bluuebunny/crossref_metadata_2025 huggingface dataset:
Extended MHD modeling of tearing-driven magnetic relaxation
Authors: Sauppe J. P. , Sovinec C. R.
Published: March 2017

Discrete relaxation events in reversed-field pinch relevant configurations are investigated numerically with nonlinear extended magnetohydrodynamic (MHD) modeling, including the Hall term in Ohm's law and first-order ion finite Larmor radius effects. Results show variability among relaxation events, where the Hall dynamo effect may help or impede the MHD dynamo effect in relaxing the parallel current density profile. The competitive behavior arises from multi-helicity conditions where the dominant magnetic fluctuation is relatively small. The resulting changes in parallel current density and parallel flow are aligned in the core, consistent with experimental observations. The analysis of simulation results also confirms that the force density from fluctuation-induced Reynolds stress arises subsequent to the drive from the fluctuation-induced Lorentz force density. Transport of the momentum density is found to be dominated by the fluctuation-induced Maxwell stress over most of the cross section with viscous and gyroviscous contributions being large in the edge region. The findings resolve a discrepancy with respect to the relative orientation of current density and flow relaxation, which had not been realized or investigated in King et al. [Phys. Plasmas 19, 055905 (2012)], where only the magnitude of flow relaxation is actually consistent with experimental results.
Molecular length effect on work function shifts at copper-organophosphonate-hafnia interfaces
Authors: Kwan Matthew , Cardinal Thomas , Mutin P. Hubert , Ramanath Ganpati
Published: March 2017

We demonstrate that inserting a mercaptan-terminated organophosphonic acid monolayer at a Cu-HfO2 interface can alter the metal work function by −0.1 eV ≤ΔΦ≤−0.4 eV. The electron spectroscopy measurements of valence band structure reveal that molecular length-induced changes in ΔΦ can exceed contributions from Cu-S and P-O-Hf bonding dipoles at the Cu-organophosphonate-HfO2 interfaces. The invariance of the organophosphonate monolayer thickness with molecular length indicates that the observed values of ΔΦ are due to differences in molecular configuration and monolayer morphology. These findings suggest that molecular length could be a knob for tuning the electronic properties of inorganic interfaces modified with a nanomolecular layer for applications.
Extreme nonlinear terahertz electro-optics in diamond for ultrafast pulse switching
Authors: Shalaby Mostafa , Vicario Carlo , Hauri Christoph P.
Published: March 2017

Polarization switching of picosecond laser pulses is a fundamental concept in signal processing [C. Chen and G. Liu, Annu. Rev. Mater. Sci. 16, 203 (1986); V. R. Almeida et al., Nature 431, 1081 (2004); and A. A. P. Pohl et al., Photonics Sens. 3, 1 (2013)]. Conventional switching devices rely on the electro-optical Pockels effect and work at radio frequencies. The ensuing gating time of several nanoseconds is a bottleneck for faster switches which is set by the performance of state-of-the-art high-voltage electronics. Here we show that by substituting the electric field of several kV/cm provided by modern electronics by the MV/cm field of a single-cycle THz laser pulse, the electro-optical gating process can be driven orders of magnitude faster, at THz frequencies. In this context, we introduce diamond as an exceptional electro-optical material and demonstrate a pulse gating time as fast as 100 fs using sub-cycle THz-induced Kerr nonlinearity. We show that THz-induced switching in the insulator diamond is fully governed by the THz pulse shape. The presented THz-based electro-optical approach overcomes the bandwidth and switching speed limits of conventional MHz/GHz electronics and establishes the ultrafast electro-optical gating technology for the first time in the THz frequency range. We finally show that the presented THz polarization gating technique is applicable for advanced beam diagnostics. As a first example, we demonstrate tomographic reconstruction of a THz pulse in three dimensions.
In-situ detection of local avalanche breakdown and large magnetoresistance in Ag/SiO2/p-Si:B/SiO2/Ag device
Authors: He Xiong , Sun Zhigang , Pang Yuyu , Li Yuechou
Published: March 2017

Local avalanche breakdown in an Ag/SiO2/p-Si:B/SiO2/Ag device was successfully detected by an in-situ detection circuit, which was composed of a p-Si:B substrate, two p-Si:B/SiO2/Ag metal-oxide-semiconductor (MOS) structures formed on it, and a voltmeter. In our device, we observed a series of discharge peaks in the voltage-current curves which were corresponding to the generation of local plasmas in avalanche regimes. The generation of local plasmas led to a sudden increase in carriers concentration in the substrate which resulted in sudden voltage drops across the detection circuit, and then the MOS structures started to discharge which led to discharge peaks observed in V-I characteristics. More interesting, we found that the shape and amplitude of discharge peaks strongly depended on the setting of current steps of current source, owing to the discharging progresses. The avalanche breakdown based magnetoresistance (MR) effects were also studied. The value of MR in avalanche breakdown regime was about 40% which was two orders of magnitude higher than the MR value in other regimes. This work provides a simple and convenient method to explore the local avalanche breakdown effect and pave a way to acquire the MR effects based on avalanche breakdown.
Loading-path dependent deformation of nanocrystalline Ta under single- and double-shock, and quasi-isentropic compression
Authors: Tang M. X. , E J. C. , Wang L. , Luo S. N.
Published: March 2017

