bluuebunny/crossref_metadata_2025 huggingface dataset:
Vortex polarity switching in magnets with surface anisotropy
Authors: Pylypovskyi Oleksandr V. , Sheka Denis D. , Kravchuk Volodymyr P. , Gaididei Yuri
Published: May 2015

Vortex core reversal in magnetic particle is essentially influenced by a surface anisotropy. Under the action of a perpendicular static magnetic field the vortex core undergoes a shape deformation of pillow- or barrel-shaped type, depending on the type of the surface anisotropy. This deformation plays a key point in the switching mechanism: We predict that the vortex polarity switching is accompanied (i) by a linear singularity in case of Heisenberg magnet with bulk anisotropy only and (ii) by a point singularities in case of surface anisotropy or exchange anisotropy. We study in details the switching process using spin-lattice simulations and propose a simple analytical description using a wired core model, which provides an adequate description of the Bloch point statics, its dynamics and the Bloch point mediated switching process. Our analytical predictions are confirmed by spin-lattice simulations for Heisenberg magnet and micromagnetic simulations for nanomagnet with account of a dipolar interaction.
Dynamics of [C3H5N2]6[Bi4Br18] by means of 1H NMR relaxometry and quadrupole relaxation enhancement
Authors: Masierak W. , Florek-Wojciechowska M. , Oglodek I. , Jakubas R. , Privalov A. F. , Kresse B. , Fujara F. , Kruk D.
Published: May 2015

1H spin-lattice field cycling relaxation dispersion experiments in the intermediate phase II of the solid [C3H5N2]6[Bi4Br18] are presented. Two motional processes have been identified from the 1H spin-lattice relaxation dispersion profiles and quantitatively described. It has been concluded that these processes are associated with anisotropic reorientations of the imidazolium ring, characterized by correlation times of the order of 10−8 s-10−9 s and of about 10−5 s. Moreover, quadrupole relaxation enhancement (QRE) effects originating from slowly fluctuating 1H-14N dipolar interactions have been observed. From the positions of the relaxation maxima, the quadrupole coupling parameters for the 14N nuclei in [C3H5N2]6[Bi4Br18] have been determined. The 1H-14N relaxation contribution associated with the slow dynamics has been described in terms of a theory of QRE [Kruk et al., Solid State Nucl. Magn. Reson. 40, 114 (2011)] based on the stochastic Liouville equation. The shape of the QRE maxima (often referred to as “quadrupole peaks”) has been consistently reproduced for the correlation time describing the slow dynamics and the determined quadrupole coupling parameters.
Complementary resistive switching behavior induced by varying forming current compliance in resistance random access memory
Authors: Tseng Yi-Ting , Tsai Tsung-Ming , Chang Ting-Chang , Shih Chih-Cheng , Chang Kuan-Chang , Zhang Rui , Chen Kai-Huang , Chen Jung-Hui , Li Yu-Chiuan , Lin Chih-Yang , Hung Ya-Chi , Syu Yong-En , Zheng Jin-Cheng , Sze Simon M.
Published: May 2015

In this study of resistance random access memory in a resistive switching film, the breakdown degree was controlled by varying forming current compliance. A SiOx layer was introduced into the ZnO layer of the structure to induce both typical bipolar resistive switching (RS) and complementary resistive switching (CRS). In addition, the SiOx layer-generated vacuum spaces in typical bipolar RS can be verified by electrical characteristics. Changing forming current compliance strikingly modifies the oxygen storage capacity of the inserted SiOx layer. CRS can be achieved, therefore, by tuning the oxygen ion storage behavior made possible by the SiOx layer.
Influence of bending resistance on the dynamics of a spherical capsule in shear flow
Authors: Dupont C. , Salsac A.-V. , Barthès-Biesel D. , Vidrascu M. , Le Tallec P.
Published: May 2015

The objective of the paper is to study the effect of wall bending resistance on the motion of an initially spherical capsule freely suspended in shear flow. We consider a capsule with a given thickness made of a three-dimensional homogeneous elastic material. A numerical method is used to model the fluid-structure interactions coupling a boundary integral method for the fluids with a shell finite element method for the capsule envelope. For a given wall material, the capsule deformability strongly decreases when the wall bending resistance increases. But, if one expresses the same results as a function of the two-dimensional mechanical properties of the mid-surface, which is how the capsule wall is modeled in the thin-shell model, the capsule deformed shape is identical to the one predicted for a capsule devoid of bending resistance. The bending rigidity is found to have a negligible influence on the overall deformation of an initially spherical capsule, which therefore depends only on the elastic stretching of the mid-surface. Still, the bending resistance of the wall must be accounted for to model the buckling phenomenon, which is observed locally at low flow strength. We show that the wrinkle wavelength is only a function of the wall bending resistance and provide the correlation law. Such results can then be used to infer values of the bending modulus and wall thickness from experiments on spherical capsules in simple shear flow.
Microsolvation of NO+ in Arn clusters: A theoretical treatment
Authors: Ben Mohamed F. E. , Slama M. , Hammami H. , Ben El Hadj Rhouma M. , Hochlaf M.
Published: May 2015

