bluuebunny/crossref_metadata_2025 huggingface dataset:
A Meta-Analysis of Neuropsychological Functioning in the Logopenic Variant of Primary Progressive Aphasia: Comparison with the Semantic and Non-Fluent Variants
Authors: Kamath Vidyulata , Sutherland Emily R. , Chaney Grace-Anna
Published: October 2019

Objectives:

The logopenic variant of primary progressive aphasia (lvPPA) has disparate pathological and anatomical features when compared to the semantic (svPPA) and non-fluent (nfvPPA) variants of PPA. As such, there is increasing need for measures that improve diagnostic accuracy particularly when etiology-specific treatments become available. In the current study, we used meta-analytic methods to establish the neuropsychological profile of lvPPA and compare it to recent findings in svPPA and nfvPPA.

Methods:

We extracted neuropsychological data from 51 publications representing 663 lvPPA patients and 1379 controls. We calculated Hedges’ g effect sizes for nine domains of neuropsychological functioning in lvPPA and assessed the influence of demographic, disease, and task characteristics on effect size magnitude. Results obtained in lvPPA were compared to findings in svPPA and nfvPPA.

Results:

In lvPPA, the magnitude of deficits in attention, math, visuospatial memory, and executive functioning were as prominent as language deficits. Within the language domain, lvPPA patients demonstrated greater naming than repetition deficits. Compared to svPPA and nfvPPA, lvPPA patients demonstrated greater neuropsychological deficits overall and greater impairment on attention, math, and visual set-shifting tests.

Conclusions:

Tests of attention, delayed visuospatial memory, visual set-shifting, and math distinguish lvPPA from svPPA and nfvPPA likely reflecting the posterior temporoparietal atrophy observed early in the course of lvPPA. These findings support the inclusion of these measures in the clinical neuropsychological assessment of lvPPA and underscore the need for additional clinicopathological and longitudinal studies of arithmetic and visuospatial memory across the PPA variants.
Multi-Session Anodal Prefrontal Transcranial Direct Current Stimulation does not Improve Executive Functions among Older Adults
Authors: Yu Junhong , Lam Charlene L.M. , Man Idy S.C. , Shao Robin , Lee Tatia M.C.
Published: October 2019

Objective:

Findings from single-session online studies highlighted the potential of using anodal prefrontal transcranial direct current stimulation (tDCS) to enhance executive functions (EF) in the context of aging. However, tDCS must be executed as a multi-session offline intervention to ascertain its viability in this context. Relatedly, findings from multi-session studies remained inconclusive. To this end, we examined the effects of multi-session anodal prefrontal tDCS on EF in an intervention.

Method:

The intervention consisted of 15 sessions; in each, healthy older participants (Agemean = 66.7) received either 15 min of 1.5 mA tDCS (Ncompleted = 35) or sham stimulation (Ncompleted = 33) while performing EF training tasks. EF measures were assessed at baseline, post-intervention, and 1-month follow-up. Hierarchical linear models were used to examine the effect of tDCS on EF outcomes.

Results:

Both groups of participants did not differ significantly in side effect ratings and attendance. There were no significant tDCS-associated gains in any EF outcomes in the intervention.

Conclusions:

Multi-session prefrontal tDCS did not lead to any significant gains in EF in the current intervention. More research is needed to optimize the use of tDCS before it can be effectively used to enhance EF among older adults.
Hospital avoidance: an integrated community system to reduce acute hospital demand
Authors: McGeoch Graham , Shand Brett , Gullery Carolyn , Hamilton Greg , Reid Matthew
Published: October 2019

Background:

Growth in emergency department (ED) attendance and acute medical admissions has been managed to very low rates for 18 years in Canterbury, New Zealand, using a combination of community and hospital avoidance strategies. This paper describes the specific strategies that supported management of acutely unwell patients in the community as part of a programme to integrate health services.

Intervention:

Community-based acute care was established by a culture of close collaboration and trust between all sectors of the health system, with general practice closely involved in the design and management of the services, and support provided by hospital specialists, coordination and diagnostic units, and competent informatics. Introduction of the community-based services was aided by a clinical guidance website and an education programme for general practice teams and allied health professionals.

Outcomes:

Attendance at EDs and acute medical admission rates have been held at low growth and, in some cases, shorter lengths of hospital stay. This trend was especially evident in elderly patients and those with ambulatory care sensitive or chronic disorders.

Conclusions:

A system of community-based care and education has resulted in sustained gains for the Canterbury health system and freed-up hospital resources. This outcome has engendered a sense of empowerment for general practice teams and their patients.
Mauss'sThe Gift, or the necessity of an institutional perspective in economics
Authors: Cedrini Mario Aldo , Ambrosino Angela , Marchionatti Roberto , Caillé Alain
Published: October 2019

The article proposes a reading of Marcel Mauss's insights into gift exchange in primitive societies through the lens of the institutional economics approach. It thus tries to demonstrate that the gift as seen by Mauss can be interpreted as an institution arising from the self-transcendence of social relationships that gifts themselves are expressly designed to create and according to which individuals orient their behavior. On this basis, we provide elements to discuss the benefits that might derive from the adoption of the institutionalist approach in economics.
Finite Thickness of Shear Bands in Frictional Viscoplasticity and Implications for Lithosphere Dynamics
Authors: Duretz Thibault , de Borst René , Le Pourhiet Laetitia
Published: October 2019