We investigate dynamic deformation of nanocrystalline Ta under single- and double-shock, and quasi-isentropic compression, with large-scale molecular dynamics simulations. Orientation mapping, selected area electron diffraction, and x-ray diffraction are implemented for microstructure analysis. Different deformation modes are found for different loading paths, and are attributed to the differences in temperature rise induced by dynamic compression. For sufficiently strong shocks, catastrophic activation of slip systems and their growth in single-shock loading with the largest temperature rise lead to amorphization and recrystallization, while stacking faults and dislocation slip dominate deformation in double-shock loading with intermediate temperature rise, and deformation twinning is the principal mode in quasi-isentropic loading with the least temperature rise.
Resistivity and low-frequency noise characteristics of epoxy-carbon composites
Authors: Pralgauskaitė Sandra , Matukas Jonas , Tretjak Marina , Macutkevic Jan , Banys Juras , Selskis Algirdas , Cataldo Antonino , Micciulla Federico , Bellucci Stefano , Fierro Vanessa , Celzard Alain
Published: March 2017

Noise and electrical transport properties of composites based on epoxy resin filled with various carbon inclusions (single-walled carbon nanotubes, high surface area carbon black, and exfoliated graphite) were investigated in depth. The temperature dependence of resistivity shows that Mott's hopping and tunneling between conductive carbon particles dominate the charge carrier transport at low temperature, whereas a positive temperature coefficient effect occurs at higher temperature. Low-frequency noise spectra of the investigated materials comprise 1/fα type components. The noise level is the highest for composites close to the percolation threshold. The percolation threshold value of the system also strongly impacts both the temperature dependence of the noise level and the resistivity. Close to the percolation threshold, the noise level increases due to the carrier tunneling throughout the polymer matrix and decreases due to the rapid expansion of the polymer matrix. In contrast, the latter has almost no influence on the noise level far above the percolation threshold, and the small kink in the temperature dependence of the noise level indicates a crossover between tunneling and thermally activated electron transport mechanisms.
Simple analytical expressions for electron pitch angle diffusion coefficients
Authors: Tripathi A. K. , Singhal R. P. , Khazanov G. V.
Published: March 2017

In the present paper, we have calculated electron pitch angle diffusion coefficients due to resonant interactions with whistler mode lower band chorus (LBC), upper band chorus (UBC), and electrostatic electron cyclotron harmonic (ECH) waves. Calculations have been performed at two values of the ratio of electron plasma frequency to gyro-frequency and thirteen representative values of electron energies for the plasma sheet electrons. The numerical data of diffusion coefficients have been fitted to simple analytical expressions for each wave mode. These analytical expressions allow for simple evaluation of pitch angle diffusion coefficients for the arbitrary pitch angle, energy, the ambient magnetic field, the wave amplitude, and the ratio of plasma frequency to gyro-frequency. In the case of LBC waves, the analytical coefficients are generally within a factor of two to the numerical coefficients, except at higher pitch angles where the numerical coefficients drop to show negligible values. Likewise, also for UBC waves, the analytical coefficients are generally within a factor of two to the numerical coefficients. The analytical coefficients for ECH waves are generally in agreement with numerical coefficients. However, the analytical expressions developed for ECH waves do not reproduce sharp fluctuations, dips, and gaps, the so-called banded structure observed in the data of numerical coefficients [A. K. Tripathi et al., Phys. Plasmas 23, 042101 (2016)] The effect of the shape variation on the profile of the wave spectral intensity and the effect of cold temperature on the numerical coefficients are also investigated. Applications of the analytical expressions of diffusion coefficients are discussed.
Defects responsible for lifetime degradation in electron irradiated n-GaN grown by hydride vapor phase epitaxy
Authors: Lee In-Hwan , Polyakov A. Y. , Yakimov E. B. , Smirnov N. B. , Shchemerov I. V. , Tarelkin S. A. , Didenko S. I. , Tapero K. I. , Zinovyev R. A. , Pearton S. J.
Published: March 2017

The effects of room temperature 6 MeV electron irradiation on the donor concentration, deep trap spectra, and diffusion lengths of nonequilibrium charge carriers were studied for undoped n-GaN grown by hydride vapor phase epitaxy. Changes in these parameters begin at a threshold electron fluence of 5 × 1015 cm−2. The diffusion lengths after this fluence decrease by a factor of 3, accompanied by a drastic increase in the density of deep electron traps with the level near Ec – 1 eV. There is a strong correlation between the changes in the density of these traps and the diffusion length of irradiated n-GaN, indicating that these centers control the lifetime in radiation damaged n-GaN. This is in sharp contrast to the starting material, where the lifetimes are controlled by other deep electron traps at Ec – 0.56 eV. The concentration of the latter is not strongly affected by high energy electron irradiation.
Synchronization in air-slot photonic crystal optomechanical oscillators
Authors: Huang Yongjun , Wu Jiagui , Flores Jaime Gonzalo Flor , Yu Mingbin , Kwong Dim-Lee , Wen Guangjun , Wong Chee Wei
Published: March 2017

In this Letter, we report observations for the optomechanical oscillator (OMO) synchronization in an air-slot photonic crystal (PhC) cavity driven by a single laser source. Two very-close mechanical modes are found in the air-slot PhC OMO cavity and can be locked to each other at drive powers above the threshold with different detunings. The improvement in phase noise (−70 dBc/Hz at 10 kHz offset) for the synchronized OMO is reported as well. The stable frequency tones obtained open a path toward reconfigurable synchronized oscillator networks.
Shifted Landau ladders and low field magneto-oscillations in high-mobility GaAs 2D hole systems
Authors: Zhang Po , Wang Jianli , Zhang Chi , Du Rui-Rui , Pfeiffer L. N. , West K. W.
Published: March 2017