At present, we investigate the structure and the stability of NO+Arn (n ≤ 54) ionic clusters using analytical potential functions. The energy of these systems is described using additive potentials with VNO+Ar and VAr–Ar representing the pair potential interactions. To find the geometry of the lowest energy isomers of the NO+Arn clusters, we use the so-called basin hopping method of Wales et al. which combines a Monte-Carlo exploration and deformation method. The reliability of our model was checked by deriving the structures of the NO+Arn systems (n = 1, 2, 3 and 4) using ab initio Moller–Plesset perturbation theory up to second order (MP2) in connection with the aug-cc-pVTZ basis set. Magic numbers for sizes n = 8, 12, 18, 22, and 25 are found and they show a high relative stability. Our results reveal that a transition in the NO+ ion coordination from 8 (square antiprism) to 12 (icosahedrons) occurs for n = 11. Examination of the stable structures of the ionic clusters demonstrates that the first solvation shell closes at n = 12. Furthermore, we found that the NO+Arn (n = 12-54) clusters are structurally very similar to the homogenous rare gas clusters with a polyicosahedral packing pattern. The distribution exhibits an additional magic number at n = 54, consistent with the completion of a second solvation sphere around NO+. The effects of microsolvation of NO+ cation in Ar clusters are also discussed. Generally, our results agree with the available experimental and theoretical findings on NO+Arn clusters and more generally on diatomics solvated in Ar clusters.
A compact 300 kV solid-state high-voltage nanosecond generator for dielectric wall accelerator
Authors: Shen Yi , Wang Wei , Liu Yi , Xia Liansheng , Zhang Huang , Pan Haifeng , Zhu Jun , Shi Jinshui , Zhang Linwen , Deng Jianjun
Published: May 2015

Compact solid-state system is the main development trend in pulsed power technologies. A compact solid-state high-voltage nanosecond pulse generator with output voltage of 300 kV amplitude, 10 ns duration (FWHM), and 3 ns rise-time was designed for a dielectric wall accelerator. The generator is stacked by 15 planar-plate Blumlein pulse forming lines (PFL). Each Blumlein PFL consists of two solid-state planar transmission lines, a GaAs photoconductive semiconductor switch, and a laser diode trigger. The key components of the generator and the experimental results are reported in this paper.
Rotationally inelastic scattering of OH by molecular hydrogen: Theory and experiment
Authors: Schewe H. Christian , Ma Qianli , Vanhaecke Nicolas , Wang Xingan , Kłos Jacek , Alexander Millard H. , van de Meerakker Sebastiaan Y. T. , Meijer Gerard , van der Avoird Ad , Dagdigian Paul J.
Published: May 2015

We present an experimental and theoretical investigation of rotationally inelastic transitions of OH, prepared in the X2Π, v = 0, j = 3/2 F1f level, in collisions with molecular hydrogen (H2 and D2). In a crossed beam experiment, the OH radicals were state selected and velocity tuned over the collision energy range 75–155 cm−1 using a Stark decelerator. Relative parity-resolved state-to-state integral cross sections were determined for collisions with normal and para converted H2. These cross sections, as well as previous OH–H2 measurements at 595 cm−1 collision energy by Schreel and ter Meulen [J. Chem. Phys. 105, 4522 (1996)], and OH–D2 measurements for collision energies 100–500 cm−1 by Kirste et al. [Phys. Rev. A 82, 042717 (2010)], were compared with the results of quantum scattering calculations using recently determined ab initio potential energy surfaces [Ma et al., J. Chem. Phys. 141, 174309 (2014)]. Good agreement between the experimental and computed relative cross sections was found, although some structure seen in the OH(j = 3/2 F1f → j = 5/2 F1e) + H2(j = 0) cross section is not understood.
Morphology control of the magnetization reversal mechanism in Co80Ni20 nanomagnets
Authors: Mercone Silvana , Zighem Fatih , Leridon Brigitte , Gaul Audrey , Schoenstein Frédéric , Jouini Noureddine
Published: May 2015

Nanowires with very different size, shape, morphology, and crystal symmetry can give rise to a wide ensemble of magnetic behaviors whose optimization determines their applications in nanomagnets. We present here an experimental work on the shape and morphological dependence of the magnetization reversal mechanism in weakly interacting Co80Ni20 hexagonal-close-packed nanowires. Non-agglomerated nanowires (with length L and diameter d) with a controlled shape going from quasi perfect cylinders to diabolos have been studied inside their polyol solution in order to avoid any oxidation process. The coercive field HC was found to follow a standard behavior and to be optimized for an aspect ratio Ld>15. Interestingly, an unexpected behavior was observed as function of the head morphology leading to the strange situation where a diabolo shaped nanowire is a better nanomagnet than a cylinder. This paradoxical behavior can be ascribed to the growth-competition between the aspect ratio Ld and the head morphology ratio dD (D being the head width). Our experimental results clearly show the importance of the independent parameter (t = head thickness) that needs to be considered in addition to the shape aspect ratio (Ld) in order to fully describe the nanomagnets magnetic behavior. Micromagnetic simulations well support the experimental results and bring important insights for future optimization of the nanomagnets morphology.
Centrifugal instability of stratified two-phase flow in a curved channel
Authors: Picardo Jason R. , Garg P. , Pushpavanam S.
Published: May 2015

