bluuebunny/crossref_metadata_2025 huggingface dataset:
Calculation of the piezoelectric and flexoelectric effects in nanowires using a decoupled finite element analysis method
Authors: Zhang Zhiqiang , Geng Dalong , Wang Xudong
Published: April 2016

A simple and effective decoupled finite element analysis method was developed for simulating both the piezoelectric and flexoelectric effects of zinc oxide (ZnO) and barium titanate (BTO) nanowires (NWs). The piezoelectric potential distribution on a ZnO NW was calculated under three deformation conditions (cantilever, three-point, and four-point bending) and compared to the conventional fully coupled method. The discrepancies of the electric potential maximums from these two methods were found very small, validating the accuracy and effectiveness of the decoupled method. Both ZnO and BTO NWs yielded very similar potential distributions. Comparing the potential distributions induced by the piezoelectric and flexoelectric effects, we identified that the middle segment of a four-point bending NW beam is the ideal place for measuring the flexoelectric coefficient, because the uniform parallel plate capacitor-like potential distribution in this region is exclusively induced by the flexoelectric effect. This decoupled method could provide a valuable guideline for experimental measurements of the piezoelectric effects and flexoelectric effects in the nanometer scale.
Measuring depletion-layer capacitance to analyze a decrease in breakdown voltage of 4H-SiC diodes
Authors: Matsushima H. , Okino H. , Mochizuki K. , Yamada R.
Published: April 2016

A decrease in breakdown voltage (VBD) in the termination area of 4H-SiC PN diodes after 64 h reverse-bias stressing was analyzed. To analyze the VBD decrease, a novel analysis method based on the results of measuring depletion-layer capacitance of the PN diodes was proposed. The measurement results indicate that the positive-charge density (QTM) at the SiO2/SiC interface of the termination area increased after the reverse-bias stressing. Besides, in the case of QTM of 1012 cm−2 at the SiO2/SiC interface, the decrease in the measured capacitance showed the same tendency as the decrease in the simulated capacitance. By comparing the measured full depletion voltage and simulated full depletion voltage, the amount of QTM was estimated. It is thus concluded that the proposed method for measuring the depletion-layer capacitance is effective for analyzing the QTM change in the termination area.
Mixed semiclassical-classical propagators for the Wigner phase space representation
Authors: Koda Shin-ichi
Published: April 2016

We formulate mixed semiclassical-classical (SC-Cl) propagators by adding a further approximation to the phase-space SC propagators, which have been formulated in our previous paper [S. Koda, J. Chem. Phys. 143, 244110 (2015)]. We first show that the stationary phase approximation over the operation of the phase-space van Vleck propagator on initial distribution functions results in the classical mechanical time propagation. Then, after dividing the degrees of freedom (DOFs) of the total system into the semiclassical DOFs and the classical DOFs, the SC-Cl van Vleck propagator and the SC-Cl Herman-Kluk (HK) propagator are derived by performing the stationary phase approximation only with respect to the classical DOFs. These SC-Cl propagators are naturally decomposed to products of the phase-space SC propagators and the classical mechanical propagators when the system does not have any interaction between the semiclassical and the classical DOFs. In addition, we also numerically compare the original phase-space HK (full HK) propagator and the SC-Cl HK propagator in terms of accuracy and efficiency to find that the accuracy of the SC-Cl HK propagator can be comparable to that of the full HK propagator although the latter is more accurate than the former in general. On the other hand, we confirm that the convergence speed of the SC-Cl HK propagator is faster than that of the full HK propagator. The present numerical tests indicate that the SC-Cl HK propagator can be more accurate than the full HK propagator when they use a same and finite number of classical trajectories due to the balance of the accuracy and the efficiency.
Femtosecond few- to single-electron point-projection microscopy for nanoscale dynamic imaging
Authors: Bainbridge A. R. , Barlow Myers C. W. , Bryan W. A.
Published: April 2016

Femtosecond electron microscopy produces real-space images of matter in a series of ultrafast snapshots. Pulses of electrons self-disperse under space-charge broadening, so without compression, the ideal operation mode is a single electron per pulse. Here, we demonstrate femtosecond single-electron point projection microscopy (fs-ePPM) in a laser-pump fs-e-probe configuration. The electrons have an energy of only 150 eV and take tens of picoseconds to propagate to the object under study. Nonetheless, we achieve a temporal resolution with a standard deviation of 114 fs (equivalent to a full-width at half-maximum of 269 ± 40 fs) combined with a spatial resolution of 100 nm, applied to a localized region of charge at the apex of a nanoscale metal tip induced by 30 fs 800 nm laser pulses at 50 kHz. These observations demonstrate real-space imaging of reversible processes, such as tracking charge distributions, is feasible whilst maintaining femtosecond resolution. Our findings could find application as a characterization method, which, depending on geometry, could resolve tens of femtoseconds and tens of nanometres. Dynamically imaging electric and magnetic fields and charge distributions on sub-micron length scales opens new avenues of ultrafast dynamics. Furthermore, through the use of active compression, such pulses are an ideal seed for few-femtosecond to attosecond imaging applications which will access sub-optical cycle processes in nanoplasmonics.
Temperature-dependence of current-perpendicular-to-the-plane giant magnetoresistance spin-valves using Co2(Mn1−xFex)Ge Heusler alloys
Authors: Page M. R. , Nakatani T. M. , Stewart D. A. , York B. R. , Read J. C. , Choi Y.-S. , Childress J. R.
Published: April 2016

