bluuebunny/crossref_metadata_2025 huggingface dataset:
The investigation of the specific behavior of a cationic block structure and its excellent flocculation performance in high-turbidity water treatment
Authors: Feng Li , Zheng Huaili , Tang Xiaomin , Zheng Xinyu , Liu Shuang , Sun Qiang , Wang Moxi
Published: April 2018

The fabrication of a cationic polyacrylamide (CPAM) with high efficiency and economy has been highly desired in the field of high-turbidity water treatment.
Asymmetric synthesis of multiple quaternary stereocentre-containing cyclopentyls by oxazolidinone-promoted Nazarov cyclizations
Authors: Volpe Rohan , Lepage Romain J. , White Jonathan M. , Krenske Elizabeth H. , Flynn Bernard L.
Published: April 2018

Ox-activated divinyl ketones undergo torquoselective Nazarov cyclization to give cyclopentanoids containing up to three new contiguous quaternary (4°) stereocentres.
Molecular dynamics simulation of charged colloids confined between hard walls: pre-melting and pre-freezing across the BCC–fluid coexistence
Authors: Eshraghi Mojtaba , Horbach Jürgen
Published: April 2018

Computer simulations of hard-core Yukawa systems confined between hard walls reveal pre-melting and pre-freezing transitions across the BCC–fluid coexistence.
Miniaturised printed monopole antenna with a linked ground plane and radiator
Authors: Ellis M.S. , Ahmed A.‐R. , Kponyo J.J. , Nourinia J. , Gbobadi Ch. , Mohammadi B.
Published: April 2018

A novel miniature wideband microstrip antenna is presented. The proposed miniature design is achieved by exploiting the idea of a quasi‐radiator. Here, a part of the radiator is connected to the ground plane through a shorting pin or via. The proposed antenna achieves a starting frequency of 1.8 GHz with a small antenna area of 20 mm2. An electrical size of 0.05λ is realised leading to a miniaturised design. The proposed antenna is broadband, compact, and produces stable radiation patterns.
Adaptive integral sliding mode control fault tolerant control for a class of uncertain nonlinear systems
Authors: Li Yuan‐Xin , Yang Guang‐Hong
Published: April 2018

This study considers the problem of adaptive sliding mode control for a class of uncertain non‐linear systems with actuator faults and external disturbances. First, a novel reinforcement learning algorithm is first introduced to design the optimal controller of nominal control systems. Then, an integral‐type sliding mode approach have been introduced to handle the difficulty caused by actuator failures and disturbance. It is shown that the actuator faults and disturbances can be compensated completely by the proposed controller, and all signals of the resulting closed‐loop system are semi‐global boundedness by choosing suitable parameters. The authors demonstrate the algorithm by applying it to two simulation examples.
Indirect adaptive neural network dynamic surface control for non‐linear time‐delay systems with prescribed performance and unknown dead‐zone input
Authors: Wu Xiaojing , Wu Xueli , Luo Xiaoyuan , Guan Xinping
Published: April 2018

The problem of tracking control is considered for a class of non‐linear time‐delay systems in the presence of unknown dead‐zone input and tracking error satisfying the prescribed performance. The new state transformation for tracking error is firstly utilised to ensure that the tracking error is within the prescribed boundaries. At the same time, the indirect adaptive neural networks and a new inequality are used to deal with the unknown non‐linear time‐delay terms and the completely unknown dead‐zone input, respectively. Then, the authors design the controller based on the dynamic surface control technique. By constructing the Lyapunov functional, it is shown that the resulting closed‐loop system is stable in the sense of uniformly ultimate boundedness and that the tracking error converges to a small residual set with the prescribed performance. Finally, simulation examples are given and the results show the effectiveness of the proposed control design method.
Non‐parametric mixture model with TV spatial regularisation and its dual expectation maximisation algorithm
Authors: Yan Shi , Yu Zihao , Liu Jun
Published: April 2018

An image segmentation method based on a non‐parametric mixture model together with total variation (TV) regularisation is proposed. The authors use a kernel density estimator as a basic mixture model, which can better separate the non‐central distributed data. To enforce its robustness, they integrate the well‐known TV regularisation into the statistical method. They use the dual method to efficiently solve the TV‐related energy and get a new dual expectation maximisation algorithm. Experiments on both synthetic images and real images show that the proposed algorithm can achieve good segmentation results. Compared with the parametric models and hidden Markov random field‐based method, the proposed method can produce better result in some cases.
Joint carrier frequency and DOA estimation using a modified ULA based MWC discrete compressed sampling receiver
Authors: Chen Tao , Liu Lizhi , Guo Limin
Published: April 2018

The uniform linear array (ULA) based modulated wideband converter discrete compressed sampling (CS) receiver is a recently introduced sub‐Nyquist sampling scheme for effective acquisition of the carrier frequency (CF) and direction‐of‐arrival (DOA) of the received radar signal. However, the ULA based system needs to correct the phase differences of the CS data in order to estimate DOA, which would cause a low DOA estimation performance. In this study, the authors propose a modified ULA based system to improve the DOA estimation performance, where another similar branch is added in each antenna to construct the proposed symmetry system. First, the received signal is mixed to basebands. Then, the mixed signals are low‐pass filtered and down‐sampled to get the CS data. Second, the two branches of the CS data received in one antenna can be utilised to estimate CF. The CS data received in the added branches can be used to estimate DOA without correcting the phase differences. Finally, simulations illustrate the validity of the proposed modified ULA based system and show the proposed system outperforms the ULA based system in DOA estimation when signal‐to‐noise ratio is more than −10dB and the number of snapshots is more than 20.
Observational constraints on key-parameters of cosmic reionisation history
Authors: Gorce A. , Douspis M. , Aghanim N. , Langer M.
Published: April 2018