We present well-developed low-field magneto-resistance oscillations originating from zero-field spin splitting (ZFSS) of heavy holes in high mobility GaAs/AlGaAs quantum wells. This low field oscillation is 1/B-periodic and emerges before the onset of Shubnikov–de Haas oscillations. The effect can be explained by resonant scattering between two Landau ladders shifted by the ZFSS gap, which in turn can be measured by comparing with the hole cyclotron energy. A front gate is fabricated to tune the ZFSS and hence the oscillation period.
Stable and efficient sky-blue organic light emitting diodes employing a tetradentate platinum complex
Authors: Li Guijie , Klimes Kody , Fleetham Tyler , Zhu Zhi-Qiang , Li Jian
Published: March 2017

A tetradentate Pt(II) complex platinum (II) [10-(9-(4-tert-butylpyridin-2-yl-κN)-9H-carbazol-2-yl-κC1)-9,10-dihydro-9,9-dimethyl-3-(1H-pyrazol-1-yl-κN2)acridine-1-yl-κC1] (PtN′1N-tBu) incorporating pyrazolyl-acridine as the lumophore was demonstrated to act as a stable and efficient sky-blue emitter. Phosphorescent organic light-emitting diode (OLED) employing PtN′1N-tBu without the electron blocking layer (EBL) achieved a high external quantum efficiency (EQE) of 15.9% and an estimated operational lifetime LT70 of 635 h at an initial luminance of 1000 cd/cm2. The device efficiency could be further improved by adding TrisPCz as EBL, reaching EQE of 17.3% and operational lifetime up to 482 h at 1000 cd/cm2.
Controlling silicon crystallization in aluminum-induced crystallization via substrate plasma treatment
Authors: Hainey Mel F. , Innocent-Dolor Jon-L , Choudhury Tanushree H. , Redwing Joan M.
Published: March 2017

The effect of reactive ion etching using chlorine or fluorine-based plasmas on aluminum-induced crystallization (AIC) of silicon on fused silica glass substrates was investigated with the goal of chemically modifying the substrate surface and thereby influencing the crystallization behavior. Chlorine etching of the glass prior to AIC resulted in six times faster silicon crystallization times and smaller grain sizes than films formed on untreated substrates while fluorine etching resulted in crystallization times double than those on untreated surfaces. The differences in crystallization behavior were attributed to changes in surface chemistry and surface energy of the glass as a result of the plasma treatment as supported by X-ray photoelectron spectroscopy and contact angle measurements. The different surface treatments were then combined with optical lithography to control the location of crystallization on the substrate surface to realize the production of patterned polycrystalline silicon films from initially continuous aluminum and silicon.
Beating Darwin-Bragg losses in lab-based ultrafast x-ray experiments
Authors: Fullagar Wilfred K. , Uhlig Jens , Mandal Ujjwal , Kurunthu Dharmalingam , El Nahhas Amal , Tatsuno Hideyuki , Honarfar Alireza , Parnefjord Gustafsson Fredrik , Sundström Villy , Palosaari Mikko R. J. , Kinnunen Kimmo M. , Maasilta Ilari J. , Miaja-Avila Luis , O'Neil Galen C. , Joe Young Il , Swetz Daniel S. , Ullom Joel N.
Published: March 2017

The use of low temperature thermal detectors for avoiding Darwin-Bragg losses in lab-based ultrafast experiments has begun. An outline of the background of this new development is offered, showing the relevant history and initiative taken by this work.
Wavelet Monte Carlo dynamics: A new algorithm for simulating the hydrodynamics of interacting Brownian particles
Authors: Dyer Oliver T. , Ball Robin C.
Published: March 2017

We develop a new algorithm for the Brownian dynamics of soft matter systems that evolves time by spatially correlated Monte Carlo moves. The algorithm uses vector wavelets as its basic moves and produces hydrodynamics in the low Reynolds number regime propagated according to the Oseen tensor. When small moves are removed, the correlations closely approximate the Rotne-Prager tensor, itself widely used to correct for deficiencies in Oseen. We also include plane wave moves to provide the longest range correlations, which we detail for both infinite and periodic systems. The computational cost of the algorithm scales competitively with the number of particles simulated, N, scaling as N In N in homogeneous systems and as N in dilute systems. In comparisons to established lattice Boltzmann and Brownian dynamics algorithms, the wavelet method was found to be only a factor of order 1 times more expensive than the cheaper lattice Boltzmann algorithm in marginally semi-dilute simulations, while it is significantly faster than both algorithms at large N in dilute simulations. We also validate the algorithm by checking that it reproduces the correct dynamics and equilibrium properties of simple single polymer systems, as well as verifying the effect of periodicity on the mobility tensor.
A multilayer multiconfiguration time-dependent Hartree simulation of the reaction-coordinate spin-boson model employing an interaction picture
Authors: Wang Haobin , Thoss Michael
Published: March 2017

The multilayer multiconfiguration time-dependent Hartree method is applied in an interaction picture to simulate dynamics of the spin-boson model in the reaction-coordinate representation. The use of the interaction picture allows a more effective description of correlation effects, especially when the coupling strength between the reaction coordinate and the bath is very strong. Examples show that in most physical regimes the efficiency is improved significantly, in some cases up to several orders of magnitude. This opens up new avenues for studying quantum dynamical problems.
Diffusion-driven destabilization of spatially homogeneous limit cycles in reaction-diffusion systems
Authors: Kuwamura Masataka , Izuhara Hirofumi
Published: March 2017