The properties of Co2(Mn1−xFex)Ge (CMFG) (x = 0–0.4) Heusler alloy magnetic layers within polycrystalline current-perpendicular-to-the plane giant magnetoresistance (CPP-GMR) spin-valves are investigated. CMFG films annealed at 220–320 °C exhibit partly ordered B2 structure with an order parameter SB2 = 0.3–0.4, and a lower SB2 was found for a higher Fe content. Nevertheless, CPP-GMR spin-valve devices exhibit a relatively high magnetoresistance ratio of ∼13% and a magnetoresistance-area product (ΔRA) of ∼6 mΩ μm2 at room temperature, which is almost independent of the Fe content in the CMFG films. By contrast, at low temperatures, ΔRA clearly increases with higher Fe content, despite the lower B2 ordering for increasing the Fe content. Indeed, first-principles calculations reveal that the CMFG alloy with a partially disordered B2 structure has a greater density of d-state at the Fermi level in the minority band compared to the Fe-free (Co2MnGe) alloy. This could explain the larger ΔRA measured on CMFG at low temperatures by assuming that s-d scattering mainly determines the spin asymmetry of resistivity as described in Mott's theory.
Non-Hermitian wave packet approximation for coupled two-level systems in weak and intense fields
Authors: Puthumpally-Joseph Raiju , Sukharev Maxim , Charron Eric
Published: April 2016

We introduce a non-Hermitian Schrödinger-type approximation of optical Bloch equations for two-level systems. This approximation provides a complete and accurate description of the coherence and decoherence dynamics in both weak and strong laser fields at the cost of losing accuracy in the description of populations. In this approach, it is sufficient to propagate the wave function of the quantum system instead of the density matrix, providing that relaxation and dephasing are taken into account via automatically adjusted time-dependent gain and decay rates. The developed formalism is applied to the problem of scattering and absorption of electromagnetic radiation by a thin layer comprised of interacting two-level emitters.
Coupling of electric charge and magnetic field via electronic phase separation in (La,Pr,Ca)MnO3/Pb(Mg1/3Nb2/3)O3-PbTiO3 multiferroic heterostructures
Authors: Zheng Ming , Wang Wei
Published: April 2016

The electric-field-tunable non-volatile resistivity and ferromagnetism switching in the (La0.5Pr0.5)0.67Ca0.33MnO3 films grown on (111)-oriented 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 ferroelectric single-crystal substrates have been investigated. By combining the 180° ferroelectric domain switching and in situ X-ray diffraction and resistivity measurements, we identify that this voltage control of order parameters stems from the domain switching-induced accumulation/depletion of charge carriers at the interface rather than induced lattice strain effect. In particular, the polarization-induced charge effect (i.e., ferroelectric field effect) is strongly dependent on the magnetic field. This, together with the charge-modulated magnetoresistance and magnetization, reveals the strong correlation between the electric charge and the magnetic field. Further, we found that this coupling is essentially driven by the electronic phase separation, the relative strength of which could be determined by recording charge-tunability of resistivity [(Δρ/ρ)charge] under various magnetic fields. These findings present a potential strategy for elucidating essential physics of perovskite manganites and delivering prototype electronic devices for non-volatile information storage.
Time-resolved investigations of the non-thermal ablation process of graphite induced by femtosecond laser pulses
Authors: Kalupka C. , Finger J. , Reininghaus M.
Published: April 2016

We report on the in-situ analysis of the ablation dynamics of the, so-called, laser induced non-thermal ablation process of graphite. A highly oriented pyrolytic graphite is excited by femtosecond laser pulses with fluences below the classic thermal ablation threshold. The ablation dynamics are investigated by axial pump-probe reflection measurements, transversal pump-probe shadowgraphy, and time-resolved transversal emission photography. The combination of the applied analysis methods allows for a continuous and detailed time-resolved observation of the non-thermal ablation dynamics from several picoseconds up to 180 ns. Formation of large, μm-sized particles takes place within the first 3.5 ns after irradiation. The following propagation of ablation products and the shock wave front are tracked by transversal shadowgraphy up to 16 ns. The comparison of ablation dynamics of different fluences by emission photography reveals thermal ablation products even for non-thermal fluences.
Response to “Comment on ‘Propagation of surface waves on a semi-bounded quantum magnetized collisional plasma’” [Phys. Plasmas 23, 044701 (2016)]
Authors: Niknam A. R. , Taheri Boroujeni S. , Khorashadizadeh S. M.
Published: April 2016

We reply to the Comment of Moradi [Phys. Plasmas 23, 044701 (2016)] on our paper [Phys. Plasmas 20, 122106 (2013)]. It is shown that TM surface waves can propagate on the surface of a semi-bounded quantum magnetized collisional plasma in the Faraday configuration in the electrostatic limit. In addition, in the Faraday configuration, one can neglect the coupling of TM and TE modes in the two limiting cases of weak magnetic field (low cyclotron frequency) and strong magnetic field (high cyclotron frequency).
Note: Proof of principle of a new type of cluster beam source with potential for scale-up
Authors: Palmer R. E. , Cao L. , Yin F.
Published: April 2016