We discuss constraints on cosmic reionisation and their implications on a cosmic star formation rate (SFR) density ρSFR model; we study the influence of key-parameters such as the clumping factor of ionised hydrogen in the intergalactic medium (IGM) CH II and the fraction of ionising photons escaping star-forming galaxies to reionise the IGM fesc. Our analysis has used SFR history data from luminosity functions, assuming that star-forming galaxies were sufficient to lead the reionisation process at high redshift. We have added two other sets of constraints: measurements of the IGM ionised fraction and the most recent result from Planck Satellite about the integrated Thomson optical depth of the cosmic microwave background τPlanck. Our analysis shows that a reionisation beginning as early as z ≥ 14 and persisting until z ~ 6 is a likely scenario. We also considered various possibilities for the evolution of fesc and CH II with redshift, and confront them with observational data cited above. We conclude that, if the model of a constant clumping factor is chosen, the fiducial value of three is consistent with observations; even if a redshift-dependent model is considered, the resulting optical depth is strongly correlated with CH II mean value at z > 7, an additional argument in favour of the use of a constant clumping factor. Similarly, a constant value of the escape fraction is favoured over a redshift-dependent model. When added as a fit parameter, we find fesc = 0.19 ± 0.04. However, this result strongly depends on the choice of magnitude limit in the derivation of ρSFR. Our fiducial analysis considers faint galaxies (Mlim = −13) and the result is a well constrained escape fraction of about 0.2, but when Mlim = −17, the number of galaxies available to reionise the IGM is not sufficient to match the observations, so that much higher values of fesc, approaching 70%, are needed.
Objectif sourire : et si l’on s’intéressait aux lèvres ?
Authors: Muller Christine , Alouini Ons , Chouvin Monique
Published: April 2018

Introduction : Le sourire ne se résume pas à un alignement dentaire. L’harmonie dentaire avec les tissus mous est le secret d’un beau sourire. Cet article très illustré se penche plus précisément sur les lèvres et leur mobilité. Matériels et méthodes : Après avoir présenté la terminologie relative aux lèvres, cet article aborde les notions de volumes, mobilité et vieillissement pour conclure sur des considérations cliniques orthodontiques. Discussion : La demande des patients adultes doit s’apprécier en connaissance de cause et susciter, de la part des praticiens, une analyse détaillée des lèvres, au repos et en fonction. L’harmonie dentaire et celle des tissus mous sont en effet indispensables à un beau sourire : une prise en charge pluridisciplinaire est souvent nécessaire. Conclusion : Redonner le sourire aux patients impose donc aux praticiens d’aller au-delà des problématiques d’occlusion dentaire.
Optimisation parodontale du sourire : adresser au bon moment pour un réel bénéfice esthétique
Authors: Dumay Muriel , Dersot Jean-Marc , Mertens Brenda
Published: April 2018

Introduction :De nos jours, la demande esthétique devient un des premiers motifs de consultation des patients. Soumis aux diktats de la beauté imposés par notre société, le sourire est un élément clé dans cette quête de l’esthétique parfaite. Ainsi, l’orthodontiste est souvent le premier spécialiste consulté par les adolescents, mais aussi de plus en plus par les adultes. Celui-ci doit être en mesure de réaliser, grâce à des outils simples, une analyse précise du patient comprenant son examen orthodontique, mais aussi parodontal avec un diagnostic parodontal esthétique.Objectifs :Dans cette analyse, l’orthodontiste doit pouvoir identifier le morphotype parodontal de son patient et évaluer si celui-ci est à risque de complications durant son traitement. L’une des principales complications est la récession parodontale. Impactant l’esthétique et suscitant l’inquiétude chez le patient, l’orthodontiste peut vite se retrouver démuni. En cas de doute, il est impératif d’orienter son patient vers l’omnipraticien ou le parodontiste.Matériels et méthodes :Les auteurs décriront dans cet article l’arbre décisionnel qui peut être un outil didactique aidant le praticien dans la prise en charge de son patient.Discussion :Une synergie dans la prise en charge globale des patients est gage d’un résultat optimal des traitements inscrivant le patient dans un schéma thérapeutique individuel et adapté.
Ceramic-on-Polyethylene Bearing Usage in Primary THA Is Associated with Reduced Readmission Risk for the Medicare Population
Authors: Lau Edmund , Baykal Doruk , Springer Bryan , Kurtz Steven
Published: April 2018