The centrifugal instability of stratified two-phase flow in a curved channel is investigated in this work. The fluids are laterally stratified between cylindrical walls of infinite extent. We focus on the limiting case of small capillary numbers (relatively high surface tension), wherein interfacial deformation and associated instabilities are suppressed. The centrifugal instability, caused by unstable gradients of angular momentum, destabilizes the axisymmetric azimuthal base flow. As in single phase Dean flow, an array of vortices is formed within each fluid at the critical Reynolds number. A numerical linear stability analysis is carried out using a recombined Chebyshev Galerkin spectral method, as well as a shooting method. Across the space of physical parameters (volume fractions, density, and viscosity ratios), six critical modes corresponding to distinct secondary flows are observed. These are classified into axisymmetric stationary vortices and rotating spiral vortices (travelling waves). Each category consists of three subtypes based on the relative vortex strength in the fluids: stronger in the outer fluid, stronger in the inner fluid, and comparable strength in both fluids. The critical mode switches amongst these six types as parameters are varied. The outer fluid is found to be more unstable than the inner fluid, even if the fluids have equal physical properties. This is explained using Rayleigh’s criterion for inviscid flows. Consequently, the arrangement of fluids has a significant impact on stability. Instability and vortex motion are promoted if the fluid with a higher density, a lower viscosity, and a larger volume fraction is placed on the outer side of the channel.
Simple theory of transitions between smectic, nematic, and isotropic phases
Authors: Emelyanenko A. V. , Khokhlov A. R.
Published: May 2015

The transitions between smectic, nematic, and isotropic phases are investigated in the framework of a unified molecular-statistical approach. The new translational order parameter is different from the one introduced in K. Kobayashi [Phys. Lett. A 31, 125 (1970)] and W. L. McMillan [Phys. Rev. A 4, 1238 (1971)]. The variance of the square sine of intermolecular shift angle along the director is introduced to take self-consistently into account the most probable location of the molecules with respect to each other, which is unique for every liquid crystal (LC) material and is mainly responsible for the order parameters and phase sequences. The mean molecular field was treated in terms of only two parameters specific to any intermolecular potential of elongated molecules: (1) its global minimum position with respect to the shift of two interacting molecules along the director and (2) its inhomogeneity/anisotropy ratio. A simple molecular model is also introduced, where the global minimum position is determined by the linking groups elongation Δ/d, while the inhomogeneity/anisotropy ratio Gβ/Gγ is determined by the ratio of electrostatic and dispersion contributions. All possible phase sequences, including abrupt/continuous transformation between the smectic and nematic states and the direct smectic-isotropic phase transition, are predicted. The theoretical prediction is in a good agreement with experimental data for some simple materials correlating with our molecular model, but it is expected to be valid for any LC material.
Real-space representation of electron correlation in π-conjugated systems
Authors: Wang Jian , Baerends Evert Jan
Published: May 2015

π-electron conjugation and aromaticity are commonly associated with delocalization and especially high mobility of the π electrons. We investigate if also the electron correlation (pair density) exhibits signatures of the special electronic structure of conjugated systems. To that end the shape and extent of the pair density and derived quantities (exchange-correlation hole, Coulomb hole, and conditional density) are investigated for the prototype systems ethylene, hexatriene, and benzene. The answer is that the effects of π electron conjugation are hardly discernible in the real space representations of the electron correlation. We find the xc hole to be as localized (confined to atomic or diatomic regions) in conjugated systems as in small molecules. This result is relevant for density functional theory (DFT). The potential of the electron exchange-correlation hole is the largest part of vxc, the exchange-correlation Kohn-Sham potential. So the extent of the hole directly affects the orbital energies of both occupied and unoccupied Kohn-Sham orbitals and therefore has direct relevance for the excitation spectrum as calculated with time-dependent DFT calculations. The potential of the localized xc hole is comparatively more attractive than the actual hole left behind by an electron excited from a delocalized molecular orbital of a conjugated system.
Chimeras in globally coupled oscillatory systems: From ensembles of oscillators to spatially continuous media
Authors: Schmidt Lennart , Krischer Katharina
Published: May 2015

We study an oscillatory medium with a nonlinear global coupling that gives rise to a harmonic mean-field oscillation with constant amplitude and frequency. Two types of cluster states are found, each undergoing a symmetry-breaking transition towards a related chimera state. We demonstrate that the diffusional coupling is non-essential for these complex dynamics. Furthermore, we investigate localized turbulence and discuss whether it can be categorized as a chimera state.
Analyzing the properties of acceptor mode in two-dimensional plasma photonic crystals based on a modified finite-difference frequency-domain method
Authors: Zhang Hai-Feng , Ding Guo-Wen , Lin Yi-Bing , Chen Yu-Qing
Published: May 2015

In this paper, the properties of acceptor mode in two-dimensional plasma photonic crystals (2D PPCs) composed of the homogeneous and isotropic dielectric cylinders inserted into nonmagnetized plasma background with square lattices under transverse-magnetic wave are theoretically investigated by a modified finite-difference frequency-domain (FDFD) method with supercell technique, whose symmetry of every supercell is broken by removing a central rod. A new FDFD method is developed to calculate the band structures of such PPCs. The novel FDFD method adopts a general function to describe the distribution of dielectric in the present PPCs, which can easily transform the complicated nonlinear eigenvalue equation to the simple linear equation. The details of convergence and effectiveness of proposed FDFD method are analyzed using a numerical example. The simulated results demonstrate that the enough accuracy of the proposed FDFD method can be observed compared to the plane wave expansion method, and the good convergence can also be obtained if the number of meshed grids is large enough. As a comparison, two different configurations of photonic crystals (PCs) but with similar defect are theoretically investigated. Compared to the conventional dielectric-air PCs, not only the acceptor mode has a higher frequency but also an additional photonic bandgap (PBG) can be found in the low frequency region. The calculated results also show that PBGs of proposed PPCs can be enlarged as the point defect is introduced. The influences of the parameters for present PPCs on the properties of acceptor mode are also discussed in detail. Numerical simulations reveal that the acceptor mode in the present PPCs can be easily tuned by changing those parameters. Those results can hold promise for designing the tunable applications in the signal process or time delay devices based on the present PPCs.
A resistively heated CeB6 emissive probe
Authors: Martin M. J. , Bonde J. , Gekelman W. , Pribyl P.
Published: May 2015