We introduce a new type of cluster beam source based on the assembly of (metal) clusters within a condensed (rare gas) matrix. The “Matrix Assembly Cluster Source” employs an ion beam to enhance collisions between metal atoms in the matrix and to sputter out clusters to form a beam. We demonstrate the formation and deposition of gold and silver nanoclusters with mean size tunable from a few atoms to a few thousand atoms. The cluster flux is equivalent to a current nanoAmp regime but potentially scalable to milliAmps, which would open up a number of interesting experiments and applications.
On the applicability of several conventional regression models for the estimation of solar global radiation component in Cameroon and Senegal sub-Saharan tropical regions
Authors: Mboumboue Edouard , Njomo Donatien , Ndiaye Mamadou Lamine , N'diaye Pape Alioune , Ndiaye Mouhamadou Falilou , Tossa Alain K.
Published: April 2016

The knowledge of the climatic parameters' evolution represents a determining factor for design, dimensioning, performance assessment, and energetic management of renewable energy conversion systems. In particular, the solar energy conversion systems are essentially sensitive to sunlight and ambient temperature. However, for the efficient functioning and better performance of renewable energy systems, the information of solar radiation and its components at particular location in the ground is very essential. But harvesting this energy efficiently is a huge challenge. In developing countries like ours, the number of observing stations is inadequate and direct measuring is not always available for various reasons. Therefore, the need for empirical relations becomes effective alternatives to estimate global solar radiation for the places where measurements are not carried out and for the places where measurement records are not available. In this paper, four empirical models are evaluated across four localities in Cameroon and Senegal and compared with the solar radiation values measured by the meteorological stations or obtained from different databases. The studied models are those of Hargreaves and Samani [J. Irrig. Drain. Eng., Am. Soc. Civ. Eng. 108(3), 225–230 (1982)], Annandale et al. [Irrig. Sci. 21, 57–67 (2002)], Bristow and Campbell [Agric. For. Meteorol. 31, 159–166 (1984)], and Goodin et al. [Agron. J. 91, 845–851 (1999)]. According to the simulation results, the mean yearly radiation received are 3.8414 kWh m−2 d−1 for Yaounde; 3.9869 kWh m−2 d−1 for Garoua; 2.2539 kWh m−2 d−1 for Dakar; and 5.9159 kWh m−2 d−1 for Gandon. Of all the models evaluated in this study, those proposed by Annandale et al. [Irrig. Sci. 21, 57–67 (2002)] and Goodin et al. [Agron. J. 91, 845–851 (1999)] produced estimates that are statistically significant at the particular confidence level, i.e., 1 − α = 99%, as the calculated t values are less than the critical t value (2.5758). Taking into account the foregoing, we can state that these models are suitable in estimating solar radiation in the localities where only air temperature data are available.
Hydrodynamic directional control of liquid metal droplets within a microfluidic flow focusing system
Authors: Gol Berrak , Kurdzinski Michael E. , Tovar-Lopez Francisco J. , Petersen Phred , Mitchell Arnan , Khoshmanesh Khashayar
Published: April 2016

Here, we investigate the directional control of Galinstan liquid metal droplets when transferring from the high-viscosity glycerol core into the parallel low-viscosity NaOH sheath streams within a flow focusing microfluidic system. In the presence of sufficient flow mismatch between the sheath streams, the droplets are driven toward the higher velocity interface and cross the interface under the influence of surface tension gradient. A minimum flow mismatch of 125 μl/min is required to enable the continuous transfer of droplets toward the desired sheath stream. The response time of droplets, the time required to change the direction of droplet transfer, is governed by the response time of the syringe pump driven microfluidic system and is found to be 3.3 and 8.8 s when increasing and decreasing the flow rate of sheath stream, respectively.
Nanopore fabrication and characterization by helium ion microscopy
Authors: Emmrich D. , Beyer A. , Nadzeyka A. , Bauerdick S. , Meyer J. C. , Kotakoski J. , Gölzhäuser A.
Published: April 2016

The Helium Ion Microscope (HIM) has the capability to image small features with a resolution down to 0.35 nm due to its highly focused gas field ionization source and its small beam-sample interaction volume. In this work, the focused helium ion beam of a HIM is utilized to create nanopores with diameters down to 1.3 nm. It will be demonstrated that nanopores can be milled into silicon nitride, carbon nanomembranes, and graphene with well-defined aspect ratio. To image and characterize the produced nanopores, helium ion microscopy and high resolution scanning transmission electron microscopy were used. The analysis of the nanopores' growth behavior allows inferring on the profile of the helium ion beam.
High-throughput shadow mask printing of passive electrical components on paper by supersonic cluster beam deposition
Authors: Caruso Francesco , Bellacicca Andrea , Milani Paolo
Published: April 2016