The authors hypothesized that unplanned readmissions, which are often caused by infections and dislocation, may be reduced with ceramic bearing usage. They also sought to confirm that the readmission rates for ceramic bearings were associated with the year of surgery. They identified 245,077 elderly patients (65+) who underwent primary total hip arthroplasty (THA) between 2010 and 2015 with known bearing types (ceramic-on-polyethylene [C-PE] ceramic-on-ceramic [COC], and metal-on-polyethylene [M-PE]) from the Medicare 100% inpatient database. Outcomes included relative risk of 30- and 90-day readmission. Propensity scores were developed to adjust for selection bias in the choice of bearing type at index surgery. Cox regression incorporating propensity score stratification (10 levels) was used to evaluate the impact of bearing selection on outcomes, after adjusting for patient-, hospital-, surgeon-related factors, as well as the year of surgery. With C-PE bearings, the unadjusted (crude) 90-day readmission rate decreased from 8.7% in 2010 to 8.3% in 2015. For COC bearings, the crude 90-day readmission rate decreased from 10.5 to 9.1% from 2010 to 2015. After adjustment, year of surgery was associated with reduced readmission risk for both types of ceramic bearings in 30-day readmissions (p < 0.05) and COC in 90-day readmissions (p < 0.001). The authors also found that C-PE bearings were associated with significantly reduced readmission risk relative to M-PE at 30 days (hazard ratio [HR]: 0.91, p < 0.001) and 90 days (HR: 0.93, p < 0.001). In terms of strength of association with 90-day readmission, however, it was ranked the ninth most associated independent factor. To the authors' knowledge, this is the first study to demonstrate an association between THA implant characteristics (in this case C-PE bearing usage) and reduced readmission rates in this context along with patient- and clinical-related factors. The readmission rates for COC were found to be comparable to M-PE.
Surgical Treatment and Long-Term Outcome of Cerebral Cavernous Malformations-Related Epilepsy in Pediatric Patients
Authors: Lin Qiao , Jia Yan-Zeng , Pei Jia-Sheng , Xiao Hui , Zhang Ting-Ting , Zhong Zhong-Hui , Wang Shou-Sen , Yang Peng-Fan
Published: April 2018

Cerebral cavernous malformations (CMs) are vascular malformations affecting any part of the central nervous system. Clinical data and surgical outcomes for 27 pediatric patients with CM-related epilepsy were retrospectively reviewed. The mean age of onset was 12.71 ± 4.09 years, and the mean duration of epilepsy was 2.34 ± 1.95 years. All 27 patients were treated with microsurgery for resection of the CMs, and the hemosiderin rim, and the secondary epileptogenic zone if necessary. The mean follow-up period was 6.34 ± 3.35 years, and the overall postoperative outcomes were positive. Note that 77.8% of patients were seizure-free postoperatively. The other patients with residual epilepsy received incomplete resection of the hemosiderin rim or the secondary epileptogenic zone due to retention of vital neurological functions. Surgical treatment for pediatric patients with symptomatic supratentorial CMs is safe and effective. Early intervention is recommended to resect CMs, the hemosiderin rim, and the epileptogenic cortex, even in cases of multiple CMs.
Sub-millisecond electron density profile measurement at the JET tokamak with the fast lithium beam emission spectroscopy system
Authors: Réfy D. I. , Brix M. , Gomes R. , Tál B. , Zoletnik S. , Dunai D. , Kocsis G. , Kálvin S. , Szabolics T. ,   JET Contributors
Published: April 2018

Diagnostic alkali atom (e.g., lithium) beams are routinely used to diagnose magnetically confined plasmas, namely, to measure the plasma electron density profile in the edge and the scrape off layer region. A light splitting optics system was installed into the observation system of the lithium beam emission spectroscopy diagnostic at the Joint European Torus (JET) tokamak, which allows simultaneous measurement of the beam light emission with a spectrometer and a fast avalanche photodiode (APD) camera. The spectrometer measurement allows density profile reconstruction with ∼10 ms time resolution, absolute position calculation from the Doppler shift, spectral background subtraction as well as relative intensity calibration of the channels for each discharge. The APD system is capable of measuring light intensities on the microsecond time scale. However ∼100 μs integration is needed to have an acceptable signal to noise ratio due to moderate light levels. Fast modulation of the beam up to 30 kHz is implemented which allows background subtraction on the 100 μs time scale. The measurement covers the 0.9 < ρpol < 1.1 range with 6-10 mm optical resolution at the measurement location which translates to 3-5 mm radial resolution at the midplane due to flux expansion. An automated routine has been developed which performs the background subtraction, the relative calibration, and the comprehensive error calculation, runs a Bayesian density reconstruction code, and loads results to the JET database. The paper demonstrates the capability of the APD system by analyzing fast phenomena like pellet injection and edge localized modes.
Performance of the fiber-optic low-coherent ground settlement sensor: From lab to field
Authors: Guo Jingjing , Tan Yanbin , Peng Li , Chen Jisong , Wei Chuanjun , Zhang Pinglei , Zhang Tianhang , Alrabeei Salah , Zhang Zhe , Sun Changsen
Published: April 2018

A fiber-optic low-coherent interferometry sensor was developed to measure the ground settlement (GS) in an accuracy of the micrometer. The sensor combined optical techniques with liquid-contained chambers that were hydraulically connected together at the bottom by using a water-filled tube. The liquid surface inside each chamber was at the same level initially. The optical interferometry was employed to read out the liquid level changes, which following the GS happened at the place where the chamber was put on and, thereby, the GS information was calculated. The laboratory effort had demonstrated its potential in the practical application. Here, the denoising algorithms on the measurement signal were carried out based on the specific environment to ensure the accuracy and stability of the system in field applications. After that, we extended this technique to the high-speed railway. The 5-days continuous measurement proved that the designed system could be applied to monitor the GS of the high-speed railway piers and approached an accuracy of ±70 μm in the field situation with a reference compensation sensor. So the performance of the sensor was suitable to the GS monitoring problem in the high-speed railway. There, the difficulties were to meet the monitoring requirement of both a large span in space and its quite tiny and slow changes.
Accessing the band alignment in high efficiency Cu(In,Ga)(Se,S)2 (CIGSSe) solar cells with an InxSy:Na buffer based on temperature dependent measurements and simulations
Authors: Schoneberg Johannes , Ohland Jörg , Eraerds Patrick , Dalibor Thomas , Parisi Jürgen , Richter Michael
Published: April 2018