The plasma potential, Vp, is a key quantity in experimental plasma physics. Its spatial gradients directly yield the electrostatic field present. Emissive probes operating under space-charge limited emission conditions float close to Vp even under time-varying conditions. Throughout their long history in plasma physics, they have mostly been constructed with resistively heated tungsten wire filaments. In high density plasmas (>1012 cm−3), hexaboride emitters are required because tungsten filaments cannot be heated to sufficient emission without component failure. A resistively heated emissive probe with a cerium hexaboride, CeB6, emitter has been developed to work in plasma densities up to 1013 cm−3. To show functionality, three spatial profiles of Vp are compared using the emissive probe, a cold floating probe, and a swept probe inside a plasma containing regions with and without current. The swept probe and emissive probe agree well across the profile while the floating cold probe fails in the current carrying region.
Hall effect measurements on thermoelectric Ca3Co4O9: On how to determine the charge carrier concentration in strongly correlated misfit cobaltites
Authors: Schrade Matthias , Norby Truls , Finstad Terje G.
Published: May 2015

The Hall coefficient RH and electrical conductivity of misfit calcium cobalt oxide (Ca2CoO3−δ)q(CoO2) (CCO) were measured at room temperature for different oxygen vacancy concentrations δ. Based on these and numerous previous results, it is shown that the charge carrier concentrations n obtained by the classical formula RH = 1/ne are between 3 and 6 × 1020 cm−3 and thereby much lower than those derived by other experimental techniques and fail to explain the observed electric properties of CCO. We show that the experimental results are well described using an earlier proposed t–J-model for strongly correlated electrons on a triangular lattice. The hopping parameter t for CCO was found to be ≈ −20 K and the charge carrier concentration of fully oxidized CCO to be 5.7 × 1021 cm−3 (0.41 hole type carriers per formula unit), in agreement with other experimental techniques.
An InP/Si heterojunction photodiode fabricated by self-aligned corrugated epitaxial lateral overgrowth
Authors: Sun Y. T. , Omanakuttan G. , Lourdudoss S.
Published: May 2015

An n-InP/p-Si heterojunction photodiode fabricated by corrugated epitaxial lateral overgrowth (CELOG) method is presented. N-InP/p-Si heterojunction has been achieved from a suitable pattern containing circular shaped openings in a triangular lattice on the InP seed layer on p-Si substrate and subsequent CELOG of completely coalesced n-InP. To avoid current path through the seed layer in the final photodiode, semi-insulating InP:Fe was grown with adequate thickness prior to n-InP growth in a low pressure hydride vapor phase epitaxy reactor. The n-InP/p-Si heterointerface was analyzed by scanning electron microscopy and Raman spectroscopy. Room temperature cross-sectional photoluminescence (PL) mapping illustrates the defect reduction effect in InP grown on Si by CELOG method. The InP PL intensity measured above the InP/Si heterojunction is comparable to that of InP grown on a native planar substrate indicating low interface defect density of CELOG InP despite of 8% lattice mismatch with Si. The processed n-InP/p-Si heterojunction photodiodes show diode characteristics from the current-voltage (I-V) measurements with a dark current density of 0.324 mA/cm2 at a reverse voltage of −1 V. Under the illumination of AM1.5 conditions, the InP/Si heterojunction photodiode exhibited photovoltaic effect with an open circuit voltage of 180 mV, a short circuit current density of 1.89 mA/cm2, an external quantum efficiency of 4.3%, and an internal quantum efficiency of 6.4%. This demonstration of epitaxially grown InP/Si heterojunction photodiode will open the door for low cost and high efficiency solar cells and photonic integration of III-Vs on silicon.
Break crops and rotations for wheat
Authors: Angus J. F. , Kirkegaard J. A. , Hunt J. R. , Ryan M. H. , Ohlander L. , Peoples M. B.
Published: May 2015