We report the rapid prototyping of passive electrical components (resistors and capacitors) on plain paper by an additive and parallel technology consisting of supersonic cluster beam deposition (SCBD) coupled with shadow mask printing. Cluster-assembled films have a growth mechanism substantially different from that of atom-assembled ones providing the possibility of a fine tuning of their electrical conduction properties around the percolative conduction threshold. Exploiting the precise control on cluster beam intensity and shape typical of SCBD, we produced, in a one-step process, batches of resistors with resistance values spanning a range of two orders of magnitude. Parallel plate capacitors with paper as the dielectric medium were also produced with capacitance in the range of tens of picofarads. Compared to standard deposition technologies, SCBD allows for a very efficient use of raw materials and the rapid production of components with different shape and dimensions while controlling independently the electrical characteristics. Discrete electrical components produced by SCBD are very robust against deformation and bending, and they can be easily assembled to build circuits with desired characteristics. The availability of large batches of these components enables the rapid and cheap prototyping and integration of electrical components on paper as building blocks of more complex systems.
Wavelength dependence of Verdet constant of Tb3+:Y2O3 ceramics
Authors: Snetkov I. L. , Permin D. A. , Balabanov S. S. , Palashov O. V.
Published: April 2016

Samples of the magneto-active material—Tb3+:Y2O3 ceramics with Tb3+ ion concentrations of 10%, 20%, 30%, and 100% (Tb2O3)—were prepared and studied. The wavelength dependence of Verdet constant in the 380 nm–1750 nm range was approximated for all investigated ceramic samples and was predicted for a pure Tb2O3 material. Tb2O3 ceramics demonstrates a more than three times higher Verdet constant in comparison with terbium gallium garnet crystal or ceramics. The linear dependence of the Verdet constant on Tb3+ ion concentration in the Tb3+:Y2O3 ceramics was demonstrated. The obtained data will be useful for fabricating magneto-optical elements of Faraday devices based on Tb3+:Y2O3 with arbitrary Tb3+ ion concentration operating at room temperature in the wavelength range of 380 nm–1750 nm.
Superconductivity enhancement in the S-doped Weyl semimetal candidate MoTe2
Authors: Chen F. C. , Luo X. , Xiao R. C. , Lu W. J. , Zhang B. , Yang H. X. , Li J. Q. , Pei Q. L. , Shao D. F. , Zhang R. R. , Ling L. S. , Xi C. Y. , Song W. H. , Sun Y. P.
Published: April 2016

Two-dimensional transition-metal dichalcogenide (TMDs) MoTe2 has attracted much attention due to its predicted Weyl semimetal state and a quantum spin Hall insulator in bulk and monolayer form, respectively. We find that the superconductivity in MoTe2 single crystal can be greatly enhanced by the partial substitution of the Te ions by the S ones. The maximum superconducting temperature TC of MoTe1.8S0.2 single crystal is about 1.3 K. Compared with the parent MoTe2 single crystal (TC = 0.1 K), nearly 13-fold in TC is improved in the MoTe1.8S0.2 one. The superconductivity has been investigated through the resistivity and magnetization measurements. MoTe2−xSx single crystals belong to weak coupling superconductors and the improvement of the superconductivity may be related to the enhanced electron-phonon coupling induced by the S-ion substitution. A dome-shaped superconducting phase diagram is obtained in the S-doped MoTe2 single crystals. MoTe2−xSx materials may provide a new platform for our understanding of superconductivity phenomena and topological physics in TMDs.
Electronic properties in a quantum well structure of Weyl semimetal
Authors: You Wen-Long , Wang Xue-Feng , Oleś Andrzej M. , Zhou Jiao-Jiao
Published: April 2016

We investigate the confined states and transport of three-dimensional Weyl electrons around a one-dimensional external rectangular electrostatic potential. The confined states with finite transverse wave vector exist at energies higher than the half well depth or lower than the half barrier height. The rectangular potential appears completely transparent to the normal incident electrons but not otherwise. The tunneling transmission coefficient is sensitive to their incident angle and shows resonant peaks when their energy coincides with the confined spectra. In addition, for the electrons in the conduction (valence) band through a potential barrier (well), the transmission spectrum has a gap of width increasing with the incident angle. Interestingly, the electron linear zero-temperature conductance over the potential can approach zero when the Fermi energy is aligned to the top and bottom energies of the potential, when only electron beams normal to the potential interfaces can pass through. The considered structure can be used to collimate the Weyl electron beams.
Broadband reflective metasurface for focusing underwater ultrasonic waves with linearly tunable focal length
Authors: Wu Xiaoxiao , Xia Xiangxiang , Tian Jingxuan , Liu Zhengyou , Wen Weijia
Published: April 2016

We report a metasurface for focusing reflected ultrasonic waves over a wide frequency band of 0.45–0.55 MHz. The broadband focusing effect of the reflective metasurface is studied numerically and then confirmed experimentally using near-field scanning techniques. The focusing mechanism can be attributed to the hyperboloidal reflection phase profile imposed by different depths of concentric grooves on the metasurface. In particular, the focal lengths of the reflective metasurface are extracted from simulations and experiments, and both exhibit good linear dependence on frequency over the considered frequency band. The proposed broadband reflective metasurface with tunable focal length has potential applications in the broad field of ultrasonics, such as ultrasonic tomographic imaging, high intensity focused ultrasound treatment, etc.
Replacing synthetic N with clovers or alfalfa in bermudagrass pastures. 1. Herbage mass and pasture carrying capacity
Authors: Beck P. , Hess T. , Hubbell D. , Gadberry M. S. , Jennings J. , Sims M.
Published: April 2016