We present a one-dimensional simulation model for high efficiency Cu(In,Ga)(Se,S)2 solar cells with a novel band alignment at the hetero-junction. The simulation study is based on new findings about the doping concentration of the InxSy:Na buffer and i-ZnO layers as well as comprehensive solar cell characterization by means of capacitance, current voltage, and external quantum efficiency measurements. The simulation results show good agreement with the experimental data over a broad temperature range, suggesting the simulation model with an interface-near region (INR) of approximately 100 nm around the buffer/absorber interface that is of great importance for the solar cell performance. The INR exhibits an inhomogeneous doping and defect density profile as well as interface traps at the i-layer/buffer and buffer/absorber interfaces. These crucial parameters could be accessed via their opposing behavior on the simulative reconstruction of different measurement characteristics. In this work, we emphasize the necessity to reconstruct the results of a set of experimental methods by means of simulation to find the most appropriate model for the solar cell. Lowly doped buffer and intrinsic window layers in combination with a high space charge at the front of the absorber lead to a novel band alignment in the simulated band structure of the solar cell. The presented insights may guide the strategy of further solar cell optimization including (alkali-) post deposition treatments.
Pulse-coupled mixed-mode oscillators: Cluster states and extreme noise sensitivity
Authors: Karamchandani Avinash J. , Graham James N. , Riecke Hermann
Published: April 2018

Motivated by rhythms in the olfactory system of the brain, we investigate the synchronization of all-to-all pulse-coupled neuronal oscillators exhibiting various types of mixed-mode oscillations (MMOs) composed of sub-threshold oscillations (STOs) and action potentials (“spikes”). We focus particularly on the impact of the delay in the interaction. In the weak-coupling regime, we reduce the system to a Kuramoto-type equation with non-sinusoidal phase coupling and the associated Fokker-Planck equation. Its linear stability analysis identifies the appearance of various cluster states. Their type depends sensitively on the delay and the width of the pulses. Interestingly, long delays do not imply slow population rhythms, and the number of emerging clusters only loosely depends on the number of STOs. Direct simulations of the oscillator equations reveal that for quantitative agreement of the weak-coupling theory the coupling strength and the noise have to be extremely small. Even moderate noise leads to significant skipping of STO cycles, which can enhance the diffusion coefficient in the Fokker-Planck equation by two orders of magnitude. Introducing an effective diffusion coefficient extends the range of agreement significantly. Numerical simulations of the Fokker-Planck equation reveal bistability and solutions with oscillatory order parameters that result from nonlinear mode interactions. These are confirmed in simulations of the full spiking model.
Path integral discussion of the improved Tietz potential
Authors: Khodja A. , Benamira F. , Guechi L.
Published: April 2018

An improved form of the Tietz potential for diatomic molecules is discussed in detail within the path integral formalism. The radial Green’s function is rigorously constructed in a closed form for different shapes of this potential. For q≤1 and 12αlnq<r<+∞, the energy spectrum and the normalized wave functions of the bound states are derived for the l waves. When the deformation parameter q is 0<q<1 or q > 0, it is found that the quantization conditions are transcendental equations that require numerical solutions. In the limit q → 0, the energy spectrum and the corresponding wave functions for the radial Morse potential are recovered.
Chemical potentials of alkaline earth metal halide aqueous electrolytes and solubility of their hydrates by molecular simulation: Application to CaCl2, antarcticite, and sinjarite
Authors: Moučka Filip , Kolafa Jiří , Lísal Martin , Smith William R.
Published: April 2018

We present a molecular-level simulation study of CaCl2 in water and crystalline hydrates formed by CaCl2 at ambient (298.15 K, 1 bar) conditions and at a high-temperature high-pressure state (365 K, 275 bars) typical of hydraulic fracturing conditions in natural-gas extraction, at which experimental properties are poorly characterized. We focus on simulations of chemical potentials in both solution and crystalline phases and on the salt solubility, the first time to our knowledge that such properties have been investigated by molecular simulation for divalent aqueous electrolytes. We first extend our osmotic ensemble Monte Carlo simulation technique [F. Moučka et al., J. Phys. Chem. B 115, 7849–7861 (2011)] to such solutions. We then describe and apply new methodology for the simulation of the chemical potentials of the experimentally observed crystalline hydrates at ambient conditions (antarcticite, CaCl2·6H2O) and at high-temperature conditions (sinjarite, CaCl2·2H2O). We implement our methodologies using for both phases the CaCl2 transferable force field (FF) based on simple point charge-extended water developed by Mamatkulov et al. [J. Chem. Phys. 138, 024505 (2013)], based on training sets involving single-ion and ion-pair low-concentration solution properties at near-ambient conditions. We find that simulations of the solution chemical potentials at high concentrations are somewhat problematic, exhibiting densities diverging from experimental values and accompanied by dramatically decreasing particle mobility. For the solid phases, the sinjarite crystalline lattice differs from experiment only slightly, whereas the simulations of antarcticite completely fail, due to instability of the crystalline lattice. The FF thus only successfully yields the sinjarite solubility, but its value m = 8.0(7) mol kg−1H2O lies well below the experimentally observed solubility range at 1 bar pressure of (12m, 15m) in the temperature interval (320 K, 400 K). We conclude that the used FF does not provide a good description of the experimental properties considered and suggest that improvement must take into account the crystalline properties.
Hall effect driven by non-collinear magnetic polarons in diluted magnetic semiconductors
Authors: Denisov K. S. , Averkiev N. S.
Published: April 2018