Permanent deformations in the lithosphere can occur in the brittle as well as in the ductile domain. For this reason, the inclusion of viscous creep and frictional plastic deformation is essential for geodynamic models. However, most currently available models of frictional plasticity are rate independent and therefore do not incorporate an internal length scale, which is an indispensible element for imposing a finite width of localized shear zones. Therefore, in computations of localization, either analytical or numerical, resulting shear zone widths tend to zero. In numerical computations, this manifests itself in a severe mesh sensitivity. Moreover, convergence of the global iterative procedure to solve the nonlinear processes is adversely affected, which negatively affects the reliability and the quality of predictions. The viscosity that is inherent in deformation processes in the lithosphere can, in principle, remedy this mesh sensitivity. However, elasto‐viscoplastic models that are commonly used in geodynamics assume a series arrangement of rheological elements (Maxwell‐type approach), which does not introduce an internal length scale. Here, we confirm that a different rheological arrangement that puts a damper in parallel to the plastic slider (Kelvin‐type approach) introduces an internal length scale. As a result, pressure and strain and strain rate profiles across the shear bands converge to finite values upon decreasing the grid spacing. We demonstrate that this holds for nonassociated plasticity with constant frictional properties and with material softening with respect to cohesion. Finally, the introduction of Kelvin‐type viscoplasticity also significantly improves the global convergence of nonlinear solvers.
On the Dependence of Cirrus Parametrizations on the Cloud Origin
Authors: Wolf Veronika , Kuhn Thomas , Krämer Martina
Published: October 2019

Parametrizations of Arctic cirrus particle size distributions are presented depending on the cloud origin, either in situ or liquid. The data set used originate from balloon‐borne measurements above Kiruna during winter. The observed particle size distributions are represented by gamma functions. The gamma coefficients exhibit large differences with regard to cloud origin. The functions for Arctic cirrus confirm established parametrizations for continental cirrus sorted by two particle size modes but differ from others depending only on temperature. We suppose that the agreement between the parametrizations of the geographically different cirrus is because in situ and liquid origin cirrus also distinguish by particle size modes. Since cloud sorting by their origin is based on physical processes which are independent of geographical region, we further hypothesize that these cloud‐type‐based parametrizations might be generally valid for use in global models and satellite retrievals, given the distribution of the cloud types is known.
Disentangling Dynamic Contributions to Summer 2018 Anomalous Weather Over Europe
Authors: Drouard Marie , Kornhuber Kai , Woollings Tim
Published: October 2019

Summer 2018 was one of the driest and hottest experienced over northwestern Europe. In contrast, over southern Europe, it was marked by cooler and wetter conditions with flooding over Greece and Spain. This contrasting pattern was particularly enhanced over a 3‐week period starting on 21 June. Two atmospheric patterns are thought to have largely contributed to this anomalous weather: the positive North Atlantic Oscillation (NAO+) and a Wave‐7 pattern. Using linear regressions on detrended data, we show that the NAO+ was mainly responsible for the observed seasonal anomalies. However, during the 3‐week period, the rare combination of the NAO+ and Wave‐7 is necessary to explain the pattern of the observed anomalies. The global warming trend and, to a lesser extent, nonlinear processes are shown to have furthermore strongly modulated the anomalies associated with these two patterns.
Direct Online Mass Spectrometry Measurements of Ice Nucleating Particles at a California Coastal Site
Authors: Cornwell G. C. , McCluskey C. S. , Levin E. J. T. , Suski K. J. , DeMott P. J. , Kreidenweis S. M. , Prather K. A.
Published: October 2019

The formation of ice in clouds can strongly impact cloud properties and precipitation processes during storms, including atmospheric rivers. Sea spray aerosol (SSA) particles are relatively inefficient as ice nucleating particles (INPs) compared to mineral dust. However, due to the vast coverage of the Earth's surface by the oceans, a number of recent studies have focused on identifying sources of marine INPs, particularly in regions lacking a strong influence from dust. This study describes the integration, validation, and application of a system coupling a continuous flow diffusion chamber with a single particle mass spectrometer using a pumped counterflow virtual impactor to remove nonnucleated particles and selectively measure the composition of INPs with a detection efficiency of 3.10 × 10−4. In situ measurements of immersion freezing INP composition were made at a coastal site in California using the integrated system. Mineral dust particles were the most abundant ice crystal residual type during the sampling period and found to be ice active despite having undergone atmospheric processing. SSA were more abundant in ambient measurements but represented only a minor fraction of the ice crystal residual population at −31 °C. Notably, the SSA particles that activated were enriched with organic nitrogen species that were likely transferred from the ocean. Calculations of ice nucleation active site densities were within good agreement with previous studies of mineral dust and SSA.
CARS-imaging guidance for fs-laser ablation precision surgery
Authors: Meyer Tobias , Ackermann Roland , Kammel Robert , Schmitt Michael , Nolte Stefan , Tünnermann Andreas , Popp Jürgen
Published: October 2019

Ultrafast optical tools for disease diagnostics and precision surgery.
Rapid detection of Shiga toxin type II using lateral flow immunochromatography test strips of colorimetry and fluorimetry
Authors: Lu Tian , Zhu Kai-Di , Huang Chao , Wen Tian , Jiao Yong-Jun , Zhu Jin , Zhang Qing , Ding Shou-Nian
Published: October 2019

Two types of lateral flow immunochromatographic test strips (LFITS) using gold nanoparticles and fluorescent CdTe quantum dots (QDs) as signal labels, respectively, were developed for Shiga toxin type II (STX2) assays.
Microscale serum extraction method for the simultaneous analysis of corticosterone and lipids
Authors: Rister Alana L. , Bidne Katie L. , Wood Jennifer R. , Dodds Eric D.
Published: October 2019