We study the diffusion-driven destabilization of a spatially homogeneous limit cycle with large amplitude in a reaction-diffusion system on an interval of finite size under the periodic boundary condition. Numerical bifurcation analysis and simulations show that the spatially homogeneous limit cycle becomes unstable and changes to a stable spatially nonhomogeneous limit cycle for appropriate diffusion coefficients. This is analogous to the diffusion-driven destabilization (Turing instability) of a spatially homogeneous equilibrium. Our approach is based on a reaction-diffusion system with mass conservation and its perturbed system considered as an infinite dimensional slow-fast system (relaxation oscillator).
Gender and second language style
Authors: Guthrie Kate Hardeman
Published: March 2017

Gender has been shown to be a salient factor in acquisition of second language variation (Adamson & Regan, 1991;Major, 2004;Meyerhoff & Schleef, 2012;Rehner, Mougeon, & Nadasdi, 2003;Schleef, Meyerhoff, & Clark, 2011). However, these studies have primarily focused on learner production of target language variation and style in the sense of attention paid to speech. There has been little focus on learner perceptions of the social meanings associated with L2 variants and styles. The present article addresses this gap in the research by examining L2 learner perceptions of a gendered style of speaking in Mandarin Chinese known assajiao. Results from a perception experiment confirm the salience of gender in the acquisition of L2 variation and show that American L2 Mandarin learners have acquired some of the social meanings associated withsajiaobut not others. An acoustic phonetic analysis ofsajiaois also presented.
Assessment planning within the context of university English language teaching (ELT) in China
Authors: Xu Yueting
Published: March 2017

Teacher assessment literacy (AL) is a concern for both educational assessment and teacher education research. As part of teacher
AL, teacher competency of assessment planning has remained underexplored. To address this gap, this study explored how a group of
20 contest-winning university English teachers in China planned for assessment through qualitative analyses of their lesson plans
and follow-up teacher interviews. The findings show that: (1) lesson plans include assessment-related components such as teaching
objectives, student background, instruction-embedded assessment, and after-class assessment tasks; (2) their assessment planning
is characterized by a clear understanding of learning goals, but an absence of rubrics and exemplars for performance assessments,
over-reliance on groups as target of assessment, and inconsistencies between learning objectives and assessment tasks; and (3)
their assessment planning was mainly intuitive and instruction-oriented. This paper concludes with a working model of assessment
planning, and discusses a future research agenda for assessment planning.
A deep semantic corpus-based approach to metaphor analysis
Authors: Dodge Ellen K.
Published: March 2017

This paper demonstrates the fruitful application of the formalization of Conceptual Metaphor Theory, combined with metaphor constructions and computational tools to a large-scale, corpus-based approach to the study of metaphor expressions. As the case study of poverty metaphor expressions illustrates, the representation of individual metaphors and frames as parts of larger conceptual networks facilitates analyses that capture both local details and larger patterns of metaphor use. Significantly, the data suggest that the two most frequently used source domain networks in poverty metaphor expressions each support different types of inferences about poverty, its effects, and possible ways to reduce or end it.
Rigaut de Berbezilh, the Physiologus Theobaldi, and the opening of animal inspiration
Authors: Kay Sarah
Published: March 2017

In two of his songs (421.1 and 421.2) the troubadour Rigaut de Berbezilh aspires to sing in response to a voice that is bestial yet somehow metaphysical. Scholars have attributed these animal images to the influence of the Physiologus, but Rigaut’s likeliest source in that tradition has not yet been identified. This article proposes to fill that lacuna by contending that the bestiary redaction closest to Rigaut’s imagery is the Physiologus Theobaldi, a verse text that unlike other bestiaries was used to teach Latin poetry and even song. In both the Physiologus Theobaldi and (though in a different way) Rigaut’s songs, animals’ breath and voice are identified with life and spirit, an identification that places these works within the wider medieval context of natural philosophical interest in pneuma. Whereas Theobaldus allegorizes his beasts in the third person, Rigaut’s first-person lyrics assume their voice, breath, life or spirit as potentially his own. He thereby opens his songs to a being that is not human. No longer anthropocentric, they enact a hybridity that we find elsewhere associated with revelation and apocalypse. The horizon of human history that opens (in Heidegger’s sense) the world of human language is thereby in turn opened up to that which it closes off, and the demarcations by which humanity defines itself are suspended.
Le miniature di Renart le Contrefait nel manoscritto Paris BnF fr. 1630
Authors: Lecco Margherita
Published: March 2017

Le manuscrit fr.1630 de la Bibliothèque Nationale de France, qui nous a transmis la rédaction A de Renart le Contrefait (1319–1322), contient 31 miniatures. Elles accompagnent fidèlement le texte, révélant la présence de certains éléments satiriques, comme le sermon que Renard prononce devant un auditoire d’oiseaux. On peut y voir une parodie du sermon que saint François avait adressé aux oiseaux, les incitant à l’obéissance et à l’humilité. Dans le Contrefait les mêmes mots poussent les animaux dans la bouche de Renart… Peut-on y voir une parodie, et donc une critique, à l’égard de saint François, de son enseignement sur la pauvreté et des Franciscains, qui semble se lire parfois dans quelques épisodes du texte?
“Una cerbia bianchissima e bella”
Authors: Pezzè Stefano
Published: March 2017