Wheat crops usually yield more when grown after another species than when grown after wheat. Quantifying the yield increase and explaining the factors that affect the increase will assist farmers to decide on crop sequences. This review quantifies the yield increase, based on >900 comparisons of wheat growing after a break crop with wheat after wheat. The mean increase in wheat yield varied with species of break crop, ranging from 0.5 t ha–1 after oats to 1.2 t ha–1 after grain legumes. Based on overlapping experiments, the observed ranking of break-crop species in terms of mean yield response of the following wheat crop was: oats < canola ≈ mustard ≈ flax < field peas ≈ faba beans ≈ chickpeas ≈ lentils ≈ lupins. The mean additional wheat yield after oats or oilseed break crops was independent of the yield level of the following wheat crop. The wheat yield response to legume break crops was not clearly independent of yield level and was relatively greater at high yields. The yield of wheat after two successive break crops was 0.1–0.3 t ha–1 greater than after a single break crop. The additional yield of a second wheat crop after a single break crop ranged from 20% of the effect on a first wheat crop after canola, to 60% after legumes. The mean yield effect on a third wheat crop was negligible, except in persistently dry conditions. The variability of the break-crop effect on the yield of a second wheat crop was larger than of a first wheat crop, particularly following canola. We discuss the responses in relation to mechanisms by which break crops affect soil and following crops. By quantifying the magnitude and persistence of break-crop effects, we aim to provide a basis for the decision to grow continuous cereal crops, strategic rotations or tactically selected break crops. In many wheat-growing areas, the large potential yield increases due to break crops are not fully exploited. Research into quantifying the net benefits of break crops, determining the situations where the benefits are greatest, and improving the benefits of break crops promises to improve the efficiency of wheat-based cropping systems.
Transcription factor PRDM8 is required for rod bipolar and type 2 OFF-cone bipolar cell survival and amacrine subtype identity
Authors: Jung Cynthia C. , Atan Denize , Ng David , Ploder Lynda , Ross Sarah E. , Klein Martin , Birch David G. , Diez Eduardo , McInnes Roderick R.
Published: May 2015

Significance

Knowledge of the molecules that guide retinal interneuron formation is incomplete. We showed that PRDI-BF1 and RIZ homology domain containing 8 (PRDM8) is required for the development of rod bipolar cells and OFF-cone bipolar subtypes as well as amacrine cell identity. Although bipolar cells were specified in
Prdm8
-null mice, rod bipolar cell differentiation was impaired, leading to their death and near absence from adult retina. This defect disrupts postphotoreceptor signal transduction, as shown by nonprogressive b-wave deficits in electroretinograms. Our findings suggest
PRDM8
as a candidate gene for human congenital stationary night blindness. They also establish PRDM8 as a component of the regulatory network governing bipolar cell development and amacrine cell diversity, aiding efforts to generate these essential interneurons in vitro.
Social deixis in motion
Authors: Luchkina Tatiana
Published: May 2015

The address term COMRADE in the 20th century Russian and Mandarin Chinese presents an attempt to neutralize and compress the category of formal address by collapsing in a single lexeme the dimensions of power, social distance, age, and gender differentials. This situation-dependent variability of politeness-import proved to be of limited efficacy on the more global, paradigmatic scale. With COMRADE falling out of use in the late 20th century, the current tendency in Russian and Mandarin is to reinforce novel forms of address and/or recover select obsolescent ATs. Both strategies suggest the contemporary address systems of these languages show a trend against reduction and towards populating the paradigm of generic address with ATs whose politeness import is specific and stable.
Korean honorifics beyond politeness markers
Authors: Yoon Sang-Seok
Published: May 2015

The purpose of this study is to show that Korean honorifics are not mere politeness markers or linguistic forms that speakers use passively, following social conventions. Rather, they are social indexes that can be used to construct one’s identity or change footing (Goffman 1981) in a given social context. The traditional understanding of honorifics has regarded them as linguistic forms reflecting relative social-positional differences and has assumed that social structure and language use have a one-to-one relationship. However, recent studies on honorifics argue that speakers of languages with an honorific system do not always choose honorifics passively based on social norms but sometimes actively and strategically choose honorific forms to meet the demands of a given context. From the perspective of social constructivism, this study examines conversations in Korean TV shows and demonstrates that Korean speakers often switch speech style from honorific to non-honorific without being rude. The present study argues that Korean speakers on TV constantly change footing and create shifting identities in order to make conversation dynamic and fun.
Goading as a social action
Authors: Mitchell Nathaniel
Published: May 2015

This paper addresses particular social actions present in a data set of short message emails where interactants use potentially impolite strategies frequently. The particular social action under analysis here is that of goading, a term coined to describe targeted banter (banter directed toward a ratified participant in interaction). However, evaluations of impoliteness are not always shared across participants in these goading sequences, as follow-up interviews show some disaffiliation between individual participants’ understanding of the prior turns. It is more common in this data set to find tokens of goading being evaluated as non-impolite rather than impolite, suggesting that participants perceive the humorous nature of goading. Yet, among a tiny community of practice of only four individuals, even these non-impolite evaluations are not always shared. This paper attempts to add to the empirical study of im/politeness to account for goading as a type of banter or jocular mockery and situate it in the ever-increasing set of actions which cannot be straightforwardly categorized as second-order politeness or as impoliteness.
Shaming, group face, and identity construction in a Russian virtual community for women
Authors: Perelmutter Renee
Published: May 2015

Impoliteness, often described as non-cooperative and norm-disrupting verbal behavior (Keinpointner 2008; Culpeper et al. 2003; Beebe 1995), can also serve important sociability functions. When tension is present between individual and group face wants, impoliteness can be used to establish, reinforce, or (re)negotiate values salient to the group (Culpeper 2011; Lea at al. 1992; Graham 2007). The intersection of impoliteness with group face concerns is especially important in polylogous online contexts (Blitvich 2010; Lorenzo-Dus at al. 2011; Perelmutter 2013). This study examines the intersection between individual and group face concerns by examining impoliteness in an online Russian-language forum dedicated to discussions of marital infidelity. This forum is frequented by both mistresses and cheated-upon wives. Mistresses post confessions, expecting and sometimes even soliciting shaming responses from other forum members; wives engage in troubles-telling and are mocked by mistresses; mistresses and wives insult and shame each other. Since the overarching societal norms and expectations of family mores and gendered behavior in the post-Soviet society are often unclear, these shaming practices help Russian-speaking women construct and negotiate their identities within a group of peers. These negotiations integrate individual, group, and societal face concerns.
Using eye-tracking to examine the reading of texts containing taboo words
Authors: Raizen Adina , Vergis Nikos , Christianson Kiel
Published: May 2015