The objective of this study was to evaluate the effects of including alfalfa (ALF, Medicago sativa L.) or a combination of white (Trifolium repens L.) and red (Trifolium pretense L.) clovers (CLVR) inter-seeded into bermudagrass (Cynodon dactylon L. Pers.) on herbage nutritive value compared with monocultures of bermudagrass fertilised with 0 (0N), 56 (56N), or 112 (112N) kg nitrogen (N)/ha over four grazing seasons. In autumn, at the end of the fourth year and in the spring before the fifth grazing season, alfalfa and clover plants were killed and the carryover N benefit of CLVR or ALF was compared with N fertilisation rates during the fifth year. Across years, N fertilisation rate increased herbage mass and carrying capacity linearly; whereas herbage production from CLVR and ALF swards was equivalent to 56N, were greater than 0N and less than 112N. Herbage mass in CLVR and ALF swards was greater than fertilised bermudagrass swards in the spring and did not differ from fertilised bermudagrass in the early summer. In late summer herbage accumulation of CLVR and ALF swards appeared to decrease, limiting the herbage mass in the legume pastures compared with 56N and 112N. Carrying capacity of CLVR and ALF swards was greater than fertilised bermudagrass in the spring and early summer, but did not differ from fertilised swards in the late summer. The N benefit of including legumes in bermudagrass swards can alleviate the reliance on synthetic N fertilisation with little overall effect on pasture carrying capacity.
Digestibility of calcium in feed ingredients and requirements of digestible calcium for growing pigs
Authors: González-Vega J. C. , Stein H. H.
Published: April 2016

Efforts to reduce phosphorus (P) excretion from pigs have increased during the past few decades and it has been recognised that interactions among dietary P, calcium (Ca), phytate, and microbial phytase exist. However, limited research has been reported on Ca digestibility, but to optimise the use of both Ca and P, digestibility values of Ca are needed. Due to endogenous losses of Ca, values for standardised total tract digestibility (STTD) of Ca in different Ca supplements and feed ingredients have been determined, and these values may be used to formulate mixed diets. Phytate may bind intrinsic Ca in feed ingredients of plant origin as well as extrinsic Ca from ingredients of animal origin or Ca supplements, but not all forms of Ca in Ca supplements will bind to phytate. Therefore, the effect of phytase on the STTD of Ca may vary depending on the amount of Ca bound to phytate and in some cases microbial phytase will result in increased STTD of Ca from animal proteins or Ca supplements. Dietary fibre may increase the STTD of Ca, but particle size and soybean oil do not influence the STTD of Ca. Requirements for digestible Ca by growing pigs has not yet been determined, but with the availability of values for the STTD of Ca in most commonly used feed ingredients, the basis for determining such values has been prepared. In conclusion, data for the STTD of Ca and the effects of microbial phytase in many feed ingredients have been determined and future research will be directed at determining the requirements for digestible Ca by different groups of pigs.
Genetic analyses on bodyweight, reproductive, and carcass traits in composite beef cattle
Authors: Pires Bruno Carlos , Tholon Patrícia , Buzanskas Marcos Eli , Sbardella Ana Paula , Rosa Jaqueline Oliveira , Campos da Silva Luiz Otávio , Torres Roberto Augusto de Almeida , Munari Danísio Prado , Mello de Alencar Maurício
Published: April 2016

In beef cattle, growth, reproductive, and carcass traits have been studied for improving productivity and quality of meat products. The aim of this study was to estimate genetic parameters for birth (BW), weaning (WW) and yearling (YW) weights, scrotal circumferences at weaning (SCW) and yearling (SCY), age at first calving (AFC), ribeye area (REA) and back fat thickness (BFT) in order to provide support for the evaluation program of the composite Canchim breed. Data on 12 967 (BW), 7481 (WW), 5131 (YW), 1447 (SCW), 1224 (SCY), 1400 (AFC), and 2082 (REA and BFT) animals were analysed using the Average Information Restricted Maximum Likelihood method under an animal model (single and multi-trait analyses). A substantial proportion of the variation in the bodyweights, scrotal circumferences and carcass traits was associated with the additive genetic term indicating that these traits may respond to the selection process. For AFC, a low heritability estimate was observed. Genetic correlations among bodyweights varied from 0.41 to 0.93. The genetic correlation among scrotal circumferences was 0.91. Important genetic correlations among YW, SCW, and SCY with AFC were observed (–0.48, –0.61, and –0.71, respectively), indicating that indirect responses to selection for these traits would be expected in the age of which the heifers calve. Furthermore, BFT presented an interesting result with calving performance due to the genetic correlation (–0.69) with AFC. Post-weaning weights showed moderate genetic correlations with REA. Many of the traits considered in the genetic evaluation of this breed are genetically correlated in a favourable manner. Genetic improvement through selection is expected for production, reproduction, and carcass traits in Canchim beef cattle.
Relative yield and profit of Australian hybrid compared with open-pollinated canola is largely determined by growing-season rainfall
Authors: Zhang Heping , Berger Jens D. , Seymour Mark , Brill Rohan , Herrmann Chris , Quinlan Richard , Knell Garren
Published: April 2016