This report details a serum extraction method for the simultaneous analysis of corticosterone and lipids from 5 μL of serum.
A microfluidic platform integrating pressure-driven and electroosmotic-driven flow with inline filters for affinity separations
Authors: Leng Weijia , Evans Kimberly , Roper Michael G.
Published: October 2019

A microfluidic platform that integrates pressure-driven flow with electroosmotic-driven flow and inline filters was developed to ease the burden of performing long-term affinity assays.
Application of carbon dots synthesized from tryptone and yeast extract in bioimaging and highly selective detection of p-nitrophenol and nickel(ii)
Authors: Qin Kunhao , Zhang Dongfang , Ding Yafang , Zheng Xiaodan , Tan Wenzhang , Xiang Yingying , Hua Jianhao , Ji Xiuling , Li Bo , Wei Yunlin
Published: October 2019

Carbon dots (CDs) possess properties appropriate for application in various fields, especially in environmental pollution detection and biological imaging.
An intermolecular C–H oxidizing strategy to access highly fused carbazole skeletons from simple naphthylamines
Authors: Rank Christian K. , Jones Alexander W. , Wall Tatjana , Di Martino-Fumo Patrick , Schröck Sarah , Gerhards Markus , Patureau Frederic W.
Published: October 2019

Highly π-extended hetero-cyclic/aromatic skeletons are of great importance as they can be utilized in many organic material based technologies.
A consensus protocol for the in silico optimisation of antibody fragments
Authors: Soler Miguel A. , Medagli Barbara , Semrau Marta S. , Storici Paola , Bajc Gregor , de Marco Ario , Laio Alessandro , Fortuna Sara
Published: October 2019

BINDesignER improves the affinity of antibodies/nanobodies in silico by simultaneously using several scoring functions for evaluating attempted mutations.
Beyond CoOx: a versatile amorphous cobalt species as an efficient cocatalyst for visible-light-driven photocatalytic water oxidation
Authors: Zhang Hongyuan , Guo Changfa , Ren Jiabin , Ning Jiqiang , Zhong Yijun , Zhang Ziyang , Hu Yong
Published: October 2019

A versatile and efficient cocatalyst based on amorphous Co species (a-Co-E) is reported, and various Bi-based semiconductors loaded with a-Co-E exhibit impressively higher photocatalytic O2 evolution activity than their CoOx-loaded counterparts.
Effects of water on the stochastic motions of propane confined in MCM-41-S pores
Authors: Gautam Siddharth , Le Tran Thi Bao , Rother Gernot , Jalarvo Niina , Liu Tingting , Mamontov Eugene , Dai Sheng , Qiao Zhen-An , Striolo Alberto , Cole David
Published: October 2019

Quasi-elastic neutron scattering (QENS) and molecular dynamics simulations (MDS) reveal the effects of water on the structure and dynamics of propane confined in 1.5 nm wide cylindrical pores of MCM-41-S.
Mechanistic insights of anionic ligand exchange and fullerene reduction with magnesium(i) compounds
Authors: Lawrence Samuel R. , Cordes David B. , Slawin Alexandra M. Z. , Stasch Andreas
Published: October 2019

Exchange of anionic ligands on the Mg22+ ion via an associative mechanism can be facile and depends on ligand sterics and shape.
Visible-light induced enhancement in the multi-catalytic activity of sulfated carbon dots for aerobic carbon–carbon bond formation
Authors: Sarma Daisy , Majumdar Biju , Sarma Tridib K.
Published: October 2019

The development of carbonaceous materials as metal-free catalysts integrating different types of catalysis in a single system represents a significant advance in cascade/tandem organic synthesis.
Lipid-soluble arsenic species identified in the brain of the marine fish skipjack tuna (Katsuwonus pelamis) using a sequential extraction and HPLC/mass spectrometry
Authors: Stiboller Michael , Freitas Fabiana P. , Francesconi Kevin A. , Schwerdtle Tanja , Nogueira António J. A. , Raber Georg
Published: October 2019

Arsenolipids detected in the brain of the marine fish skipjack tuna (Katsuwonus pelamis) using HPLC/mass spectrometry.
Rich topologies of monolayer ices via unconventional electrowetting
Authors: Liu Yuan , Gao Yurui , Zeng Xiao Cheng
Published: October 2019

Accurate manipulation of a substance on the nanoscale and ultimately down to the level of a single atom or molecule is an ongoing subject of frontier research.
The azide–alkyne cycloaddition catalysed by transition metal oxide nanoparticles
Authors: Molteni Giorgio , Ferretti Anna M. , Trioni Mario Italo , Cargnoni Fausto , Ponti Alessandro
Published: October 2019

Fe3O4, MnFe2O4, CoFe2O4, MnO, and α-MnS nanoparticles catalyse the title reaction by the ligation of the azide on the surface of the nanoparticle.
Planar, narrowband, and tunable photodetection in the near-infrared with Au/TiO2 nanodiodes based on Tamm plasmons
Authors: Yu Tong , Zhang Cheng , Liu Huimin , Liu Jianhui , Li Ke , Qin Linling , Wu Shaolong , Li Xiaofeng
Published: October 2019