In this letter, we develop the theory of Hall effect driven by non-collinear magnetic textures (topological Hall effect—THE) in diluted magnetic semiconductors (DMSs). We show that a carrier spin-orbit interaction induces a chiral magnetic ordering inside a bound magnetic polaron (BMP). The inner structure of non-collinear BMP is controlled by the type of spin-orbit coupling, allowing us to create skyrmion- (Rashba) or antiskyrmion-like (Dresselhaus) configurations. The asymmetric scattering of itinerant carriers on polarons leads to the Hall response which exists in weak external magnetic fields and at low temperatures. We point out that DMS-based systems allow one to investigate experimentally the dependence of THE both on a carrier spin polarization and on a non-collinear magnetic texture shape.
Enhanced thermoelectric performance through grain boundary engineering in quaternary chalcogenide Cu2ZnSnSe4
Authors: Zhu Yingcai , Liu Yong , Tan Xing , Ren Guangkun , Yu Meijuan , Hu Tiandou , Marcelli Augusto , Xu Wei
Published: April 2018

Quaternary chalcogenide Cu2ZnSnSe4 (CZTSe) is a promising wide band-gap p-type thermoelectric material. The structure and thermoelectric properties of lead substituted Cu2ZnSn1-xPbxSe4 are investigated. Lead primarily exists in the framework of PbSe as demonstrated by x-ray diffraction and calculation of x-ray absorption near-edge structure spectroscopy. The second phase distributes at the boundaries of CZTSe with thickness in several hundreds of nanometer. With appropriate grain boundary engineering, the enhancement of power factor and a decrease of thermal conductivity can be achieved simultaneously. As a result, a maximum figure of merit zT of 0.45 is obtained for the sample with x=0.02 at 723K.
Deterministic control of radiative processes by shaping the mode field
Authors: Pellegrino D. , Pagliano F. , Genco A. , Petruzzella M. , van Otten F. W. , Fiore A.
Published: April 2018

Quantum dots (QDs) interacting with confined light fields in photonic crystal cavities represent a scalable light source for the generation of single photons and laser radiation in the solid-state platform. The complete control of light-matter interaction in these sources is needed to fully exploit their potential, but it has been challenging due to the small length scales involved. In this work, we experimentally demonstrate the control of the radiative interaction between InAs QDs and one mode of three coupled nanocavities. By non-locally moulding the mode field experienced by the QDs inside one of the cavities, we are able to deterministically tune, and even inhibit, the spontaneous emission into the mode. The presented method will enable the real-time switching of Rabi oscillations, the shaping of the temporal waveform of single photons, and the implementation of unexplored nanolaser modulation schemes.
Designs for thermal harvesting with nonlinear coordinate transformation
Authors: Ji Qingxiang , Fang Guodong , Liang Jun
Published: April 2018

In this paper a thermal concentrating design method was proposed based on the concept of generating function without knowing the needed coordinate transformation beforehand. The thermal harvesting performance was quantitatively characterized by heat concentrating efficiency and external temperature perturbation. Nonlinear transformations of different forms were employed to design high order thermal concentrators, and corresponding harvesting performances were investigated by numerical simulations. The numerical results shows that the form of coordinate transformation directly influences the distributions of heat flows inside the concentrator, consequently, influences the thermal harvesting behaviors significantly. The concentrating performance can be actively controlled and optimized by changing the form of coordinate transformations. The analysis in this paper offers a beneficial method to flexibly tune the harvesting performance of the thermal concentrator according to the requirements of practical applications.
Fabrication and characterization of NiO based metal−insulator−metal diode using Langmuir-Blodgett method for high frequency rectification
Authors: Azad Ibrahim , Ram Manoj K. , Goswami D. Yogi , Stefanakos Elias
Published: April 2018

Thin film metal–insulator–metal (MIM) diodes have attracted significant attention for use in infrared energy harvesting and detection applications. As demonstrated over the past decades, MIM or metal-insulator-insulator-metal (MIIM) diodes can operate at the THz frequencies range by quantum tunneling of electrons. The aim of this work is to synthesize required ultra-thin insulating layers and fabricate MIM diodes using the Langmuir-Blodgett (LB) technique. The nickel stearate (NiSt) LB precursor film was deposited on glass, silicon (Si), ITO glass and gold coated silicon substrates. The photodesorption (UV exposure) and the thermodesorption (annealing at 100 °C and 350 °C) methods were used to remove organic components from the NiSt LB film and to achieve a uniform homogenous nickel oxide (NiO) film. These ultrathin NiO films were characterized by EDS, AFM, FTIR and cyclic voltammetry methods, respectively. The MIM diode was fabricated by depositing nickel (Ni) on the NiO film, all on a gold (Au) plated silicon (Si) substrate. The current (I)-voltage (V) characteristics of the fabricated diode were studied to understand the conduction mechanism assumed to be tunneling of electron through the ultra-thin insulating layer. The sensitivity of the diode was measured to be as high as 35 V-1. The diode resistance was ∼100 ohms (at a bias voltage of 0.60 V), and the rectification ratio was about 22 (for a signal voltage of ±200 mV). At the bias point, the diode response demonstrated significant non-linearity and high asymmetry, which are very desirable characteristics for applications in infrared detection and harvesting.
Evaluation of the simulated physiological oocyte maturation (SPOM) system on F1 Gyr × Holstein oocytes and embryos
Authors: Leal Gabriela Ramos , Monteiro Clara Ana dos Santos , Saraiva Helena Fabiana Reis de Almeida , Camargo Agostinho Jorge dos Reis , Rodrigues André Luís Rios , Oliveira Clara Slade , Vasconcelos Carlos Otávio de Paula , Nogueira Luiz Altamiro Garcia , Serapião Raquel Varella
Published: April 2018