Experimental pragmatics research on (im)politeness generally employs “off-line” methodologies, meaning that data reflect ratings or understanding of given texts or interactions after they have been processed. “On-line” methods allow for moment-by-moment data collection as input is processed. We discuss advantages of using one on-line method, eye-tracking, in experimental pragmatics research. We also consider experimental design difficulties inherent in creating stimuli. We take as a specific example a recent study of how readers process English taboo words portrayed as being uttered by more or less typical speakers in more or less appropriate situations. We demonstrate early influences of pragmatic information, essentially concurrent with lexical access. The timing of these influences in the ongoing language processing cannot be captured using off-line methods. Further, our on-line data suggest that part of impoliteness judgments may be formed before they reach the threshold of conscious understanding.
Impoliteness electrified
Authors: Jiang Xiaoming , Zhou Xiaolin
Published: May 2015

Being polite is an effective way to facilitate interpersonal communication. One of the key issues is how the human cognitive system perceives verbal politeness and deals with the cases in which politeness principles are violated. By using event-related potentials (ERPs), we aim to address the nature of real time processing of disrespectful reference in Mandarin utterance interpretation. The consistency between the social status of the communicating partners and the use of second-person pronoun was manipulated as a testing case. Participants read utterances in which the social status of the communicating partners was either consistent with the pronoun (e.g. respectful) or violated the pronoun (e.g. disrespectful), while undergoing the recording of electrophysiological activity on the scalp. Earlier research has demonstrated that semantic, syntactic and inferential pragmatic processing could be manifested in different ERP effects. Our ERP findings demonstrated that successful handling of disrespectful address may engage semantic-pragmatic mechanisms (as reflected by a N400 and late negativity effect), rather than a mechanism dealing with grammatical error. Moreover, the ERP responses were modulated by individual differences in tolerance to the disrespectful usage, gender, and social interactive ability. These ERP indices of real time processing of disrespectful utterances are consistent with the “conventionalization view” in im/politeness theory (Culpeper 2011; Terkourafi 2002, 2003, 2005).
Agrobacterium-mediated transient MaFT expression in mulberry (Morus alba L.) leaves
Authors: Wu Su-Li , Yang Xiao-Bing , Liu Li-Qun , Jiang Tao , Wu Hai , Su Chao , Qian Yong-Hua , Jiao Feng
Published: May 2015

To optimize Agrobacterium-mediated transient transformation assay in mulberry (Morus alba L.), various infiltration methods, Agrobacterium tumefaciens (A. tumefaciens) strains, and bacterial concentrations were tested in mulberry seedlings. Compared with LBA4404, GV3101 harboring pBE2133 plasmids presented stronger GUS signals at 3 days post infiltration using syringe. Recombinant plasmids pBE2133:GFP and pBE2133:GFP:MaFT were successfully constructed. Transient expression of MaFT:GFP protein was found in leaves, petiole (cross section), and shoot apical meristem (SAM) of mulberry according to the GFP signal. Moreover, MaFT:GFP mRNA was also detected in leaves and SAM via RT-PCR and qRT-PCR. An efficient transient transformation system could be achieved in mulberry seedlings by syringe using A. tumefaciens GV3101 at the OD600 of 0.5. The movement of MaFT expression from leaves to SAM might trigger the precocious flowering of mulberry.
β-Galactosidase from Ginkgo biloba seeds active against β-galactose-containing N-glycans: purification and characterization
Authors: Rahman Md Ziaur , Maeda Megumi , Kimura Yoshinobu
Published: May 2015

In this study, we purified an acidic β-galactosidase to homogeneity from Ginkgo biloba seeds (β-Gal’ase Gb-1) with approximately 270-fold purification. A molecular mass of the purified β-Gal’ase Gb-1 was estimated about 35 kDa by gel filtration and 32 kDa by SDS-PAGE under non-reducing condition, respectively. On the other hand, β-Gal’ase Gb-1 produced a single band with a molecular mass of 16 kDa by SDS-PAGE under reducing condition. The N-terminal amino acid sequences of 32 kDa and 16 kDa molecules were the same and identified as H-K-A-N-X-V-T-V-A-F-V-M-T-Q-H-, suggesting that β-Gal’ase Gb-1 may function as a homodimeric structure in vivo. When complex-type N-glycans containing β-galactosyl residues were used as substrates, β-Gal’ase Gb-1 showed substantial activity for β1-4 galactosyl residue and modest activity for β1-3 galactosyl residue with an optimum pH near 5.0. Based on these results, the involvement of β-Gal’ase Gb-1 in the degradation of plant complex-type N-glycans is discussed.
Chronology January–March 2015
Authors: Bilderling Sophie Shihab
Published: May 2015