Schematic diagram of the proposed Au/TiO2 Schottky photodetector and the energy collection and loss distributions in the proposed and reference devices.
Prussian blue-coated lanthanide-doped core/shell/shell nanocrystals for NIR-II image-guided photothermal therapy
Authors: Wang Xin , Li Hui , Li Feng , Han Xiaojun , Chen Guanying
Published: October 2019

A lanthanide-based theranostic agent for image-guided photothermal therapy.
Excitation and analyzation of different surface plasmon modes on a suspended Ag nanowire
Authors: Wu Yunkun , Lu Liu , Chen Yang , Feng Lantian , Qi Xiaozhuo , Ren Hong-Liang , Guo Guang-Can , Ren Xifeng
Published: October 2019

Excitation of different SPP modes on a suspended silver nanowire and their far-field detection.
Controllable MXene nano-sheet/Au nanostructure architectures for the ultra-sensitive molecule Raman detection
Authors: Yu Muni , Liu Sisi , Su Dong , Jiang Shenglin , Zhang Guangzu , Qin Yanfeng , Li Ming-Yu
Published: October 2019

SERS spectroscopy aims to augment the relatively weak molecular vibrations based on electromagnetic and chemical enhancement mechanisms, and offers a potential way for material identification, even up to the single-molecule level, under atmospheric conditions.
Plasmon enhanced up-conversion nanoparticles in perovskite solar cells for effective utilization of near infrared light
Authors: Park Jiyoon , Kim Kihyeun , Jo Eun-Jung , Kim Woochul , Kim Hyeonghun , Lee Ryeri , Lee Jun Young , Jo Ji Young , Kim Min-Gon , Jung Gun Young
Published: October 2019

The power conversion efficiency of perovskite solar cells is enhanced by the combined effects of the utilization of NIR in UCNPs and surface plasmon resonance phenomena at the UCNP/top gold electrode interface.
Substituent-oriented C–N bond formation via N–H insertion or Wolff rearrangement of 5-aryl-1H-pyrazoles and diazo compounds
Authors: Zuo Youpeng , He Xinwei , Ning Yi , Tang Qiang , Xie Mengqing , Hu Wangcheng , Shang Yongjia
Published: October 2019

Substituent-oriented C–N bond formation of 5-aryl-1H-pyrazoles with diazo compounds.
Stereochemistry of spongosoritins: beyond optical rotation
Authors: N. L. Batista Andrea , dos Santos Fernando M. , Valverde Alessandra L. , Batista Joao M.
Published: October 2019

A combination of spectroscopic methods reveals the dependence of the chiroptical properties of spongosoritins on achiral structural features.
Dimeric benzoboroxoles for targeted activity against Mycobacterium tuberculosis
Authors: Guy Collette S. , Murray Kathryn , Gibson Matthew I. , Fullam Elizabeth
Published: October 2019

Dimeric benzoboroxoles that are covalently linked by a short scaffold enhance selective anti-tubercular activity.
UV-induced vesicle to micelle transition: a mechanistic study
Authors: Machado Craig A. , Tran Roger , Jenkins Taylor A. , Pritzlaff Amanda M. , Sims Michael B. , Sumerlin Brent S. , Savin Daniel A.
Published: October 2019

The morphology of self-assembled block copolymer aggregates is highly dependent on the relative volume fraction of the hydrophobic block.
Blue thermally activated delayed fluorescence emitters incorporating acridan analogues with heavy group 14 elements for high-efficiency doped and non-doped OLEDs
Authors: Matsuo Kyohei , Yasuda Takuma
Published: October 2019

Blue thermally activated delayed fluorescence emitters incorporating phenazasiline and phenazagermine as donor units are developed, and their structural, photophysical, and electroluminescent properties are systematically investigated.
Ruthenium based antimicrobial theranostics – using nanoscopy to identify therapeutic targets and resistance mechanisms inStaphylococcus aureus
Authors: Smitten Kirsty L. , Fairbanks Simon D. , Robertson Craig C. , Bernardino de la Serna Jorge , Foster Simon J. , Thomas Jim A.
Published: October 2019

A detailed study on the uptake and antimicrobial activity of a RuIItheranostic complex with wild-typeS. aureus, MRSA, and other mutants has identified the specific resistance mechanisms that Gram-positive bacteria display against this lead.
A bi-component supramolecular gel for selective fluorescence detection and removal of Hg2+ in water
Authors: Yang Hai-Long , Sun Xiao-Wen , Zhang You-Ming , Wang Zhong-Hui , Zhu Wei , Fan Yan-Qing , Wei Tai-Bao , Yao Hong , Lin Qi
Published: October 2019

A bi-component supramolecular gel (RQ) was successfully constructed by the assembly of the gelators R and Q. The obtained the RQ exhibits excellent self-healing property. Interestingly, the RQ has been successfully applied in selective fluorescent detection and removal of Hg2+ in water.
Freshness ratio of information: a new metric for age of information
Authors: Lee Y.
Published: October 2019

The age of information is the time elapsed since the generation of the last successfully received update message. In this Letter, the authors propose a new metric, freshness ratio of information (FRoI), defined as the fraction of time the age does not exceed a predefined freshness threshold. In addition, they analyse the FRoI for two different system models.
Mapping prior information onto LMI eigenvalue‐regions for discrete‐time subspace identification
Authors: Ricco Rodrigo A. , Teixeira Bruno O.S.
Published: October 2019

