Air and bone stimulation in vestibular evoked myogenic potentials in patients with unilateral Ménière’s disease and in controls
Authors: Guajardo-Vergara Carlos , Pérez-Fernandez Nicolas
Published: April 2019

Objectives:

To describe the vestibular evoked myogenic potential (VEMP) response to air-conducted sound (ACS) and bone-conducted vibration (BCV) in patients with unilateral definite Ménière's disease (MD), and the contribution to the usual ACS evaluation of the bone-air index (BAI) and interaural asymmetry ratio (IAR) in the diagnosis.

Methods:

A case–control study was designed. Fifty-one patients (25 men and 26 women) with an average age of 55 years, and 31 healthy volunteers with no history of vertigo and hearing loss, were included. The BAI was used as a new parameter to describe the amplitude of the response.

Results:

Only n10 latency ACS evoked was significantly longer than in controls. The ACS cVEMP p13-n23 amplitude of the affected ear of patients with MD was lower than in the non-affected ear (p = .023) and the control group (.001). The IAR was significantly higher in patients with MD both for the ACS and for the BCV cVEMP compared to the control group: p = .004 and .001, respectively. Significant differences were found in oVEMP n10-p16 amplitude between ACS and BCV in the patients with MD (p = .002). The BAI in oVEMP showed a significant increase in the affected ear compared to the control group (p = .001). The acoustic stimulus in cVEMP was the only one that showed significant differences in amplitude according to degree of hearing loss (p = .039).

Conclusions:

The joint use of an acoustic and vibratory stimulus is an interesting option to characterize the results in this group. The BAI provides useful complementary information, and also turns out to give added value to the traditional VEMP assessment by ACS. We recommend its use when Ménière's disease is suspected.
Micrometer-scale molecular dynamics simulation of microstructure formation linked with multi-phase-field simulation in same space scale
Authors: Shibuta Yasushi , Sakane Shinji , Miyoshi Eisuke , Takaki Tomohiro , Ohno Munekazu
Published: April 2019

The micrometer-scale polycrystalline microstructure is directly obtained from a 10 billion atom molecular dynamics (MD) simulation of the nucleation and growth of crystals from an undercooled melt, which is performed on a graphics processing unit-rich supercomputer. The grain size distribution in the as-grown microstructure obtained from the MD simulation largely deviates from that resulting from steady-state growth in ideal grain growth, whereas the distribution of the disorientation angle between grains in contact with each other basically agrees with a random distribution. The atomistic configuration of the polycrystalline microstructure is then converted into a phase-field profile (diffuse interface description) of a phase-field model (PFM) and the subsequent grain growth is examined by multi-phase-field (MPF) simulation. A significant achievement in this study is direct mapping of the atomistic configuration into the phase-field profile used in the MPF simulation since only representative parameters for larger-scale model (e.g. interatomic potentials for MD and interfacial parameters for PFM) are extracted from a smaller‐scale simulation in conventional multi-scale modeling. Our new achievement supported by high-performance supercomputing can be regarded as an evolution of multi-scale modeling, which we call inter-scale modeling to differentiate it from conventional multi-scale modeling.
Neural network approximation of Bayesian models for the inference of ion and electron temperature profiles at W7-X
Authors: Pavone A , Svensson J , Langenberg A , Höfel U , Kwak S , Pablant N , Wolf R C
Published: April 2019

In this paper, we describe a method for training a neural network (NN) to approximate the full model Bayesian inference of plasma profiles from x-ray imaging diagnostic measurements. The modeling is carried out within the Minerva Bayesian modeling framework where models are defined as a set of assumptions, prior beliefs on parameter values and physics knowledge. The goal is to use NNs for fast ion and electron temperature profile inversion from measured image data. The NN is trained solely on artificial data generated by sampling from the joint distribution of the free parameters and model predictions. The training is carried out in such a way that the mapping learned by the network constitutes an approximation of the full model Bayesian inference. The analysis is carried out on images constituted of 20 × 195 pixels corresponding to binned lines of sight and spectral channels, respectively. Through the full model inference, it is possible to infer electron and ion temperature profiles as well as impurity density profiles. When the network is used for the inference of the temperature profiles, the analysis time can be reduced down to a few tens of microseconds for a single time point, which is a drastic improvement if compared to the ≈4 h long Bayesian inference. The procedure developed for the generation of the training set does not rely on diagnostic-specific features, and therefore it is in principle applicable to any other model developed within the Minerva framework. The trained NN has been tested on data collected during the first operational campaign at W7-X, and compared to the full model Bayesian inference results.
Investigation of fine structure formation of guide field reconnection during merging plasma startup of spherical tokamak in TS-3U
Authors: Tanabe H. , Cao Q. , Tanaka H. , Ahmadi T. , Akimitsu M. , Sawada A. , Inomoto M. , Ono Y.
Published: April 2019

Ion heating/transport and its fine structure formation process through magnetic reconnection have been investigated by high guide field tokamak merging experiments in TS-3 and TS-3U. In addition to the previously reported demonstration of high-temperature plasma startup without center solenoid, the detailed fine structure formation process of reconnection heating has been revealed using new 96CH/320CH ultra-high-resolution 2D ion Doppler tomography diagnostics. By identifying the double-axis field configuration with the X-point on the midplane using in situ magnetic probe diagnostics, the detailed measurement successfully revealed that the ion temperature profile forms two types of characteristic heating structure, both around the X-point and downstream. The former is affected by the Hall effect to form a tilted heating profile, while the latter is affected by the transport process which a forms a poloidal double-ring-like structure. The achieved ion heating mostly depends on the reconnecting component of the magnetic field, and the contribution of the guide field to decrease the heating efficiency tends to be saturated in the high guide field regime. Under the influence of better toroidal confinement with higher guide field, the downstream ion heating is transported vertically, mostly by parallel heat conduction, and finally forms a poloidal ring-like hollow distribution aligned with the closed flux surface at the end of merging.
Vacuum solution for Solov’ev’s equilibrium configuration in tokamaks
Authors: Xu Tao , Fitzpatrick Richard
Published: April 2019

In this work, we construct a tokamak plasma equilibrium generated by a combination of currents flowing within the plasma and in distant external magnetic field coils. The plasma toroidal current density takes the simple form

inside the plasma (where r and z are cylindrical coordinates, and a, b, and R are constants), and is zero in the surrounding vacuum. The Grad–Shafranov equation possesses a well-known exact analytic solution within the plasma due to Solov’ev. We use a Green’s function method to compute the poloidal magnetic flux generated by plasma currents, together with a parameterized homogeneous solution to the Grad–Shafranov equation (that is well-behaved at small r and z), to construct the vacuum solution. The vacuum solution is matched to the analytic solution on the last closed magnetic flux surface (LCFS) to determine the parameters in the homogeneous solution. This procedure is performed for both up–down-symmetric double-null and up–down-asymmetric single-null equilibria. We find that any magnetic X-points on the LCFS are distorted due to the fact that one quadrant is filled by a current-carrying plasma, whereas the other three are filled by a vacuum in which no current flows. In particular, the vacuum quadrant opposite the plasma-filled quadrant expands at the expense of the other three quadrants.