The present study aimed to evaluate the effect of the simulated physiological oocyte maturation (SPOM) system on F1 Gyr × Holstein oocytes and embryos by evaluating the meiotic arrest, embryo production rates, total number of cells and lipid score. Three experiments were conducted and the following three experimental groups were formed according to in vitro maturation (IVM) treatments: CONTROL 1 (TCM 199 medium without FBS), CONTROL 2 (commercial medium) and SPOM (TCM 199 medium with forskolin and 3-isobutyl-1-methylxanthine (IBMX) in pre-IVM and extended IVM with cilostamide). In the first experiment (ovum pick-up), a significant (P < 0.05) reduction in the percentage of matured oocytes in SPOM group was observed. In the second (slaughterhouse ovaries) and third (ovum pickup) experiments, the cleavage and blastocyst rates were reduced (P < 0.05) in the SPOM group. There was no significant (P > 0.05) difference in total number of cells among the groups. No difference (P > 0.05) was found on lipid score among the groups at Day 7 of development, in both Experiments 2 and 3. At Day 9 (Experiment 2), only the CONTROL 2 showed a significant increase (P > 0.05) compared with the other treatments. It was concluded that under our conditions, the SPOM system was efficient in prolonging meiotic arrest on Gyr × Holstein oocytes, offering the oocytes in vitro conditions more similar to those found in vivo; however, it adversely affected embryo production rates and promoted no beneficial effect on the total number of cells and the lipid score.
Physiological responses of drought tolerance in orchardgrass (Dactylis glomerata) in association with persistence and summer dormancy
Authors: Saeidnia Fatemeh , Majidi Mohammad Mahdi , Mirlohi Aghafakhr , Ahmadi Benyamin
Published: April 2018

The genetic basis of physiological responses to drought and its association with productivity, persistence and summer dormancy is not clear in orchardgrass (Dactylis glomerata L.). Thirty-six orchardgrass genotypes were evaluated under water stress and non-stressed conditions during 2 years (2013–14). High genotypic variation was observed for all of the agronomic and physiological traits. Water stress reduced dry matter yield, relative water content and chlorophyll content while significantly increasing carotenoids, water-soluble carbohydrates, proline and chlorophyll a : b ratio. The results indicated that carotenoids and proline accumulation could not be used for discriminating drought-tolerant genotypes of orchardgrass, whereas water-soluble carbohydrates may be used to achieve this purpose. Moreover, the results showed that the stable genotypes that have lower changes in productivity from normal to water-stress environments also have more persistence. No association was found between summer dormancy and drought tolerance measured by both physiological and yield-based drought-tolerance indices. Some of the drought-tolerant genotypes had relatively high persistence and better autumn recovery, a characteristic useful for the development of new synthetic varieties.
A collaboratively derived environmental research agenda for Galápagos
Authors: Izurieta Arturo , Delgado Byron , Moity Nicolas , Calvopiña Monica , Cedeño Iván , Banda-Cruz Gonzalo , Cruz Eliecer , Aguas Milton , Arroba Francisco , Astudillo Iván , Bazurto Diana , Soria Mónica , Banks Stuart , Bayas Steve , Belli Simone , Bermúdez Rafael , Boelling Nicolai , Bolaños Jimmy , Borbor Mercy , Brito Ma. Lorena , Bucheli Leopoldo , Campbell Karl , Carranza David , Carrión Jorge , Casafont Maria , Castro Xavier , Chamorro Sandra , Chávez Juan , Chicaiza David , Chumbi René , Couenberg Paulina , Cousseau David , Cruz Marilyn , d'Ozouville Noemí , de la Guía Cristina , de la Torre Giorgio , Díaz Carla Molina , Duchicela Jessica , Endara Daniel , Garcia Vanessa , Gellibert Cynthia , Gibbs James , Guzmán Juan Carlos , Heylings Pippa , Iglesias Andrés , Izurieta Juan Carlos , Jaramillo Patricia , Klingman Asleigh , Laurie Andrew , Leon Patricia , Medina Jaime , Mendieta Edison , Merlen Godfrey , Montalvo Carla , Naula Edwin , Páez-Rosas Diego , Peralta Manuel , Peralvo Marcos , Piu Mario , Poma José , Pontón José , Pozo Mireya , Proaño Daniel , Ramos Mónica , Rousseaud Ana , Rueda Danny , Salinas Pelayo , Salmoral Gloria , Saraguro Silvia , Simón-Baile Débora , Tapia Washington , Teran Byron , Valverde Marilú , Vargas Andrea , Vega Josué , Velásquez Wilson , Vélez Alberto , Verdesoto Santiago , Villarraga Hernán G. , Vissioli Fernando , Viteri-Mejía Cesar , Norris-Crespo Lucía , Cooke Sophia C. , Toral-Granda M. Veronica , Sutherland William J.
Published: April 2018