In subspace identification, prior information can be used to constrain the eigenvalues of the estimated state‐space model by defining corresponding linear matrix inequality (LMI) regions. In this study, first the authors argue on what kind of practical information can be extracted from historical data or step‐response experiments to possibly improve the dynamical properties of the corresponding model and, also, on how to mitigate the effect of the uncertainty on such information. For instance, prior knowledge regarding the overshoot, the period between damped oscillations and settling time may be useful to constrain the possible locations of the eigenvalues of the discrete‐time model. Then, they show how to map the prior information onto LMI regions and, when the obtaining regions are non‐convex, to obtain convex approximations.
Simple adaptive trajectory tracking control of underactuated autonomous underwater vehicles under LOS range and angle constraints
Authors: Li Jian , Du Jialu , Zhu Guibing , Lewis Frank L.
Published: October 2019

In this study, the authors propose a simple adaptive trajectory tracking control scheme for underactuated autonomous underwater vehicles (AUVs) subject to unknown dynamic parameters and disturbances under asymmetric time‐varying line‐of‐sight (LOS) range and angle constraints. A simple error mapping function is constructed to transform the LOS range and angle constraint problems of AUVs trajectory tracking into the problem of the boundedness of transform variable, such that any constraint boundaries of LOS range and angle can be handled. The compounded uncertain item caused by the unknown dynamic parameters and disturbances is transformed into a linear parametric form with only three unknown parameters called virtual parameters. Based on the above, a simple adaptive trajectory tracking control law is developed using dynamic surface control technique, where the adaptive laws online provide the estimations of virtual parameters. As a result, the proposed trajectory tracking control scheme is simple to compute and easy to implement in engineering applications. Strict stability analysis indicates that the designed control law makes AUVs track the desired trajectory within the LOS range and angle constraints and guarantees the boundedness of all signals of the closed‐loop control system. Simulation results and comparison verify the effectiveness of the designed control scheme.
Consensus control of higher‐order Lipschitz non‐linear multi‐agent systems based on backstepping method
Authors: Li Guipu , Wang Xiangyu , Li Shihua
Published: October 2019

The consensus problem of higher‐order Lipschitz non‐linear multi‐agent systems is studied. For the leaderless case, by using the backstepping method, a distributed recursive linear control scheme is proposed. In the recursive control design, based on feedback domination method, the Lipschitz conditions of the unknown non‐linearities are organically used in the virtual controller design. The proposed recursive controllers guarantee that the leaderless multi‐agent systems reach global consensus asymptotically. For the leader‐follower case, first, baseline distributed recursive controllers are designed via backstepping method and feedback domination technique. Then with the baseline recursive controllers, a kind of linear sliding‐mode surface and the corresponding sliding‐mode controllers are proposed for the consensus tracking error system. Under the proposed sliding‐mode controllers, the leader‐follower multi‐agent systems reach global consensus asymptotically. Besides, simulations verify the validity of the proposed distributed control algorithms for both cases.
Stability and guaranteed cost analysis of switched positive systems with mode‐dependent dwell time and sampling
Authors: Wang Peng , Zhao Jun
Published: October 2019

This study handles the issues of stability and guaranteed cost for switched positive systems based on a novel multiple linear copositive Lyapunov functions approach. Two different switching policies are devised. The first one relies on continuous time strategy and the other depends on the sampled‐data strategy. The designed switching policies not only render the considered systems globally exponentially stable with a pre‐specified adequate level of performance, but also decrease the switching frequency to rule out the Zeno behaviour. New stability conditions are presented in form of linear vector equality as well as linear vector inequalities, which can be readily solved by employing Linprog function. Moreover, based on the attained stability results, the authors further research an infinite time cost function. The effectiveness of the proposed methods is validated and illustrated via simulation results.
Stabilisation of highly non‐linear continuous‐time hybrid stochastic differential delay equations by discrete‐time feedback control
Authors: Mei Chunhui , Fei Chen , Fei Weiyin , Mao Xuerong
Published: October 2019

In this study, the authors consider how to use discrete‐time state feedback to stabilise hybrid stochastic differential delay equations. The coefficients of these stochastic differential delay equations do not satisfy the conventional linear growth conditions, but are highly non‐linear. Using the Lyapunov functional method, they show that a discrete feedback controller, which depends on the states of the discrete‐time observations, can be designed to make the solutions of such controlled hybrid stochastic differential delay equations asymptotically stable and exponentially stable. The upper bound of the discrete observation interval is also given in this study. Finally, a numerical example is given to illustrate the proposed theory.
Investigation of filtering of rain streaks affected video sequences under various quantisation parameter in HEVC encoder using an enhanced V‐BM4D algorithm
Authors: Jayaraman Thiyagarajan , Chinnusamy Gowri Shankar
Published: October 2019

This study proposes an enhanced video block matching four‐dimensional (V‐BM4D) denoising algorithm for highly correlated rain streaks pattern video sequence in high‐efficiency video coding (HEVC) encoder. Removal of structural rain streaks from high definition (HD) video sequences are challenging issues in real‐time video application. Temporal information of original video sequences is distorted among the successive video frames due to the presence of natural degradation parameters such as fog, smog and rain streaks. Rain streaks are highly correlated structural noise pattern, which affects the nature of video frame compared to other natural degradations. Existing HEVC encoder is employed with in‐loop filtering to protect the temporal information of original video sequences from rain streaks pattern. However, in‐loop filtering is unable to remove the highly directional oriented rain pattern from video frames. To retain temporal information among the successive video frames, enhanced block matching denoising block is adopted in HEVC coder. The proposed enhanced VBM4D‐ based in‐loop filtering eliminates the various level of rain streaks from the HD video sequences by temporal information prediction in 4D platform. Experimental results demonstrate that the proposed denoising algorithm yields better peak signal to noise ratio value and provides better bit rate saving for various HEVC configuration.
Analysis and structural optimisation of bed structure for CNC lathe based on modal strain energy sensitivity
Authors: Guang‐chen Xu , Xing‐wei Sun
Published: October 2019