Considering European literature’s relationship with animals, it is immediately evident that the stag (and its feminine counterpart, the doe) performs a prominent role, and that this role has evolved considerably throughout cultures and centuries. Of further interest is the symbology associated with white stags and hinds, creatures which make several appearances in Western literature and art. Whilst the meanings they carry vary according to space and time, their main feature – being guiding animals – remains basically constant. After a presentation of the most important values of the symbol from the classics to French literature, this paper aims to explore its recurrences in Italian literature in the 14th and 15th century, in order to confirm the survival of the guiding pattern and to unravel the relationships between the Italian examples and their precedents.
Spanish validation of the Servant Leadership Short Scale for young adults and adolescents / Validación de la Escala de Liderazgo de Servicio Versión Abreviada en español para jóvenes adultos y adolescentes
Authors: Rivera Reynaldo G. , Santos David , Martín-Fernández Manuel
Published: March 2017

The aim of the current study was to validate a shortened Spanish version of the Servant Leadership Profile (SLP). In Study 1, a number of experts evaluated and reduced the original scale to 14 items and named the revised version the Servant Leadership Short Scale (SLSS). An exploratory factor analysis conducted with a sample of 1,001 students revealed two possible structure solutions, a one-factor solution and a two-correlated factor solution. Study 2 used a different sample of 456 students to examine the explored structures using confirmatory factor analysis. A one-factor solution was proposed (χ2/ df = 3.4, CFI = .91, TLI = .90, RMSEA = .07, SRMR = .06). Finally, in Study 3, servant leadership was used as a predictor of self-efficacy ( b = .685, p < .001) and demonstrated good predictive validity. This model explained 41.55% of the variance on self-efficacy. Reliability analyses of the three studies showed that this 14-item Spanish version had high internal consistency. Together, the results of the three studies support the application of the SLSS in future research.
What is behind envy? Approach from a psychosocial perspective / ¿Qué se esconde detrás de la envidia? Aproximación desde una perspectiva psicosocial
Authors: Navarro-Carrillo Ginés , Beltrán-Morillas Ana-María , Valor-Segura Inmaculada , Expósito Francisca
Published: March 2017

Envy strongly influences many spheres of social life. However, the psychology of envy is still in its infancy. A theoretical and empirical examination of envy was performed with a psychosocial focus via two exploratory studies. In Study 1 ( N = 141), participants were asked to describe an event in which they experienced envy, indicating which people they envied and the reasons for that envy. In Study 2 ( N = 311), the relationship between envy and several psychosocial variables such as self-efficacy, self-esteem and perceived control were analysed, as well as the predisposition to express aggressive behaviours in response to this emotion. The results of Study 1 revealed that friends were the most envied people, and abilities or personal skills were the most frequent sources of envy. Likewise, the results of Study 2 showed that self-efficacy, self-esteem and perceived control predicted envy, which in turn predicted the expression of verbal aggressive behaviours.
Residual stresses in cold-wire gas metal arc welding
Authors: Costa E. S. , Assunção P. D. C. , Dos Santos Emanuel B. F. , Feio L. G. , Bittencourt M. S. Q. , Braga E. M.
Published: March 2017

This work compares the welding residual stresses of the cold-wire gas metal arc welding and conventional gas metal arc welding processes. Two techniques were used to measure the residual stresses: X-ray diffraction and acoustic birefringence. The base metal used was carbon manganese steel plates of 9.5- mm thickness. The results showed that the introduction of the cold-wire tends to decrease the residual stresses, suggesting that the introduction of the cold wire decreases the amount of heat given to the base metal, and consequently lowers residual stresses.
Universal and particular in morphological processing: Evidence from Hebrew
Authors: Farhy Yael , Veríssimo João , Clahsen Harald
Published: March 2017

Do properties of individual languages shape the mechanisms by which they are processed? By virtue of their non-concatenative morphological structure, the recognition of complex words in Semitic languages has been argued to rely strongly on morphological information and on decomposition into root and pattern constituents. Here, we report results from a masked priming experiment in Hebrew in which we contrasted verb forms belonging to two morphological classes, Paal and Piel, which display similar properties, but crucially differ on whether they are extended to novel verbs. Verbs from the open-class Piel elicited familiar root priming effects, but verbs from the closed-class Paal did not. Our findings indicate that, similarly to other (e.g., Indo-European) languages, down-to-the-root decomposition in Hebrew does not apply to stems of non-productive verbal classes. We conclude that the Semitic word processor is less unique than previously thought: Although it operates on morphological units that are combined in a non-linear way, it engages the same universal mechanisms of storage and computation as those seen in other languages.
Carotid Body Denervation Markedly Improves Survival in Rats With Hypertensive Heart Failure
Authors: Fujii Kana , Saku Keita , Kishi Takuya , Oga Yasuhiro , Tohyama Takeshi , Nishikawa Takuya , Sakamoto Takafumi , Ikeda Masataka , Ide Tomomi , Tsutsui Hiroyuki , Sunagawa Kenji
Published: March 2017

BACKGROUND

Hypertension is a major cause of heart failure. Excessive sympathoexcitation in patients with heart failure leads to poor prognosis. Since carotid body denervation (CBD) has been shown to reduce sympathetic nerve activity in animal models of hypertension and heart failure, we examined if bilateral CBD attenuates the progression of hypertensive heart failure and improves survival.

METHODS

We randomly allocated Dahl salt-sensitive rats fed a high-salt diet from 6 weeks of age into CBD (n = 31) and sham-operation (SHAM; n = 50) groups, and conducted CBD or SHAM at 7 weeks of age. We examined the time course of 24-hour urinary norepinephrine (uNE) excretion, blood pressure (BP) and the percent fractional shortening assessed by echocardiography, and estimated the pressure–natriuresis relationship at 14 weeks of age. Finally, we assessed hemodynamics, histological findings, and survival at 16 weeks of age.