This chronology of events in the North and South Caucasus has been compiled based mainly on Reuters (www.reuters.com/news/world), Radio Free Europe/Radio Liberty (www.rferl.org), Caucasian Knot (www.eng.kavkaz-uzel.ru) and the Jamestown Foundation (www. jamestown.org) and Civil Georgia (www.civil.ge).
Conjugacy classes of non-translations in affine Weyl groups and applications to Hecke algebras
Authors: Rostami Sean
Published: May 2015

Let

W
~

=
Λ
⋊

W

∘

\widetilde {W} = \Lambda \rtimes W_{\circ }

be an Iwahori-Weyl group of a connected reductive group

G
G

over a non-archimedean local field. The subgroup

W

∘

W_{\circ }

is a finite Weyl group, and the subgroup

Λ
\Lambda

is a finitely generated abelian group (possibly containing torsion) which acts on a certain real affine space by translations. We prove that if

w
∈

W
~

w \in \widetilde {W}

and

w
∉
Λ

w \notin \Lambda

, then one can apply to

w
w

a sequence of conjugations by simple reflections, each of which is length-preserving, resulting in an element

w

′

w^{\prime }

for which there exists a simple reflection

s
s

such that

ℓ
(
s

w

′

)
,
ℓ
(

w

′

s
)
>
ℓ
(

w

′

)

\ell ( s w^{\prime } ), \ell ( w^{\prime } s ) > \ell ( w^{\prime } )

and

s

w

′

s
≠

w

′

s w^{\prime } s \neq w^{\prime }

. Even for affine Weyl groups, a special case of Iwahori-Weyl groups and also an important subclass of Coxeter groups, this is a new fact about conjugacy classes. Further, there are implications for Iwahori-Hecke algebras

H

\mathcal {H}

of

G
G

: one can use this fact to give dimension bounds on the “length-filtration” of the center

Z
(

H

)

Z ( \mathcal {H} )

, which can in turn be used to prove that suitable linearly independent subsets of

Z
(

H

)

Z ( \mathcal {H} )

are a basis.
Cellular context–mediated Akt dynamics regulates MAP kinase signaling thresholds during angiogenesis
Authors: Hellesøy Monica , Lorens James B.
Published: May 2015

The formation of new blood vessels by sprouting angiogenesis is tightly regulated by contextual cues that affect angiogeneic growth factor signaling. Both constitutive activation and loss of Akt kinase activity in endothelial cells impair angiogenesis, suggesting that Akt dynamics mediates contextual microenvironmental regulation. We explored the temporal regulation of Akt in endothelial cells during formation of capillary-like networks induced by cell–cell contact with vascular smooth muscle cells (vSMCs) and vSMC-associated VEGF. Expression of constitutively active Akt1 strongly inhibited network formation, whereas hemiphosphorylated Akt1 epi-alleles with reduced kinase activity had an intermediate inhibitory effect. Conversely, inhibition of Akt signaling did not affect endothelial cell migration or morphogenesis in vSMC cocultures that generate capillary-like structures. We found that endothelial Akt activity is transiently blocked by proteasomal degradation in the presence of SMCs during the initial phase of capillary-like structure formation. Suppressed Akt activity corresponded to the increased endothelial MAP kinase signaling that was required for angiogenic endothelial morphogenesis. These results reveal a regulatory principle by which cellular context regulates Akt protein dynamics, which determines MAP kinase signaling thresholds necessary drive a morphogenetic program during angiogenesis.
Control of the spindle checkpoint by lateral kinetochore attachment and limited Mad1 recruitment
Authors: Krefman Nathaniel I. , Drubin David G. , Barnes Georjana
Published: May 2015

We observed the dynamic recruitment of spindle checkpoint proteins Mad1 and Bub1 to detached kinetochores in budding yeast using real-time live-cell imaging and quantified recruitment in fixed cells. After induced de novo kinetochore assembly at one pair of sister centromeres, Mad1 appeared after the kinetochore protein Mtw1. Detached kinetochores were not associated with the nuclear envelope, so Mad1 does not anchor them to nuclear pore complexes (NPCs). Disrupting Mad1's NPC localization increased Mad1 recruitment to detached sister kinetochores. Conversely, increasing the number of detached kinetochores reduced the amount of Mad1 per detached kinetochore. Bub1 also relocalized completely from the spindle to detached sister centromeres after kinetochore assembly. After their capture by microtubules, Mad1 and Bub1 progressively disappeared from kinetochores. Sister chromatids that arrested with a lateral attachment to one microtubule exhibited half the Mad1 of fully detached sisters. We propose that detached kinetochores compete with alternate binding sites in the nucleus to recruit Mad1 and Bub1 from available pools that are small enough to be fully depleted by just one pair of detached kinetochores and that lateral attachment licenses Mad1 removal from kinetochores after a kinetic delay.
QVZ: lossy compression of quality values
Authors: Malysa Greg , Hernaez Mikel , Ochoa Idoia , Rao Milind , Ganesan Karthik , Weissman Tsachy
Published: May 2015

Motivation

Recent advancements in sequencing technology have led to a drastic reduction in the cost of sequencing a genome. This has generated an unprecedented amount of genomic data that must be stored, processed and transmitted. To facilitate this effort, we propose a new lossy compressor for the quality values presented in genomic data files (e.g. FASTQ and SAM files), which comprise roughly half of the storage space (in the uncompressed domain). Lossy compression allows for compression of data beyond its lossless limit.