Based on the modal analysis of the finite element model of the bed, the position of the modal strain energy (MSE) concentration in the first mode is selected, and the sensitivity analysis method is used to optimise the design size of the bed. The optimisation results show that the first‐order MSE can be distributed evenly after optimisation, and the quality of the bed can be reduced. At the same time, the blindness of structural optimisation can be reduced and the optimisation efficiency can be improved. This optimisation design process and method can be extended to other machine tool parts, and provide the important approach and theory reference for machine tool dynamic characteristics improvement and structure optimisation.
Advances in entomological laser radar
Authors: Brydegaard Mikkel , Jansson Samuel
Published: October 2019

During the past decade, the authors have developed and applied optical remote sensing instrumentation for in situ remote surveillance and quantification of the aerofauna. The sparse structure of aerofauna makes optical focusing challenging, but the authors solved this issue through applying the century old Scheimpflug condition. With this approach, the authors have managed to reduce size, cost and complexity of atmospheric lidars and accomplished an effective tool for ecological entomology capable of counting thousands of insects per hour. Due to the high sensitivity and resolution in time and space, the authors can retrieve target modulation signatures in the kHz range for target classification purposes. As opposed to the cm waves in entomological radar, the authors rely on near infrared (IR) light ∼1 μm. This allows superior beam quality, negligible ground clutter and applications close over ground or within vegetation structure. Near IR light can assess both molecular and microstructural properties of the target through differential absorption and depolarisation. Here the authors give the background of entomological lidar, summarise the authors’ recent progress and put it in context with contemporary work. The authors outline applications, ongoing activities and state of the art. The authors discuss future prospects and challenges.
Implementation and optimisation of pulse compression algorithm on open CL‐based FPGA
Authors: Feng Yingxu , Hu Shanqing , Li Xingming , Yu Jiacheng
Published: October 2019

As Moore's law meets bottlenecks, the demand for heterogeneous parallel processing systems is increasing. Field‐programmable gate arrays (FPGAs) are becoming more efficient acceleration devices due to their powerful processing performance, and the CPU + FPGA architecture under the OpenCL framework has become the trend of heterogeneous parallel processing systems. This study focuses on the optimisation of pulse compression algorithm in FPGA based on OpenCL, which plays an important role in modern radar signal processing systems. By using double cache for ping–pang storage of data between matched filter and inverse fast Fourier transform (IFFT), an optimised processing method is proposed by using a pipeline and verify the method by using Arria 10 GX1150 FPGA with two groups of 2 GB DDR3; the results show that the proposed method can achieve 2.89× performance improvement over the conventional implementation.
Automated scheme for linearisation points selection in TPWL method applied to non‐linear circuits
Authors: Kalra Shifali , Nabi Mashuq‐un
Published: October 2019

Trajectory piecewise linear (TPWL) approximation is a well‐known model order reduction technique for non‐linear systems. It involves weighted summation of the dimensionally reduced linear systems obtained at certain points on the system trajectory. The points at which the linearised systems are produced are called linearization points (LP). The LPs are important as they decide the quality and the complexity of the approximation. The criterion of selecting LPs play a crucial role as the fidelity of the reduced model depends upon it. According to the previous methods, a new linearised model is formed whenever the distance of the linear model being simulated from all the previously selected LPs is greater than some chosen distance. This distance is heuristically chosen in the conventional LP selection schemes. This article proposes a new criterion of selecting the distance and the LPs that not only removes the ambiguity but also enhances the performance of the approximation. With the proposed scheme, much smaller number of LPs are needed and the distances are computed automatically, instead of being arbitrarily selected. A number of relevant examples are presented, showing the advantages of the method, both in the number of LPs and in the error of the TPWL approximation.
Design and development of an AlGaN/GaN heterostructure nano‐ATT oscillator: experimental feasibility studies in THz domain
Authors: Chakraborty Debraj , Maity Biswajit , Mukherjee Moumita
Published: October 2019

Numerical analysis followed by experimental investigations are done with heterostructure GaN/AlGaN single drift MIxed Tunnelling and Avalanche Transit Time (MITATT) devices grown on Si〈111〉 substrate, at around 1 THz. A generalised self‐consistent, nonlinear Mixed Quantum Drift‐Diffusion (MQDD) simulator is developed and used for designing p++ ‐n− ‐n‐n++ type room temperature solid‐state source within 0.75–1.1 THz regime. The epitaxial heterojunction layers are grown by III–V nitride molecular beam epitaxy which has enabled the realisation of GaN/AlGaN periodic structure on Si〈111〉 substrate with AlN buffer layer. For the first time, the realisation of heterostructure III–V Nitride MITATT oscillator at sub‐mm wave/terahertz (THz) frequencies is done. The device is observed to oscillate at 1 THz with ∼4%. A comparison of MQDD model with experimental (On wafer DC testing) results for heterojunction GaN/AlGaN MITATT diodes shows generalised agreement in terms of breakdown voltage (∼27 V) and efficiency (∼4%). First experimental results of GaN/AlGaN heterostructure MITATT diode are reported and compared with the theoretical predictions obtained through MQDD model.
Free vibration of FG nanobeam using a finite‐element method
Authors: Uzun Busra , Yaylı Mustafa Özgur , Deliktaş Babur
Published: October 2019