Australian canola growers have new technology options including hybrid and herbicide technologies, which have offered yield and profitability advantages in other canola-growing regions of the world. This study compared the yield and gross margins of hybrid and open-pollinated (OP) canola from different herbicide tolerance groups: triazine-tolerant, Roundup Ready, Clearfield and conventional across a wide range of environments in south-western Australia, and in the National Variety Trial network in southern Australia to investigate the relative advantages of these technologies. There were significant differences in yield responsiveness between hybrid and OP canola, the magnitude of which was determined by the growing-season rainfall/available water to the crop. Hybrid out-yielded OP canola in favourable environments where rainfall was high and the growing season was long. However, in areas of low rainfall where yield potential was low, hybrids showed little yield advantage over OP. In contrast, there were no differences in yield response between the four herbicide tolerance groups across the rainfall zones. The economic analysis showed that the break-even yield for hybrids versus OP canola was 1.25 t/ha for triazine-tolerant canola, 0.7 t/ha for Roundup Ready canola, and 1.7 t/ha for hybrid Clearfield canola. The gross margin analysis suggested that hybrid triazine-tolerant, Clearfield and Roundup Ready canola was more profitable than the OP system in the medium (growing-season rainfall of 265–330 mm) and high (330 mm) rainfall environments, but not profitable in the lower (<265 mm) rainfall area because the cost associated with hybrid seed outweighed the small yield benefit. The sensitivity analysis indicated that ± 10% changes in canola price and seed cost shifted the break-even yield by ± 0.1 t/ha. Our study makes a case for Australian canola breeders to maintain OP canola varieties, rather than shifting their focus entirely to hybrids, to underpin continued productivity and profitability in lower rainfall areas.
Joint representation of translational and rotational components of optic flow in parietal cortex
Authors: Sunkara Adhira , DeAngelis Gregory C. , Angelaki Dora E.
Published: April 2016

Significance

As we navigate through the world, we experience both translations (changes in position) and rotations (changes in orientation). Although several studies have examined how the visual system represents the translational component of self-motion, few have evaluated the neural representation of rotations, especially when translations and rotations occur simultaneously. We measured responses of neurons in parietal cortex to visually simulated combinations of translations and rotations. We find that many parietal neurons jointly encode the translational and rotational components of self-motion in a multiplicatively separable fashion, which simplifies perceptual estimation of both components. These results suggest that the brain performs sophisticated processing of visual motion to extract both translation direction and rotation velocity, such that we may perform complex navigational tasks.
Fluency/resistancy and domestication/foreignisation
Authors: Kruger Haidee
Published: April 2016

This paper argues for the addition of a cognitive perspective to the concepts of fluency/resistancy and
domestication/foreignisation. Given the disjunctions between the ontological levels (and analytical levels of specificity) implied
in these concepts (cognitive, linguistic and socio-cultural), the paper first sets out an argument for how these ontologies are
related, demonstrating how cognitive processing, and specifically cognitive effort for both translators and readers, form a
second-level constituent of both these sets of concepts, by drawing on usage-based theories of language. From within this
conceptual frame, the paper turns its attention to an empirical investigation. The study demonstrates how a combination of product
and process methods may be utilised to explore the cognitive effort involved in domesticating and foreignising choices. The
findings of the study are used to formulate some suggestions regarding how investigations of cognitive effort in translation may
contribute to an understanding of fluency/resistancy and domestication/foreignisation in diverse contexts.
The professional backgrounds of translation scholars. Report on a survey
Authors: Torres-Simón Esther , Pym Anthony
Published: April 2016

A survey of 305 translation scholars shows that some 96 percent of them have translated or interpreted “on a regular basis,” with
translation/interpreting being or having been a main or secondary activity for 43 percent of the scholars. Translation scholars
would also seem to be particularly mobile (71 percent have spent more than one year in a country other than their own) and come
from diverse academic and professional backgrounds (33 percent were not engaged in translation and interpreting in their
mid-twenties). These figures indicate that translation scholars not only have considerable practical experience of translation but
also come from a wide range of occupational and cultural backgrounds. Asked about desirable relations between scholarly work and
professional practice, respondents indicated benefits for both sides (although a slight majority stressed a unidirectional
relationship where scholarly work benefits from professional practice), and teaching is often indicated as the link between the
two. However, about a quarter of the scholars indicated that there need not be a relationship between scholarship
and professional practice.
Characterization of the venom of the vermivorous cone snail Conus fulgetrum
Authors: Abdel-Wahab Mohammed , Miyashita Masahiro , Kitanaka Atsushi , Juichi Hironori , Sarhan Moustafa , Fouda Maged , Abdel-Rahman Mohamed , Saber Samy , Nakagawa Yoshiaki
Published: April 2016

Over 200 components with molecular mass ranging mainly from 400 to 4000 Da were characterized from the venom of the vermivorous cone snail Conus fulgetrum that inhabit Egyptian Red Sea. One major component having a molecular mass of 2946 Da was purified by HPLC, and its primary structure was determined by a combination of Edman degradation and MS/MS analysis.
The Ottoman occupation of Batumi, 1918: a view from below
Authors: Forestier-Peyrat Etienne
Published: April 2016