RESULTS

Compared to SHAM, CBD significantly reduced 24-hour uNE at 12, 14, and 16 weeks of age, shifted the pressure–natriuresis relationship leftward without changing its slope, and attenuated the increase in BP. CBD preserved percent fractional shortening (34.2 ± 1.2 vs. 29.1 ± 1.3%, P < 0.01) and lowered left ventricular end-diastolic pressure (5.0 ± 0.9 vs. 9.0 ± 1.4 mm Hg, P < 0.05). Furthermore, CBD significantly attenuated myocardial hypertrophy (P < 0.01) and fibrosis (P < 0.01). Consequently, CBD markedly improved survival (relative risk reduction: 64.8%).

CONCLUSIONS

CBD attenuated the progression of hypertension and worsening of heart failure possibly through sympathoinhibition, and markedly improved survival in a rat model of hypertensive heart failure.
Sequential computation of elementary modes and minimal cut sets in genome-scale metabolic networks using alternate integer linear programming
Authors: Song Hyun-Seob , Goldberg Noam , Mahajan Ashutosh , Ramkrishna Doraiswami
Published: March 2017

Motivation

Elementary (flux) modes (EMs) have served as a valuable tool for investigating structural and functional properties of metabolic networks. Identification of the full set of EMs in genome-scale networks remains challenging due to combinatorial explosion of EMs in complex networks. It is often, however, that only a small subset of relevant EMs needs to be known, for which optimization-based sequential computation is a useful alternative. Most of the currently available methods along this line are based on the iterative use of mixed integer linear programming (MILP), the effectiveness of which significantly deteriorates as the number of iterations builds up. To alleviate the computational burden associated with the MILP implementation, we here present a novel optimization algorithm termed alternate integer linear programming (AILP).

Results

Our algorithm was designed to iteratively solve a pair of integer programming (IP) and linear programming (LP) to compute EMs in a sequential manner. In each step, the IP identifies a minimal subset of reactions, the deletion of which disables all previously identified EMs. Thus, a subsequent LP solution subject to this reaction deletion constraint becomes a distinct EM. In cases where no feasible LP solution is available, IP-derived reaction deletion sets represent minimal cut sets (MCSs). Despite the additional computation of MCSs, AILP achieved significant time reduction in computing EMs by orders of magnitude. The proposed AILP algorithm not only offers a computational advantage in the EM analysis of genome-scale networks, but also improves the understanding of the linkage between EMs and MCSs.

Availability and Implementation

The software is implemented in Matlab, and is provided as supplementary information.

Supplementary information

Supplementary data are available at Bioinformatics online.
Creation of a Regional Human Milk Assembly
Authors: Spatz Diane L. , Evans Amanda , Froh Elizabeth
Published: March 2017

Background:

The 2011 Surgeon General's Call to Action to Support Breastfeeding highlights a need for optimizing lactation-based education for all health professionals; however, few schools of nursing and medicine offer lactation-based curriculum. In an effort to address these gaps in education and care, the director of the lactation program at a large urban children's hospital developed and instituted the annual regional Human Milk Assembly (HMA), a half-day collaborative meeting of the hospital's regional and referral hospitals' neonatal intensive care unit (NICU) nursing staff, to address lactation-based educational and training needs of all participating institutions.

Purpose:

The purpose of this study was to determine whether and how participating HMA hospitals implemented the best practices surrounding human milk and breastfeeding shared by the host institution during a 10-year span of the HMA.

Methods:

A prospective descriptive study was designed using an electronic web-based survey (SurveyMonkey.com) to elicit participant data. Quantitative data were analyzed using descriptive statistics whereas qualitative data were analyzed for themes via content analysis.

Results:

Thirty-one of the 50 hospitals surveyed responded to the electronic survey for a total of 34 individual participants. Seventeen of the 22 (77%) of best practices were implemented at rates of over 50%.

Implications for Practice:

By enabling a culture of transparency and sharing, hospital staff can be encouraged to implement best practices across a network of regional care centers.

Implications for Research:

This annual regional HMA could be a model for other areas and research should be conducted to evaluate such programs nationwide.
Efficacy and Safety of Crystalline Valsartan/Sacubitril (LCZ696) Compared With Placebo and Combinations of Free Valsartan and Sacubitril in Patients With Systolic Hypertension: The RATIO Study
Authors: Izzo Joseph L. , Zappe Dion H. , Jia Yan , Hafeez Kudsia , Zhang Jack
Published: March 2017

We compared the systolic blood pressure (SBP)-lowering efficacy and safety of crystalline valsartan/sacubitril (LCZ696, an angiotensin receptor blocker–neprilysin inhibitor) 400 mg daily against valsartan (320 mg once daily) alone or coadministered with placebo or increasing doses of free sacubitril (50, 100, 200, or 400 mg once daily) to identify the optimal antihypertensive combination dose. This multicenter, double-blinded, 7-arm parallel-group study recruited patients with mild-to-moderate systolic hypertension (office SBP 150–179 mm Hg). Primary-dependent variable was change in office SBP from baseline to week 8. At entry (n = 907), mean age was 61.5 years, sitting office BP 160/90.2 mm Hg, and mean 24-hour ambulatory BP 142/82.1 mm Hg; 852 participants completed the study. At week 8, there were greater reductions in sitting office SBP and 24-hour ambulatory SBP with LCZ696 400 mg than with valsartan 320 mg (−5.7 and −3.4 mm Hg, respectively, P < 0.05 each). The SBP reduction with LCZ696 400 daily was similar to coadministered free valsartan 320 mg and sacubitril 200 mg. Effects were similar in those older and younger than 65 years, and active therapies had adverse event rates similar to placebo. We conclude that crystalline valsartan/sacubitril 400 mg daily (1) is superior to valsartan 320 mg daily for lowering SBP, (2) has similar efficacy to the combination of free valsartan 320 mg plus free sacubitril 200 mg, (3) represents the optimal dosage for systolic hypertension in patients of any age, and (4) is safe and well tolerated.
A Slight Smell of Lemon
Authors: Feliu Catherine , Cazaubon Yoann , Fouley Aurélie , Guillemin Hélène , Gozalo Claire , Djerada Zoubir
Published: March 2017