In this work, a non‐local finite‐element formulation is developed to analyse free vibration of functionally graded (FG) nanobeams considering power‐law variation of material through thickness of the nanobeam. The Euler–Bernoulli beam theory based on Eringen's non‐local elasticity theory with one length scale parameter is used to model the FG nanobeam. To this end, two types of FG nanobeams composed of two different materials are analysed by using the developed non‐local finite‐element formulation. First FG nanobeam is made of alumina (Al2O3) and steel, whereas second one is composed of silicon carbide (SiC) and stainless steel (SUS304). Numerical results are presented to show the effect of power‐law exponent (k) and nanostructural length scale (e0a/L) on the free vibration of FG nanobeams.
The Gaia reference frame for bright sources examined using VLBI observations of radio stars
Authors: Lindegren Lennart
Published: October 2019

Context. Positions and proper motions of Gaia sources are expressed in a reference frame that ideally should be non-rotating relative to distant extragalactic objects, coincident with the International Celestial Reference System (ICRS), and consistent across all magnitudes. For sources fainter than 16th magnitude, this is achieved through Gaia’s direct observations of quasars. At brighter magnitudes, it is difficult to validate the quality of the reference frame because comparison data are scarce.

Aims. The aim of this paper is to examine the use of very long baseline interferometry (VLBI) observations of radio stars to determine the spin and orientation of the bright reference frame of current and future Gaia data releases.

Methods. Simultaneous estimation of the six spin and orientation parameters makes optimal use of VLBI data and makes it possible to include even single-epoch VLBI observations in the solution. The method is applied to Gaia Data Release 2 (DR2) using published VLBI data for 41 radio stars.

Results. The VLBI data for the best-fitting 26 sources indicate that the bright reference frame of Gaia DR2 rotates relative to the faint quasars at a rate of about 0.1 mas yr−1, which is significant at the 2σ level. This supports a similar conclusion based on a comparison with stellar positions in the HIPPARCOS frame. The accuracy is currently limited because only a few radio sources are included in the solution, by uncertainties in the Gaia DR2 proper motions, and by issues related to the astrophysical nature of the radio stars.

Conclusions. While the origin of the indicated rotation is understood and can be avoided in future data releases, it remains important to validate the bright reference frame of Gaia by independent observations. This can be achieved using VLBI astrometry, which may require re-observing the old sample of radio stars as well as measuring new objects. The unique historical value of positional measurements is stressed and VLBI observers are urged to ensure that relevant positional information is preserved for the future.
The CARMENES search for exoplanets around M dwarfs
Authors: Fuhrmeister B. , Czesla S. , Hildebrandt L. , Nagel E. , Schmitt J. H. M. M. , Hintz D. , Johnson E. N. , Sanz-Forcada J. , Schöfer P. , Jeffers S. V. , Caballero J. A. , Zechmeister M. , Reiners A. , Ribas I. , Amado P. J. , Quirrenbach A. , Bauer F. F. , Béjar V. J. S. , Cortés-Contreras M. , Díez-Alonso E. , Dreizler S. , Galadí-Enríquez D. , Guenther E. W. , Kaminski A. , Kürster M. , Lafarga M. , Montes D.
Published: October 2019

The He I infrared (IR) triplet at 10 830 Å is an important activity indicator for the Sun and in solar-type stars, however, it has rarely been studied in relation to M dwarfs to date. In this study, we use the time-averaged spectra of 319 single stars with spectral types ranging from M0.0 V to M9.0 V obtained with the CARMENES high resolution optical and near-infrared spectrograph at Calar Alto to study the properties of the He I IR triplet lines. In quiescence, we find the triplet in absorption with a decrease of the measured pseudo equivalent width (pEW) towards later sub-types. For stars later than M5.0 V, the He I triplet becomes undetectable in our study. This dependence on effective temperature may be related to a change in chromospheric conditions along the M dwarf sequence. When an emission in the triplet is observed, we attribute it to flaring. The absence of emission during quiescence is consistent with line formation by photo-ionisation and recombination, while flare emission may be caused by collisions within dense material. The He I triplet tends to increase in depth according to increasing activity levels, ultimately becoming filled in; however, we do not find a correlation between the pEW(He IR) and X-ray properties. This behaviour may be attributed to the absence of very inactive stars (LX∕Lbol < −5.5) in our sample or to the complex behaviour with regard to increasing depth and filling in.
Theoretical wind clumping predictions of OB supergiants from line-driven instability simulations across the bi-stability jump
Authors: Driessen F. A. , Sundqvist J. O. , Kee N. D.
Published: October 2019

Context. The behaviour of mass loss across the so-called bi-stability jump, where iron recombines from Fe IV to Fe III, is a key uncertainty in models of massive stars. Specifically, while an increase in mass loss is theoretically predicted, this has not yet been observationally confirmed. However, radiation-driven winds of hot massive stars are known to exhibit clumpy structures triggered by the line-deshadowing instability (LDI). This wind clumping severely affects empirical mass-loss rates inferred from ρ2-dependent spectral diagnostics. Thus, if clumping properties differ significantly for O and B supergiants across the bi-stability jump, this may help alleviate current discrepancies between theory and observations.

Aims. We investigated with analyt
ical and numerical tools how the onset of clumpy structures behave in the winds of O supergiants (OSG) and B supergiants (BSG) across the bi-stability jump.