Galápagos is one of the most pristine archipelagos in the world and its conservation relies upon research and sensible management. In recent decades both the interest in, and the needs of, the islands have increased, yet the funds and capacity for necessary research have remained limited. It has become, therefore, increasingly important to identify areas of priority research to assist decision-making in Galápagos conservation.
This study identified 50 questions considered priorities for future research and management. The exercise involved the collaboration of policy makers, practitioners and researchers from more than 30 different organisations. Initially, 360 people were consulted to generate 781 questions. An established process of preworkshop voting and three rounds to reduce and reword the questions, followed by a two-day workshop, was used to produce the final 50 questions. The most common issues raised by this list of questions were human population growth, climate change and the impact of invasive alien species. These results have already been used by a range of organisations and politicians and are expected to provide the basis for future research on the islands so that its sustainability may be enhanced.
Shannon information entropies for rectangular multiple quantum well systems with constant total lengths*
Authors: Solaimani M , Sun Guo-Hua , Dong Shi-Hai
Published: April 2018

We first study the Shannon information entropies of constant total length multiple quantum well systems and then explore the effects of the number of wells and confining potential depth on position and momentum information entropy density as well as the corresponding Shannon entropy. We find that for small full width at half maximum (FWHM) of the position entropy density, the FWHM of the momentum entropy density is large and vice versa. By increasing the confined potential depth, the FWHM of the position entropy density decreases while the FWHM of the momentum entropy density increases. By increasing the potential depth, the frequency of the position entropy density oscillation within the quantum barrier decreases while that of the position entropy density oscillation within the quantum well increases. By increasing the number of wells, the frequency of the position entropy density oscillation decreases inside the barriers while it increases inside the quantum well. As an example, we might localize the ground state as well as the position entropy densities of the 1st, 2nd, and 6th excited states for a four-well quantum system. Also, we verify the Bialynicki–Birula–Mycieslki (BBM) inequality.
Commentary on “Numbers of solutions of equations in finite fields” by André Weil
Authors: Goresky Mark
Published: April 2018

Immediately following the commentary below, this previously published article is reprinted in its entirety: André Weil, “Numbers and solutions of equations in finite fields”, Bull. Amer. Math. Soc., 55 (1949), no. 5, 497–508.
Commentary on “Nonunique tangent maps at isolated singularities of harmonic maps” by Brian White
Authors: Minicozzi William
Published: April 2018

Immediately following the commentary below, this previously published article is reprinted in its entirety: Brian White, “Nonunique tangent maps at isolated singularities of harmonic maps”, Bull. Amer. Math. Soc. (N.S.) 26 (1992), no. 1, 123–129.
Semi‐Parametric Generalized Additive Vector Autoregressive Models of Spatial Basis Dynamics
Authors: Guney Selin , Goodwin Barry K. , Riquelme Andrés
Published: April 2018

An extensive line of research has examined linkages among spatially‐distinct markets. We apply semi‐parametric, generalized additive vector autoregressive models to a consideration of basis linkages among North Carolina corn and soybean markets. An extensive suite of linearity tests suggests that basis and price relationships are nonlinear. Marginal effects, transmission elasticities, and generalized impulse responses are utilized to describe patterns of adjustment among markets. The semi‐parametric models are compared to standard threshold vector autoregressive models and are found to reveal more statistical significance and substantially more nonlinearity in basis adjustments. Marginal effects are nonlinear and impulse responses suggest greater adjustments to extreme shocks and asymmetric adjustment patterns. The results provide evidence in favor of efficiently linked markets.
DEsingle for detecting three types of differential expression in single-cell RNA-seq data
Authors: Miao Zhun , Deng Ke , Wang Xiaowo , Zhang Xuegong
Published: April 2018

The excessive amount of zeros in single-cell RNA-seq (scRNA-seq) data includes ‘real’ zeros due to the on-off nature of gene transcription in single cells and ‘dropout’ zeros due to technical reasons. Existing differential expression (DE) analysis methods cannot distinguish these two types of zeros. We developed an R package DEsingle which employed Zero-Inflated Negative Binomial model to estimate the proportion of real and dropout zeros and to define and detect three types of DE genes in scRNA-seq data with higher accuracy.

Availability and implementation

The R package DEsingle is freely available at Bioconductor (https://bioconductor.org/packages/DEsingle).

Supplementary information

Supplementary data are available at Bioinformatics online.
On K-Polystability of cscK Manifolds with Transcendental Cohomology Class
Authors: Sjöström Dyrefelt Zakarias
Published: April 2018

In this paper we study K-polystability of arbitrary (possibly non-projective) compact Kähler manifolds admitting holomorphic vector fields. As a main result we show that existence of a constant scalar curvature Kähler (cscK) metric implies geodesic K-polystability, in a sense that is expected to be equivalent to K-polystability in general. In particular, in the spirit of an expectation of Chen–Tang [28] we show that geodesic K-polystability implies algebraic K-polystability for polarized manifolds, so our main result recovers a possibly stronger version of results of Berman–Darvas–Lu [10] in this case. As a key part of the proof we also study subgeodesic rays with singularity type prescribed by singular test configurations and prove a result on asymptotics of the K-energy functional along such rays. In an appendix by R. Dervan it is moreover deduced that geodesic K-polystability implies equivariant K-polystability. This improves upon the results of [39] and proves that existence of a cscK (or extremal) Kähler metric implies equivariant K-polystability (resp. relative K-stability).
Efficient common-envelope ejection through dust-driven winds
Authors: Glanz Hila , Perets Hagai B
Published: April 2018