We present here an example of urine substituted with a yellow cleaning product that leads us to develop the main risks to consider in urine toxicology analysis, ie, adulteration and analytical interferences, and how to deal with them. This grand round highlights the importance of the dialog between the clinician and a TDM consultant for optimal care of the patient.
SUCCESSFUL CLOSURE OF FULL-THICKNESS MACULAR HOLES SECONDARY TO MACULAR VITELLIFORM LESIONS
Authors: Galvin Justin C. , Chua Brian E. , Fung Adrian T.
Published: March 2017

Purpose:

To describe the first reported cases of full-thickness macular holes secondary to vitelliform lesions that were successfully closed with vitrectomy surgery and gas tamponade.

Methods:

Two female patients developed visual loss secondary to bilateral vitelliform lesions and associated full-thickness macular holes. The patients underwent 25-gauge pars plana vitrectomy, internal limiting membrane peeling, and 26% sulfur hexafluoride gas, followed by 3 days of face-down positioning.

Results:

In both patients, the macular holes remain closed 3 and 25 months postoperatively.

Conclusion:

Vitrectomy surgery with gas tamponade may successfully close full-thickness macular holes secondary to macular vitelliform lesions.
PRESUMED RETINAL PIGMENT EPITHELIUM TUMOR ORIGINATING FROM UNILATERAL RETINAL PIGMENT EPITHELIUM DYSGENESIS
Authors: Gal-Or Orly , Finger Paul T. , Fisher Yale L. , Yannuzzi Lawrence A. , Freund K. Bailey
Published: March 2017

Purpose:

To describe a patient with a presumed retinal pigment epithelium (RPE) tumor originating from unilateral RPE dysgenesis.

Methods:

Case report.

Results:

A 30-year-old woman with an unremarkable medical and ocular history was referred for an evaluation of progressive central metamorphopsia in her left eye. Visual acuity was 20/20 in her right eye and 20/25 in her left eye. Funduscopic examination of the left eye revealed an elevated mass within an area of unilateral RPE dysgenesis showing hyperpigmentation and hypopigmentation with scalloped margins. Fundus autofluorescence of the lesion showed a marginal pattern of hyperautofluorescence and hypoautofluorescence that was the inverse of the fluorescein angiography pattern. A well-circumscribed subretinal mass appeared to originate from the unilateral RPE dysgenesis lesion with surrounding subretinal fluid extending beneath the fovea. Ultrasonography showed medium-to-high reflectivity of the mass with no evidence of choroidal involvement. Optical coherence tomography showed a subretinal hyporeflective mass consistent with a tumor of RPE origin. The tumor appeared to invade the overlying retina where fluorescein angiography showed hyperfluorescent leakage and OCT angiography showed retinal vascular deformation. Indocyanine green angiography showed no evidence of choroidal neovascularization. Findings in the right fundus were normal. Over a 5-month follow-up, intravitreal anti–vascular endothelial growth factor therapy induced a resolution of subretinal exudation and modest reduction in tumor thickness.

Conclusion:

To the authors' knowledge, this is the first report of a presumed RPE tumor described as originating from unilateral RPE dysgenesis. Multimodal imaging was crucial for establishing the diagnosis and showing that the patient's visual symptoms were a product of the exudation produced by the tumor's invasion of the retina.
SEROUS RETINOPATHY ASSOCIATED WITH CISPLATIN TREATMENT
Authors: Langevin Spencer , Chang Jonathan S. , Chang Stanley
Published: March 2017

Background/Purpose:

To describe a case of serous retinopathy and associated photoreceptor atrophy after intravenous cisplatin therapy.

Methods:

Evaluation was performed using electroretinogram, optical coherence tomography, fundus autofluorescence, and funduscopic examinations to assess the extent of retinal disease, toxicity, and eventual atrophy.

Results:

A 56 year-old man with metastatic small cell carcinoma with vision changes after initiation of cisplatin therapy. The patient developed loss of vision to 20/400. A serous retinopathy was found on spectral domain optical coherence tomography with associated outer retinal atrophy and subretinal fibrosis. He developed outer ellipsoid layer atrophy after discontinuation of cisplatin therapy. He had patchy hypoautofluorescent areas in his macula on fundus autofluorescence and decreased cone response and slowed b-wave on electroretinogram. The serous retinopathy resolved with discontinuation of cisplatin and the malignancy was further managed with etoposide without recurrence of subretinal serous fluid or further vision loss.

Conclusion:

Commonly used to treat various solid tumors, cisplatin is not without significant neurologic, ocular, and retinal toxicities. Multimodal imaging may further the authors' understanding of toxicity and this case highlights the benefits of optical coherence tomography, especially with color vision deviation or visual acuity change.
RE-INTERVENTION IN DE NOVO VITREOUS OPACITIES AFTER PARS PLANA VITRECTOMY IN FAMILIAL AMYLOIDOTIC POLYNEUROPATHY TTR VAL30METPORTUGUESE PATIENTS
Authors: Ferreira Natália Novais , Cunha Dias David Afonso , Afonso Carvalho Rui Pedro , Pardal Monteiro Coelho Maria Teresa
Published: March 2017

Purpose:

To report management of de novo vitreous amyloid opacities after previous pars plana vitrectomy in familial amyloidotic polyneuropathy transthyretin Val30Met.