Methods. We derived a scaling relation for the linear growth rate of the LDI for a single optically thick line and applied it in the OSG and BSG regime. We ran 1D time-dependent line-driven instability simulations to study the non-linear evolution of the LDI in clumpy OSG and BSG winds.

Results. Linear perturbation analysis for a single line shows that the LDI linear growth rate Ω scales strongly with stellar effective temperature and terminal wind speed: Ω∝v∞2Teff4. This implies significantly lower growth rates for (the cooler and slower) BSG winds than for OSG winds. This is confirmed by the non-linear simulations, which show significant differences in OSG and BSG wind structure formation, with the latter characterized by significantly weaker clumping factors and lower velocity dispersions. This suggests that lower correction factors due to clumping should be employed when deriving empirical mass-loss rates for BSGs on the cool side of the bi-stability jump. Moreover, the non-linear simulations provide a theoretical background towards explaining the general lack of observed intrinsic X-ray emission in single B-star winds.
Silver-Promoted Regioselective Oxidative Decarboxylative C–H Alkylation of Phenanthridines with Carboxylic Acids
Authors: Huang Tianyin , Yu Yang , Wang Hui , Lin Yifan , Ma Yurui , Wang Haoyu , Ding Chang-Hua , Xiao Junjie , Xu Bin
Published: October 2019

A novel oxidative decarboxylative C–H alkylation of phenanthridines with carboxylic acids was developed for the efficient synthesis of multi-substituted phenanthridine derivatives. The given method features easy availability of starting materials, high regioselectivity, and mild conditions. Furthermore, a one-pot synthesis of multi-substituted phenanthridine derivatives was realized by the reaction of biphenyl isocyanides and carboxylic acid.
Treating the Underlying Cystic Fibrosis Transmembrane Conductance Regulator Defect in Patients with Cystic Fibrosis
Authors: Cuyx Senne , De Boeck Kris
Published: October 2019

Detailed knowledge of how mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene disturb the trafficking or function of the CFTR protein and the use of high-throughput drug screens have allowed novel therapeutic strategies for cystic fibrosis (CF). The main goal of treatment is slowly but surely shifting from symptomatic management to targeting the underlying CFTR defect to halt disease progression and even to prevent occurrence of CF complications. CFTR potentiators for patients with class III mutations, mutation R117H (and in United States also for patients with specific residual function mutations) and the combination of a CFTR modulator plus a potentiator for patients homozygous for F508del, are the two classes of modulators that are in use in the clinic. Approval of these therapeutics has progressively expanded to include both younger patients and a wider range of CFTR mutations. For a significant proportion of patients with CF, current treatment is however still insufficient or unavailable.

This review provides an overview of the clinical trial results and the real-life efficacy data of approved CFTR modulators. In addition, we discuss the entire pipeline of CFTR modulators: novel potentiators and correctors, amplifiers, stabilizers, and read-through agents. Furthermore, we discuss other strategies to improve CFTR function like nonsense-mediated decay inhibitors, modified transfer ribonucleic acids, antisense oligonucleotides, and genetic therapies.

CFTR modulators are already changing the face of CF and the pipeline of new therapies continues to be exciting.
E-tunable magnetic susceptibility and reversible magnetization switching in YIG/Pt/PMN-PZT/Pt heterostructure by low electric and magnetic fields
Authors: Han Liuyang , Ponchel Freddy , Rémiens Denis , Lasri Tuami , Tiercelin Nicolas , Wang Genshui , Pernod Philippe
Published: October 2019

The electric field (E) controlled magnetism in the multiferroic heterostructure comprising polycrystalline yttrium iron garnet (YIG) film, Pt electrodes, and lead magnesium niobate-lead zirconate titanate (PMN-PZT) ceramic is presented in this work. The electric-field-dependent magnetization and susceptibility of YIG film reveal the strain-mediated transformation of magnetocrystalline anisotropy. A strong converse magnetoelectric (CME) effect has been observed in the YIG/Pt/PMN-PZT/Pt heterostructure, and the CME coefficient can reach 17 × 10−8 s/m at 0 Oe and 4.2 kV/cm. The reversible magnetization switching by means of a low voltage pulse (±4.6 kV/cm) can be realized at 0 Oe in the YIG/Pt/PMN-PZT/Pt heterostructure, and the E-tunable susceptibility can reach Δχ/χ0+ = 55.5% at 20 Oe and 4 kV/cm. These results show great potential in power-efficient magnetoelectric components for information storage and tunable devices.
Micromagnetic analysis and optimization of spin-orbit torque switching processes in synthetic antiferromagnets
Authors: Tremsina E. A. , Roschewsky N. , Salahuddin S.
Published: October 2019

Based on micromagnetic simulations, we show that it is possible to achieve spin–orbit torque field-free switching of a synthetic antiferromagnet comprised of two ferromagnetic layers with perpendicular magnetic anisotropy, sitting on top of a conventional antiferromagnet. Field-free magnetization reversal is propelled by the competing exchange fields and spin torques. Although some antiferromagnetic coupling is necessary to switch both ferromagnetic layers, strong Ruderman-Kittel-Kasuya-Yosida inhibits the switching process due to the strong repelling forces experienced by both FM layers. The switching happens through domain nucleation and propagation and is aided by Dzyaloshinskii–Moriya interactions. The overall heterostructure is applicable in conjunction with a magnetic tunnel junction, where the free layer is comprised of the proposed synthetic antiferromagnet.