This article presents for the first time in English an eye-witness’s account of the Ottoman occupation of the Black Sea port of Batumi in 1918. Written by a Russian resident of Batumi, V.P. Mel’nikov, the document is held in the archives of the Ach’ara State Museum, Georgia. It offers rare insights into daily life under Ottoman occupation, making a contribution to the general history of occupation policies during the First World War, the history of the Ottoman invasion of Transcaucasia, and the local history of Ach’ara under occupation. The translation of the document is preceded by a commentary explaining the historical context and historiographic significance of Mel’nikov’s account.
The role of carbon and nitrogen on the H-mode confinement in ASDEX Upgrade with a metal wall
Authors: Beurskens M.N.A. , Dunne M.G. , Frassinetti L. , Bernert M. , Cavedon M. , Fischer R. , Järvinen A. , Kallenbach A. , Laggner F.M. , McDermott R.M. , Potzel S. , Schweinzer J. , Tardini G. , Viezzer E. , Wolfrum E.
Published: April 2016

Carbon (CD4) and nitrogen (N2) have been seeded in ASDEX Upgrade (AUG) with a tungsten wall and have both led to a 20–30% confinement improvement. The reference plasma is a standard target plasma with I
p /B
T  =  1 MA/2.5 T, total input power P
tot ~ 12 MW and normalized pressure of β
N ~ 1.8. Carbon and nitrogen are almost perfectly exchangeable for the core, pedestal and divertor plasma in this experiment where impurity concentrations of C and N of 2% are achieved and Z
eff only mildly increases from ~1.3 to ~1.7. As the radiation potentials of C and N are similar and peak well below 100 eV, both impurities act as divertor radiators and radiate well outside the pedestal region. The outer divertor is purposely kept in an attached state when C and N are seeded to avoid confinement degradation by detachment. As reported in earlier publications for nitrogen, carbon is also seen to reduce the high field side high density (the so-called HFSHD) in the scrape off layer above the inner divertor strike point by about 50%. This is accompanied by a confinement improvement for both low (δ ~ 0.25) and high (δ ~ 0.4) triangularity configurations for both seeding gases, due to an increase of pedestal temperature and stiff core temperature profiles. The electron density profiles show no apparent change due to the seeding. As an orthogonal effect, increasing the triangularity leads to an additionally increased pedestal density, independent of the impurity seeding. This experiment further closes the gap in understanding the confinement differences observed in carbon and metal wall devices; the absence of carbon can be substituted by nitrogen which leads to a similar confinement benefit. So far, no definite physics explanation for the confinement enhancement has been obtained, but the experimental observations in this paper provide input for further model development.
Toroidal modelling of RMP response in ASDEX Upgrade: coil phase scan, q95 dependence, and toroidal torques
Authors: Liu Yueqiang , Ryan D. , Kirk A. , Li Li , Suttrop W. , Dunne M. , Fischer R. , Fuchs J.C. , Kurzan B. , Piovesan P. , Willensdorfer M.
Published: April 2016

The plasma response to the vacuum resonant magnetic perturbation (RMP) fields, produced by the ELM control coils in ASDEX Upgrade experiments, is computationally modelled using the MARS-F/K codes (Liu et al 2000 Phys. Plasmas

7

3681, Liu et al 2008 Phys. Plasmas

15

112503). A systematic investigation is carried out, considering various plasma and coil configurations as in the ELM control experiments. The low q plasmas, with

q

95

∼
3.8

(q
95 is the safety factor q value at 95% of the equilibrium poloidal flux), responding to low n (n is the toroidal mode number) field perturbations from each single row of the ELM coils, generates a core kink amplification effect. Combining two rows, with different toroidal phasing, thus leads to either cancellation or reinforcement of the core kink response, which in turn determines the poloidal location of the peak plasma surface displacement. The core kink response is typically weak for the n  =  4 coil configuration at low q, and for the n  =  2 configuration but only at high q (

q

95

∼
5.5

). A phase shift of around 60 degrees for low q plasmas, and around 90 degrees for high q plasmas, is found in the coil phasing, between the plasma response field and the vacuum RMP field, that maximizes the edge resonant field component. This leads to an optimal coil phasing of about 100 (−100) degrees for low (high) q plasmas, that maximizes both the edge resonant field component and the plasma surface displacement near the X-point of the separatrix. This optimal phasing closely corresponds to the best ELM mitigation observed in experiments. A strong parallel sound wave damping moderately reduces the core kink response but has minor effect on the edge peeling response. For low q plasmas, modelling shows that both the resonant electromagnetic torque and the neoclassical toroidal viscous (NTV) torque (due to the presence of 3D magnetic field perturbations) contribute to the toroidal flow damping, in particular near the plasma edge region. For high q plasmas, however, significant amount of torque is also produced in the bulk plasma region, and the contributions from the electromagnetic, the NTV, and the torque associated with the Reynolds stress, all play significant roles.
State‐Level Cooperative Extension Spending and Farmer Exits
Authors: Goetz Stephan J. , Davlasheridze Meri
Published: April 2016