Results

The proposed algorithm QVZ exhibits better rate-distortion performance than the previously proposed algorithms, for several distortion metrics and for the lossless case. Moreover, it allows the user to define any quasi-convex distortion function to be minimized, a feature not supported by the previous algorithms. Finally, we show that QVZ-compressed data exhibit better performance in the genotyping than data compressed with previously proposed algorithms, in the sense that for a similar rate, a genotyping closer to that achieved with the original quality values is obtained.

Availability and implementation

QVZ is written in C and can be downloaded from https://github.com/mikelhernaez/qvz.

Contact

mhernaez@stanford.edu or gmalysa@stanford.edu or iochoa@stanford.edu

Supplementary information

Supplementary data are available at Bioinformatics online.
“Lordy, Lordy, Look Who’s 40!” The Journal of Consumer Research Reaches a Milestone
Authors: Rapp Justine M. , Hill Ronald Paul
Published: May 2015

The Journal of Consumer Research has completed four decades as one of the top journals in the larger field of marketing as well as the premier outlet for research on consumer behavior. This elite status is based, in part, on its stated objective as a multidisciplinary journal that allows for a variety of topics, methods, and populations that are central to collectives of scholars from many social sciences and methodological orientations. While a few articles have reviewed the level of diversity within the journal and among its peers, none to date has taken an expansive look at what is studied, how it is examined, and which consumers are used to determine the validity of our theoretical contributions. Thus this article looks across the life span of JCR to address these issues and finds considerable progress along with major areas that should be addressed by the community of researchers that constitutes our field.
The Value of Time
Authors: Festjens Anouk , Janiszewski Chris
Published: May 2015

Ten studies are used to document that time is valued in accordance with a double-kinked value function. There is a zone of indifference for small time gains (losses), increasing marginal utility (disutility) for moderate time gains (losses), and diminishing marginal utility (disutility) for large time gains (losses). Moderate amounts of time exhibit increasing marginal utility (disutility) because larger blocks of time provide a more diverse set of usage opportunities. It is only when it is difficult to imagine how more (less) time would be beneficial (detrimental) that there is diminishing marginal utility (disutility) for time. Thus time valuation shows increasing marginal utility when there is a time deficit, but diminishing marginal utility when there is a time surplus. These findings have implications for how other resources might be valued.
CMR—basic principles
Authors: Wright Jeremy , Bogaert Jan
Published: May 2015

Recent advances have enabled CMR to come close to the goal of a complete examination of the cardiovascular system by a single modality. It can provide relevant information on most aspects of heart structure, global and regional ventricular function, valve function, flow patterns, myocardial perfusion, coronary anatomy, and myocardial viability, all obtained non-invasively in a single study in 30–60 min. The aim of this chapter is to describe the physics and practical aspects of CMR and then explore the available pulse sequences, so that the clinical utility of CMR can be maximized.
New technical developments in CMR
Authors: Razavi Reza , Sohal Manav , Chen Zhong , Harrison James
Published: May 2015

Technical developments in cardiac magnetic resonance (CMR) are changing our practice and opening up new avenues of research and clinical application. In this chapter three important areas are addressed that are moving from research into important clinical applications. First, the use of quantitative T1 mapping in characterizing myocardial tissue, particularly of the left ventricle. This area has expanded substantially over the last few years and T1 mapping techniques are now being used to study a number of conditions, including myocardial infarction and different cardiomyopathies. Second, the area of atrial imaging and the use of gadolinium late-enhancement and T2-weighted imaging to characterize the morphology of the left atrium. This has become increasingly important in the assessment of patients with atrial fibrillation, both as a way of classifying patients in terms of the severity of atrial disease and the likelihood of response to catheter ablation therapies, and also as a way of assessing the effects of these ablation therapies particularly when patients require redo procedures. Finally, the use of MRI conditional pacemakers, which have become available and now allow patients with pacemakers to undergo MRI studies.
Imaging during cardiac interventions
Authors: Rincón Luis M. , Zamorano José L.
Published: May 2015

Development and expansion of percutaneous interventional procedures in the catheterization laboratories during the last years have raised the need of imaging techniques capable to identify cardiac structures, guide the procedure, and exclude possible complications. Among different imaging techniques, echocardiography offers the advantage of its mobility and capability to assess different cardiac structures in real time. It has become the preferred method for a wide variety of cardiac procedures before, during, and after these interventions. Electrophysiology has also experienced a major change, as anatomy has proven to play a key role in arrhythmogenesis. This has forced a shift from an electrophysiologically guided procedure to an anatomically guided procedure, where imaging guiding has become essential to ensure an accurate knowledge of intra-cardiac anatomy and complement cardiac electrograms.

Echocardiography plays an important function in three aspects for interventional cardiology: prior to the procedure, it provides information for the selection of patients; during the procedure, it can monitor and guide the intervention; and afterwards, it assesses the results. In the last years, 3D-transoesophageal echocardiography (3D-TEE) and intra-cardiac echocardiography (ICE) have proved their utility and safety, providing information regarding anatomy and physiology in real time. There is no question that the use of imaging techniques can enhance the results and safety of these procedures. The particular features of each intervention and the variety of techniques currently available force cardiologists from the fields of echocardiography, interventional cardiology, and electrophysiology to know the strengths and weaknesses of each imaging modality in order to reach their best performance.