Common-envelope evolution (CEE) is the short-lived phase in the life of an interacting binary system during which two stars orbit inside a single shared envelope. Such evolution is thought to lead to the inspiral of the binary, the ejection of the extended envelope, and the formation of a remnant short-period binary. However, detailed hydrodynamical models of CEE encounter major difficulties. They show that following the inspiral most of the envelope is not ejected; though it expands to larger separations, it remains bound to the binary. Here we propose that dust-driven winds can be produced following the CEE. These can evaporate the envelope following similar processes operating in the ejection of the envelopes of AGB (Asymptotic Gian Branch) stars. Pulsations in an AGB star drive the expansion of its envelope, allowing the material to cool down to low temperatures thus enabling dust condensation. Radiation pressure on the dust accelerates it, and through its coupling to the gas it drives winds that eventually completely erode the envelope. We show that the inspiral phase in CE binaries can effectively replace the role of stellar pulsation and drive the CE expansion to scales comparable with those of AGB stars, and gives rise to efficient mass-loss through dust-driven winds.
Canada-Wide Epidemic of emm74 Group A Streptococcus Invasive Disease
Authors: Teatero Sarah , McGeer Allison , Tyrrell Gregory J , Hoang Linda , Smadi Hanan , Domingo Marc-Christian , Levett Paul N , Finkelstein Michael , Dewar Ken , Plevneshi Agron , Athey Taryn B T , Gubbay Jonathan B , Mulvey Michael R , Martin Irene , Demczuk Walter , Fittipaldi Nahuel
Published: April 2018

Background

The number of invasive group A Streptococcus (iGAS) infections due to hitherto extremely rare type emm74 strains has increased in several Canadian provinces since late 2015. We hypothesized that the cases recorded in the different provinces are linked and caused by strains of an emm74 clone that recently emerged and expanded explosively.

Methods

We analyzed both active and passive surveillance data for iGAS infections and used whole-genome sequencing to investigate the phylogenetic relationships of the emm74 strains responsible for these invasive infections country-wide.

Results

Genome analysis showed that highly clonal emm74 strains, genetically different from emm74 organisms previously circulating in Canada, were responsible for a country-wide epidemic of >160 invasive disease cases. The emerging clone belonged to multilocus sequence typing ST120. The analysis also revealed dissemination patterns of emm74 subclonal lineages across Canadian provinces. Clinical data analysis indicated that the emm74 epidemic disproportionally affected middle-aged or older male individuals. Homelessness, alcohol abuse, and intravenous drug usage were significantly associated with invasive emm74 infections.

Conclusions

In a period of 20 months, an emm74 GAS clone emerged and rapidly spread across several Canadian provinces located more than 4500 km apart, causing invasive infections primarily among disadvantaged persons.
Characteristics and Predictive Value of PD-L1 Status in Real-World Non–Small Cell Lung Cancer Patients
Authors: Tseng Jeng-Sen , Yang Tsung-Ying , Wu Chih-Ying , Ku Wen-Hui , Chen Kun-Chieh , Hsu Kuo-Hsuan , Huang Yen-Hsiang , Su Kang-Yi , Yu Sung-Liang , Chang Gee-Chen
Published: April 2018

Immunotherapy targeting the programmed cell death-1 (PD-1) and programmed cell death-ligand 1 (PD-L1) pathway has emerged as an effective treatment for lung cancer patients. It is important to evaluate the practicality of PD-L1 testing in real-world practice. A total of 211 non–small cell lung cancer patients were enrolled to detect 5 driver mutations and PD-L1 status (22C3 and SP263 assays) and to evaluate the characteristics of PD-L1 expression and its predictive value of immunotherapy. The PD-L1 positive (≥1%) and strong positive (≥50%) rate by SP263 assay was 27.0% and 12.8%. The concordance rates between 2 PD-L1 assays while using 1%, 10%, 25%, and 50% positive tumor cells as the cutoffs were 76.8%, 81.5%, 90.5%, and 94.3%, respectively. Smokers and patients without known actionable driver mutation were more likely to present strong positive PD-L1 [adjusted hazard ratio, 5.00 (95% confidence interval—CI, 1.60-15.64); P=0.006 and 3.59 (95% CI, 1.25-10.33); P=0.018, respectively]. Higher levels of smoking were associated with higher PD-L1 expressions. None of the EGFR, ALK, HER2, or BRAF

V600E
-mutant nonsmokers displayed strong positive PD-L1 expression by SP263 assay. Among patients undergoing PD-1 checkpoint inhibitors therapy, high PD-L1 expression by SP263 was associated with a longer progression-free survival [adjusted hazard ratio, 0.15 (95% CI, 0.03-0.71); P=0.017]. In conclusion, our results suggest that PD-L1 status remains an important predictor of immunotherapy efficacy. The concordance between 22C3 and SP263 assays was greater at a higher cutoff level of positivity. Patients without known actionable driver mutation, along with smokers, particularly those having high smoking pack-years, were more likely to have strong PD-L1 expression.