Numerous studies have evaluated the impact of Extension on farm productivity and related outcomes. Here we use annual data from 1983 to 2010 covering the 50 U.S. states to examine the impact of Extension on net changes in the number of farmers. The historical transition of farmers out of U.S. agriculture raises the question of whether Cooperative Extension and underlying Hatch‐funded research spending keeps farmers in agriculture or accelerates their exit. On balance, nearly 500,000 more farmers left than entered agriculture over the period studied. We estimate that without Extension, as many as 137,700 (or 28%) additional farmers would have disappeared on net. Overall, Extension programs are a remarkably cost effective way of keeping farmers in agriculture. Alternatively, shifting just 1.5% of federal farm program payments to Extension would have reduced net exits over this period by an estimated 11%, or 55,000 farmers.
OxyBS: estimation of 5-methylcytosine and 5-hydroxymethylcytosine from tandem-treated oxidative bisulfite and bisulfite DNA
Authors: Houseman E. Andres , Johnson Kevin C. , Christensen Brock C.
Published: April 2016

Summary: The use of sodium bisulfite (BS) treatment followed by hybridization to an Illumina Infinium BeadChip (HumanMethylation450 and MethylationEPIC) is a common method for interrogating 5-methylcytosine (5mC) at single nucleotide resolution. However, standard treatment of DNA with BS does not allow disambiguation of 5mC from an additional cytosine modification, 5-hydroxymethylcytosine (5hmC). Recently, it has been demonstrated that paired BS and oxidative bisulfite (oxBS) treatment on the same sample followed by hybridization to an Infinium microarray permits the differentiation of 5hmC from 5mC. Nevertheless, estimation of 5hmC and 5mC from tandem-treated arrays has been shown to produce irregular estimates of cytosine modifications.

Results: We present a novel method using maximum likelihood estimation to accurately estimate the parameters of unmethylated cytosine (5C), 5mC and 5hmC from Infinium microarray data given the signal intensities from the oxBS and BS replicates.

Availability and Implementation: OxyBS is an R package available on CRAN.

Contact:  Andres.Houseman@oregonstate.edu

Supplementary information:  Supplementary data are available at Bioinformatics online.
Shape complementarity and hydrogen bond preferences in protein–protein interfaces: implications for antibody modeling and protein–protein docking
Authors: Kuroda Daisuke , Gray Jeffrey J.
Published: April 2016

Motivations: Characterizing protein–protein interfaces and the hydrogen bonds is a first step to better understand proteins’ structures and functions toward high-resolution protein design. However, there are few large-scale surveys of hydrogen bonds of interfaces. In addition, previous work of shape complementarity of protein complexes suggested that lower shape complementarity in antibody–antigen interfaces is related to their evolutionary origin.

Results: Using 6637 non-redundant protein–protein interfaces, we revealed peculiar features of various protein complex types. In contrast to previous findings, the shape complementarity of antibody–antigen interfaces resembles that of the other interface types. These results highlight the importance of hydrogen bonds during evolution of protein interfaces and rectify the prevailing belief that antibodies have lower shape complementarity.

Contact:  jgray@jhu.edu

Supplementary Information:  Supplementary data are available at Bioinformatics online.
Beta-Poisson model for single-cell RNA-seq data analyses
Authors: Vu Trung Nghia , Wills Quin F. , Kalari Krishna R. , Niu Nifang , Wang Liewei , Rantalainen Mattias , Pawitan Yudi
Published: April 2016

Motivation: Single-cell RNA-sequencing technology allows detection of gene expression at the single-cell level. One typical feature of the data is a bimodality in the cellular distribution even for highly expressed genes, primarily caused by a proportion of non-expressing cells. The standard and the over-dispersed gamma-Poisson models that are commonly used in bulk-cell RNA-sequencing are not able to capture this property.

Results: We introduce a beta-Poisson mixture model that can capture the bimodality of the single-cell gene expression distribution. We further integrate the model into the generalized linear model framework in order to perform differential expression analyses. The whole analytical procedure is called BPSC. The results from several real single-cell RNA-seq datasets indicate that ∼90% of the transcripts are well characterized by the beta-Poisson model; the model-fit from BPSC is better than the fit of the standard gamma-Poisson model in > 80% of the transcripts. Moreover, in differential expression analyses of simulated and real datasets, BPSC performs well against edgeR, a conventional method widely used in bulk-cell RNA-sequencing data, and against scde and MAST, two recent methods specifically designed for single-cell RNA-seq data.

Availability and Implementation: An R package BPSC for model fitting and differential expression analyses of single-cell RNA-seq data is available under GPL-3 license at https://github.com/nghiavtr/BPSC .

Contact:  yudi.pawitan@ki.se or mattias.rantalainen@ki.se

Supplementary information:  Supplementary data are available at Bioinformatics online.
e23D: database and visualization of A-to-I RNA editing sites mapped to 3D protein structures
Authors: Solomon Oz , Eyal Eran , Amariglio Ninette , Unger Ron , Rechavi Gidi
Published: April 2016

Summary: e23D, a database of A-to-I RNA editing sites from human, mouse and fly mapped to evolutionary related protein 3D structures, is presented. Genomic coordinates of A-to-I RNA editing sites are converted to protein coordinates and mapped onto 3D structures from PDB or theoretical models from ModBase. e23D allows visualization of the protein structure, modeling of recoding events and orientation of the editing with respect to nearby genomic functional sites from databases of disease causing mutations and genomic polymorphism.

Availability and Implementation:  http://www.sheba-cancer.org.il/e23D

Contact:  oz.solomon@live.biu.ac.il or Eran.Eyal@sheba.health.gov.il