Methods:

This work is a retrospective observational consecutive case series of five eyes of four patients. Demographic data, transthyretin mutation involved, age at the beginning of disease, duration of disease, treatment (liver transplant or tafamidis), time between vitrectomy and re-intervention, and ophthalmologic changes were evaluated. Surgical re-intervention included phacoemulsification with intraocular lens implantation in phakic eyes, re-vitrectomy as complete as possible with posterior capsulectomy, and internal limiting membrane peeling if wrinkling of internal retinal surface was present.

Results:

All patients had transthyretin Val30Met mutation, and three were women. Mean age of onset of the disease was 52 ± 11.0 years, and average evolution time of the disease was 8 years. Three patients had been submitted to liver transplant 4, 9, and 15 years before. Time between first vitrectomy and surgical re-intervention was longer than 2 years in all cases. Two eyes had amyloid deposits on anterior lens surface and pupillary border with scalloped pupil. Two eyes were phakic. Glaucoma was present in two eyes; one of them had previous trabeculectomy. All cases had vitreous opacities behind posterior lens capsule and at vitreous base area. After re-intervention, no further recurrence was observed (average follow-up of 10 months).

Conclusion:

De novo vitreous amyloid opacities may occur several years after pars plana vitrectomy. Amyloid deposition in vitreous cavity was observed only in strong vitreous adherence locations (behind posterior lens capsule and at vitreous base area). The authors expect that this procedure, an extensive re-vitrectomy associated with posterior capsulectomy, will prevent de novo vitreous amyloid opacities.
EXTREME DIURNAL VARIATION OF CENTRAL MACULAR THICKNESS IN DIABETIC MACULAR EDEMA
Authors: Sambhav Kumar , Grover Sandeep , Chalam Kakarla V.
Published: March 2017

Purpose:

Spectral domain optical coherence tomography is an established modality to quantify diabetic macular edema (DME). Change in central subfield thickness exceeding 3% to 6% in DME is likely to be significant. In this case of DME, we describe an extreme bilateral variation in central macular thickness on spectral domain optical coherence tomography over two consecutive days without any treatment.

Methods:

The patient with DME and nonproliferative diabetic retinopathy underwent visual acuity testing, slit-lamp biomicroscopy, and dilated fundus examination. The patient also underwent spectral domain optical coherence tomography and digital fluorescence angiography. Findings are described in case report.

Results:

There was an overnight decrease of central subfield thickness from 360 microns to 291 microns (69 [∼19%] microns) in the right eye and from 404 microns to 293 microns (111 [∼27%] microns) in the left eye.

Conclusion:

Extreme fluctuations in retinal thickness in central involving DME are unusual, and the exact mechanism of this fluctuation is poorly understood.
Magnetic Resonance Imaging Characteristics of a Baerveldt Glaucoma Implant
Authors: Anderson Daniel M. , Schwope Ryan B. , Reiter Michael J. , Suhr Abraham W.
Published: March 2017

Purpose:

Evaluate for normative postoperative magnetic resonance imaging (MRI) characteristics of a Baerveldt Glaucoma Implant (BGI).

Design:

Prospective case series.

Participants:

Seven subjects with uncontrolled glaucoma requiring a primary superotemporal BGI.

Methods:

Subjects prospectively underwent sequential MRI orbital scans without contrast at 0 to 2 weeks, 6 to 8 weeks, and 4 to 6 months after implantation of a BGI model 103-250. Masked to the postoperative time course, a radiologist measured bleb and implant characteristics.

Main Outcome Measures:

Linear measurements of the maximum bleb height at the anterior, middle, and posterior sections of the endplate were measured. Intraocular pressure (IOP) was correlated to bleb height.

Results:

On axial T2-weighted images, the height of fluid below and above the BGI endplate increased from the initial to the final MRI images: 0.49 mm to 1.83 mm and 0.57 mm to 1.08 mm (middle 1/3), respectively. On coronal T2-weighted images, fluid below and above the BGI endplate increased from 0.47 mm to 1.53 mm and 0.49 mm to 1.38 mm, respectively. Maximum inverse correlation between bleb height and IOP was observed at the 6 to 8 week coronal T2 images (r=−0.963, P=0.002).

Conclusions:

Fluid collections and endplate characteristics are easily visualized with MRI. Dynamic changes occur over the early postoperative time course. Bleb height is inversely correlated to IOP at 6 to 8 weeks, but disappears at 4 to 6 months.
Sonographic Findings of Abdominal Tuberculosis in Children With Pulmonary Tuberculosis
Authors: Bélard Sabine , Heller Tom , Orie Viyanti , Heuvelings Charlotte C. , Bateman Lindy , Workman Lesley , Grobusch Martin P. , Zar Heather J.
Published: March 2017

Ultrasound reports of 102 children with microbiologically confirmed or clinically diagnosed pulmonary tuberculosis (TB) showed that 23 of 37 (64%) and 23 of 65 (36%) had TB suggestive abdominal lymphadenopathy, and 16 of 37 (44%) and 8 of 65 (13%) had splenic microabscesses, respectively. Splenic microabscesses were associated with HIV infection (P = 0.041). These data suggest that pulmonary TB is often complicated by abdominal TB in children.